Ci a ion: Nakonieczny, D.S.;
An onowicz, M.; SimhaMa ynko a,
G.; Ke n, F.; Pazou ko á, L.; E u ,
K.; Hüpsch, M. PA-12-Zi conia-
Alumina-Cenosphe es 3D P in ed
Composi es: Accele a ed Ageing and
Role o he S e ilisa ion P ocess o
Physicochemical P ope ies. Polyme s
2022,14, 3152. h ps://doi.o g/
10.3390/polym14153152
Academic Edi o s: Vamsee
Vadlamudi and Mu hu Ram
P abhu Elenchezhian
Recei ed: 22 June 2022
Accep ed: 28 July 2022
Published: 2 Augus 2022
Publishe ’s No e: MDPI s ays neu al
wi h ega d o ju isdic ional claims in
published maps and ins i u ional a il-
ia ions.
Copy igh : © 2022 by he au ho s.
Licensee MDPI, Basel, Swi ze land.
This a icle is an open access a icle
dis ibu ed unde he e ms and
condi ions o he C ea i e Commons
A ibu ion (CC BY) license (h ps://
c ea i ecommons.o g/licenses/by/
4.0/).
polyme s
A icle
PA-12-Zi conia-Alumina-Cenosphe es 3D P in ed Composi es:
Accele a ed Ageing and Role o he S e ilisa ion P ocess o
Physicochemical P ope ies
Damian S. Nakonieczny 1,2,3,* , Magdalena An onowicz 3, G ažyna SimhaMa ynko a 2, F ank Ke n 1,
Lenka Pazou ko á4, Ka ol E u 5and Michał Hüpsch 3
1Ins i u e o Manu ac u ing Technologies o Ce amic Componen s and Composi es, Uni e si y o S u ga ,
70569 S u ga , Ge many; [email p o ec ed]
2Nano echnology Cen e, CEET, VŠB—Technical Uni e si y o Os a a, 17. Lis opadu 15,
708733 Os a a-Po uba, Czech Republic; [email p o ec ed]
3Depa men o Biomedical Enginee ing, Silesian Uni e si y o Technology, Akademicka 2A,
44-100 Gliwice, Poland; [email p o ec ed] (M.A.); [email p o ec ed] (M.H.)
4IT4 Inno a ions, VŠB—Technical Uni e si y o Os a a, 17. Lis opadu 15,
708733 Os a a-Po uba, Czech Republic; [email p o ec ed]
5Facul y o Chemis y, Depa men o Chemical O ganic Technology and Pe ochemis y,
Silesian Uni e si y o Technology, K zywous ego 4, 44-100 Gliwice, Poland; ka [email p o ec ed]
*Co espondence: [email p o ec ed]; Tel.: +48-791-515-766
Abs ac :
The aim o his s udy was o conduc a i icial ageing es s on polyme -ce amic composi es
p epa ed om polyamide PA-12 polyme ma ix o medical applica ions and h ee di e en a ian s
o ce amic ille s: zi conia, alumina and cenosphe es. Be o e ageing, he samples we e subjec ed
o e hyl oxide s e iliza ion. The composi e a ian s we e p epa ed o 3D p in ing using he used
deposi ion modeling me hod. The con ol g oup consis ed o uns e ilized samples. Samples we e
subjec ed o a i icial ageing in a high-p essu e au ocla e. Ageing condi ions we e calcula ed om he
modi ied Hamme lich A henius kine ic equa ion. Ageing was ca ied ou in a i icial sali a. A e
ageing he composi es we e subjec ed o mechanical ( ensile s eng h, ha dness, su ace oughness)
es ing, chemical and s uc u al (MS, FTIR) analysis, elec on mic oscopy obse a ions (SEM/EDS)
and abso babili y measu emen s.
Keywo ds:
polyme -ce amic composi es; accele a ed ageing es s; s e ilisa ion; PA-12; zi conia;
alumina; cenosphe es
1. In oduc ion
The ield o bioma e ials enginee ing con inues o see an inc eased in e es in com-
posi es, especially in den al and o hopaedic applica ions [
1
,
2
]. This is due o he ac
ha he use o composi es in medicine sol es many o he p oblems ha a ec me allic
bioma e ials including co osion, suscep ibili y o mic obial colonisa ion and human issue-
implan mechanical misma ch [
3
–
5
]. Polyme -ce amic composi es (PCCs) ha e ecei ed
pa icula a en ion due o hei desi able physico-chemical p ope ies such as ab asion
esis ance, he possibili y o achie ing a Young’s Modulus simila o ha o human bones,
aes he ic bene i s, easy machinabili y and bioa ailabili y [
6
,
7
]. PCCs a e al eady used
in es o a i e den is y o epai ing ee h wi h ca ies, while in den al p os he ics hey
a e used o CAD/CAM milling blocks [
8
,
9
]. Addi ionally mobile es o a ions also use
PCCs o p os heses and implan -suppo ed sc ews [
10
,
11
]. Wi h ega d o o hopaedic
applica ions, PCCs a e u ilised in os eosyn hesis implan s (i.e., pla es, in amedulla y nails
and spinal implan componen s) [
12
