Sus ainable au omo i e componen s o in e io doo ims
Uni e si y o Po o | Facul y o Enginee ing
Mechanical Enginee ing Depa men
Sus ainable au omo i e componen s o in e io doo
ims
Disse a ion submi ed o he Facul y o Enginee ing o he Uni e si y o Po o o ob aining he
deg ee o Doc o o Philosophy in Leade s o Technological Indus ies o he MIT-Po ugal P og am
Nuno Alexand e de Oli ei a Calçada Lou ei o
Mechanical Enginee | Mas e in Indus ial Design
PORTO, 2013
Supe iso
P o esso José Luís Soa es Es e es
Assis an P o esso | Mechanical Enginee ing Depa men Facul y o Enginee ing | Uni e si y o Po o | Po ugal
Co-Supe iso s
P o esso Júlio Césa Machado Viana
Associa e P o esso | Polyme Enginee ing Depa men Enginee ing School | Uni e si y o Minho | Po ugal
P o esso Sa yab a a Ghosh
Head o Resea ch and De elopmen | Ca bo undum Uni e sal Limi ed| India

This wo k has been done unde he Enginee ing Design and Ad anced Manu ac u ing (EDAM) ocus a ea o MIT-PORTUGAL
P og am. This p og am is an in e na ional collabo a ion o Massachuse s Ins i u e o Technology, Facul y o Enginee ing o
Uni e si y o Po o, Uni e si y o Minho and Ins i u o Supe io Técnico.
This wo k has he inancial suppo o he Po uguese Founda ion o Science and Technology (Fundação pa a a Ciência e
Tecnologia) h ough he PhD G an SFRH/BD/42978/2008 and h ough he p ojec MIT-P /EDAM-SMS/0030/2008 -
Assessmen and De elopmen o in eg a ed Sys ems o Elec ic Vehicles on he scope o QREN – POPH – Topology 4.1
Ad anced Fo ma ion Scope. (Co-pa icipa ed by he Eu opean Social Found and by MEC na ional ounds).
~
Ao meu ilho João Dinis,
pa a que semp e saiba que, com abalho,
odos os sonhos se conc e izam.
To my son, João Dinis,
o always know ha , wi h wo k,
all d eams come ue.
Sus ainable au omo i e componen s o in e io doo ims
x i
Abs ac
In he las ew yea s, bioma e ials ha e been a a ge o in e es a scien i ic, echnological esea ch and
indus ial le el. The inc easing o he en i onmen al conce n and he excessi e use o pe ol esou ces ha e
conduc ed o he de elopmen o new ma e ials, biocomposi es, which will achie e a g ea impo ance in o
he u u e.
I ’s a ac ha , allied o weigh educ ion, he au omo i e indus y can bene i om he inclusion o hese
ma e ials in ca s, no only because o he ins alled ea o decline and ex inc ion o oil ese es, bu also
because o he s ong legisla ion ha o ces an inc easing inco po a ion o hese ma e ials in au omobiles.
This opic p esen s a big po en ial because i seeks o ind solu ions o a sus ainable de elopmen wi h
en i onmen al conce ns in o de o be able o ob ain biodeg adable solu ions o he in e io doo ims.
Since he main pu pose o his wo k is o c ea e a bio-composi e ha is sui able o eplace he exis ing in e io
doo ims, he wo k has ocused on ob aining ha bio-composi e, aking accoun in o he aw-ma e ials cos
educ ion and he main enance o he manu ac u ing p ocess o cu en doo ims.
The e o e PLA and PHA blends mechanical and mo phological beha io ha e been s udied in o de o de ine
he bes ma ix o use in his s udy.
Subsequen ly i was s udied he inco po a ion o cellulosic ibe o adjus he p ope ies o mee he equi ed
alues.
Th oughou his epo , i ’s possible o ind a desc ip ion o he a ious asks pe o med in he de elopmen o
his p ojec . The wo k began wi h a e iew o he li e a u e abou biocomposi es ma e ials.
Then i ’s p esen ed he expe imen al wo k. The s udy o he choice o ma ix and p ocessing pa ame e s,
ollowed by he s udy o he ibe s inco po a ion is p esen ed. Ha ing de ined he composi e he wo k ends
wi h he p oduc ion o an in e io doo im made in o his bio-composi e o demons a e he po en iali y o
hese ma e ials.
In conclusion i e i ies ha he ma ix con aining 70% PLA and 30% PHA (weigh ac ion) has he bes
p ope ies o he in e io doo ims. The inco po a ion o 20% o ibe imp o es he he mal beha io o he
composi e, p o ing ha i is possible o eplace he pe ol-based polyme s o hese biocomposi es wi hou
comp omising he mechanical beha io o in e io doo ims.

Nuno Calçada Lou ei o
x ii
Résumé
Les bioma é iaux son de enus un suje d’in é ê , au cou s des de niè es années, soi dans la eche che
scien i ique e echnologique, soi dans l’indus ie. Les p éoccupa ions c oissan es a ec l’en i onnemen e
l’u ilisa ion excessi e des essou ces pé oliè es son à l’o igine de la eche che e dé eloppemen des
ma é iaux nou eaux, les bio-composi es, ès impo an s pou l’a eni .
L’indus ie au omobile béné icie a de l’u ilisa ion de ces ma é iaux, no ammen pa la éduc ion du poids des
oi u es. En plus, ils pou on ê e une al e na i e ace à la c ain e de diminu ion e épuisemen des ése es
de pé ole e épond on a o ablemen à la o e législa ion qui oblige à une inco po a ion p og essi e de ces
ma é iaux dans les oi u es.
Ce suje p ésen e un g and po en iel, puisque il pe me de ou e des solu ions pou un dé eloppemen
du able, a ec des p éoccupa ions écologiques, a in d’ob eni des solu ions biodég adables pou les panneaux
in é ieu es des oi u es.
É an donné que l’objec i de ce a ail es la c éa ion d’un bio-composi e qui pe me le emplacemen des
panneaux de po es des oi u es, ou es les déma ches on eu comme objec i l’ob en ion de ce bio-
composi e, en enan comp e la éduc ion des dépenses en ma iè es p emiè es e le main ien du p ocessus
de ab ica ion des panneaux ac uels.
Ainsi, on a é udié mécaniquemen e mo phologiquemen les mélanges de PLA e PHA a in de dé ini la ma ice
la plus co ec e pou l’applica ion dési ée. Ensui e, on a é udié l’inco po a ion des ib es pou l’ajus emen des
p op ié és nécessai es.
Le long du ex e, il es possible de ou e la desc ip ion des di é en s p océdés d’in es iga ion au ni eau de
ce p oje . Le a ail a commencé pa une analyse a en i e de la li é a u e su les ma é iaux bio-composi es.
Ensui e, on p ésen e le a ail expé imen al éalisé. Le choix de la ma ice e des pa amè es du p ocessus,
sui i de l’é ude de l’inco po a ion des ib es. Une ois le composi e dé ini, on a e miné le a ail pa la
p oduc ion d’une pièce pou démon e le po en iel de ces ma é iaux.
En conclusion, on é i ie que la ma ice composée de 70% PLA e 30% PHA ( ac ion massique) p ésen e les
p op ié és idéales pou l’applica ion p oposée. L’inco po a ion de 20% de ib e dans ce e ma ice pe me une
amélio a ion impo an e du compo emen he mique de ce ma é iel, en p ou an , ainsi, qu’il es possible de
emplace des polymè es d’o igine pé oliè e pa ces bio-composi es, sans, ou e ois, comp ome e le
compo emen mécanique e he mique des panneaux in é ieu es des po es des oi u es.
Sus ainable au omo i e componen s o in e io doo ims
x iii
Abs ak
Bioma e ialen wu den das in e essenziel in den le z en Jah en im um ang de wissenscha lichen und
echnologischen Fo schung und in de Indus ie. S eigende umwel bewuss sein und den übe mäßigen Einsa z
on Öl-Ressou cen üh e zu eine e höh en En wicklung neue Ma e ialien, Biocomposi es, die eine g oße
Zukun Bedeu ung haben wi d.
Es is eine Ta sache, dass, gepaa mi de Gewich s eduk ion, die Au omobilindus ie kann on de Einbindung
diese S o e in Au os p o i ie , nich nu wegen de Angs o Ve all und Auslöschung ins allie Öl ese en,
sonde n auch wegen de s a ken Rech s o sch i en, die e o de eine zunehmende in eg a ion diese
Ma e ialien in Au os.
Dieses hema s ell ein g oßes po enzial, weil es um Lösungen ü eine nachhal ige En wicklung zu inden mi
Umwel belangen, um in de Lage sein, biologisch abbauba e Lösungen ü die Innen e kleidung des Au os
e hal en soll.
Da de Haup zweck diese Suchung au eine Bio-Composi es scha en die bes ehende Mach Au oinnen aum
Pla en e se zen kann, ha die Suchung übe den E hal de a ige bio-Ve bund konzen ie , un e
Be ücksich igung de Kos en eduk ion on Rohs o en und Wa ung on He s ellungsp ozess de ak uellen
Zellen.
Dahe wu den Mischungen aus PLA und PHA mo phologisch und mechanisch un e such , um die bes en Ma ix
zu Ve wendung bei de Un e suchung zu de inie en.
Anschließend wu de die Einbindung on cellulose ase n un e such , um die gewünsch en Eigenscha en
einzus ellen.
In diesem Be ich inden Sie eine Besch eibung de e schiedenen Au gaben bei de En wicklung dieses
P ojek es du chge üh . Die A bei begann mi eine g ündlichen Analyse de Li e a u übe Biocomposi es
Ma e ialien.
Dann s ellen wi die expe imen elle A bei . Die Wahl de Ma ix und Ve a bei ungspa ame e , du ch
Un e suchung de Einbindung on Fase n olg . Nach de De ini ion de Ve bund wu de We ks ück P oduk ion
beende , um die Fähigkei diese Ma e ialien zu demons ie en.
Abschließend, es schein , dass die Ma ix mi 70% PLA und 30% PHA (Gewich san eil) die bes en Eigenscha en
ü die Anwendung un e Be ücksich igung ha . Die Eina bei ung on 20% Fase in diese Ma ix e besse die
he mische Leis ung des Ma e ials, was beweis , dass es möglich is , die Polyme e aus E döl gewonnene ü
diese Biocomposi es ohne die mechanischen Tü innen e kleidungen e se zen.
Nuno Calçada Lou ei o
xix
Con en s
LIST OF SYMBOLS ....................................................................................................................................... XXIII
LIST OF ABBREVIATIONS ............................................................................................................................. XXV
LIST OF FIGURES ........................................................................................................................................ XXVII
LIST OF TABLES .......................................................................................................................................... XXXI
CHAPTER 1. INTRODUCTION ............................................................................................................................ 1
1.1
I
NTRODUCTION
................................................................................................................................................. 1
1.2
P
ETROL TREND
.................................................................................................................................................. 1
1.3
A
UTOMOTIVE
C
OMPONENTS
............................................................................................................................... 3
1.4
T
HE FUTURE FOR
A
UTOMOTIVE
C
OMPONENTS
........................................................................................................ 8
R
EFERENCES
......................................................................................................................................................... 11
CHAPTER 2. LITERATURE REVIEW ................................................................................................................... 13
2.1
I
NTRODUCTION
............................................................................................................................................... 13
2.1.1 E
NGINEERING
P
LASTICS
............................................................................................................................. 15
2.2.2
T
YPES OF
P
OLYMERS
................................................................................................................................. 15
2.2
B
IODEGRADABLE
P
OLYMERS
.............................................................................................................................. 17
2.2.1 B
IODEGRADABLE
P
OLYMERS USED
............................................................................................................... 19
2.3
P
OLY
(L
ACTIC
A
CID
) .......................................................................................................................................... 19
2.3.1 PLA
P
RODUCTION
.................................................................................................................................... 20
2.3.2 PLA
P
ROPERTIES
...................................................................................................................................... 22
2.3.3 PLA
B
IODEGRADATION
............................................................................................................................. 23
2.3.4 PLA
B
ASED
C
OMPOSITES
........................................................................................................................... 25
2.4
P
OLY
H
YDROXY
A
LKANOATE
(PHA) ...................................................................................................................... 26
2.4.1 PHA
PROPERTIES
..................................................................................................................................... 29
2.4.2 PHA
BIODEGRADATION
............................................................................................................................. 29
2.4.3 PHA
BASED
C
OMPOSITES
.......................................................................................................................... 30
2.5
N
ATURAL
F
IBERS
............................................................................................................................................. 31
2.5.1 F
IBERS
C
LASSIFICATION
............................................................................................................................. 32
2.5.2 C
ELLULOSIC FIBERS
:
A
DVANTAGES AND
D
ISADVANTAGES
................................................................................. 35
2.5.3 C
ELLULOSIC FIBERS
:
P
ORTUGUESE
M
ARKET AND
E
XTRACTION
T
ECHNOLOGY
........................................................ 36
2.6
C
OMPOSITE
M
ATERIALS
.................................................................................................................................... 39
2.6.1 M
ATRICES
.............................................................................................................................................. 39
2.6.2 R
EINFORCEMENTS
.................................................................................................................................... 40
2.6.3 T
HERMOPLASTIC
M
ATRIX
C
OMPOSITES
........................................................................................................ 40
2.6.4 C
OMPOSITE
P
RODUCTION INTO THE AUTOMOTIVE INDUSTRY
............................................................................ 42
2.6.5 B
ULK
M
OULDING
C
OMPOUNDING
/
S
HEET
M
OULDING
C
OMPOUNDING
............................................................. 42
2.6.6 I
NJECTION
M
OULDING
.............................................................................................................................. 44
R
EFERENCES
......................................................................................................................................................... 46
Sus ainable au omo i e componen s o in e io doo ims
xx
CHAPTER 3. MOTIVATION, OBJECTIVES AND RESEARCH APPROACH.............................................................. 49
3.1
M
OTIVATION AND OBJECTIVES
........................................................................................................................... 49
3.2
R
ESEARCH
A
PPROACH
...................................................................................................................................... 49
3.3
T
HESIS
S
TRUCTURE
.......................................................................................................................................... 51
R
EFERENCES
......................................................................................................................................................... 52
CHAPTER 4. MATERIALS AND METHODS ........................................................................................................ 53
4.1
M
ATERIALS
.................................................................................................................................................... 53
4.1.1 P
OLYHIDROXYALKANOATE
–
PHA ................................................................................................................ 53
4.1.2 P
OLY
(L
ACTIC
A
CID
)
–
PLA ......................................................................................................................... 54
4.1.3 C
ELLULOSIC
F
IBERS
................................................................................................................................... 54
4.1.4 P
REPARATION OF THE
B
LENDS
.................................................................................................................... 54
4.1.5 P
REPARATION OF THE
C
OMPOSITE
M
ATERIAL
................................................................................................ 55
4.2
D
ETERMINATION OF
M
ECHANICAL
P
ROPERTIES
..................................................................................................... 57
4.2.1
T
ENSILE
T
EST
........................................................................................................................................... 57
4.2.2
F
LEXURAL
T
EST
........................................................................................................................................ 58
4.2.3
I
MPACT
T
EST
........................................................................................................................................... 58
4.3
D
ETERMINATION OF
T
HERMAL
P
ROPERTIES
.......................................................................................................... 59
4.3.1
H
EAT
-D
EFLECTION
T
EMPERATURE
............................................................................................................... 59
4.3.2
D
IFFERENTIAL
S
CANNING
C
ALORIMETRY
....................................................................................................... 60
4.4
D
ETERMINATION OF
M
ORPHOLOGICAL
P
ROPERTIES
............................................................................................... 61
4.4.1
O
PTICAL
M
ICROSCOPY
.............................................................................................................................. 61
4.4.2
W
IDE
-A
NGLE
X-R
AY
D
IFFRACTION
.............................................................................................................. 61
4.4.3
S
CANNING
E
LECTRON
M
ICROSCOPY
............................................................................................................. 62
R
EFERENCES
......................................................................................................................................................... 64
CHAPTER 5. MECHANICAL CHARACTERIZATION OF PHA/PLA BLENDS............................................................ 65
5.1
M
ECHANICAL PROPERTIES PREDICTION MODELS
..................................................................................................... 66
5.1.1 R
ULE OF
M
IXTURES
.................................................................................................................................. 66
5.1.2 K
ERNER
-U
EMURA
-T
AKAYANAGI MODEL
....................................................................................................... 66
5.1.3 N
ICOLAIS
-N
ARKIS MODEL
.......................................................................................................................... 67
5.1.4 B
ÉLA
-P
UKÁNSKY MODEL
............................................................................................................................ 67
5.2
M
ECHANICAL
T
ESTING
...................................................................................................................................... 68
5.2.1 F
LEXURAL
P
ROPERTIES
.............................................................................................................................. 68
5.2.2 T
ENSILE
P
ROPERTIES
................................................................................................................................. 68
5.2.3 I
NSTRUMENTED
P
ROPERTIES
...................................................................................................................... 69
5.2.4 H
EAT
D
EFLECTION
T
EMPERATURE
(HDT)
M
EASUREMENTS
.............................................................................. 69
5.3
R
ESULTS AND
D
ISCUSSION
................................................................................................................................. 69
5.4
C
ONCLUSIONS
................................................................................................................................................. 77
R
EFERENCES
......................................................................................................................................................... 79
CHAPTER 6. MORPHOLOGICAL CHARACTERIZATION OF PHA/PLA BLENDS .................................................... 81
6.1
I
NTRODUCTION
............................................................................................................................................... 81
6.2
M
ORPHOLOGICAL
C
ALCULATIONS BASED ON
DSC
RESULTS
...................................................................................... 82
6.3
R
ESULTS AND
D
ISCUSSION
................................................................................................................................. 82
Nuno Calçada Lou ei o
xxi
6.3.1 WAXD
M
EASUREMENTS
........................................................................................................................... 82
6.3.2 DSC
OF
I
NJECTION
M
OLDED
PHA/PLA
BLENDS
............................................................................................ 83
6.4
C
ONCLUSIONS
................................................................................................................................................. 90
R
EFERENCES
......................................................................................................................................................... 91
CHAPTER 7. CHARACTERIZATION OF PHA/PLA – CELLULOSIC FIBERS COMPOSITES........................................ 93
7.1
I
NTRODUCTION
............................................................................................................................................... 93
7.2
M
ECHANICAL PROPERTIES PREDICTION MODELS
..................................................................................................... 94
7.2.1 M
ODIFIED
H
ALPIN
-T
SAI
E
QUATION
(
M
HT) ................................................................................................... 94
7.2.2 I
SHAI AND
C
OHEN MODEL
(IC
M
) ................................................................................................................. 95
7.2.3 R
ULE OF
M
IXTURES
(ROM) ...................................................................................................................... 95
7.3
R
ESULTS AND
D
ISCUSSION
................................................................................................................................. 96
7.3.1 T
ENSILE BEHAVIOR
.................................................................................................................................... 96
7.3.2 F
LEXURAL BEHAVIOR
................................................................................................................................. 98
7.3.3 I
MPACT BEHAVIOR
.................................................................................................................................. 100
7.3.4 H
EAT
D
EFLECTION
T
EMPERATURE
(HDT)
MEASUREMENT
.............................................................................. 103
7.3.5 M
ICROSCOPY ANALYSIS
........................................................................................................................... 104
7.4
C
ONCLUSIONS
............................................................................................................................................... 106
R
EFERENCES
....................................................................................................................................................... 107
CHAPTER 8. APPLICATION OF BIO-COMPOSITES INTO AUTOMOTIVE INTERIOR PARTS ................................ 109
8.1
R
ESULTS COMPILATION
................................................................................................................................... 109
8.2
P
RODUCTION
T
ECHNOLOGY
............................................................................................................................. 111
8.3
C
OMPOSITE
S
ELECTION
................................................................................................................................... 112
8.4
A
UTOMOTIVE PART
........................................................................................................................................ 113
8.5
C
ONCLUSIONS
............................................................................................................................................... 114
CHAPTER 9. FINAL REMARKS AND FUTURE WORKS ..................................................................................... 117
9.1
F
INAL
R
EMARKS
............................................................................................................................................ 117
9.2
F
UTURE
W
ORKS
............................................................................................................................................ 118
APPENDIXES ................................................................................................................................................ 119
A.1
D
ATASHEET OF
P
OLYHYDROXYALKANOATE
.......................................................................................................... 121
A.2
D
ATASHEET OF
P
OLY
(L
ACTIC
A
CID
) ................................................................................................................... 123
A.3
D
ATASHEET OF
A
CYLONITRILE
B
UTADIENE
S
TYRENE
............................................................................................. 127
A.4
D
ATASHEET OF
P
OLY
P
ROPYLENE
...................................................................................................................... 133
A.5
G
ENERAL
R
EFERENCES
.................................................................................................................................... 139
A.6
P
UBLICATIONS DUE TO THIS WORK
.................................................................................................................... 141