,
13
]. An impo an issue when conside ing composi es
as bioma e ials is o de e mine hei esis ance o deg ada ion in body luid en i onmen s.
When using composi es as bioma e ials, a en ion should be paid o ac o s such as pH,
Polyme s 2022,14, 3152. h ps://doi.o g/10.3390/polym14153152 h ps://www.mdpi.com/jou nal/polyme s
Polyme s 2022,14, 3152 2 o 21
physiologically ele an empe a u e (i.e., 37
◦
C), a iable mechanical loads and in e ac ion
wi h biological compounds (i.e., p o eins) [
14
,
15
]. I is impo an o no e ha he implan ed
ma e ial will emain in he body o mo e han 2 yea s, so he e is a need o p edic he exac
beha iou o he ma e ial du ing his pe iod in he body. Mo eo e , expe imen al da a can
be used o p edic he beha iou o he implan ma e ial du ing long- e m use. Hukins e al.
epo ed se e al kine ic ela ionships ha a e an ex ension o he Hemme lich equa ion
esul ing om he simpli ied p o ocol o accele a ed ageing o medical de ices [
15
,
16
].
Based on hese equa ions, i is possible o app oxima ely de e mine he e e ence empe -
a u e a which he e ec s begin and wha appea s o be he simples p ac ical solu ion.
Howe e , his app oach only conside s empe a u e as a ac o in ageing and does no ake
in o accoun o he a iables such as medical s e ilisa ion o he ma e ial, luid simula ing
body luids o compounds simula ing o ganic compounds (i.e., p o eins, a s, e c.). In e -
es ing algo i hms o hos ile en i onmen , ele a ed empe a u e and cyclic de o ma ion
can be ound in he epo on polyme and polyme composi es accele a ed ageing and
li e ime p edic ion echniques p esen ed by Maxwell e al. [
17
]. Maxwell e al. epo ed
ageing as a unc ion o empe a u e o e ime akes he o m o he equa ions o A henius
and A ami [
17
]. The epo con ains nume ous algo i hm a ian s, mos o which a e
modi ica ions and expansions o he A henius equa ion. Howe e , he simples and mos
app op ia e equa ion appea s o be a simple powe equa ion simila o he Hemme lich
equa ion [
16
,
17
]. In he a ailable da a, howe e , he e is a lack o co ela ion be ween
he accele a ed ageing es s and ageing p o ocols o PCC bioma e ials, as is he case o
zi conium oxide [18], and he en i onmen in which ageing akes place.
The main aim o his s udy was o ca y ou accele a ed ageing es s o PCCs consis ing
o Z O
2
and Al
2
O
3
, cenosphe es (CSs) as ille s and PA-12 as a polyme ma ix om which
samples o deg ada ion es s we e p epa ed in he o m o used deposi ion modelling
(FDM) 3D p in ing ilamen s. Polyamides ha e p omising applica ions in 3D p in ing
and composi e p epa a ion [
19
,
20
]. A second objec i e o he s udy was o de e mine he
e ec o he ype o s e ilisa ion and he medium used o accele a ed ageing es s on he
physicochemical p ope ies o bo h ypes o PCCs. Samples we e p epa ed o s eng h
es s acco ding o ISO 527:2012 [
21
]. Addi ionally, samples we e di ided in o 2 g oups:
(I) uns e ilised and (II) e hylene oxide (EO) s e ilised. A i icial ageing es s we e conduc ed
in high-p essu e au ocla es in he en i onmen o a i icial sali a unde ageing condi ions
calcula ed om he A henius kine ic equa ion modi ied by Hamme lich [
15
,
16
]. The
mechanical p ope ies ( ensile s eng h, ha dness and su ace oughness), abso babili y,
su ace opog aphy and chemical composi ion o he PCCs as well as he chemical compo-
si ion o he simulan solu ion we e analysed a e ageing. The mo i a ion o conduc ing
his s udy was o de e mine he e ec o medical s e iliza ion and a i icial ageing on he
composi es we had p e iously p epa ed om PA-12. These issues a e impo an because
hey allow us o assess he impac o he medical s e iliza ion p ocess commonly used
o implan s. An addi ional aspec o he esea ch conduc ed is o p edic he beha io o
he implan ma e ial unde a i icial sali a condi ions—and hus o p edic he ma e ial’s
beha io unde long- e m condi ions. In ea lie s udies, we ocused on a simple app oach
o he eachabili y o composi es in a e y simpli ied model wi h empe a u e. In his s udy,
ollowing ou ea lie expe imen s, we added a kine ic model o ep esen changes in human
body condi ions, which we e no accu a ely ep esen ed in ea lie es s.
2. Ma e ials and Me hods
2.1. Ma e ials and Samples
2.1.1. Ce amic Fille Modi ica ion
The samples we e p epa ed as desc ibed in ou p e ious s udies [
22
,
23
]. Zi conia
(ZRO-T6 IMERYS), alumina (Sumi omo, Sumico undum AA-18) and 90
µ
m ac ion o
pu i ied cenosphe es (o igin: GRES-2 Powe plan , Kazakhs an) we e modi ied by a wo-
s ep p ocess: (I) e ching in pi anha solu ion and (II) su ace modi ica ion wi h APTES (3-
aminop opyl ie hoxysilane). The e ching solu ion was p epa ed using H
2
SO
4
(CAS: 7664-
Polyme s 2022,14, 3152 3 o 21
93-9, 95%, Ac os O ganics), and H
2
O
2
(CAS: 7722-84-1, 30%, STANLAB) in a olume ic
a io o 3:1. The powde s we e pou ed oge he wi h Pi anha solu ion in o a ound-
bo omed lask and hea ed unde cons an e lux (100
◦
C, 15 min, con inuous s i ing a
350 pm). Then, he ce amics we e washed unde acuum wi h a wa e pump wo imes
wi h 500 mL o deionized wa e . The pH o he ce amic slu ies was neu alized wi h
ammonia wa e (CAS 1336-21-6, 25%, AVANTOR). In he second s age, all ce amics we e
e ched in APTES (3-aminop opyl ie hoxysilane; CAS: 919-30-2, Ac os O ganics, A Cp10%
solu ion o APTES in 2-p opanol (P OH) (CAS: 67-63-0, Ac os O ganics). Slu ies we e
s i ed on a magne ic s i e (30
◦
C, 24 h, 250 pm). A e mixing, he suspension was
exposed o ul asound ( = 37 kHz, powe 120%, 50 min, 30
◦
C, degas mode). All ce amics
we e il e ed unde educed p essu e wi h a wa e pump. Then, he powde s we e d ied
( o ced ai d ye , 12 h, 80
◦
C) and calcined in a mu le u nace (RENFERT Magma) a 450
◦
C
in an ai a mosphe e ( empe a u e g adien 9
◦
/min, iso he mal holding o 2 h, samples
cooled oge he wi h he u nace).
2.1.2. Filamen P epa a ion
Polyme -ce amic ilamen s we e p epa ed wi h a win-sc ew ex ude o he com-
pounding and a single sc ew ex ude o he ilamen p epa a ion. To a oid hyd olysis,
he PA-12 (VESTAMID PA12, E onik) g anula e was p e-d ied a 50
◦
C o 10 h. Alumina,
zi conia and CSs we e d ied a 150
◦
C o 10 h. The molecula weigh o PA-12 anged
om 9100 o 16,600 g
·
mol
−1
. The EBVP 25/44D ex ude om O.M.C. SRL (Sa onno, I aly)
was used o compounding. The ce amic powde and he polyme g anules we e dosed
g a ime ically wi h a mass a io: o 20% ce amic powde o 80% polyme (PA) o CSs and
30:70% o zi conia and alumina. The mass h oughpu se up was 4.2 kg/h a 100 pm and
260 ◦C ex ude empe a u e a he exi . Single-sc ew ex ude om DR. COLLIN
GmbH (Ebe sbe g, Ge many) was used o shaping wi h a 3 kg/h mass h oughpu
a 14 pm. A e ex usion, he polyme ce amic mel was pulled wi h a pull-o o ce
which depended on he c ys alliza ion deg ee o he ca ie ma e ial. To se he pull-o
o ce, ilamen diame e s be ween 1.6 and 1.8 mm we e equi ed and eco ded using a
WIREMASTER and he ODAC 18 XY lase head om Zumbach (O pund, Swi ze land).
2.1.3. Sample P epa a ion
Sample p epa a ion me hods we e analogous o hose conduc ed in p e ious s ud-
ies [
21
,
22
]. Samples we e p epa ed by FDM p in ing on a 3D p in e (Double P255 by
3D Gence, Gliwice, Poland). In acco dance wi h he ecommenda ions o ISO 527:2012
[A], ype 1BA samples we e p epa ed, which a e p e e ed o machined specimens. The
cha ac e is ic dimensions o he samples a e shown in Figu e 1and Table 1. The 3D models
we e modelled in SolidWo ks 2020 so wa e (Dassaul Sys èmes SolidWo ks Co po a ion,
Wal ham, MA, USA). In o de o ead he ile by he p in e , he ile was sa ed in he STL
o ma , and he app op ia e p in ing pa ame e s we e selec ed using 3D Gence Slice 4.0.
so wa e (3D Gence, Gliwice, Poland).
Table 1. Sample dimensions.
Dimensions o he Sample Dimensions, mm
l3—o e all leng h 75
l1—leng h o na ow pa allel-sided po ion 30.5
— adius 37
l2—dis ance be ween b oad pa allel-sided po ions 57.5
b2—wid h a ends 10
b1—wid h o na ow po ion 5
h— hickness 2.35
L0—gauge leng h 25
L—ini ial dis ance be ween g ips 54
Polyme s 2022,14, 3152 4 o 21
Polyme s2022,14,xFORPEERREVIEW4o 21