Sus ainable au omo i e componen s o in e io doo ims
xxii
Nuno Calçada Lou ei o
xxiii
Lis o Symbols
$ Uni ed S a es Dolla
ΔC
P
[J.ºC.g
-
1
] Hea Capaci y
ΔH
cc
[J.g
-
1
] En halpy o Cold C ys alliza ion
∆
H


[J.g
-
1
] En halpy o mel ing
ΔH
m
[J.g
-
1
] En halpy o usion
σ
b
[Pa] Blend Maximum S ess
σ
c
[Pa] Composi e Maximum S ess
σ
[Pa] Fibe Maximum S ess
σ
m
[Pa] Ma ix Maximum S ess
σ
max
[Pa] Maximum S ess
υ
[ ] Poisson Coe icien
υ
d
[ ] Dispe sed Phase Poisson Coe icien
υ
m
[ ] Ma ix Poisson Coe icien
Ø
[%] Weigh F ac ion
Ø
ib
[%] Fibe Weigh F ac ion
Ø
d
[%] Dispe sed Phase Weigh F ac ion
Ø
max
[%] Nielson maximum packaging ac ion
ζ
[ ] Eins ein Coe icien
B
[ ]
Béla-Pukásnky Load-bea ing capaci y
C
P
[kJ.(kg.K)
-
1
] Speci ic Hea a Cons an p essu e
E [Pa] Young’s Modulus
E
c
[Pa] Composi e Young’s Modulus
E
b
[Pa] Blend Young’s Modulus
E
d
[Pa] Dispe sed Phase Young’s Modulus
E
[Pa] Flexu al Young’s Modulus
E
ib
[Pa] Fibe Young’s Modulus
E
m
[Pa] Ma ix Young’s Modulus
H [kJ.kg
-
1
] En halpy
K [ ] Nicolais-Na kis In e ac ion Cons an
Q [kg.h
-
1
] Mass low a e
T
c
T
cc
[ºC] Cold C ys alliza ion Tempe a u e
T
g
[ºC] Glass T ansi ion Tempe a u e
T
m
[ºC] Mel ing Tempe a u e
V
[%] Fibe Volume F ac ion
x
c
[%] C ys allini y
w
w
[%] Weigh ac ion
Sus ainable au omo i e componen s o in e io doo ims
xxi
Nuno Calçada Lou ei o
xx
Lis o Abb e ia ions
A
ABS Ac yloni ile Bu adiene S y ene
ASTM Ame ican Socie y and Tes ing Ma e ials
B
bbl ba el
BIW Body-in-whi e
BMC Bulk Molding Compound
BP Béla-Pukánsky Model
BTU B i ish The mal Uni
C
CIM
Compound Injec ion Moulding
CO
2
Ca bon Dioxide
D
DSC Di e en ial Scanning Calo ime y
E
ELV End-o -Li e Vehicle
EU Eu opean Union
F
FAO Food and Ag icul u e O ganiza ion o he Uni ed Na ions
FEUP Facul y o Enginee ing o Uni e si y o Po o
FRP Fibe Rein o ced Plas ic
H
HDT Hea -De lec ion Tempe a u e
I
ICm Ishai and Cohen model
ISEP School o Enginee ing o Poly echnic Ins i u e o Po o
ISO In e na ional O ganiza ion o S anda diza ion
ISPGaya Poly echnic Supe io Ins i u e Gaya
IUPAC In e na ional Union o Pu e and Applied Chemis y
K
KUT Ke ne -Uemu a-Takayanagi Model
Sus ainable au omo i e componen s o in e io doo ims
xxxii

Nuno Calçada Lou ei o
1
Chap e 1.
In oduc ion
1.1 In oduc ion
The p ese a ion o ou en i onmen equi es ha we s op using ma e ials ha will las inde ini ely. In he las
yea s he ecological conce ns de elops a na u al in e es o he na u al ma e ials and eco-solu ions.
In o he au omo i e a ea, esea ches a e explo ing na u al ibe s, such as lax, hemp and kena , [1] as an eco-
al e na i e o glass ibe s.
The Kyo o P o ocol has pushed he Eu opean Union Membe S a es o ind ways o educe emissions.
As expec ed he anspo sec o , who in 2004 was esponsible o 30% o UK ene gy-consump ion, is one o
he i s a eas o be s udied[2].
1.2 Pe ol end
I ’s easy o unde s and ha pe ol p ice ules all he o he p ices. Ene gy, plas ics, assembling lines and
me allic ma e ials p ices a e di ec ly o indi ec ly connec ed wi h he pe ol p ice.
I ’s possible o e i y ha in 2008 he inancial c ises o igina ed by he c ash o Lehman B o he s d i es o a
c ash o he oil p ices.
The inancial specula ion leads he oil p ices o inc ease and i ’s expec ed ha i will con inues his end o
he nex yea s.
Sus ainable au omo i e componen s o in e io doo ims
2
Figu e 1.1 – E olu ion o Oil P ice (sou ce: US Ene gy In o ma ion Adminis a ion)
Since he plas ics use in au omo i e pa s a e manly Polyp opylene(PP) o Ac iloni ile-Bu adiene-S y ene
(ABS) and hese a e pe ol-based polyme s i ’s easy o unde s and ha wi h he inc ease o he oil p ice, he
p ice o PP, ABS and ene gy will also inc ease.
Figu e 1.2 – E olu ion o PP p ice pe on (sou ce: www.plas ma .com)
Nuno Calçada Lou ei o
3
Figu e 1.3 – E olu ion o ene gy p ice (sou ce: US Ene gy In o ma ion Adminis a ion)
Wi h all his igu es i ’s easy o achie e ha he u u e o au omo i e indus y goes o c ea e ligh e ca s ha
a e no dependen o pe ol-based polyme s and wi h engines ha will spend less uel.
1.3 Au omo i e Componen s
The subs i u ion o au omo i e componen s made om glass- ibe composi es o he na u al ibe s
composi es, in addi ion o he educ ion o he p oblems due o ecycling o he ehicles, d i es o a dec ease
o uel consump ion and gases emission. Tha means ha his subs i u ion con ibu es o a be e li e quali y.
The na u al ibe - illed he moplas ics a e 35-40% ligh e han he glass ibe analogs[1]. Associa ing he
weigh dec easing o a be e c ash abso bance and sound insula ion i ’s possible o ealize he p o i achie ed
when applied o doo ims, ins umen panels, package ays, glo e boxes, a m es s and sea backs.
The i s a emp o use “na u al” composi e ma e ials p obably was made by Hen y Fo d in he ea ly 1930s.
Hen y Fo d walked in o his company’s esea ch labo a o y wi h a bag o chicken bones, dumped hem on he
desk and asked his echnicians o see wha hey could make ou o hem. They esponded by expe imen ing
wi h a a ie y o na u al ma e ials including can aloupes, ca o s, co ns alks, cabbages and onions in a sea ch
o ma e ials o build an o ganic ca body. In 1940, Fo d scien is s disco e ed ha soybean oil could be used o
make high-quali y pain enamel and could also be molded in o a ibe -base plas ic.
In 1941, composi es, pa icula ly hose based on na u al ibe s ein o cemen s ecei ed inc eased a en ion.
Du ing he Wo ld Wa II, sea s and uselages in o ai c a s we e made in hose ma e ials due o he sho age o
aluminum a ha ime. An example is he “GORDON-AEROLITE” a composi e o unidi ec ional, unbleached lax
ya n imp egna ed wi h phenolic esin and ho p essed. This ma e ial was used in ai c a uselages. A ha
ime also appea s a co on-polyme composi e, which was epo edly he i s ibe - ein o ced plas ic used by
he mili a y, o ai c a ada .
In 1942, Hen y Fo d de eloped he i s p o o ype composi e ca made om hemp ibe s. The ca didn’ go o
gene al p oduc ion due o economic limi a ions a he ime.
Sus ainable au omo i e componen s o in e io doo ims
4
Be ween 1950 and 1960 in Eu ope, he body o he Eas Ge man “T aban ” ca was one o he i s o be buil
o m ma e ials con aining co on ibe s in o a polyes e ma ix.
In 1996, he E-Class ehicle om Me cedes in eg a es a ju e-based doo panels.
In he las decade, bio- ibe ein o ced polyme composi es ha e been emb aced by Eu opean ca make s o
doo panels, sea backs, headline s, package ays, dashboa ds, and unk line s.
Table 1.1 – Au omo i e manu ac u es, models and componen s using bio- ibe s [3-4]
Au omo i e
Manu ac u e
Model and Applica ion
Audi TT, A2, A3, A4, A4 A an ,, A4 Va ian (1997), A6, A8 (1997) , Roads e , Coupe: Sea Back, side
and back doo panel, boo lining, ha ack, spa e i e lining.
BMW Se ie 3, Se ie 5, Se ie 7: Doo inse , Doo panels, Headline panel, boo lining, sea back.
Ci oen C4 (2001)
Daimle - Ch ysle Class A, Class C, Class E, Class S: Doo panels, windshield, Dashboa d, business able, pilla
co e panel;
Class A, T a ego Bus: Ex e io unde body p o ec ion im;
Class M: Ins umen al panel
Class S: 27 pa s manu ac u ed om bio ibe s
Fia Pun o, B a a, Ma ea,
Al a Romeo 146 and 156, Spo wagon
Fo d Mondeo CD 162 (1997); Focus; Couga (1998); Mondeo (2000), : Doo inse s, Doo panels, B-
pilla and co e , Boo line , pa cel ay, mo o p o ec ion (co e unde shield)
MAN Bus (1997)
Mi subishi Space S a : Doo panels;
Col : Ins umen al panels
Nissan Miscellaneous models
Opel / Vauxhall As a, Vec a, Za i a: Headline panel, doo panels, doo inse s, pilla co e panel,
ins umen al panel, ea shel panel, column co e ;
Peugeo New 406 model
Renaul Clio, Twingo
Ro e Ro e 2000 and o he s: Insula ion, ea s o age shel and panel
Saab Coupe (1998): doo inse s; doo panels
SEAT Doo panels, doo inse s, sea backs
Toyo a Miscellaneous models
Volkswagen Gol A4, Passa Va ian , Gol A4 Va ian (1998), Bo a: Doo panel, Doo inse s, sea back,
boo lid inish panel, boo line , ea lap lining, pa cel ay;
Vol o C70, V70, Coupe (1998): Doo inse s, pa cel ay;
Nowadays, in he USA mo e han 1.5 million ehicles a e he subs a e o choice o bio ibe s such as kena ,
ju e, lax, hemp and sisal and he moplas ic polyme s such as polyp opylene and polyes e .
Bio ibe s composi es a e, nowadays, used also in he ex e io componen s o an au omo i e.
Daimle Ch ysle ’s inno a i e applica ion o abaca ibe s in ex e io unde loo p o ec ion o passenge ca s
has been ecen ly ecognized.
Nuno Calçada Lou ei o
5
Figu e 1.4 – Au omo i e doo in-line , ins umen al panel made om bio- ibe ein o ced composi es [4]
Figu e 1.5 – Unde loo p o ec ion im o Me cedes A Class made om banana ibe [4]
O he ex e io pa s ( on bumpe , unde loo im o bus) om lax ibe ein o ced composi es will ollow.
The au omo i e company Fo d is using composi es o kena ibe s and polyp opylene o he doo panels o
he Fo d Mondeo.
The Me cedes S-Class has, ac ually, 27 componen s manu ac u ed in bio- ibe s ein o ced composi es wi h a
o al weigh o 43 kg ep esen ing an inc easing o 73% composi e weigh .