h— hickness2.35
L0—gaugeleng h25
L—ini ialdis ancebe weeng ips54

Figu e1.Sample ype1BA o s eng h es [21].
In he i s s age,geome icsamples o bo hma e ialswe ep in eda ex ude 
empe a u es anging om200–220°C o e i y hequali yo  hesu aceandin e laye 
bonds.Thep in ingpa ame e sa eshownin heTable2.Thep in edsampleswe e
s o eda 23°Cand20% ela i ehumidi y.
Table2.P ocessingpa ame e so  hesoaking es samples.
P in ingPa ame e s 
Ma e ialPA‐Z O2PA‐Al2O3
Nozzlediame e (mm)0.5mm0.5mm
Laye  hickness(mm)0.35mm0.35mm
Buildo ien a ion×(ho izon ally)×(ho izon ally)
In illdensi y100%100%
In illpa e nLinea aligned(0°)Linea aligned(0°)
Ou e laye s22
Ex ude  emp.(°C)210°C210°C
The ollowing ableshows hedesigna ionsandnumbe o samplesp epa ed o  he
expe imen s(Table3).Tocompa e epea abili yinmechanical es ing, i esampleswe e
p epa ed o eachg oup.A o alo 40sampleswe ep epa ed.
Table3.Sampledesc ip ion.
SamplesDesc ip ionNon‐S e ilisedSamplesS e ilisedSamples
PA12Pu epolyamidePA12_NS
(5samples)
PA12_S
(5samples)
PA12_Z O2Polyamideandzi coniaPA12_Z O2_NS
(5samples)
PA12_Z O2_S
(5samples)
PA12_Al2O3PolyamideandaluminaPA12_Al2O3_NS
(5samples)
PA12_Al2O3_S
(5samples)
PA12_CSPolyamideandcenosphe ePA12_CS_NS
(5samples)
PA12_CS_S
(5samples)
2.2.S e iliza ion
S e iliza ionwaspe o medine hyleneoxide(EO)inanANAPROLENE74s e i‐
lize .Sampleswe einse edin os anda ds e iliza ionslee esmadeo pape .S e iliza‐
ionwasca iedou basedon hemanu ac u e ’ss anda dp og amp o ided o poly‐
Figu e 1. Sample ype 1BA o s eng h es [21].
In he i s s age, geome ic samples o bo h ma e ials we e p in ed a ex ude
empe a u es anging om 200–220
◦
C o e i y he quali y o he su ace and in e laye
bonds. The p in ing pa ame e s a e shown in he Table 2. The p in ed samples we e s o ed
a 23 ◦C and 20% ela i e humidi y.
Table 2. P ocessing pa ame e s o he soaking es samples.
P in ing Pa ame e s
Ma e ial PA-Z O2PA-Al2O3
Nozzle diame e (mm) 0.5 mm 0.5 mm
Laye hickness (mm) 0.35 mm 0.35 mm
Build o ien a ion ×(ho izon ally) ×(ho izon ally)
In ill densi y 100% 100%
In ill pa e n Linea aligned (0◦) Linea aligned (0◦)
Ou e laye s 2 2
Ex ude emp. (◦C) 210 ◦C 210 ◦C
The ollowing able shows he designa ions and numbe o samples p epa ed o he
expe imen s (Table 3). To compa e epea abili y in mechanical es ing, i e samples we e
p epa ed o each g oup. A o al o 40 samples we e p epa ed.
Table 3. Sample desc ip ion.
Samples Desc ip ion Non-S e ilised Samples S e ilised Samples
PA12 Pu e polyamide PA12_NS
(5 samples)
PA12_S
(5 samples)
PA12_Z O2Polyamide and zi conia PA12_Z O2_NS
(5 samples)
PA12_Z O2_S
(5 samples)
PA12_Al2O3Polyamide and alumina PA12_Al2O3_NS
(5 samples)
PA12_Al2O3_S
(5 samples)
PA12_CS Polyamide and cenosphe e PA12_CS_NS
(5 samples)
PA12_CS_S
(5 samples)
2.2. S e iliza ion
S e iliza ion was pe o med in e hylene oxide (EO) in an ANAPROLENE 74 s e ilize .
Samples we e inse ed in o s anda d s e iliza ion slee es made o pape . S e iliza ion was
ca ied ou based on he manu ac u e ’s s anda d p og am p o ided o polyme s. A e
s e iliza ion, he samples we e ae a ed in he slee es o 28 days in o de o e apo a e he
esidual EO.
Polyme s 2022,14, 3152 5 o 21
2.3. A i icial Ageing P o ocol
A i icial ageing was ca ied ou acco ding o he da a and model ecommenda ions o
p e ious s udies [
15
–
17
,
24
–
26
]. On his basis, he kine ic model o he A henius equa ion
ans o med by Hamme lich was selec ed as he mos sui able o ou in es iga ions:
=Q10
∆T
10 (1)
whe e:
—accele a ed ageing ac o (AAF),
Q10—conse a i e ageing ac o , ◦C−1
∆T— empe a u e a ia ion, ◦C
whe e:
∆T=T−TREF (2)
whe e:
TREF— e e ence empe a u e ( ep esen a i e o e ec s o ageing de e mina ion), ◦C
T—ele a ed empe a u e (used o accele a ed ageing e ec s), ◦C
This equa ion is based on he empi ical p inciple ha inc easing he empe a u e by
abou 10
◦
C oughly doubles he a e o many polyme eac ions [
15
]. The e o e, he Q
10
ac o o his case will ake he alue o 2 when T= 10 ◦C and will equally ake he o m:
=2T−TREF
10 (3)
In addi ion, he a i icial ageing ime (ATT), which is ela ed o he li e es o eal- ime
equi alen (RTE), mus also be aken in o accoun [17,26,27]:
ATT =RTE
(4)
whe e:
RTE—days,
Based on he li e a u e and da a om ageing cha s (equi alen o one yea o oom-
empe a u e ageing plo ), 1 yea was selec ed as he RTE [
15
,
25
,
26
]. Thus, ageing pa ame e s
we e de e mined o condi ions in physiological luids a ele a ed empe a u es:
•
simula ed body solu ion (SBF)—a i icial sali a (acco ding o EN ISO 10993-15:2000,
chemical composi ion, Table 4),
•Q10—2,
•T—97 ◦C,
•TREF—37 ◦C,
•RTE—365 days.
=2(97−37)
10
=64
ATT =365
64
ATT =5.7 days
ATT =136 h 48 min
Table 4. SBF—A i icial sali a chemical composi ion.
Compound Na2HPO4NaCl KSCN KH2PO4NaHCO3KCl
Concen a ion, g/L 0.260 0.700 0.330 0.200 1.500 1.200

Polyme s 2022,14, 3152 6 o 21
2.4. A i icial Ageing P ocess
Composi e samples we e kep sealed in high-p essu e au ocla es (Ca l ROTH, Model-
1 wi hou p essu e gauge) and illed wi h a i icial sali a (Table 4). Au ocla es we e placed
in a o ced-ai d ye (Binde FED) a 97
◦
C o 5.7 days. A e he exposu e ime in a i icial
sali a, he samples we e subjec ed o es s desc ibed below.
2.5. Mechanical Tes s
The s a ic ensile es was conduc ed in acco dance wi h he ecommenda ions o he
s anda d EN ISO 527:2012 wi h a ensile speed o 5 mm/min, using he MTS C i e ion
Model 45 machine wi h a 10 kN o ce senso and MTS Tes Sui e so wa e (Eden P ai ie,
MN, USA). The sepa a ion be ween he g ippe s was 54 mm. Upon es comple ion, he
maximum b eaking o ce Fmax [N], he Young’s Modulus E [MPa], elonga ion a b eak
A [%] and ensile s eng h Rm [MPa] we e de e mined. Tes s we e ca ied ou using
a s anda d MTS ex ensome e . Fi e s udies we e pe o med o each ype o sample.
Measu emen s o mic oha dness we e ca ied ou using he Oli e and Pha ins umen al
me hod, which is a measu e o he esis ance o a ma e ial o pe manen de o ma ion o
damage and is de ined as he quo ien o he maximum applied loading o ce and he
p ojec ed con ac a ea be ween he inden e and he es sample [
27
]. The me hodology
was c oss- e e enced wi h o he s udies [
28
]. The es s we e ca ied ou using he open
pla o m equipped wi h a Mic o-Combi-Tes e by CSM Ins umen s (Mic o-Combi-Tes e ,
CSM ins umen s a company o An on Paa , Peseux, Swi ze land) using a Vicke s inden e .
The mic omechanical p ope ies we e de e mined on he basis o ma e ial de o ma ion as a
esul o inden a ion o he sample wi h Vicke s inden e o which a 100 mN maximal load
was applied. The alue o he loading o ce and he pene a ion dep h o he inden e blade
we e eco ded con inuously du ing he en i e cycle (loading and unloading). Loading and
unloading a es we e 200 mN/min wi h a 5 s hold ime o he sample a maximum load.
The alue he inden e load was esul ing. The mic oha dness esul is he a e age o
10 measu emen s measu ed longi udinally and ans e sely ac oss he en i e su ace a ea.
The alues o inden a ion ha dness (HIT) and Vicke s ha dness (HVIT) we e de e mined.
2.6. FTIR—Fou ie T ans o m In a ed
Tes s we e ca ied ou using a Shimadzu IR T ace -100 Fou ie T ans o m In a ed
Spec opho ome e (Michelson in e e ome e , beam spli e : KB ge manium coa ed, ligh
sou ce: high-ene gy ce amics, de ec o : DLATGS de ec o ) using a mul i- e lec ion ATR
a achmen equipped wi h a diamond p ism. The de ice was calib a ed wi h a closed ATR
a achmen , o eco d he backg ound image. Then, he es samples we e placed on he
diamond and p essed agains he p ism wi h a dynamome ic sc ew, each ime wi h he
same o ce. In o de o analyze and in e p e he cha ac e is ic bands o he es ed samples,
he ansmission spec a we e eco ded on a mul i- e lec ion de ice. The analysis was
pe o med au oma ically using he dedica ed LabSolu ion IR so wa e (Shimadzu, Kio o,
Japan) p o ided by he spec ome e manu ac u e . To minimize e o , 100 coun s we e
pe o med wi h a esolu ion o 4 cm
−1
o each analysis. All measu emen s we e ca ied
ou in he medium in a ed ange o 4000–400 cm−1.
2.7. MS—Mass Spec ome y
The PA-12 s anda d was dilu ed in me hanol and sonica ed ia ul asound o 1 h
o pa ially dissol e i in he sol en . The es samples we e dilu ed wi h me hanol and
also sonica ed wi h ul asound o 1 h. These solu ions we e hen examined by MS. High
esolu ion MS analyses we e pe o med on a Wa e s Xe o G2 Q-TOF mass spec ome e
(Wa e s Co po a ion, Mil o d, MA, USA) equipped wi h an elec osp ay ioniza ion (ESI)
sou ce ope a ing in posi i e ion modes. MS da a we e collec ed om 100 o 2000 Da
in posi i e ion mode wi h scan ime o 0.1 s. To ensu e accu a e mass measu emen s,
da a we e collec ed in cen oid mode and mass was co ec ed du ing acquisi ion using
leucine enkephalin solu ion as an ex e nal e e ence (Lock-Sp ayTM), which gene a ed