Sus ainable au omo i e componen s o in e io doo ims
6
Figu e 1.6 – Me cedes S Class componen s made om di e en bio- ibe ein o ced composi es [4]
Figu e 1.7 – Model U Fo d Hyb id-Elec ic Ca . Co n based ma e ials a e used in o he in e io oo ab ic and loo
ma ing. Soy and co n-de i ed esins eplace ca bon black in he i es. Syn he ic polyes e is use o co e sea s [5]
Nowadays app oxima ely 18 million o au omobiles and Lo ies a e manu ac u ed in Eu ope pe yea . Each uni
possesses be ween 5 o 10 kg o ibe which indica es a po en ial ma ke o 90.000 o 100.000 ons pe yea o
ibe .
Taking in o accoun he 37 million o ca s and ligh ans ha a e manu ac u ed in he es o he wo ld he
global po en ial ma ke o na u al ibe s ises o 250.000 o 500.000 ons pe yea .
Nuno Calçada Lou ei o
7
Each au omobile is abou 8% plas ics and composi es, which can be ansla ed in a ound 245 lbs(79kg)/ ehicle.
[6]
The po en ial o composi es ma e ials p o ide a wide ange o pa s and componen s – body panels,
suspension, s ee ing and b akes among o he s.
The assessmen o he iabili y o composi es in au omo i e applica ions is based on he e y limi ed cos
in o ma ion cu en ly a ailable.
Figu e 1.8 – Cos S uc u e Compa isons o BIW designs [6]
The compa a i e s udy, whom some esul s a e p esen ed in o igu e 1.8, o wo composi e monocoque Body-
in-whi e (BIW) indica es ha he ma e ial cos con ibu es wi h 60% o he o al cos o ca bon ibe -
ein o ced he moplas ics, bu con ibu es only 27% wi h s ell unibody and 29% i used glass ibe - ein o ced
he mose s. The nex able compa es he cos s o a ious BIW designs on USD/lb basis.
Table 1.2 – Cos Componen compa isons o a ious BIW designs (USD/lb) [6]
BIW Design Ma e ial Labo Eqp Tooling O he To al
S eel Unibody 0,60 0,42 0,37 0,40 0,45 2,24
Glass- ein o ced The mose Monocoque 1,38 1,64 0,36 0,57 0,74 4,68
Ca bon- ein o ced The moplas ic Monocoque 4,55 1,61 0,30 0,44 0,65 7,55
(sou ce: Die enbach e al. (1996a))
The ecyclabili y o he moplas ics shows a g ea p omise bu he wo k should de elop he cos -e ec i e
means o ecycling including he ibe sepa a ion.
Sus ainable au omo i e componen s o in e io doo ims
8
1.4 The u u e o Au omo i e Componen s
Faced wi h p essu es o p oduce uel-e icien , low-pollu ion ehicles and “g een” ca s, he au omo i e
indus y is looking o eco- iendly composi es.
The usual composi es p esen a pollu ed and in ensi e ene gy p oduc ion. Glass, ca bon and a amid ibe
ein o ced polyes e , epoxy o simila esins a e di icul o ecycle and ha d o dispose. [5]
The Eu opean Union egula ions equi e ha , by 2015, all new ehicles should be 95% ecyclable. Fo ha he
use o he moplas ics, ha can be he mally ecycled o p oduce new p oduc s, will be good solu ion o ha .
Fo ein o ce ins ead using he non- ecyclable common ibe s, he au omo i e manu ac u es a e also seeking
o new ma e ials. The new gene a ion o ibe s, based on ag icul u al p oduc s is al eady being in wi h
mechanical p ope ies ha a e sui able o some au omo i e applica ions.
Table 1.3 – Compa ison o p ope ies o a ious na u al and syn he ic ibe s [5]
Fibe Speci ic G a i y
[g.cm
-3
]
Tensile S eng h
[GPa]
Speci ic S eng h
[GPa/(g.cm
-3
)]
Tensile Modulus
[GPa]
Speci ic Modulus
[GPa/(g.cm
-3
)]
Sp uce pulp 0,60 0,98-1,77 1,63-2,95 10-80 17-133
Sisal 1,20 0,08-0,50 0,07-0,42 3-98 3-82
Flax 1,20 2,00 1,60 85 71
E-Glass 2,60 3,50 1,35 72 28
Ke la ® 49 1,44 3,90 2,71 131 91
Ca bon (s anda d) 1,75 3,00 1,71 235 134
Ligh weigh , s ong and low-cos he bio- ibe s a e poised o eplace glass and mine al ille s in nume ous
in e io pa s. [4]
In he las decade, bio- ibe ein o ced polyme composi es ha e been emb aced by he Eu opean ca
manu ac u es o se e al in e io pa s (doo panels, sea backs, headline s, package ays, dashboa ds, unk
line s, e c).
This end eaches ac ually he No h Ame ica. In he USA mo e han 1,5 million ehicles a e he subs a e o
choice o bio ibe s.
On a e age each au omo i e can use a ound 20 m
2
o ibe s o ab ics, wo en o non-wo en based
composi es. This is an inc easing end due o he ad an ages o ligh weigh , high s eng h and day-by-day
lowe ing cos s o ex ile p oduc s [4].
The Eu opean and No h Ame ican ma ke o bio- ibe s ein o ced plas ics composi es eached 685000 on in
2002 wi h a alue o 775 million USD. The majo au omo i e manu ac u e Eu opean coun y – Ge many – is
inc easing he consump ion o bio- ibe s ( om 4000 on in o 1996 o 18000 on in o 2003).
Nuno Calçada Lou ei o
9
Figu e 1.9 – To al consump ion o bio- ibe s wi hin Wes e n Eu ope; 2005 and 2010 a e p edic ions [4]
Many au omo i e componen s a e now made om bio- ibe ein o ced composi e ma e ials.
Howe e , hese composi es p esen a he moplas ic ma ix bu no a biodeg adable one. Tha d i es us o a
s age ha he au omo i e pa can be eu ilized, ep ocessed bu no decomposed wi hou a ec ing he
en i onmen .
Figu e 1.10 – LFTs applica ions in au omo i e pa s [7]
Long ibe ein o ced he moplas ics (LFT), used p ima ily in au omo i e applica ions, con inue o show s ong
g ow h as hey eplace me al, sho ibe ein o ced he moplas ics, and he mose plas ics such as SMC and
BMC.
R. Babinsky [7] es ima es consump ion was 160.000 – 190.000 me ic ons o LFTs in 2006. The same s udy
es ima es ha in No h Ame ica and Eu ope, abou 80% o he egional olume o LFTs goes in o au omo i e
applica ions.
Sus ainable au omo i e componen s o in e io doo ims
16
• The mose s - These polyme s when hea ed, su e i e e sible chemical eac ions ha o igin
in e molecula c oss-connec ions. The esul is a e icula ed s uc u e which is in usible;
• The moplas ics – These polyme s when hea ed mel s, and hey can be hea ed and cooled any ime.
These polyme s, due o hese cha ac e is ic, can be p ocessed by he adi ional me hods: Injec ion,
ex usion and olling;
The p ope ies o he enginee ing plas ics a e s ic ly connec ed wi h he aw-monome and he chemical
eac ion used o p oduce he polyme .
Nowadays i ’s possible o p ocess polyme s by h ee chemical p ocesses:
• Polyaddi ion – The monome s p esen s a double-connec ion ca bon-ca bon. In his p ocess, he
o ma ion o sub-p oduc s doesn’ exis and he inal molecula weigh s can each a magni ude o 10
5
-
10
6
;
• Polycondensa ion - In his p ocess, he o ma ion o sub-p oduc s exis s, and hese sub-p oduc s mus
be emo ed o he eac ion en i onmen . The molecula weigh s each a magni ude o 10
4
;
• Chemical modi ica ion – This p ocess consis s in he polyme s chemical modi ica ion. The changes on
he molecula weigh , he physical and mechanical beha io o he modi y polyme s allows a hugh
di e si ica ion o he polyme s applica ions;
As said be o e heses polyme s can be di ided in o h ee g oups: Elas ome s, he moplas ics and he mose s.
Figu e 2.4 - Eu opean Plas ics Demand by Segmen and esin ype 2011
2
2
Sou ce: Plas icsEu ope Ma ke Resea ch G oup (PEMRG)

Nuno Calçada Lou ei o
17
As al eady ela ed in o Chap e 1, he au omo i e indus y is using he moplas ic polyme s o he au omo i e
plas ic pa s. Fo ha eason he ocus will be se led on his kind o ma e ials.
2.2 Biodeg adable Polyme s
Biodeg adable polyme s (biopolyme s) a e he moplas ic polyme s ob ained om enewable esou ces,
syn hesized mic obially, o syn hesized om pe oleum-based chemicals. Th ough blend o wo o mo e
biopolyme s a new biopolyme may be designed o speci ic equi emen s. Thus biodeg adabili y is no only a
unc ion o o igin bu also o chemical s uc u e and deg ading en i onmen .
Biodeg adable polyme s can be de ine as hose polyme s ha a e capable o unde going decomposi ion
p ima ily h ough enzyma ic ac ion o mic oo ganisms in o CO
2
, me hane, ino ganic compounds, o biomass,
in a speci ied pe iod o ime.
As seen in o igu e 2.5, i ’s possible o ob ain se e al biopolyme s om di e en sou ces, e en om pe ol.
Figu e 2.5 - Classi ica ion o Biopolyme s
[1-2]
Sus ainable au omo i e componen s o in e io doo ims
18
The au omo i e indus y, as discussed in o Chap e 1, is ying o ha e g een pa s. Fo achie ing ha objec i e
i s necessa y no only ha he polyme p esen s biodeg adable p ope ies bu also ha he o igin is also
g een, eason why he p esen s a e-o -a will ocus he enewable sou ce polyme s only.
O iginally, biopolyme s we e in ended o be used in packaging indus ies, a ming, and o he applica ions wi h
mino s eng h equi emen s.
The basic idea behind he biopolyme s is aken om na u e’s cycle. E e y yea 100 billion o ones o o ganic
ma e ial a e gene a ed by pho osyn hesis all o e he globe. Mos o his ma e ial is con e ed back in o
s a ing p oduc s, ca bon dioxide and wa e by mic o-o ganisms.
This cycle is he ole-model o biopolyme s, which a e made om enewable aw ma e ials ob ained om
ag icul u al p oduc ion o ag icul u al sub-p oduc s o was e.
When he biopolyme pa s as each i s end, i can be compos ed, closing he loop.
Figu e 2.6 - Ideal closed loop li e-cycle o biodeg adable p oduc s
[1]
The, ye , high cos o biopolyme s and he pe o mance limi a ions a e majo ba ie s o he widesp ead
accep ance as subs i u e o adi ional non-biodeg adable polyme s by he biodeg adable polyme s. Howe e
he high cos is no due o he aw ma e ial bu i is mainly a ibu ed o he low olume o p oduc ion.
Nuno Calçada Lou ei o
19
2.2.1 Biodeg adable Polyme s used
The use o biodeg adable polyme s om enewable esou ces o eplace he pe o-sou ce polyme s is
inc easing wo ldwide. The ac ual g owing o pe oleum cos and he o e use o land ills combined wi h
en i onmen al ac o s and policies a e making a swi on he gene al sense o he use o biopolyme s[3].
Se e al biopolyme s and hei blends a e being used in o a la ge spec um o u ili ies. This new ype o
polyme s allied o he li e-cycle-analysis is making a u no e in he polyme indus y.
Howe e , i ’s manda o y o ind biopolyme s blends wi h p ope ies ha ul ill he p oduc ´s echnical
speci ica ions a a low p ice, dec easing he a io p ice/quali y.
F om he uni e se o biodeg adable polyme s om na u al esou ces, he Polyhyd oxyalcanoa e (PHA)
p esen s mechanical p ope ies ha can eplace a la ge spec um o pe o-sou ce polyme s, namely in he
au omo i e indus y. Howe e , due o i s ac ual p ice, he solu ion isn’ economically iable o mass
consump ion. Polylac ic acid (PLA) is a lowe cos polyme bu does no mee ully he equi emen s o
polyme s o au omo i e componen s, o example, in e ms o empe a u e esis ance. To make a compe i i e
solu ion is necessa y o educe he p ice o he inal polyme . One way is o blend PHA wi h a less expensi e
biopolyme , such as PLA.
Mos o he biodeg adable polyme s con ain hyd olysable linkages such as amide, es e , u ea and u e hane
along he polyme chains. Howe e , he use o alipha ic polyes e s (such as PLA) due o hei use ul
biodeg adabili y and hei e sa ili y ega ding physical, chemical and biological p ope ies is mos a ac i e.
2.3 Poly(Lac ic Acid)
Poly(lac ic Acid) (PLA) is a polyme de i ed om lac ic acid (2-hyd oxy p opionic acid). PLA is a igid
he moplas ic biodeg adable polyes e polyme ha can be semi-c ys alline o o ally amo phous, depending
on he s e eopu i y o he polyme backbone. PLA is he i s commodi y polyme p oduced om annually
enewable esou ces.
The PLA p oduc ion p esen s nume ous ad an ages:
1- I can be ob ained om a enewable ag icul u al sou ce – co n, suga cane, s a ch;
2- The p oduc ion consumes ca bon dioxide;
3- I p o ides signi ican ene gy sa ings;
4- The PLA is ecyclable and compos able;
5- I can help imp o e a m economies;
6- The physical an mechanical p ope ies can be manipula ed h ough he polyme a chi ec u e;
The nex igu e p esen s a li e-cycle model o PLA.
Sus ainable au omo i e componen s o in e io doo ims
20
Figu e 2.7 - Li e-cycle model o PLA [4]
2.3.1 PLA P oduc ion
The PLA can be manu ac u ed by ca bohyd a e e men a ion o chemical syn hesis.
In 1780 he i s building block o PLA ha was isola ed om sou milk by he Swedish chemis Scheele and he
i s comme cializa ion has been in 1881. [5]
Lac ic acid is he simples hyd oxyl acid wi h an asymme ic ca bon a om and i exis s in wo op ically ac i e
con igu a ions, he L (+) and D (-) isome s.
Figu e 2.8 - Polyme iza ion o L-Lac ic acid o L-PLA by di ec condensa ion o by ing opening ia he L-lac ide [6]
Nuno Calçada Lou ei o
21
The L-Lac ic Acid (2-hydo xy p opionic acid) is he simples hyd oxyl and he na u al and mos common o m o
his acid. The asymme ic ca bon a om d i es o p oduc ion o wo op ical isome s: he L-Lac ic Acid (+)
p oduced by mammalian and he D-Lac ic Acid (-) p oduced by mammalian and o he mic oo ganisms.
Figu e 2.9 - Chemical S uc u e o L (le ) and D ( igh ) Lac ic Acid [4]
The lac ic acid is made by bac e ial e men a ion o ca bohyd a es. The e men a ion p ocesses o ob ain lac ic
acid can be classi ied acco ding o he ype o bac e ia used.
In he He e o e men a i e me hod less han 1.8 moles o lac ic acid pe mole o hexose is p oduced along wi h
signi ican le els o o he me aboli es such as ace ic acid, e hanol, glyce ol, manni ol and ca bon dioxide.
In he Homo e men a i e me hod an a e age o 1.8 moles o lac ic acid pe mole o hexose and mino le els o
o he me aboli es a e p oduced. This con e sion yields 90 g lac ic acid pe 100 g glucose.
Since homo e men a i e pa hways lead o g ea e yields o lac ic acid and lowe le els o byp oduc s, hese
pa hways a e mainly used by indus y. The majo i y o he e men a ion p ocesses nowadays use a genus o
Lac obacilli which yields a high a e o lac ic acid.
These bac e ia a e classi ied as homo e men a i e, and he
gene al p ocessing condi ions include a pH o 5.4 o 6.4, a empe a u e o 38 o 42 ºC and a low oxygen
concen a ion.
The main sou ces a e, in gene al, simple suga s such as glucose and mal ose om co n o po a o, suc ose om
cane o bee suga and lac ose om cheese whey.
The p oduc ion a e depends o he p oduc ion ype. Gene ally, ba ch p ocesses p oduce 1 o 4,5 g /(l.h) o
lac ic acid while con inuous p ocesses p oduce 3 o 9,0 g/(l.h) . I ’s possible o each a a e o nea o 76 g/(l.h)
i i ’s use cell ecycle eac o s.

Sus ainable au omo i e componen s o in e io doo ims
22
Figu e 2.10 – Non-sol en p ocess o p epa e Poly(Lac ic Acid) [4]
In o de o p oduce PLA o indus ial p ocesses is necessa y ha he polyme possess adequa e he mal
s abili y o p e en deg ada ion and main ain he molecula weigh and p ope ies. PLA unde goes he mal
deg ada ion a empe a u es abo e 200 ºC by hyd olysis, lac ide e o ma ion, oxida i e main chain scission
and in a- o in e molecula anses e i ica ion eac ions. [5]
The PLA homopolyme s p esen s a T
g
a ound 55ºC and a T
m
o 175ºC.
2.3.2 PLA P ope ies
PLA is a unique polyme ha in many ways beha es like PET, bu also pe o ms a lo like PP.
The p ope ies o PLA a e de e mined by he polyme a chi ec u e (i.e. he s e eochemical makeup o he
backbone) and he molecula mass, which is con olled by he addi ion o hyd oxylic compounds. The abili y o
con ol he s e eochemical a chi ec u e allows a p ecise con ol o e he speed o c ys alliza ion and he
deg ee o c ys allini y.
Tha abili y allows, also, he con ol o he mechanical p ope ies and he p ocessing empe a u es o he
ma e ial.
I ’s possible also o con ol he deg ada ion beha io since i is s ongly dependen o he c ys allini y o he
polyme .
Due o i s good s eng h p ope ies, ilm anspa ency, biodeg adabili y, biocompa ibili y and a ailabili y om
enewable sou ces, he PLA is comme cially in e es ing.
The physical cha ac e is ics o PLA a e e y dependen on i s ansi ion empe a u es o common quali ies
such as densi y, hea capaci y and mechanical and heological p ope ies.
Nuno Calçada Lou ei o
23
In he solid s a e PLA can be ei he amo phous o semic ys alline depending on he s e eochemis y and
he mal his o y.
Fo he amo phous PLA he glass ansi ion empe a u e (T
g
) de e mines he uppe use empe a u e o mos
comme cial applica ions.
Figu e 2.11 – Me as able s a es o amo phous PLAs [4]
Fo semic ys alline PLAs, bo h T
g
(ap ox. 58 ºC) and mel ing poin (T
m
), 130-230 ºC a e impo an o
de e mining he use empe a u es ac oss a ious applica ions. T
g
and T
m
a e s ongly a ec ed by he o e all
op ical composi ion, p ima y s uc u e, he mal his o y and molecula weigh .
Figu e 2.12 – Me as able s a es o semic ys alline PLAs [4]
2.3.3 PLA Biodeg ada ion
As men ioned ea lie , he biopolyme s a e polyme s ha a e chemically syn hesized o biosyn hesized du ing
g ow h cycles o all o ganisms. Some mic o-o ganism and enzymes, al eady iden i ied, a e capable o
deg ading hem.
Unde ypical use condi ions, PLA is e y s able and will e ain i s molecula weigh and physical p ope ies o
yea s.
Howe e unde condi ions o high empe a u e and high humidi y PLA will deg ade quickly and disin eg a e
wi hin weeks o mon hs.
PLA and i s copolyme s deg ade o non- oxic b eakdown p oduc s unde ce ain condi ions o empe a u e
and mois u e con en . The deg ada ion occu s ini ially by a non-enzyma ic hyd oly ic p ocess. Howe e he
mass and he shape o he PLA pa can be p ese ed un il ex ensi e deg ada ion has aken place.
Sus ainable au omo i e componen s o in e io doo ims
24
The p ima y mechanism o deg ada ion is hyd olysis and clea age o he es e linkages in he polyme
backbone, ollowed by bac e ial a ack on he agmen ed esidues.
In he ini ial phase, he high molecula weigh polyes e chains hyd olyze ( o a lowe molecula weigh
oligome s) and a e wa e pene a ion his molecula weigh dec ease apidly due he PLA solubili y in wa e
only a e y low molecula weigh .
Figu e 2.13 – PLA Hyd olysis and molecula weigh loss [4]
The a e o hyd olysis is de e mined by i s in insic a e cons an , wa e concen a ion, acid o base ca alys ,
empe a u e and mo phology. Since PLA is e y wa e pe meable his hyd olysis eac ion is au oca aly ic.
Figu e 2.14 – Au oca aly ic Hyd olysis eac ion [1]
In he nex s eps o he deg ada ion se e al enzymes can ca alyze PLA hyd olysis. The mos common enzymes
a e he P o einase K, P onase and B omelain.
The enzymes a e la ge molecules and a e unable o di use h ough he PLA c ys alline egions. Enzyma ic
in ol emen can p oduce po es and agmen a ion making mo e polyme egions accessible o he enzymes.
Nuno Calçada Lou ei o
25
2.3.4 PLA Based Composi es
The PLA composi es can be ca ego ized in o wo di e en g oups: one in which p oduc s a e mainly used in
he ield o medical applica ions and a second g oup in which applica ions a e in he ield o s uc u al plas ics
in ended o o he uses.
PLA composi es o medical applica ions ha e o en been ein o ced wi h bioac i e mine al ille s like zi conia,
magnesium oxide, icalcium phospha e o hyd oxyapa i e. The ein o ced by ca bon ibe s is also used.
The main eason o he use o hese ypes o composi es is o mimic he mechanical p ope ies and beha io
o he bones in su gical applica ions.
The e a e se e al easons o use PLA as a ma ix in o na u al ibe biocomposi es.
• PLA is nowadays he mos ad anced biopolyme in e ms o comme cializa ion;
• PLA has good mechanical p ope ies ha a e simila o hose o he polys y ene;
• PLA can be mel -p ocessed wi h s anda d p ocessing equipmen s a empe a u es below hose a
which na u al ibe s s a o deg ade;
The e a e innume ous s udies o PLA composi es.
Bledzki and Jaszkiewicz s udied he composi es o PLA ein o ced wi h Ju e, Abaca o Man-made cellulose. [7]
They concluded ha by adding 30% (w ) o man-made cellulose, an inc ease in ensile s eng h o up o 50%
can be achie ed, and in a e age i ’s possible o ob ain an imp o emen o a ound 30%.
Figu e 2.15 – S ess-s ain cu es o he es ed composi es [7]
Oksman, Sk i a s and Selin [8] in es iga es i PLA can be used as ma ix in composi e sys ems whe e na u al
ibe s a e used as ein o cemen s. They concluded ha PLA wo ks e y well as ma ix ma e ial o na u al
ibe composi es. The composi e s eng h is abou 50% be e compa ed o simila PP/ lax ibe composi es,
which a e used oday in many indus ial applica ions. The s i ness o PLA is inc eased om 3.4 o 8.4 GPa wi h
an addi ion o 30 w .% lax ibe s. Gene ally hese esul s indica e ha PLA na u al ibe composi es ha e
mechanical p ope ies high enough o use ins ead o con en ional he moplas ic composi es.
Sus ainable au omo i e componen s o in e io doo ims
32
This new dilemma d i es o he e-bo n use o na u al ibe s, no only o he applica ions om he pas , bu
also o p oduce new composi e ma e ials.
The use o na u al ibe s om ege able sou ces in he p oduc ion o composi e ma e ials has inc easing
du ing he las decade, especially in o he au omo i e indus y.
Due o he commi men be ween he esis ance, s i ness and weigh , he composi es ein o ce wi h na u al
ibe s o m ege able sou ces a e compe ing wi h he “con en ional composi es” in pa icula wi h he ones
ha a e ein o ced wi h glass- ibe . Na u al ibe s such as lax, hemp, ju e, sisal o co on a e om enewable
na u e, cheape , wi h a mino densi y, ha e be e speci ic s i ness and a mino en i onmen al impac since
ha hey a e biodeg adable and easily ecyclable.
Table 2.4 - Mechanical P ope ies o Na u al Fibe s [6] [21]
Fibe Speci ic G a i y Tensile S eng h
(MPa)
Modulus (GPa) Elonga ion a
b eak (%)
Speci ic Modulus
Ju e 1,3 393 55 1,16 - 1,5 38
Sisal 1,3 510 28 3 – 7 22
Flax 1,5 344 27 2,7 – 3,2 50
Sunhemp 1,07 389 35 --- 32
Pineapple 1,56 170 62 --- 40
The na u al ibe s p esen s some limi a ions han need o be esol e so hey can e ec i ely compe e wi h glass
ibe s.
The h ee majo limi a ions a e:
• The weak in e acial adhesion wi h he syn he ic polyme s – specially he he moplas ics;
• The high capabili y o wa e abso p ion;
• The low he mal esis ance due o i s o ganic na u e;
To o e come hese limi a ions, he na u al ibe s can be submi ed o supe icial ea men s ha allows he
de elopmen o composi es wi h good mechanical p ope ies, bigge du abili y and eliabili y due o he
ope a ing condi ions.
2.5.1 Fibe s Classi ica ion
Na u al ibe s a e subdi ided based on hei o igins as exp essed in o igu e 2.20:
Figu e 2.20 - Fibe s classi ica ion [1] [22]