Polyme s 2022,14, 3152 7 o 21
e e ence ions a m/z 556.2771 Da ([M + H]
+
) in posi i e ESI mode. The accu a e mass and
composi ion o he molecula ion adduc s we e calcula ed using he MassLynx so wa e
(Wa e s) inco po a ed wi h he ins umen . Pa ame e s and se ings a e p esen ed below in
Table 5. 9 samples we e analyzed; 8 we e samples aged in SBF and one was a blank sample
o a i icial sali a.
Table 5. MS pa ame e s.
Se ings Cha ac e is ics
Pola i y: ES+
Analyze : Resolu ion Mode
Capilla y (kV): 40,000
Sampling Cone: 200,000
Ex ac ion Cone: 40,000
Sou ce Tempe a u e (◦C): 120
Desol a ion Tempe a u e (◦C): 200
Cone Gas Flow (L/H ): 50.0
Desol a ion Gas Flow (L/H ): 500.0
2.8. SEM/EDS—Scanning Elec on Mic oscopy/Ene gy Dispe si e Spec oscopy
Mo phology obse a ions o samples we e made using a TESCAN VEGA scanning
elec on mic oscope (SEM) equipped wi h seconda y elec ons (SE) and backsca e ed elec-
ons (BSE) de ec o s in low acuum. Chemical composi ion was de e mined using ene gy
dispe si e X- ay spec oscopy (EDS, Ox o d Ins umen s EDS p obe wi h Az ec so wa e).
2.9. Sa u a ion Tes
By applying he me hod used o de e mine he abso bency o polyme s exposed o
boiling wa e , he abso bency o he composi e samples was de e mined. A e a i icial
ageing, samples we e weighed on an analy ical balance wi h an accu acy o
±
1 mg and
hen d ied in a o ced ai ci cula ion d ye (Binde FED) o 24 h a 50
◦
C. The abso babili y
o he p epa ed composi es was hen calcula ed om he equa ion below:
A=m2−m1
m2
·100% (5)
whe e:
A—abso babili y, %
m2—sample weigh a e ageing, g
m1—sample weigh a e d ying, g
The en i e s udy was designed as ollows: he samples we e di ided in o wo main
g oups: non-s e ilized (NS) 20 samples, and s e ilized (S) also 20 samples (Table 3). On his
basis, he e ec o s e iliza ion was assessed. Wi h ega d o s e iliza ion, all 40 samples
we e subjec ed o he ageing p o ocol ou lined abo e. This app oach made i possible o
de e mine exac ly wha he impac o s e iliza ion and a i icial ageing is. The p ocess
low-cha wi h sample desc ip ion below shows he ex en o sample p epa a ion and
in es iga ions (Figu e 2). The p ocess low diag am is complemen a y o he able (see
Table 3).
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Figu e2.P ocess lowcha .
3.Resul sandDiscussion
3.1.Resul s
3.1.1.MechanicalTes ing
Mic oha dness
Mic oha dness es  esul s o allsamplesa ep esen edinTable6.Measu emen s
we e akenindi e en a easo  hesamplesandnodi e enceswe e oundac oss he
en i ea ea.
Table6.Mic oha dness esul so  es edsamples.
PA12_NSPA12_SPA12
Z O2_NS
PA12
Z O2_S
PA12
Al2O3_NS
PA12
Al2O3_S
PA12
CS_NS
PA12
CS_S
Vicke sha dness,
HVIT12±211±29±216±915±113±427±222±4
Mic oha dness
HIT,MPa122±19113±9100±20174±18125±9142±31290±7240±10
TensileTes 
The ensile es  esul so  hespecimensPA12,PA12_Z O2,PA12_Al2O3and
PA12_CSin hei ini ial/non‐s e ilised(NS)s a eanda e s e ilisa ion(S)a eshownin
Figu es3–5.
Figu e 2. P ocess low cha .
3. Resul s and Discussion
3.1. Resul s
3.1.1. Mechanical Tes ing
Mic oha dness
Mic oha dness es esul s o all samples a e p esen ed in Table 6. Measu emen s we e
aken in di e en a eas o he samples and no di e ences we e ound ac oss he en i e a ea.
Table 6. Mic oha dness esul s o es ed samples.
PA12_NS PA12_S PA12
Z O2_NS
PA12
Z O2_S
PA12
Al2O3_NS
PA12
Al2O3_S
PA12
CS_NS
PA12
CS_S
Vicke s ha dness, HVIT 12 ±2 11 ±2 9 ±2 16 ±9 15 ±1 13 ±4 27 ±2 22 ±4
Mic oha dness HIT,MPa 122 ±19 113 ±9 100 ±20 174 ±18 125 ±9 142 ±31 290 ±7 240 ±10
Tensile Tes
The ensile es esul s o he specimens PA12, PA12_Z O
2
, PA12_Al
2
O
3
and PA12_CS
in hei ini ial/non-s e ilised (NS) s a e and a e s e ilisa ion (S) a e shown in Figu es 3–5.
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Figu e3.Young’sModuluso  hePA12,PA12_Z O2,PA12_Al2O3andPA12_CSsamplesin hei 
non‐s e ilised/ini ials a eanda e s e ilisa ion.

Figu e4.Elonga iona ul ima e ensiles eng ho  hePA12,PA12_Z O2,PA12_Al2O3and
PA12_CSsamplesin hei non‐s e ilised/ini ials a eanda e s e ilisa ion.

Figu e5.Ul ima e ensiles eng ho  hePA12,PA12_Z O2,PA12_Al2O3andPA12_CSsamplesin
hei non‐s e ilised/inini ials a eanda e s e ilisa ion.
Figu e 3.
Young’s Modulus o he PA12, PA12_Z O
2
, PA12_Al
2
O
3
and PA12_CS samples in hei
non-s e ilised/ini ial s a e and a e s e ilisa ion.
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Figu e3.Young’sModuluso  hePA12,PA12_Z O2,PA12_Al2O3andPA12_CSsamplesin hei 
non‐s e ilised/ini ials a eanda e s e ilisa ion.

Figu e4.Elonga iona ul ima e ensiles eng ho  hePA12,PA12_Z O2,PA12_Al2O3and
PA12_CSsamplesin hei non‐s e ilised/ini ials a eanda e s e ilisa ion.

Figu e5.Ul ima e ensiles eng ho  hePA12,PA12_Z O2,PA12_Al2O3andPA12_CSsamplesin
hei non‐s e ilised/inini ials a eanda e s e ilisa ion.
Figu e 4.
Elonga ion a ul ima e ensile s eng h o he PA12, PA12_Z O
2
, PA12_Al
2
O
3
and PA12_CS
samples in hei non-s e ilised/ini ial s a e and a e s e ilisa ion.
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Figu e3.Young’sModuluso  hePA12,PA12_Z O2,PA12_Al2O3andPA12_CSsamplesin hei 
non‐s e ilised/ini ials a eanda e s e ilisa ion.

Figu e4.Elonga iona ul ima e ensiles eng ho  hePA12,PA12_Z O2,PA12_Al2O3and
PA12_CSsamplesin hei non‐s e ilised/ini ials a eanda e s e ilisa ion.

Figu e5.Ul ima e ensiles eng ho  hePA12,PA12_Z O2,PA12_Al2O3andPA12_CSsamplesin
hei non‐s e ilised/inini ials a eanda e s e ilisa ion.
Figu e 5.
Ul ima e ensile s eng h o he PA12, PA12_Z O
2
, PA12_Al
2
O
3
and PA12_CS samples in
hei non-s e ilised/in ini ial s a e and a e s e ilisa ion.
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samples.Thee ec o su acemodi ica ion o all ypeso  ille s(p esenceo Na oms)is
well isible.On heo he hand,a aceo  hedeg ada ionp ocessisappa en due o he
p esenceo KandClions,whichmayo igina e omKSCNo KCl.Howe e ,noco e‐
la ioncanbes a edwi hce ain yas owhich ypeso ma e ialsha eahighe a ini y o 
abso bingcompounds omSBF.Theobse a ions o FTIRwe ealsoco ela edwi h he
esul s omMS(Figu e11A,B).Noe idenceo PA‐12deg ada ioninSBFwas oundin
he es eda i icialsali asamplesa e ageing.

Figu e13.SEMmic og aphsused ocompa eb eak h oughso (A)PA12_Z O2_NSand(B)
PA12_Z O2_Ssamples.

Figu e 13.
SEM mic og aphs used o compa e b eak h oughs o (
A
) PA12_Z O
2
_NS and
(B) PA12_Z O2_S samples.
Polyme s2022,14,xFORPEERREVIEW16o 21
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samples.Thee ec o su acemodi ica ion o all ypeso  ille s(p esenceo Na oms)is
well isible.On heo he hand,a aceo  hedeg ada ionp ocessisappa en due o he
p esenceo KandClions,whichmayo igina e omKSCNo KCl.Howe e ,noco e‐
la ioncanbes a edwi hce ain yas owhich ypeso ma e ialsha eahighe a ini y o 
abso bingcompounds omSBF.Theobse a ions o FTIRwe ealsoco ela edwi h he
esul s omMS(Figu e11A,B).Noe idenceo PA‐12deg ada ioninSBFwas oundin
he es eda i icialsali asamplesa e ageing.

Figu e13.SEMmic og aphsused ocompa eb eak h oughso (A)PA12_Z O2_NSand(B)
PA12_Z O2_Ssamples.

Figu e 14.
SEM mic og aphs used o compa e b eak h oughs o (
A
) PA12_ Al
2
O
3
_NS and (
B
) PA12_
Al2O3_S samples.

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Figu e14.SEMmic og aphsused ocompa eb eak h oughso (A)PA12_Al
2
O
3
_NSand(B)
PA12_Al
2
O
3
_Ssamples.