Nuno Calçada Lou ei o
33
All plan ibe s ( ege able) a e composed o cellulose while animal ibe s consis o p o eins (hai , silk and
wool). Plan ibe s can include bas (o s em) ibe s, lea o ha d ibe s, wood, ce eal s aw and o he g ass
ibe s.
Na u al ibe s can be compa ed wi h a composi e ma e ial consis ed by cellulose ib ils embedded in lignin
ma ix. [17] The cellulose ib ils a e aligned along he leng h o he ibe , and he ein o cing e iciency is
ela ed o he na u e o cellulose and i s c ys allini y.
Table 2.5 - Comme cially Impo an Fibe Sou ces [1]
Fibe Species Wo ld P oduc ion
(10
3
on)
O igin
Wood ( >10,000 species) 1,750,000 S em
Bamboo ( > 1,250 species) 10,000 S em
Co on lin Gossypium sp. 18,450 F ui
Ju e Co cho us sp. 2,300 S em
Kena Hibiscus cannabinus 970 S em
Flax Linum usi a issimum 830 S em
Sisal Aga e sisilana 378 Lea
Roselle Hibiscus sabda i a 250 S em
Hemp Cannabis sa i a 214 S em
Coi Cocos nuci e a 100 F ui
Ramie Boehme ia ni ia 100 S em
Abaca Musa ex iles 70 Lea
The ege able/plan ibe s can be u he sub-di ided in o subg oups, as showed in he nex igu e:
Figu e 2.21- Vege able ibe classi ica ion [1]
The mos impo an o he na u al ibe s in e ms o au omo i e indus y a e, wi h no doub , he s em ibe s
subg oup.
They a e called by ha name because hei o igin is he s em o he plan . The plan s em is composed o an
inne woody co e su ounded by bundles o long hollow ibe s and an ou e p o ec i e skin.
Sus ainable au omo i e componen s o in e io doo ims
34
Figu e 2.22 – S uc u e o bio ibe [22]
Since he main unc ion o he s em is o s abilize he plan , i ’s logical ha he s em ha e plan ibe s wi h
good mechanical p ope ies. This a ibu e in conjunc ion wi h a low densi y ensu es ha s em ibe s ha e he
po en ial o be ou s anding ein o cemen s in ligh weigh composi e pa s.
The ad an ages o using s em ibe s in he au omo i e indus y a e:
• Renewable and sus ainable plan ibe esou ce;
• Recyclable;
• Weigh sa ing be ween 10 and 30%;
• Cos sa ings;
• Abundan supply which is accessible o ca manu ac u ing plan s in many egions o he wo ld;
Table 2.6 – Fibe cha ac e is ics and g owing a ea o comme cially a ailable ibe s [4]
Nuno Calçada Lou ei o
35
Nowadays an inc easing ma ke is appea ing due o he ege able ibe s.
Figu e 2.23 - To al consump ion o na u al ibe s in Eu ope [1]
The wo ld’s supply o na u al esou ces is being deple ed, he demand o sus ainable and enewable ma e ials
con inues o ise.
Figu e 2.24 - Use o na u al ibe s in he Ge man au omo i e indus y 1996–
––
–2002 ( onnes) [33]
2.5.2 Cellulosic ibe s: Ad an ages and Disad an ages
The bio ibe wo ld is ull o examples whe e cells o g oups o cells a e designed o s eng h and s i ness.
Cellulose is a na u al polyme wi h high s eng h and s i ness pe weigh , and i ’s he building ma e ial o long
ib ous cells.
Sus ainable au omo i e componen s o in e io doo ims
36
In gene al, he ibe consis s o a wood co e su ounded by a s em.
Wi hin he s em he e a e a numbe o ibe bundles, which con ain indi idual ibe cells o ilamen s. These
ilamen s a e made o cellulose and hemicellulos, bonded oge he by a ma ix, no mally lignin o pec in. The
p incipal di e ences be ween he indi idual ibe s a e: ibe quali ies, lignin con en and odo .
The inc easing o in e es in lignocellulosic ibe s is due mainly o hei economical p oduc ion wi h ew
equi emen s o equipmen and low speci ic weigh , which esul s in a highe speci ic s eng h and s i ness
when compa ed o glass ein o ced composi es.
The bio ibe s, such as he cellulosic ibe s, a e nonab asi e o mixing and molding equipmen . They ha e a
posi i e en i onmen al impac and wi h a p oduc ion ha equi es li le ene gy.
Howe e he inhe en pola and hyd ophilic na u e o lignocellulosic ibe s and he non-pola cha ac e is ics o
he common he moplas ics esul s in o a compounding di icul ies leading o non-uni o m dispe sion o he
ibe s wi hin he ma ix which impai s he e iciency o he composi e. This is p obably he majo disad an age
o biocomposi es.
Ano he p oblem is ela ed o he p ocessing empe a u es ha o his ype o ibe s a e es ic ed o 200 ºC
once ha he ege able ibe s deg ade a high empe a u es. This will ame he ma ix choice.
Ano he se back is he high mois u e abso p ion o he bio ibe s leading o swelling and p esence o oids a
he in e ace, which leads o a poo mechanical p ope ies and educes dimensional s abili y o he
composi es.
Is clea ha he ad an ages ou weigh he disad an ages and mos o he sho comings ha e emedial
measu es in he o m o chemical ea men s.
2.5.3 Cellulosic ibe s: Po uguese Ma ke and Ex ac ion Technology
The bes way o ob ain cellulosic ibe s is o use he pulp was es om he pape plan s.
In he no h o Po ugal and in he Galiza egion (Spain) is possible o coun 824000 ha o Pine ees and
468000 ha o Eucalyp us ees. [23]
To p ocess and ans o m he wood in pape his eu o- egion coun s wi h 9 indus ial plan s. F om hese 9
plan s, 2 a e he mochemical pape pulp plan s. The o he 7 can be di ided in 5 plan s o p oduce MDF and 2
o p oduce ibe boa d.
Nuno Calçada Lou ei o
37
Figu e 2.25 – No he n Ibe ian Peninsula Wood T ans o ma ion Plan s Geo-localiza ion [23]
The p ocess o ex ac ibe s om he wood is a chemically hea y and equi es a pa allel sys em o pu i y he
p oduced was es o dec ease he en i onmen al impac .
The p ocess is qui e simila i we a e ex ac ing pine ibe s o eucalyp us ibe s. The main di e ences a e a he
chemical compounds used.
In igu e 2.26 i ’s p esen ed a simpli ied diag am o a ypical pulp and pape p ocess.
Fo composi e applica ions he ibe s don’ goes h ough all p ocess desc ibed bu a e bleaching he pulp
goes o he seconda y ma ke pulp.

Sus ainable au omo i e componen s o in e io doo ims
38
Figu e 2.26 – Simpli ied diag am o a ypical pulp and pape p ocess [24]
Nuno Calçada Lou ei o
39
2.6 Composi e Ma e ials
A Composi e Ma e ial (o composi e) can be de ined as a mic o o mac oscopic combina ion o wo o mo e
dis inc ma e ials.
The associa ion o hese ma e ials aims o c ea e a new ma e ial wi h be e p ope ies han he ones who
o igin i .
The composi e ma e ials exis and hey a e being used o se e al cen u ies.
P obably he oldes e e ence o composi e ma e ials appea s in he Holly Bible, and desc ibe ha he Jewish
sla es a e o ced by he Egyp ians o p oduce b icks om he mix u e o s aw and mud.
5
In he VII Cen u y he Japanese sabe s we e made by s eel and i on.
Nowadays i ’s possible o ind composi e ma e ials e e ywhe e, s a ing in he glass o ou house windows,
passing by he conc e e use in cons uc ion.
The composi e ma e ials a e, echnically, he e ogeneous and aniso opic ma e ials and ha means ha he
mechanical p ope ies a e depending o he di ec ion and he place whe e he solici a ion occu s.
Typically, a composi e ma e ial is cons i u ed by a ma ix - a homogeneous esin o polyme ma e ial, and
ein o cemen – a s ong ma e ial bonded in o he ma ix o imp o e i s mechanical p ope ies.
2.6.1 Ma ices
The pu pose o a Composi e Ma ix is o bind he ein o cemen oge he . This binding is made due o he
cohesi e and adhesi e cha ac e is ics o he ma ix ma e ial.
When unde load, esins may mic oc ack and c aze. Due o he coalescence o mic oc acks, he ma ix may
o m la ge c acks. I ’s also possible o ha e a debonded o he ein o ce ibe . I anyone o hese ac o s
occu ed i ’s possible o ha e a composi e wi h p ope ies a lowe han he desi ed ones.
Tha ’s way he ma ix is he “weak link” o any composi e ma e ial.
None heless, he ma ix esin p o ides many essen ial unc ions.
The composi e ma ix is esponsible o keep he ein o ce in o he p ope o ien a ion and posi ion, o
dis ibu e he load mo e o less e enly among he ibe s, p o ides esis ance o c ack p opaga ion and
damage, and also p o ides all o he in e lamina shea s eng h o he composi e.
Fu he mo e, i ’s ma ix esponsibili y he o e all se ice empe a u e limi a ions.
5
Exodus 5,7
Sus ainable au omo i e componen s o in e io doo ims
40
2.6.2 Rein o cemen s
One o he objec i es o he ein o cemen s is o suppo mos o he load ha a e applied in o he composi e
ma e ial.
Since he ein o cemen s a e, by de aul , agile ma e ials hey don’ con ibu e o he impac beha io o he
composi e.
Howe e , he ein o cemen s a e mo e igid and s i ene han he ma ix ma e ial. These cha ac e is ics gi e
o he composi e a high mechanical beha io .
To a ma e ial ein o ce e ec i ely a ma ix, i mus ha e he ollowing cha ac e is ics:
• A Young Modulus highe han he ma ix (minimum wice bigge );
• Tensile S ess bigge han he ma ix ensile s ess;
• A geome y ha allows he combina ion wi h he ma ix and wi h he inal o m o he pa ;
• Ha e a good adhesion wi h he ma ix;
• Don’ eac chemically wi h he ma ix;
No mally, he ein o ce addi ion, occu s o imp o e he mechanical beha io , s i ness, co osion esis ance,
he mal conduc i i y, c eep and a igue esis ance.
2.6.3 The moplas ic Ma ix Composi es
The composi es can be di ided in o classes in a ious manne s. The i s di ision, and he mos common one, is
o di ed by he ma ix ma e ial. In his case he di ision is he moplas ic ma ix composi es and he mose
ma ix composi es.
O he di ision is oo di ed by he ein o ce ma e ial. In his case he di ision is much mo e complex since i ’s
possible o ha e an innume ous numbe o ein o ce ma e ials.
The moplas ic esins a e po en ially use ul as ma ices o ad anced composi es. The moplas ic esins p esen
h ee ad an ages when compa ed o he mose s esins.
• P ocessing can be as e since no cu ing eac ion is equi ed. The moplas ic composi es only equi e
hea ing, shaping and cooling;
• The mechanical p ope ies a e a ac i e, in pa icula , high delamina ion esis ance and damage
ole ance, low mois u e abso p ion and he excellen chemical esis ance o semic ys alline polyme s;
• The moplas ic composi es o e ad an ages in e ms o en i onmen al aspec s. They ha e e y low
oxici y since hey do no con ain eac i e chemicals ( he e o e s o age li e is in ini e). Because i is
possible o emel and dissol e such he moplas ics, hei composi es a e also easily ecycled o
combined wi h o he ecycled ma e ials;
In he au omo i e indus y, he moplas ic composi es a e used ex ensi ely, because hey allow as p ocessing
cycles o ai ly la ge componen s. In he ield o injec ion molded componen s, he he moplas ic composi es,
no mally, a e used wi h sho ibe s (5-10mm) in molding pelle s.
Nuno Calçada Lou ei o
41
The moplas ics esins can ha e an amo phous o a semi-c ys alline s uc u e. I he s uc u e is amo phous,
he polyme chains don’ p esen long- ange o de , which may be iewed as polyme glasses and, in he
absence o colo pigmen s, hese polyme s, a e usually anspa en .
On he o he hand, c ys alline polyme s ha e egions o molecula o de .
Due o he la ge size o polyme chains inhibi s he pe ec c ys alliza ion; he c ys alline he moplas ics
co ec ly mus be desc ibed as semi-c ys alline, since he deg ee o c ys allini y ne e eaches 100%. So, he
semi-c ys alline he moplas ics a e eally a wo-phase ma e ials wi h a c ys alline and an amo phous phase.
Table 2.7 - Cha ac e is ic empe a u es o he moplas ic esins [25]
Polyme IUPAC
designa ion
S uc u e T
g
(ºC) T
m
(ºC) P ocessing
Tempe a u e (ºC)
Polyamide 6,6 PA6,6 C ys alline 55 265 270-320
Polyamide 12 PA12 C ys alline 35 180 220-260
Polyamide-imide PAI Amo phous 275 None 350-400
Polybu ylene e eph hala e PBT C ys alline 20 240 260-290
Polyca bona e PC Amo phous 150 None 280-330
Polye he E he Ke one PEEK C ys alline 143 343 380-400
Polye he imide PEI Amo phous 217 None 335-420
Polye he -sulphone PES Amo phous 220 None 300-320
Polye hylene e eph hala e PET C ys alline 70 265 280-310
Polyphenylene Sul ide PPS C ys alline 90 280 300-340
Polyp opylene PP C ys alline -10 165 200-240
Polysulphone PSU Amo phous 190 None 300-350
The use o polyme composi es is o g ea in e es in he iew o a mo e in elligen u iliza ion o en i onmen al
and inancial esou ces. Se e al wo ks ha e being done o c ea e ull biodeg adable composi es by he
eplacemen o he pe ol-based polyme s and syn he ic ibe ein o cemen o enewable-sou ce polyme s
and ibe s. These g een composi es, ye , p esen s some limi a ions ega ding mainly duc ili y, p ocessabili y
and dimensional s abili y [26].
I can be s a ed ha he comme cial ma ke is s ill in an opening phase (especially in Eu ope) o hese ypes o
composi es. The e o e much can s ill be done in o de inding new applica ions, imp o ing he p ope ies, he
appea ance and he ma ke abili y o hese ma e ials. All o hese issues equi e, and con inue o equi e,
signi ican esea ch e o s in o de o:
• ind new o mula ions ( i gin o ecycled polyme s, adi ional o biodeg adable polyme s; ype,
appea ance, quali y and amoun o he ille s);
• Co ec ly cha ac e ize a all e ms he new composi es;
• Apply hem o he mos sui able applica ions;
• Re ine and eadjus he p ocessing echniques.
As soon as he ma ke o hese composi es inc eases, educ ion o cos s and imp o emen o he quali y will
be achie ed.
Sus ainable au omo i e componen s o in e io doo ims
48

Nuno Calçada Lou ei o
49
Chap e 3.
Mo i a ion, Objec i es and Resea ch App oach
3.1 Mo i a ion and objec i es
The mo i a ion o his wo k a ises he ac ha all he OEM’s a e ying o inpu mo e eco- iendly ma e ials
in o he ca s. Al hough he esea ch on his a ea is hugh i is ocus on na u al ibe s composi es o pe ol-based
he moplas ics so hey can achie ed he legal imposed en i onmen al indexes wi hou using he pe ol-based
polyme s.
The use o only one enewable-sou ce polyme will d i e us o a much mo e expensi e polyme .
The main objec i es o his wo k a e easy o s a e. I ’s necessa y o de elop a new composi e ma e ial ha
possesses he minimal p ope ies o eplace he pe ol-based polyme s used in o he in e io doo ims. Tha
new composi e mus be p ocessed by he usual echnological p ocess o manu ac u ing hese ype o pieces –
injec ion molding. Allied o ha , his new composi e ma e ial mus be biodeg adable and mus ha e a
enewable-sou ce o igin.
3.2 Resea ch App oach
This sec ion desc ibes he esea ch app oach used o achie e he goal o his hesis.
As al eady desc ibe in o chap e 2, he PLA is he cheape biodeg adable polyme . Howe e he nea PLA
doesn’ ul ill all he in e io doo ims equi emen s. The blending wi h PHA ies o each he mechanical
equi emen s. The PLA/PHA blends ha e he mechanical capabili y o eplace he used pe ol-base polyme s
bu in e ms o se ice empe a u e s ays lowe han he equi ed alue.
The inco po a ion o cellulosic ibe s will y o imp o e he se ice empe a u e and mechanical beha io .
Sus ainable au omo i e componen s o in e io doo ims
50
Once ha he idea is o op imize a h ee ma e ial composi e, he combina ions o he h ee componen s can
be ansla ed in o an eno mous se s o samples, es s and da a analysis ha can ake oo much ime o
analyses.
Figu e 3.1– Va iable in e ac ion o eaching he op imal solu ion
As possible o conclude by analysis he igu e 3.1, o each o a good subs i u e o he pe ol-based polyme s
ac ually in use o in e io doo ims, i ’s necessa y o make a composi e wi h a polyme blend as a ma ix and
he co ec weigh ac ion o cellulosic ibe s.
The app oach ha is been chosen s a s wi h a wo a iable model, and wi h ha he ma ix polyme blend
will be op imize. A e ha he weigh ac ion o ibe s will be de e mined based in o a one a iable model.
Since he ma ix is esponsible o he mechanical beha io o he composi e he blended polyme ma ix will
be op imized compa ing he mechanical beha io wi h he mechanical beha io o he ac ual polyme s used
in o in e io doo ims.
A e ha , he he mal beha io will be op imized by he addic ion o he ibe s.
All he es s we e pe o med aking accoun he ASTM o ISO s anda ds.
Fo he ma ix, ele en di e en samples we e p epa ed, wi h in e als o 10% o a ia ion o he phases,
s a ing in pu e PHA samples and ended in he pu e PLA samples (PHA/PLA a ios o [100:0] o [0:100]). The
alues be ween he a ios we e ex apola ed om he nea by da a.
A e chosen he bes PHA/PLA a io, he in oduc ion o he ibe s s a s wi h he bes PLA/Fibe a io
desc ibed in he li e a u e (20% w ) [1] and, a e ha , a ± 10% ibe weigh ibe we e es ed.
The da a ex apola ion will gi e us he bes ma ix/ ibe a io.
The esea ch app oach can be summa ized in o he nex igu e.
Nuno Calçada Lou ei o
51
Figu e 3.2 – Scheme o hesis esea ch s a egy
3.3 Thesis S uc u e
To e lec all his esea ch wo k, his hesis s a s, in chap e 1, o explain he mo i a ion ha ene gizes all he
wo k.
In chap e 2 i ’s p esen ed he li e a u e e iew o all opics ha a e ela ed wi h his wo k and in chap e 3 i
is p esen ed he pa h o each he inal objec i e.
The used ma e ials and he pe o med es s and speci ica ions a e p esen ed in o chap e 4.
Chap e 5 and chap e 6 p esen s, espec i ely, he mechanical and mo phological cha ac e iza ion o PHA/PLA
blends ha d i es o he selec ion o he bes composi e ma ix.
Chap e 7 p esen s he s udy o he ibe inco po a ion and he selec ion o he bes ma ix/ ibe ela ion.
On chap e 8 he p oduc ion o a demons a ion pa is ela ed.
This wo k ends in, chap e 9, wi h he inal ema ks and he indica ion o some u u e wo ks ha migh be
done.
Sus ainable au omo i e componen s o in e io doo ims
52
Re e ences
[1] D. Guima ães, E ei o das condições de injecção nas p op iedades de PLA e o çado com ib as celulósicas, Mas e
Thesis in Polyme Enginee ing, Uni e si y o Minho, Po ugal (2009)
Nuno Calçada Lou ei o
53
Chap e 4.
Ma e ials and Me hods
This chap e desc ibes he ma e ials, expe imen al p o ocols and cha ac e iza ion echniques used in his
hesis.
4.1 Ma e ials
4.1.1 Polyhid oxyalkanoa e – PHA
The Polyhyd oxyalkanoa e used is p oduced by Na u eplas ® (F ance) unde he ade name PHI002.
PHI002 is a he moplas ic esin o PHA made om bac e ial e men a ion and is speci ically de eloped o
injec ion molding. The de ailed da ashee can be ound in he Appendix A.1.
Howe e , he main p ope ies a e ansc ibed in o able 4.1
Table 4.1 – PHA Technical da a
Mel empe a u e (ºC) 145 - 155
Deg ada ion empe a u e (ºC) 200
Tensile S eng h a b eak (MPa) 35
Tensile elonga ion a b eak (%) 2
Tensile Modulus (MPa) 2950
HDT A (1,8 MPa) (ºC) 72,5
Densi y 1,25 (±0,05)
MFI (190 ºC/2.16 kg) (g/600 s) 15-30

Sus ainable au omo i e componen s o in e io doo ims
54
4.1.2 Poly(Lac ic Acid) – PLA
The Poly(Lac ic Acid) used is p oduced by Na u eWo ks LLC® (USA) unde he ade name INGEO biopolyme
3251D.
INGEO 3251D is designed o injec ion molding applica ions. This g ade p esen s a highe mel low capabili y
and a highe low capabili y. The de ailed da ashee can be ound in he Appendix A.2.
Howe e , he main p ope ies a e ansc ibed in o able 4.2
Table 4.2 – PLA Technical da a
Mel empe a u e (ºC) 188 - 210
Tensile S eng h a b eak (MPa) 48
Tensile elonga ion a b eak (%) 2,5
Densi y 1,24
MFI (190 ºC/2.16 kg) (g/600 s) 30-40
4.1.3 Cellulosic Fibe s
The cellulose ibe s used in his wo k come om he Po ucel K a pape ac o y, loca ed in Viana do Cas elo
and i o igin is he Eucalyp us Globulus ees.
They ha e been emo ed o he p oduc ion line a e he inal chemical ea men and be o e en e in he
pape p oduc ion line, which means ha he ibe s we e bleached and disin eg a ed.
The bulk ibe s a e composed essen ially o cellulose (~85%) and glucu onoxylan (~15%). The main p ope ies
a e exp essed in o able 4.3
Table 4.3 – Eucalyp us Globulus ibe gene al p ope ies [1-2]
A e age ibe diame e (μm) 10,9
A e age ibe leng h (mm) 0,66
Tensile S eng h a b eak (MPa) 160
Tensile elonga ion a b eak (%) 5,2
Tensile Modulus (GPa) 17,4
Flexu al Modulus (GPa) 16
Flexu al S engh a b eak (MPa) 130
Densi y 1,6
4.1.4 P epa a ion o he Blends
The polyme s we e d ied in o an o en a e 60ºC o 24 hou s be o e p ocessing and kep in o sepa a e Ziploc
bags. Jus be o e he injec ion, he polyme s a e weighed and hen mix in o a o a ional chambe . When he
mix u e pe iod ends he blend is injec ed in o a Fe oma ik Milac on K85 injec ion machine, being p oduced
ensile es specimens.
Nuno Calçada Lou ei o
55
The mold empe a u e was 20 ºC and he injec ion empe a u e p o ile is desc ibed in igu e 4.1.
Figu e 4.1 – Injec ion Tempe a u e p o ile
The empe a u e p o ile was es ablished by combining he mel ing empe a u e o he polyme s, he
deg ada ion empe a u e and he injec ion molding condi ions sugges ed by he supplie ´s da ashee s. The
o he injec ion pa ame e s we e he ollowing: injec ion eloci y: 20 mm/s (co esponding o an injec ion low
a e o 6,3 cm3/s). Ele en di e en samples we e p epa ed wi h in e als o 10w % o a ia ion o he
ma e ial´s a ios: PHA/PLA a io o : [100:0] (pu e PHA), [90:10], [80:20, [70:30], [60:40], [50:50], [40:60],
[30:70], [20:80], [10:90] and [0:100] (pu e PLA).
The blends we e injec ion molded in he o m o specimens wi h dimensions acco ding o he espec i e
s anda d.
Figu e 4.2 – Used ensile specimen injec ion mold
4.1.5 P epa a ion o he Composi e Ma e ial
To p epa e he Bio-composi e he p ocess used was he same o he p epa a ion o blends.
Howe e be o e injec ion i was necessa y o ex ude he bio-composi e and palle ize i .
The ex usion akes place in o a win sc ew Cope ion Ex ude (We ne & P leide e ).
Figu e 4.3 – Cope ion Ex ude
Sus ainable au omo i e componen s o in e io doo ims
56
The ex ude empe a u e p o ile used is exp essed in o igu e 4.4.
Figu e 4.4 – Ex ude Tempe a u e P o ile
This pa icula equipmen possesses h ee independen hoppe s, one o each componen .
Figu e 4.5 – Hoppe s Sys em
Adjus ing he eeding h oa o each hoppe i ’s possible o adjus he weigh ac ion o he ex uded
composi e. The used mass low a e is exp essed in o able 4.4.
Table 4.4 – Ex usion low a es
Q
o al
Q
PHA
Q
PLA
Q
Fibe
90% Ma ix / 10% Fibe 4 kg/h 1,08 kg/h 2,52 kg/h 0,4 kg/h
80% Ma ix / 20% Fibe 4 kg/h 0,96 kg/h 2,24 kg/h 0,8 kg/h
70% Ma ix / 30% Fibe 1 kg/h 0,21 kg/h 0,49 kg/h 0,3 kg/h
A e he composi e ex usion, ma e ial goes o ex ude inco po a ed palle ize o be ca ed and he keep i
in o Ziploc bags un il s a s he injec ion p epa a ion p ocedu e.
Nuno Calçada Lou ei o
57
Figu e 4.6 – Palle ize cu ing Sys em
4.2 De e mina ion o Mechanical P ope ies
4.2.1 Tensile Tes
The measu emen o he ensile p ope ies was made acco ding o ASTM D638. Fo ha i has been used a
Shimadzu AG-X 10 kN uni e sal es ing machine, equipped wi h a 50 mm ex ensome e .
Figu e 4.7 – Tensile es Appa a us
Acco ding o he s anda d he sample geome y was a ype III, wi h a g ip dis ance o 150 mm. The c osshead
eloci y was o 5 mm/min and he es s we e pe o med in a s anda d labo a o y a mosphe e o 23±2ºC and
50±5% ela i e humidi y.
Sus ainable au omo i e componen s o in e io doo ims
64
Re e ences
[1] H. Sa as ano J ., P.G. Wa den, R.S.P. Cou s, B azilian was e ib es as ein o cemen o cemen e-based composi es,
Cemen & Conc e e Composi es, ol.22, pp. 379-384 (2000)
[2] V. Agopyan, H. Sa as ano J ., V.M. John, M.A. Cinco o, De elopmen s on ege able ib e-cemen based ma e ials in
São Paulo, B azil: an o e iew, Cemen & Conc e e Composi es, ol.27 , pp. 527-536 (2005)
[3] ASTM s anda d D 638 – 03 S anda d Tes Me hod o Tensile P ope ies o Plas ics (2010)
[4] ASTM s anda d D 790 – 10 S anda d Tes Me hod o Flexu al P ope ies o Un ein o ced and Rein o ced Plas ics and
Elec ical Insula ing Ma e ials (2010)
[5] ISO s anda d 6603 – 2 De e mina ion o mul iaxial impac beha io o igid plas ics - Pa 2: Ins umen ed punc u e
es (2000)
[6] ISO s anda d 75 - 2 De e mina ion o empe a u e o de lec ion unde load - Pa 2: Plas ics and eboni e (2004)
[7] ASTM D7426-08 – S anda d Tes Me hod o assignmen o he DSC p ocedu e o de e mining T
g
o a polyme o an
elas ome ic compound (2008)

Nuno Calçada Lou ei o
65
Chap e 5.
Mechanical Cha ac e iza ion o PHA/PLA Blends
8
This chap e p esen s an in es iga ion abou he mechanical beha io o PHA/PLA blends.
The blend mechanical p ope ies can be op imized ough he a ia ion o he PHA con en s on he blend. The
lexu al and ensile p ope ies we e es ima ed by di e en models: Rule o Mix u es, Ke ne –Uemu a–
Takayanagi model, Nicolai-Na kis model and Béla-Pukánsky model. This aimed a in es iga ing he adhesion
be ween he wo ma e ial phases. The esul s an icipa e a good adhesion be ween bo h polyme ic phases
when PHA is he dispe se phase. Fo ensile modulus, a linea ela ionship is ound, ollowing he ules o
mix u es (o a KUT model wi h pe ec adhesion be ween phases) deno ing a good adhesion be ween he
8
Adap ed om N.C. Lou ei o, J.L. Es e es, J.C. Viana, S. Ghosh: “Mechanical Cha ac e iza ion o Polyhyd oxyalkanoa e and
Poly(Lac ic Acid) Blends”, Jou nal o The moplas ic Composi e Ma e ials (accep ed)
Sus ainable au omo i e componen s o in e io doo ims
66
phases o e he composi ion ange. The inco po a ion o PHA in he blend leads o a dec ease o he lexu al
modulus bu , a he same ime, inc eases he ensile modulus.
The impac ene gy a ies o e 157% o e he en i e blend composi ion. Fo blends wi h PHA weigh ac ion
lowe han 50% he impac s eng h o he blend is highe han he pu e base polyme s. The highes syne ge ic
e ec is ound when he PLA is he ma ix and PHA he dispe se phase o he blend PHA/PLA o 30/70. The
second maximum is ound o he in e se composi ion o 70/30.
PLA has a Hea De lec ion Tempe a u e subs an ially lowe han PHA. Fo he blends, he HDT inc eases wi h
he inc emen upon he % o inco po a ion o PHA. Up o 50% PHA (PLA as ma ix), he HDT is p ac ically
cons an and equal o PLA alue. O e his poin (PHA ma ix), he HDT o he polyme blends inc eases linea ly
wi h % o addi ion o PHA.
5.1 Mechanical p ope ies p edic ion models
The mechanical p ope ies o he blends (indica ed by subsc ip b) can be p edic ed by usual models assuming
di e en in e acial beha io s:
• Well dispe se phases wi h pe ec adhesion ( ules o mix u es)
• sphe ical inclusions o one polyme in a con inuous polyme ma ix wi h pe ec adhesion o no
adhesion (KUT model)
• sphe ical inclusions wi h a iable in e phase in e ac ions, anging om poo o good adhesion (NN
model);
These models will be desc ibed in he ollowing. They will be used o in e p e he adhesion be ween he
polyme s phases wi hin he blend.
5.1.1 Rule o Mix u es
The ule o mix u es (ROM) conside s pe ec adhesion be ween he ma ix (indica ed by subsc ip m) and he
dispe sed phase (indica ed by subsc ip d) and a pe ec dispe sion o he sphe ical inclusions in he ma ix.
This model can be used o p edic he ini ial modulus and he ensile s ess, espec i ely.
E

=


E

E

−
1

×
∅

+
1

×
E

(5.1)
σ

=


σ

σ

−
1

×
∅

+
1

×
σ

(5.2)
whe e E
b
is he ini ial modulus o he blend, E
d
is he ini ial modulus o he dispe se phase, E
m
is he ini ial
modulus o he ma ix, Ø
d
is he olume ac ion o he dispe se phase, σ
b
is he maximum s ess o he blend,
σ
d
is he maximum s ess o he dispe se phase, and σ
m
is he maximum s ess o he ma ix.
5.1.2 Ke ne -Uemu a-Takayanagi model
Nuno Calçada Lou ei o
67
The Ke ne –Uemu a–Takayanagi (KUT) model ea s he blends as sphe ical inclusions o one polyme , ha ing
an ini ial module o Ed, in a con inuous ma ix o ano he polyme ha ing Em. The Poisson’s a io o he ma ix
(υm) is aken o be 0,49 [1]. This model has wo a ia ions. One assumes pe ec adhesion (eq.5. 3) a he
blend in e ace and he o he assumes no adhesion. (eq.5.4).
E

=
E




!
υ
"
#
$
"
%

&
'
υ
"
#
$
(


!
υ
"
#

$
"
$
(
#
∅
(

7
−
5
υ
m
#
E
m
+

8
−
10
υ
m
#
E
d
+

8
−
10
υ
m
#

$
"
$
(
#
∅
(
-
(5.3)
E

=
E




!
υ
"
#
$
"


!
υ
"
#

$
"
#
∅
(

7
−
5
υ
m
#
E
m
+

8
−
10
υ
m
#

$
"
#
∅
(
-
(5.4)
5.1.3 Nicolais-Na kis model
In he Nicolais–Na kis (NN) model, he in e phase in e ac ion cons an – K - is a unc ion o he blend
s uc u e. Fo sphe ical inclusions, K= 1.21 s ands o he ex eme case o poo adhesion; in e phase adhesion
akes place o alues o K < 1.21. When K=0, he adhesion is su icien so ha he polyme ma ix s eng h will
no dec ease, ha is, .
/
=.
0
Tha means ha he be e adhesion appea s when K is low[1].
The NN model assumes ha bo h phases a e o a no-adhe en ype and he maximum s ess is a unc ion o
ei he he a ea ac ion o he olume ac ion o he dispe sed phase. The NN model is gi en by:
σ

=
1
1
−
K
∅

3
4
⁄
6
×
σ

(5.5)
In his wo k, he calcula ion o K alues by adjus men o equa ion 5.5 o he expe imen al da a gi es a
measu e o he adhesion be ween bo h phases.
5.1.4 Béla-Pukánsky model
In he Béla-Pukánsky (BP) model, he maximum ensile s ess o he blend is de e mined by he maximum
s ess o he ma ix, he olume ac ion o he dispe sed phase and he e ec i e load-bea ing c oss sec ion:
7
8
=
7
9

:
−
∅
;
:
+
<
.
>
∅
;

?

@
∅
;
#
(5.6)
B is a pa ame e ha ela es he load-bea ing capaci y o he dispe se phase and depends on he size o he
con ac su ace be ween he polyme and he dispe se phase and on he p ope ies o he in e phase ha is
o med. The lowe he B pa ame e he lowe is he phase´s adhesion (i.e., no-adhesion case). The highes B is,
he be e is he adhesion be ween phases. The agg ega ion dec eases he su ace a ailable o he polyme ,
and he e o e d i es a dec easing o he alue o B. [1]
Sus ainable au omo i e componen s o in e io doo ims
68
The calcula ion o his ac o allows he es ima ion o he load-bea ing capaci y o he dispe sed phase in he
blend.
Table 5.1 esumes he models adop ed in his wo k and he in o ma ion ha hey gi e o he in e p e a ion o
he blend s uc u e.
Table 5.1 – Models used in his wo k o in e p e blend s uc u e.
Model Eq. Blend s uc u e In e p e a ion Use
ROM (5.1)
(5.2)
Sphe ical polyme inclusions in a
con inuous polyme ma ix wi h
pe ec adhesion
pe ec adhesion and
dispe sion
Fi o he model o E and σ
KUT (5.3)
(5.4)
Sphe ical polyme inclusions in a
con inuous polyme ma ix wi h
pe ec adhesion o no adhesion
a) pe ec adhesion
b) no adhesion
Fi o he model o E
NN (5.5) Sphe ical inclusions wi h a iable
in e phase in e ac ions, anging
om poo o good adhesion
K - in e phase in e ac ion
cons an , unc ion o he
blend s uc u e
K adjus men o σ alues:
K= 1.21 – no adhesion
K < 1.21 – phase´s adhesion
K=0 – no p ope y dec emen
BP (5.6) Blend s ess de e mined by he
ma ix s ess, dispe sed phase
olume ac ion and he e ec i e
load-bea ing c oss sec ion
B - load-bea ing capaci y
o he dispe se phase. I
depends on he size o
he con ac su ace and
in e phase p ope ies
B adjus men ( o σ alues):
Lowes B means lowe adhesion
Highes B means be e adhesion
5.2 Mechanical Tes ing
5.2.1 Flexu al P ope ies
A Uni e sal Ti a es 2705 5kN Machine was used o measu e he lexu al p ope ies acco ding o ASTM D790
s anda d. I has been used a 3-poin lexu al es , wi h a c osshead speed o 2,56 mm/min and a spam o 96
mm. Tes s we e pe o med a oom empe a u e (23 ºC). The en isaged lexu al p ope ies assessed we e he
ini ial modulus, he maximum s ess and he s ain a maxim s ess. A leas 11 specimens we e es ed o each
blend composi ion.
5.2.2 Tensile P ope ies
To measu e he ensile p ope ies acco ding o ASTM D638, a uni e sal mechanical es ing machine Shamidzu
AG-X 100kN, equipped wi h a 50 mm Shamidzu ex ensome e , was used. The c osshead eloci y used was o 5
Nuno Calçada Lou ei o
69
mm/min and he es es we e pe o med a oom empe a u e (23 ºC). A g ip dis ance o 150 mm was used.
The en isaged ensile p ope ies assessed we e he ini ial modulus, he maximum/yield s ess and he s ain a
b eak. A leas 11 specimens we e es ed o each blend composi ion.
5.2.3 Ins umen ed P ope ies
Ins umen ed impac es s a e pe o med acco ding ISO 6603-2 s anda d in a CEAST F ac o is plus pendulum
impac machine ( eloci y o 1 m/s). All pe o med es s we e ca ied ou in a s anda d labo a o y a mosphe e
o 23±2ºC and 50±5% ela i e humidi y. F om he o ce-displacemen cu e, he impac oughness was
calcula ed. The impac da a p esen ed a e he a e age o 7 measu emen s.
5.2.4 Hea De lec ion Tempe a u e (HDT) Measu emen s
To measu e he Hea De lec ion Tempe a u e, HDT, acco ding o ISO 75-2, RAY-RAN HDT appa a us was used.
This es used he me hod HDT A wi h a s ess s a e o 1,8 MPa and an inc easing empe a u e speed o
120ºC/h. The es s we e ca ied ou in a s anda d labo a o y a mosphe e o 23±2 ºC and 50±5 % ela i e
humidi y. The p esen ed HDT esul s a e he a e age alues o h ee measu emen s.
5.3 Resul s and Discussion
The esul s o he ensile es s o he PHA/PLA blends a e gi en in Table 5.2.
Table 5.2 – Tensile p ope ies o PHA/PLA blends
PHA/PLA Blend
[Mass F ac ion]
Tensile Modulus
[GPa]
Maximum S ess
[MPa]
S ain a maximum S ess
[%]
[0:100] 3,62 ± 0,03 59,17 ± 0,7 2,5 ± 0,03
[10:90] 3,15 ± 0,21 51,35 ± 1,0 2,4 ± 0,07
[20:80] 3,32 ± 0,06 43,61 ± 0,6 2,0 ± 0,13
[30:70] 3,36 ± 0,07 46,02 ± 1,5 2,0 ± 0,06
[40:60] 3,63 ± 0,05 43,19 ± 0,6 1,9 ±0,10
[50:50] 3,55 ± 0,05 40,36 ± 4,1 1,7 ± 0,39
[60:40] 3,62 ± 0,06 43,02 ± 0,4 1,9 ± 0,02
[70:30] 3,69 ± 0,08 39,21 ± 0,4 1,8 ± 0,06
[80:20] 3,73 ± 0,25 35,99 ± 5,6 1,6 ± 0,26
[90:10] 3,74 ± 0,11 28,04 ± 3,7 1,3 ± 0,14
[100:0] 3,81 ± 0,12 29,19 ± 0,2 1,6 ± 0,19
Based on he p edic i e models, he es ima ed mechanical p ope ies a e p esen ed in Table 5.3.
Table 5.3 – P edic ed Tensile Modulus
PHA/PLA Blend
[Mass F ac ion]
Tensile Modulus [GPa]
ROM KUT pe ec
adhesion
KUT no adhesion
[0:100] 3,62 3,62 3,62
[10:90] 3,64 3,64 3,06
[20:80] 3,66 3,66 2,56
[30:70] 3,68 3,68 2,11

Sus ainable au omo i e componen s o in e io doo ims
70
[40:60] 3,70 3,70 1,72
[50:50] 3,72 3,72 1,43
[60:40] 3,73 3,73 1,80
[70:30] 3,75 3,75 2,22
[80:20] 3,77 3,77 2,69
[90:10] 3,79 3,79 3,21
[100:0] 3,81 3,81 3,81
Fig.5.1 shows he e olu ion o he ini ial modulus wi h he PHA weigh ac ion, based on he da a om ables
5.2 and 5.3.
Figu e 5.1 –Tensile ini ial modulus esul s and p edic ed alues om models
The inc ease o PHA on he blend esul s in a gene al inc ease o he ini ial ensile modulus. This is expec ed
since he ini ial modulus o PHA is sligh ly highe han PLA. In Figu e 5.1 a e also p esen ed he p edic ions o E
based on he abo emen ioned models: ROM and KUT models wi h pe ec and no adhesion be ween phases.
Two main issues can be wi hd awn: i) he KUT model wi h no adhesion does no gi e good p edic ions o E; ii)
he ROM and KUT model wi h pe ec adhesion bo h gi e good p edic ions o he a ia ion o E wi h he weigh
ac ion o PLA in he blend. The maximum de ia ion be ween he KUT pe ec adhesion p edic ion and he
expe imen al alue is abou 5 %. These esul s an icipa e a good adhesion be ween bo h phases in he
PHA/PLA blends. Ne e heless, o low le els o inco po a ion o PHA (up o 30%), whe e PLA is expec an ly
he ma ix, he expe imen al da a seems o de ia e om he pe ec adhesion models, sugges ing a dec ease
on he adhesion be ween bo h polyme ic phases when PHA is he dispe se phase.
The maximum s ess o he blends can be es ima ed om he abo e p esen ed p edic ion models. F om he
NN and BP models, he pa ame e s K and B can be calcula ed gi ing es ima ions o he in e phase in e ac ion
and o he load-bea ing capaci y o he dispe se phase, espec i ely. The calcula ed alues a e exp essed in
Table 5.4 o each blend.
Table 5.4 – Calcula ed Values o K and B o PLA/PHA blends
PHA/PLA Blend
[Mass F ac ion]
K
(NN model)
B
(BP model)
[10:90] 0,55 2,0
Nuno Calçada Lou ei o
71
[20:80] 0,74 1,7
[30:70] 0,47 2,3
[40:60] 0,48 2,3
[50:50] 0,49 2,3
[60:40] 0,37 4,0
[70:30] 0,42 4,0
[80:20] 0,44 4,2
[90:10] 0,56 2,9
AVERAGE 0,50 2,1 (PLA Ma ix)
3,8 (PHA Ma ix)
Figu e 5.2 shows he a ia ion o K and B wi h he weigh ac ion o PHA. K alues a e always lowe han 1.21,
meaning ha a good adhesion be ween bo h phases is achie ed. The alues o B pa ame e a e also ela i ely
high, indica ing a good adhesion be ween phases. Fu he mo e, in he PLA ac ion 50-60% he alues o K
show a d op and ha o B a sudden inc emen , which can be a ibu ed o phase in e sion in he blends.
Again, o he low le els o inco po a ion o PHA (PHA as dispe se phase) he K alues a e highe indica ing a
lowe adhesion be ween bo h phases when PLA is he ma ix. Fo his dilu ion egime, he B alues a e lowe ,
indica ing a lowe load-bea ing capaci y o he PHA dispe se phase, also due o he low ensile s eng h o his
phase.
Figu e 5.2 –Va ia ions o K and B pa ame e s o NN and BP models wi h weigh ac ion o PHA
In Table 5.5 a e p esen ed he p edic ions o he ensile s ess o ROM, NN (wi h di e en K alues) and BP
(wi h a e age B alue) models o he a ious PHA/PLA mass ac ions. Fo pe cen ages o inco po a ion o
PHA highe han 60% (PLA as ma ix), he NN and BP models do no gi e good ag eemen wi h expe imen al
da a.
Table 5.5 – Models p edic ions o Maximum S ess
PHA/PLA Blend
[Mass F ac ion]
Maximum S ess [MPa]
ROM NN BP
K=0 K=0,5 K=1,21 B=2,3
[0:100] 59,17 58,26 58,26 58,26 58,26
[10:90] 56,17 58,26 51,98 43,07 52,79
[20:80] 53,17 58,26 48,29 34,15 49,22
Sus ainable au omo i e componen s o in e io doo ims
72
[30:70] 50,18 58,26 45,20 26,67 46,46
[40:60] 47,18 58,26 42,44 19,99 43,85
[50:50] 44,18 58,26 39,91 13,85 40,89
[60:40] 41,18
[70:30] 38,19
[80:20] 35,19
[90:10] 32,19
[100:0] 29,19
Fig. 5.3 shows he a ia ions o he ensile maximum s ess wi h % o PHA and espec i e models p edic ions.
Figu e 5.3 – Tensile Maximum S ess Resul s and P edic ed Values
The inc ease o PHA on he blends d i es o a gene al dec easing o he Maximum S ess. The ROM i s well
wi h he expe imen al da a o he la ge amoun s o inco po a ion o PHA, sugges ing a e y good adhesion
be ween PHA ma ix and he PLA dispe se phase. Fo low % o PHA he phase adhesion is small, he
expe imen al da a de ia es om ROM. In his egime, he alues o K and B we e adjus ed in o de o i be e
he models p edic ions. Values o K = 0,5 and B=2,3 we e ound up o %PHA o 50% (abo e his alue, a bes i
is ob ained o K=-1,2 and B=4,0). These alues ega ding bo h NN and BP models co obo a e ha he
in e phase adhesion is p omo ed when PLA is he dispe se phase.
The lexu al es esul s o he blends a e gi en in Table 5.6.
The expe imen al a ia ion o he lexu al module as unc ion o he PHA ac ion is small, o 3,52%.
Table 5.6 – Flexu al P ope ies o PHA/PLA blends
PHA/PLA Blend
[Mass F ac ion]
Flexu al Modulus
[GPa]
Maximum S ess
[MPa]
S ain a maximum
S ess [%]
[0:100] 3,59± 0,06 80,52 ± 2,6 2,3 ± 0,1
[10:90] 3,41 ± 0,08 57,36 ± 3,1 2,2 ± 0,1
[20:80] 3,46 ± 0,06 70,87 ± 4,7 2,6 ± 0,2
[30:70] 3,53 ± 0,02 62,30 ± 7,1 2,1 ± 0,4
Nuno Calçada Lou ei o
73
[40:60] 3,79 ± 0,01 55,31 ± 2,6 1,6 ± 0,1
[50:50] 3,61 ± 0,08 79,93 ± 2,4 3,1 ± 0,1
[60:40] 3,56 ± 0,11 46,49 ± 3,0 1,3 ± 0,1
[70:30] 3,42 ± 0,03 66,10 ± 0,6 2,4 ± 0,1
[80:20] 3,42 ± 0,10 47,32 ± 2,9 1,5 ± 0,1
[90:10] 3,44 ± 0,22 53,94 ± 3,5 2,2 ± 0,4
[100:0] 3,40 ± 0,10 53,97 ± 0,6 2,2 ± 0,1
Fig.5.4 shows he a ia ions o E
wi h % o PHA and espec i e models p edic ions. Con e sely, o he ensile
modulus, he e o he lexu al modulus he ROM does no applies o e he ull ange o composi ions. Only o
high % o inco po a ion o PHA (as ma ix), he ROM is alid. In he case o PHA as dispe se phase, he
a ia ions o E
wi h PHA ac ion a e no conclusi e. The E
o he blends seems o be mo e sensi i e o he
mo phology o he low ac ion componen (e.g., dispe sion, size, aspec a io).
Also, ROM and KUT-adhesion models gi e he same p edic ions o E
as unc ion o PHA ac ion, wi h
maximum e o o 7.9% (an a e age o 2.1%).
Figu e 5.4 - Flexu al Young’s Modulus Resul s and P edic ed Values.
Fig. 5.5 shows he a ia ions o maximum lexu al s ess wi h % o PHA and espec i e models p edic ions.
Again, he inc ease o PHA on he blends d i es o a gene al dec easing o he Maximum S ess. As o he
lexu al modulus, he a ia ions o σ
max
wi h % o PHA a e subjec ed o high luc ua ions. In gene al, he ROM
does no gi e sa is ac o y p edic ions, e en o la ge amoun s o inco po a ion o PHA. Fo low % o PHA he
expe imen al alues a e always smalle han he ones p edic ed by ROM, his e idencing a low le el o
adhesion be ween bo h phases. This also happened in he ensile esponse: when PHA is he dispe se phase,
he adhesion is small. In his egime, he alues o K and B we e also adjus ed in o de o i be e he models
p edic ions. Values o K = 0,48 and B=2,2 we e ound up o %PHA o 50% o bo h NN and BP models,
espec i ely. These alues a e e y close o he ob ained on he ensile es s (K = 0,45 and B=2,3). Adjus men s
o he case o PLA as dispe se phase, gi es K= 0,22 and B=2,6. The K alue is educed subs an ially when
compa ed wi h PHA as dispe se phase, his meaning a be e adhesion be ween phases; B sligh ly inc eases as
a e lex o his be e adhesion, bu he load-bea ing capaci y o he dispe se phase seems o emain
Sus ainable au omo i e componen s o in e io doo ims
80

Nuno Calçada Lou ei o
81
Chap e 6.
Mo phological Cha ac e iza ion o PHA/PLA Blends
9
6.1 In oduc ion
Poly (lac ic acid), PLA, is a polyme p oduced by he e men a ion o simple suga s, such as glucose and
mal ose om co n o po a o, suc ose om cane o bee suga and lac ose om cheese [1]. I ’s a linea
alipha ic polyes e he moplas ic used as packaging ma e ials and in p oduc ion o clo hs, ca pe iles, su gical
and biomedical de ices among o he s. The PLA has a mel ing empe a u e anging om 188º a 210 ºC, and he
glass ansi ion empe a u e, Tg, o 55-60 ºC ( hese empe a u es a e dependen upon he op ical
composi ion, he p ima y s uc u e, he molecula weigh , and he he momechanical his o y upon cooling).
PLA has been blended wi h o he polyme s in o de o ob ain be e mechanical p ope ies and/o cos
educ ion. Se e al s udies ha e been made on blends o PLA wi h poly(ε-cap olac one), PCL[2],
poly(bu ylac yla e), PBA [3], and ac yloni ile bu adiene s y ene, ABS[4].
Polyhyd oxyalkanoa e, PHA, is a gene ic designa ion o polyes e polyme s p oduced by he bac e ial
e men a ion o suga s and lipids. These polyes e s a e a ca bon s o age and ene gy ese es in bac e ia, such
as Rals onia Eu opha, Bacillus Mega e ium, Azo obac e ch oococum. By con olling he copolyme s
composi ion is possible o ailo mos o he mechanical p ope ies o PHA [5].The PHAs a e highly c ys alline
polyes e s (abo e 50%) wi h mel ing empe a u es anging om 120º o 180ºC, depending on he chemical
composi ion [6]. The Tg is a ound 5ºC.
The blending o hese wo polyme s, PHA/PLA, allows ob aining ma e ials wi h imp o ed p ope ies, being less
cos ly han chemical modi ica ions o syn hesis o ailo -made copolyme s. The p ope ies o he PHA/PLA
9
Adap ed om N.C. Lou ei o, J.L. Es e es, J.C. Viana, S. Ghosh, Mo phological s udy on Polyhyd oxyalkanoa es and Poly(Lac ic
Acid) blends ob ained by injec ion moulding, Jou nal o Mac omolecula Science, Pa B - Physics (submi ed)
Sus ainable au omo i e componen s o in e io doo ims
82
blends can be easily modi ied by changing he polyme s o co-polyme s molecula weigh o by a ying he
blend composi ion. [7-8]
In his chap e , he mo phology de elopmen du ing injec ion molding o blends o PHA/PLA has been
in es iga ed.
6.2 Mo phological Calcula ions based on DSC esul s
F om he DSC he mog ams se e al pa ame e s we e e alua ed. The deg ees o c ys allini y (x
A
) o he pu e
polyme s we e es ima ed using eq.6.1
B
C


∆
D
E
∆
D
FF
∆
D
E
G
(6.1)
whe e,
o
m
H∆
is he en halpy o 100 % c ys alline PHA as 146 J.g-1 [3], and PLA had 93 J.g-1, espec i ely [10].
∆H
0
is he en halpy o usion. Fo he PHA/PLA blends a di e en app oach was ollowed. In his case, since
he cold c ys alliza ion is due o PLA and he c ys alliza ion o PHA and PLA, i ’s necessa y o ake in o accoun
no only he c ys alliza ion beha io o he base polyme s alone, bu also he in e ac ion o he wo polyme s
in o he blend. Fo ha , in a i s app oach, he deg ee o c ys allini y o he blends is gi en by:
B
C

∆
H
0

∆
H
CC
∆
H
0
,
JKL

∙
∅
JKL

∆
H
0
,
JDL

∙
∅
JDL
(6.2)
This equa ion ela es he en halpy o usion o he blend (ΔH
m
) and he en halpy o cold c ys alliza ion (ΔH
cc
)
wi h he en halpy o mel ing o he nea polyme s ( and ) and hei weigh ac ion (Ø
PLA
and Ø
PHA
). The weigh ing o he en halpy o mel ing o he base polyme s h ough he weigh ac ion o bo h
polyme s will gi e a mo e ealis ic alue o he en halpy o mel ing o he conside ed blend.
6.3 Resul s and Discussion
6.3.1 WAXD Measu emen s
Figu e 6.1 e eals he di ac og am o he as-molded injec ion molded samples o nea PLA, nea PHA, and
PHA/PLA blends. The scan shows no peak o nea PLA samples, sugges ing ha PLA is amo phous unde he
he momechanical condi ions o injec ion molding. On he con a y, PHA c ys allized o a signi ican ex en ,
wi h di ac ion peaks a 2θ alues a 13.52º and 16.88º [11-12]. The mos in ense peak o PHA is a 2θ alues
a 13.52º, o igina ing om 020 plane. The weak e lec ion peaks a 2ϴ=16.88º a e o igina ing 110 plane.
Nuno Calçada Lou ei o
83
10 12 14 16 18 20
0 / 100
10 / 90
20 / 80
30 / 70
40 / 60
50 / 50
60 / 40
70 / 30
80 / 20
90 / 10
13.52
o
16.88
o
100 / 0
In ensi y
(a b. uni .)
2
θ
(؛)
PHA / PLA
Figu e 6.1 - WAXD aces o injec ion molded PHA/PLA blends.
Fo blends, he scans can be di ided in o wo di e en egimes: (i) he inc easing ac ion o PLA in PHA, (ii) he
o he is inc easing ac ion o PHA in PLA. The addi ion o PLA in PHA e ealed ha he in ensi y o e lec ion a
2θ =13.52º emained ela i ely same o mo e in ense up o 70/30 PHA / PLA composi ion, compa ed o nea
PHA. Howe e , he in ensi y o he peak a 2θ =13.52º dec eases mono onically wi h inc easing ac ion PLA,
and he peak almos disappea s wi h 40/60 PHA/PLA composi ion.
I is wo h o men ion he e ha PLA is a semic ys alline polyme wi h a slow a e o c ys alliza ion. PLA
c ys allizes signi ican ly om miscible polyme blends wi h he mos in ense B agg peak o 2θ=16.88º [13-14],
howe e is possible o no e ha nea PLA does no c ys allize du ing s anda d ope a ing condi ions o injec ion
molding. The eason o “ he appa en inc ease peak in ensi y a 2θ=13.52º, and g adual dec ease in peak
in ensi y a 2θ=16.88º” equi es u he s uc u al expe imen a ion o es ablish. F om 40 / 60 o 90 /10
PHA/PLA composi ion, he only e lec ion peak is a 2ϴ=13.52º. The supp ession o peak a 2θ=16.88º, which is
he mos peak o c ys alline PLA and a less in ense o PHA sugges s he ollowing: (a) he e is a s ong
in e ac ion be ween PLA and PHA c ys als, and (b) PLA do no c ys allize om PHA/PLA blends, unde he
p esen he momechanical en i onmen o injec ion molding.
6.3.2 DSC o Injec ion Molded PHA/PLA blends
The i s hea ing o PLA e ealed he ypical he mal ansi ions along he empe a u e axis: (i) a glass
ansi ion, (ii) an exo he mic cold c ys alliza ion, and (iii) an endo he mic mel ing – see Fig. 6.2. The deg ee o
c ys allini y o PLA was 1.5 %, es ima ed om Eq. 1. This low deg ee o c ys allini y o injec ion molded PLA is
ai ly in good ag eemen wi h he esul s epo ed elsewhe e [10].
Sus ainable au omo i e componen s o in e io doo ims
84
90PHA
80PHA
70PHA
60PHA
50PHA
40PHA
30PHA
20PHA
10PHA
0PHA
100PHA
-20 0 20 40 60 80 100 120 140 160 180 200
Endo
Hea Flow
(W.g
-1
)
Tempe a u e
(
o
C)
1W .g
-1
Figu e 6.2 – DSC he mog ams o he PHA/PLA blends in he hea ing un.
( om op o bo om he weigh ac ion o PLA inc eases and he weigh ac ion o PHA dec eases)
Table 6.1 – DSC da a o PHA, PLA and PHA/PLA blends.
PHA w
(%)
PLA w
(%)
T
g
(ºC) ΔC
P
(J.g
-1
.ºC)
T
cc
(ºC)
ΔH
cc
(J.g
-1
)
T
m
(ºC)
ΔH
m
(J.g
-1
)
x
c
(%)
PHA PLA Fox eq. PLA PHA PLA
0 100 - 63.7 63.7 0.575 97.9 29.5 177.7 30.9 1.5
10 90 7.5 61 33.0 0.229 0.254 -- 27.6 172.5 40.7 13.8
20 80 7.5 45.8 22.3 0.204 0.255 102.2 15.5 170.5 46.2 31.7
30 70 6.5 55.2 16.8 0.215 0.307 105.8 18.9 172.3 45.4 27.0
40 60 - 58.9 13.5 0.129 0.215 112.1 10.1 172.5 51.3 41.3
50 50 - 54.6 11.3 0.095 0.19 97.4 13.8 171.2 53.9 39.6
60 40 7.0 53.7 9.7 0.404 1.01 72.5 15.9 169.9 62.6 45.4
70 30 6.5 57.5 8.5 0.366 1.22 90 10.4 171.2 69.7 56.8
80 20 6.2 56.2 7.6 0.34 1.7 88 1.8 171.5 66.2 60.8
90 10 - 58.6 6.8 0.329 3.29 100 -- 177 67 62.3
100 0 6.2 - 6.2 -- -- -- -- 170.3 65.5 60.1
Wi hin he scan ange, he injec ion molded PHA showed only an endo he mic mel ing peak a 170.3 ºC. I is
wo h o men ion ha he T
g
o PHA was de ec ed in he scan a 6.2 ºC. The deg ee o c ys allini y o injec ion
molded PHA was 60.1 %. The mold empe a u e, 20 ºC i.e. well abo e he T
g
allowed he highly lexible PHA
segmen s o c ys allize signi ican ly.
Figu e 6.3 e eals ha he Tg o PLA shows a end o dec ease wi h inc easing ac ion o PHA. Simila ly, he
Tg o PHA shows an upwa d end wi h inc easing ac ion o PLA. The blend T
g
be ween he T
g, PHA
(6.2 ºC) and
he T
g, PLA
(63.7 ºC) indica e ha PLA and PHA we e pa ially miscible in he p ocessed blends.
Nuno Calçada Lou ei o
85
Figu e 6.3 – Va ia ion o he wo glass ansi ion empe a u es wi h he weigh ac ion o PHA in he blend.
The blend miscibili y can be de i ed om he compa ison o measu ed T
g
alues wi h hose p edic ed by he
Fox equa ion [16], gi en by:
1
N
O
,
/PQRS

∅
JKL
N
O
,
JKL

∅
JDL
N
O
,
JDL
(6.3)
Whe e T
g
, T
g,PHA
and T
g,PLA
a e he glass ansi ion empe a u es o he blend, PHA and PLA espec i ely. Fo
T
g,PHA
and T
g,PLA
he alues a e ob ain expe imen ally and a e, espec i ely, 6,2ºC and 63,7 ºC. The weigh
ac ions o he base polyme s in he blend a e gi en by Ø
PLA
and Ø
PHA
, espec i ely. The Fox equa ion
calcula es he T
g
o he blend assuming ha he base polyme s a e comple ely miscible one in he o he . When
compa ing he expe imen al da a wi h he heo e ical Fox model (Table 2) is possible o obse e ha when
PHA is he ma ix polyme (%PHA>60%) he blend p esen s some miscibili y. This miscibili y is con i med by
he shi ing o he T
g
om he nea polyme alue. The phase in e sion o he blends is no easy o iden i y in
Fig. 6.3.
Fig. 6.4 shows he e ec o inc easing he PHA weigh ac ion in he hea capaci y a he PLA glass ansi ion,
ΔC
p
. Pu e PLA shows he highes hea capaci y, ΔC
p
= 0,575 (J.g
-1
.ºC). The hea capaci y a he glass ansi ion is
a measu e o he ac ion o he amo phous phase (o PLA in his case) ha elaxes a T
g
. In e es ingly, wo
egimes can be ound in Figu e 6, depending upon he ype o ma ix in he blend. Fo low pe cen ages o
inco po a ion o PHA, PHA is he dispe sed phase and PLA is he ma ix. Adding a small amoun o PHA o he
blend (10PHA/90PLA) is enough o educe i s hea capaci y by 60%, indica ing ha he amo phous phase o
PLA becomes less mobile. Inc easing he amoun o PHA u he educes ΔC
P
o he blend. Fo he
50PHA/50PLA blend he lowes ΔC
P
is ob ained, being educed by 84%. Then, be ween 50-60% ac ion o PHA,
PLA becomes he dispe sed phase and PHA he ma ix. This co esponds o a change on he hea capaci y o
PLA in he blend ha suddenly inc eases, bu s ill being lowe han ha o pu e PLA ( educ ion o 30% o he
60PHA/40PLA). Phase in e sion is clea ly iden i ied by changes on ΔC
P
o his PHA/PLA blend. Fu he mo e, he

Sus ainable au omo i e componen s o in e io doo ims
86
amoun o mobile PLA amo phous phase a T
g
is educed when PLA is he dispe se phase, bu no as much
when i is he ma ix. Inc easing mo e he amoun o PHA, u he educes ΔC
P
, bu no eaching he same
dec emen as PLA as ma ix ( educing mo e han 43% o 90PHA/10PLA). I ’s possible o assume ha , since ΔC
P
is di ec ly connec ed wi h he mobili y o he chains o he blend, he PLA ma ix blends a e mo e lexible ha
he PHA ma ix blends.
Figu e 6.4 – Va ia ion o he hea capaci y a he glass ansi ion o PLA wi h he weigh ac ion o PHA in he blend.
Figu e 6.5 shows he a ia ion o he cold c ys alliza ion empe a u e o PLA wi h he pe cen age o
inco po a ion o PHA. Again wo dis inc e olu ions a e e iden . When PLA is he ma ix, T
cc
inc eases wi h
%PHA, s a ing om pu e PLA T
cc
. This inc emen on T
cc
means a delay on he cold c ys alliza ion o PLA and an
expec an educ ion on i s deg ee o c ys allini y wi h inc easing o %PHA. A 50-60% PHA, phase in e sion
occu s wi h a high dec emen upon T
cc
o PLA. PHA becomes he ma ix and he cold c ys alliza ion o he PLA
dispe sed phase occu s a a lowe empe a u e, inducing he c ys alliza ion. As he %PHA s ill inc eases, T
cc
inc eases again.
Figu e 6.5 – Va ia ion o he cold c ys alliza ion empe a u e o PLA wi h he weigh ac ion o PHA in he blend.
The a ia ion o he cold c ys alliza ion en halpy o PLA, ΔH
cc
wi h %PHA is shown in Figu e 6.6 (ΔH
cc
da a was
been weigh ed by he amoun o PLA in he blend). Gene ally, ΔH
cc
dec eases wi h %PHA inc emen . This
0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0 10 20 30 40 50 60 70 80 90 100
Cp - PLA/J.g
-1
K
-1
% PHA
Nuno Calçada Lou ei o
87
dec emen means ha PLA c ys allizes mo e du ing he p ocessing s ages as PHA is added o he blend. The
a ia ions a e highe when he PLA is he ma ix ( om 30 o 7 J/g).
Figu e 6.6 – Va ia ion o he cold c ys alliza ion en halpy o PLA wi h he weigh ac ion o PHA in he blend
.
Conside ing he mel ing peak, T
m
o he blends does no change signi ican ly o e he blend’s composi ions
(be ween 170.3-172.5 ºC), close o he mel ing empe a u e o PHA o 170.3 ºC. No e ha he mel ing
empe a u e o PLA is a ound 175-180 ºC and his peak should be o e lapped by he mel ing peak o PHA. I
can be concluded ha he blend composi ion does no ha e an e ec on hickness o c ys alline s uc u es o
PHA (i.e., T
m
is cons an ).
As expec ed, he pu e PHA p esen s a highe deg ee o c ys allini y, X
C
=60.1%, han PLA, X
C
=1.5%, which is
essen ially amo phous. Figu e 6.7 shows he a ia ions o he deg ee o c ys allini y o he blends wi h he
%PHA (weigh ed by he composi ion acco ding o equa ion 2) and conside ing only he con ibu ion o PHA o
he mel ing peak. In bo h cases, X
C
inc eases wi h %PHA. The deg ee o c ys allini y o PLA is lowe when i is
he dispe sed phase, which can be explained by he nuclea ing ac ion o PHA in he PLA ma ix o by he
di e en cooling condi ions ha PLA expe iences when cold down om he blended mel .
Sus ainable au omo i e componen s o in e io doo ims
88
Figu e 6.7 – Va ia ions o he deg ee o c ys allini y o he blend wi h he weigh ac ion o PHA. χ
c
was calcula ed
assuming a weigh ed con ibu ion o he wo polyme s and single con ibu ion o PHA o he mel ing peak.
Figu e 6.8 p esen s he ac u e su aces o nea polyme s and hei blends. The SEM images show
in e es ingly a clea change on he blend mo phology a he phase in e sion (c.a. 50%PHA) whe e a lamella
mo phology is de eloped. This mo phology de elops in he blends only when PHA is he ma ix and becomes
mo e e iden as he amoun o PLA inc eases, and a esul o he he momechanical en i onmen applied
du ing p ocessing, wi h a p e e en ial o ien a ion in he low di ec ion. On he o he hand, a mo e ine
s uc u e o he PHA dispe sed phase is e ealed in he PLA ma ix blends.
I is also e iden he mo e b i le cha ac e o he nea PLA, which ea u e a highly smoo h ac u e su ace,
when compa ed wi h he ough one o he nea PHA. This is also shown by he blends: when PHA is he ma ix
he ac u e su aces a e oughe . I is expec ed a di e en oughness o he blends.
0
10
20
30
40
50
60
70
0 20 40 60 80 100
Xc (%)
% PHA
pu e polyme s
blend weigh ed (eq. 2)
blend-PLA
Nuno Calçada Lou ei o
89
Figu e 6.8 – SEM images o ac u e su aces o PHA/PLA blends (magni ica ion o 500x).
100 % PHA 90 % PHA 80 % PHA
70 % PHA 60 % PHA
50 % PHA
40 % PHA 30 % PHA
20 % PHA 10 % PHA 0 % PHA
Sus ainable au omo i e componen s o in e io doo ims
96
7.3 Resul s and Discussion
7.3.1 Tensile beha io
The esul s o he ensile es s o he composi es a e gi en in Table 7.1. An expe imen al s ess-s ain
demons a i e cu e o each specimen is shown in o igu e 7.1. The ho izon al s ep ep esen s he ime o
ex ensome e emo al du ing he es .
Figu e 7.1 – Tensile S ess-S ain Cu es ob ained expe imen ally
Table 7.1 - Tensile P ope ies o PHA/PLA composi es ein o ced wi h cellulosic ibe
Fibe a io
[Mass F ac ion]
Tensile modulus
[GPa]
Maximum
s ess [MPa]
S ain a maximum
s ess [%]
0 % 3.36 ± 0.07 40.00 ± 1.5 2.0 ± 0.06
10 % 4.29 ± 0.37 44.21 ± 1.4 2.7 ± 0.33
20 % 5.14 ± 0.31 49.01 ± 1.6 2.4 ± 0.31
30 % 10.01 ± 0.34 79.72 ± 1.2 1.9 ± 0.18
Based on he p edic i e models, he es ima ed mechanical p ope ies a e p esen ed in Table 7.2.
Table 7.2 – P edic ed and Expe imen al ensile modulus
Rein o ce Fibe
[Mass F ac ion]
Tensile Modulus [GPa]
expe imen al ROM mHT ICm
0 % 3.36 ± 0.07 3.36 3.36 3.36
10% 4.29 ± 0.37 4.72 4.34 3.69
20% 5.14 ± 0.31 6.09 5.38 4.14
30% 10.01 ± 0.34 7.45 6.47 4.72

Nuno Calçada Lou ei o
97
Fig. 7.2 shows he e olu ion o he modulus, E, wi h he ein o ced ibe weigh ac ion.
Figu e 7.2 – Expe imen al ensile modulus, E, esul s and p edic ed alues om he mic omechanical models
The inc ease o ibe con en esul s in a gene al inc emen on he ini ial ensile modulus o he composi e.
This is expec ed because he ibe con ibu es o he s i ness o he inal composi e. In Fig. 7.2 a e also
p esen ed he p edic ions o E based on he abo e men ioned models: ROM, mHT and ICm.
ROM model supposes ha he ibe and he ma ix p esen a pe ec adhesion.
The ICm is based in a cubic app oxima ion. The esul s show ha his model p o ides he lowes p edica ion,
meaning ha he based hypo hesis o he model is no sui able o his speci ic composi e.
mHT equa ion supposes ha he ibe p esen s a homogenous dis ibu ion h ough he ma ix. The mHT
equa ion gi es an excellen p edic ion o E o inco po a ion un il 20% (w ) o cellulosic ibe s. Analyzing only
un il 20% (w ) o ibe inco po a ion, he maximum de ia ion be ween mHT equa ion and he expe imen al
alues is only abou 3.5%, and o he ROM his de ia ion eaches 18%. This an icipa es a homogenous
dispe sion o he ibe h ough he ma ix. Fo 30 w % o ibe s, he models unde p edic he expe imen al
alue. This may esul om se e al ac o s including, no only he da a ob ain om he ibe s, bu also om
he geome ic assump ions om he adop ed models.
In Table 7.3 a e p esen ed he expe imen al alues and he p edic ions o he maximum ensile s ess o ROM
and mHT models o he a ious ibe inco po a ion a ios.
Table 7.3 – Expe imen al and P edic ed ensile S esses
Rein o ce Fibe
[Mass F ac ion]
Tensile S ess [MPa]
Expe imen al ROM mHT
0 % 40.00 ± 1.5 40.00 40.00
10% 44.21 ± 1.4 49.54 44.83
20% 49.01 ± 1.6 59.52 49.91
30% 79.72 ± 1.2 69.97 52.24
Sus ainable au omo i e componen s o in e io doo ims
98
Fig. 7.3 shows he a ia ions o he maximum ensile s ess wi h he w % o ibe and espec i e models
p edic ions.
Figu e 7.3– Tensile Maximum S ess Resul s and P edic ed Values
The maximum s ess o he composi es can be also es ima ed wi h an excellen ag eemen om he abo e
p esen ed p edic ion models, namely he mHT equa ion. This equa ion gi es e y good p edic ions
inco po a ion o ibe s un il 20 w %. Un il his pe cen age, he maximum de ia ion be ween mHT equa ion
and he expe imen al alues is abou 1.3%, and o he ROM is abou 20%. Again, o 30 w % o ibe s, he
models unde p edic he expe imen al alue.
7.3.2 Flexu al beha io
The lexu al es esul s o he blends a e gi en in Table 7.4. An expe imen al s ess-s ain demons a i e cu e
o each specimen is depic ed in o igu e 7.4.
Nuno Calçada Lou ei o
99
Figu e 7.4 – Flexu al S ess-S ain Cu es ob ained expe imen ally
Table 7.4 – Flexu al P ope ies o PHA/PLA composi es ein o ced wi h cellulosic ibe
Fibe a io
[Mass F ac ion]
Flexu al Modulus
[GPa]
Maximum S ess
[MPa]
S ain a maximum S ess
[%]
0 % 3.09 ± 0.13 77.49 ± 1.54 4.00 ± 0.29
10% 4.44 ± 0.07 82.51 ± 1.22 3.14 ± 0.22
20% 5.59 ± 0.09 89.02 ± 1.36 2.78 ± 0.12
30% 6.35 ± 0.19 85.36 ± 1.57 2.11 ± 0.04
Fig. 7.5 shows he a ia ions o E
wi h % o ibe and espec i e alues o he p edic ion model (ROM). As o
he ensile modulus, he ROM sugges s ha o ibe inco po a ion supe io o 20% he ibe dis ibu ion is
non-homogeneous.
Con e sly, o he ensile modulus, he ROM models gi es accep able p edic ions up o 30% o inco po a ion o
ibe s.
Sus ainable au omo i e componen s o in e io doo ims
100
Figu e 7.5 – Flexu al Modulus, E
, Resul s and P edic ed Values om model
Fig. 7.6 shows he a ia ions o maximum lexu al s ess wi h % ibe and espec i e models p edic ions. Again,
he inc emen on he ibe con en leads o a gene al inc easing o he maximum lexu al s ess o he
composi e. Howe e he inco po a ion o mo e han 20% o ibe esul s on a educ ion on he maximum
lexu al s ess, and a di e gence om he heo e ical p edic i e alue. In gene al, he ROM gi es e y good
p edic ions o ibe inco po a ion le els below 20%.
Figu e 7.6 – Flexu al Maximum S ess Resul s and P edic ed Values
7.3.3 Impac beha io
Figu e 7.7 p esen s he impac o ce o e ime du ing he impac es o he composi es. The inco po a ion o
ibe imp o es he ene gy abso p ion capabili ies o he composi es. Howe e due o he non-homogeneous
dis ibu ion o he ibe in he 30% ibe -composi e, he impac oughness appea s o dec ease because he
ibe bundles may ac as s ess concen a o s, leading o ac u e o he composi e.
Nuno Calçada Lou ei o
101
The impac esul s o he es ed composi es a e gi en in Table 7.5. The impac ene gy (o oughness)
es ablishes he amoun o ene gy ha he ma e ial can abso bed un il i b eaks.
Table 7.5 – Composi e Impac p ope ies
Fibe a io
[Mass F ac ion] Impac ene gy [J] De lec ion a b eak
[mm]
0 % 1.7 ± 0.2 4.6 ± 1.4
10% 2.8 ± 0.5 4.8 ± 0.4
20% 2.8 ± 0.2 4.4 ± 0.8
30% 2.3 ± 0.3 3.2 ± 0.8
Figu e 7.7 – Expe imen al impac o ce e sus ime o he ins umen ed impac es s
The a ia ions o he impac oughness wi h ibe weigh ac ion a e depic ed in Fig. 7.8. The maximum
oughness is ound o composi es wi h 10 and 20 w % o ibe s. The inco po a ion o 30% o ibe s leads o a
composi e wi h a bad impac beha io wi h 18% less capabili y o abso bing ene gy conside ing he o he ibe
inco po a ions.

Sus ainable au omo i e componen s o in e io doo ims
102
Figu e 7.8 – Impac oughness.
The a ia ions o he maximum de lec ion wi h ibe w a e depic ed in Fig. 7.9. The addi ion o cellulosic ibe s
dec eases he maximum de lec ion o he composi es.
Figu e 7.9 – Impac maximum de lec ion o a ious eco-composi es.
The inco po a ion o 30% o ibe s d i es o a composi e wi h dec easing on he de o ma ion capabili ies a
b eak o a ound 33%.
Nuno Calçada Lou ei o
103
7.3.4 Hea De lec ion Tempe a u e (HDT) measu emen
The Hea De lec ion Tempe a u e (HDT) esul s a e gi en in Table 7.6 and Fig. 7.10 o all ibe composi ions.
Table 7.6 – Hea -De lec ion Tempe a u e o composi es
Fibe a io [Mass F ac ion] HDT [ºC]
0 % 48.5 ± 0.9
10% 49.2 ± 0.6
20% 56.0 ± 0.2
30% 51.7 ± 0.2
Figu e 7.10 – Expe imen al HDT e olu ion o e ibe composi ion
As expec ed he inco po a ion o ibe s inc eases he HDT. The maximum syne ge ic e ec is ob ained wi h he
inco po a ion o 20% o ibe s leading o an inc easing o 15% on he HDT alue.
Sus ainable au omo i e componen s o in e io doo ims
104
7.3.5 Mic oscopy analysis
The p e ious mechanical cha ac e iza ion highligh s he e ec s o he adhesion be ween he polyme ic ma ix
and he cellulosic ibe and o he dispe sion o ibe s.
The op ical mic oscopy analysis images a e shown in Figu e 7.11 and SEM analysis in ig.7.12. The
inco po a ion o 30% w o ibe leads o a non-homogeneous composi e and he inco po a ion un il 20% w
d i es o a homogeneous composi e.
Figu e 7.11 – Op ical mic oscopy analysis (magni ica ion 20x).
As possible o e i y in igu e 7.12, he ma ix is a pe ec ly miscible one. Is no possible o iden i y a PLA o a
PHA phase in he ma ix.
The SEM analysis also co obo a es ha he ibe dispe sion is homogenous un il each he 20% w . A e ha
he dispe sion s a s o andom and los he homogenei y.
As seen in ig. 7.13 he SEM analysis e eals ha he ibe s a e deboned o he ma ix inducing a lowe
in e acial adhesion. This in e acial beha io jus i ies he de ia ion o he expe imen al da a and he
p edica ed alues based in o pe ec adhesion.
10% ibe
20% ibe
30% ibe
Nuno Calçada Lou ei o
105
Figu e 7.12 – SEM Analysis
.
Figu e 7.13 – De ail o he in e ace ma ix- ibe ob ain in SEM Analysis (20% ibe w )
Sus ainable au omo i e componen s o in e io doo ims
112
Figu e 8.2 – CIM equipmen
8.3 Composi e Selec ion
Based in ables 8.1, 8.2 and 8.3 is possible o plo a 6 dimension ada cha ( igu e 8.3) ha will emphasize he
ela ion o all hese pa ame e s.
As seen in he igu e, he alues o he impac abso bed ene gy a e qui e di e en . Tha di e ence can ha e
o igina ed in he eloci y o he es which is no indica ed in o he consul ed da abase.
In his wo k i was used an impac eloci y o 1m/s bu is common in o he gene ic polyme indus y ha his
eloci y ounds he 4,4 m/s.
Rega ding he HDT, is possible o see ha he ABS p esen s he highes alue. Howe e he alue p esen ed is
an a e age o all ABS g ades ac ually in he ma ke .
I ’s possible o ha e an ABS wi h a HDT lowe han he s udied composi es.
By analyzing he ada cha is possible o conclude ha he composi e wi h 20% ibe (ligh -g ay shadow) is
he one ha p esen be e o equal p ope ies in all he dimensions.
Fo p oducing he au omo i e pa s i ’s going o be used he composi e ha p esen s he equal o be e
p ope ies in all dimensions.
By analyzing he 6D ada cha is possible o conclude ha he composi e wi h 20% ibe (g ay shadow) is he
one ha ul ill he p e ious s a emen . The only dimension ha his composi e p esen a weake beha io is
on impac , bu as ha e been said be o e hese alues needs some con i ma ion ha ou bound he aim o his
hesis.

Nuno Calçada Lou ei o
113
Figu e 8.3 – 6 Dimension ada cha ma e ials compa ison
8.4 Au omo i e pa
To demons a e he possibili y o using his composi e and he CIM echnology a pa was
injec ed.
I was chosen a cabin ligh suppo pa om a well-known OEM om a 2008 model.
The o iginal pa is p oduced in an ABS/PA6 blend by injec ion moulding.
Figu e 8.4 – O iginal Pa
Sus ainable au omo i e componen s o in e io doo ims
114
Using he injec ion pa ame e s al eady op imized in he p e ious chap e s on a CIM equipmen wi h
a composi e ma e ial o med by a [PHA:PLA] [30:70] ma ix and a a io o 20% w o cellulosic ibe is
possible o ob ain he same pa bu in o bio-deg adable composi e.
Figu e 8.5 – eco-composi e pa
As can be seen by compa ing igu e 8.4 and 8.5 he pa p oduce in eco-composi e p esen s he
same geome y. Tha allows he easy eplacemen o he ac ual pa o his one and also allows he
inco po a ion o he sys ems and pa s ha a e in eg a ed in o he cabin in e io ligh pa .
Is possible o see, in ig. 8.6, ha e en he small de ails can be ep oduced wi h his composi e.
Figu e 8.6 – eco-composi e pa de ail
As happens nowadays he pa colo can be adjus wi h pigmen s.
8.5 Conclusions
The easibili y o p oducing in e io pa s on he s udied eco-composi es has been in es iga ed.
Composi es wi h a [30:70] [PHA:PLA] ma ix and wi h a ibe con en o 10% and 20% (w ) we e compa ed
wi h he mos used pe ol-based polyme s o au omo i e in e io pa s (PP and ABS)
Nuno Calçada Lou ei o
115
The inco po a ion o 20% w ibe leads o an eco-composi e ha p esen s he bes p ope ies o all
biopolyme blends and biocomposi es s udied.
When compa ed wi h ABS and PP, his eco-composi e, no mally, p esen s equal o be e p ope ies, excluding
he impac abso bed ene gy.
Is possible o conclude ha his composi e can e eal himsel an op ion o eplace he pe ol-based polyme s
in some cabin in e io pa s applica ions has demons a ed in his pa case-s udy.
Sus ainable au omo i e componen s o in e io doo ims
116
Nuno Calçada Lou ei o
117
Chap e 9.
Final Rema ks and Fu u e Wo ks
9.1 Final Rema ks
The p incipals expec ed esul o his hesis is ocus on he de elopmen o a concep o an eco-e icien
au omo i e doo in e io im using 100 % o enewable sou ces ma e ials, whils mee ing ac ual applicable
c ashwo hiness s anda ds and aes he ics equi emen s.
The wo k epo ed in his hesis p oo ha he p ope ies o biodeg adable composi es can be ailo ed by a
ca e ul selec ion o he nea polyme o polyme blends ha compose he ma ix and he co ec inco po a ion
o ein o ce ibe s.
Fo he ma ix a blend o PHA and PLA we e chosen ecu ing o a s udy o e he ull a io o composi ions.
The mechanical and mo phological beha io we e s udy and he [PHA:PLA] [30:70] blend was chosen o be he
ma ix o he biodeg adable composi e ha will be de eloped.
As men ioned be o e ([10], chap e 7), aking accoun p e ious wo ks, he ibe inco po a ion can’ be supe io
o 30% (w ).
To asse he bes ibe ac ion inco po a ion composi es wi h a [PHA:PLA] [30:70] ma ix and wi h a ibe
con en un il 30% (w ) we e in es iga ed.

Sus ainable au omo i e componen s o in e io doo ims
118
Compa ing all he esul s is possible o conclude ha o au omo i e in e io pa s, he bes biodeg adable
composi e ha his wo k achie es is a composi e wi h a ma ix compose by [PHA:PLA] [30:70] (w ) and wi h a
ibe inco po a ion o 20% (w ).
Using he ac ual p oduc ion p ocess is possible o p ocess au omo i e in e io pa s wi h his composi e as
demons a ed in he case-s udy.
The e o e is possible o s a ha he p ima y objec i e o his wo k has been achie ed and he o mula ion o a
100% enewable-sou ce composi e capable o eplace he pe ol-based polyme s use in o in e io doo ims
has been iden i ied.
9.2 Fu u e Wo ks
Fo u u e wo ks based in his hesis is possible o wo ks in six di e en a eas:
1
s
a ea – Di ec ly connec ed wi h his wo k: S udy he mechanical beha io o he injec ed composi e in o
he CIM equipmen . S udy he in luence o he Impac Veloci y on he Abso bed Ene gy o compa e wi h
pe ol-based polyme s. S udy he in e ace be ween ibe and ma ix. Op imize he adhesion be ween he
ma ix and he ibe ecu ing o chemical and he mo-physical ibe s ea men s.
2
nd
a ea – Ma ix: In his sec ion is possible o s udy o he enewable-sou ce polyme s, such as PHB, PGA,
PBA, o eplace PHA and/o PLA.
3
d
a ea – Fibe s: S udy he inco po a ion o o he ibe s such as coconu , lax, co on, hemp, ju e, sisal
among o he s. Is also possible o s udy he inco po a ion o wo en and p e-imp egna ed ibe s.
4
h
a ea – O he applica ions: De eloped and es his composi e o s uc u al pa s use i in mode a e
s ess s a es. S udy he inco po a ion o his composi e in o o he anspo sys ems and o he s indus ial
sec o s.
5
h
a ea – P ocessing Technology: I sugges he s udy o p ocessing his composi es and composi e pa s,
by o he echnologies such as comp ession moulding, Vacuum con o ma ion, e c.
6
h
a ea – Long Te m Composi e Cha ac e iza ion: S udy he long e m beha io such as a igue, c eep,
eal deg ada ion p ocess, sola exposi ion, mois u e deg ada ion and chemical deg ada ion occu ing by
he con ac wi h lub ican s and o he en i onmen al agen s.
Nuno Calçada Lou ei o
119
Appendixes
Sus ainable au omo i e componen s o in e io doo ims
120
Nuno Calçada Lou ei o
121
A.1
Da ashee o Polyhyd oxyalkanoa e