Figu e15.SEMmic og aphsused ocompa eb eak h oughso (A)PA12_CS_NSand(B)
PA12_CS_Ssamples.
Acompa isono  hee ec o ageingonmechanicalp ope ieswaspe o med o 
samples omea lie s udies[22,32]andsamples om hiss udy ha hadbeenagedbu 
no s e ilized(NS_Se ies).Weob ained he ollowing esul s:
 o composi eswi hZ O
2
, o composi eswi hou ageing he alueswe eE=0.63GPa,
UTS=11MPa,elonga ion9%,HVIT=11,HIT,=120MPa;while o composi esa e 
ageing:E=0.64GPa,UTS=18MPa,elonga ion24%,HVIT=9,HIT,=100MPa;
 o composi eswi hAl
2
O
3
, o composi eswi hou ageing he alueswe eE=0.62
GPa,UTS=13MPa,elonga ion14%,HVIT=17,HIT,=175MPa;while o composi es
a e ageing:E=0.48GPa,UTS=17MPa,elonga ion23%,HVIT=15,HIT,=125MPa;
 o composi eswi hCS, o composi eswi hou ageing he alueswe eE=0.82GPa,
UTS=21MPa,elonga ion10%,HVIT=29,HIT,=302MPa;while o composi esa e 
ageing:E=0.68GPa,UTS=21MPa,elonga ion10%,HVIT=27,HIT,=290MPa;
Hence,i canbeconcluded ha  hecomposi ewi hCSis hemos suscep ible o
changesinp ope iesa e ageing.O all hecomposi e a ian s,i isin e es ing ono e ha 
PA_12_CSdidno changeelonga ionin ension— o  heo he s,aclea inc easeinduc ili y
isappa en .Thisismos likely ela ed o he olumeo  hece amic ille —wi haninc ease
in olume,adec easein hecomposi e’splas ici yandadec easein he alueo Young’s
Modulusisobse ed.Theanalysiso  hee ec o ageingshows ha ,ingene al,E‐modulus
andha dnessdec easeand hecomposi ebecomesmo educ ile(PA_12_CSisdi e en 
due o hesigni ican  olumesha eo CS,making hecomposi es i e ).
Mo phologychangeswe eobse edinSEMmic og aphs(Figu es12–15),whichco ‐
ela edwi h he esul s om hemechanical es s.Inuns e ilizedEOcomposi es,elonga ed
PA‐12 ibe sa  heb eak h oughwe eobse edp o inghighe duc ili yo NSsamplesin
compa isonwi hSsamples.Thisobse a ionwasmos appa en  o PA12_Al2O3_NS
samplesinFigu e14A.Incon as , hesedi e enceswe eno obse ed o composi eswi h
CSs(Figu e15).Thiscanbeexplainedby he ac  ha CSsha eahighe deg eeo packing
in hepolyme ma ixandmo e andomdispe sion hanzi coniaandalumina,whichis
Figu e 15.
SEM mic og aphs used o compa e b eak h oughs o (
A
) PA12_CS _NS and
(B) PA12_CS_S samples.
Wi h ega d o ying o de e mine he e ec o accele a ed ageing on he p epa ed
PCC’s, FTIR and mechanical es s we e chosen. F om all spec a, no nega i e e ec o
a i icial ageing in SBF was ound. Fo pu e PA-12 be o e and a e ageing (spec a in
Figu es 5and 6), he esul s a e shown in Table 7. And o PA-12 wi h ce amic ille s
(Figu es 7–9), he esul s om he spec a a e shown in Table 8. No unc ional g oups
ha could o igina e om a i icial sali a we e iden i ied, pa icula ly phospha es and
chlo ides (Table 4). Only he p esence o ni ogen and silicon compounds om he APTES
su ace modi ica ion p ocess was con i med, which we ha e al eady obse ed in p e ious
s udies [
23
]. The obse a ions om FTIR we e ela ed o he esul s om he EDS, which
a e shown in he able (Table 8). No signi ican di e ences we e obse ed o any o he
samples. The e ec o su ace modi ica ion o all ypes o ille s (p esence o N a oms)
is well isible. On he o he hand, a ace o he deg ada ion p ocess is appa en due o
he p esence o K and Cl ions, which may o igina e om KSCN o KCl. Howe e , no
co ela ion can be s a ed wi h ce ain y as o which ypes o ma e ials ha e a highe a ini y
o abso bing compounds om SBF. The obse a ions o FTIR we e also co ela ed wi h
he esul s om MS (Figu e 11A,B). No e idence o PA-12 deg ada ion in SBF was ound in
he es ed a i icial sali a samples a e ageing.
A compa ison o he e ec o ageing on mechanical p ope ies was pe o med o
samples om ea lie s udies [
22
,
32
] and samples om his s udy ha had been aged bu
no s e ilized (NS_Se ies). We ob ained he ollowing esul s:
•
o composi es wi h Z O
2
, o composi es wi hou ageing he alues we e
E = 0.63 GPa,
UTS = 11 MPa, elonga ion 9 %, HVIT = 11, HIT, = 120 MPa; while o composi es a e
ageing: E = 0.64 GPa, UTS = 18 MPa, elonga ion 24 %, HVIT = 9, HIT, = 100 MPa;
•
o composi es wi h Al
2
O
3
, o composi es wi hou ageing he alues we e
E = 0.62 GPa,
UTS = 13 MPa, elonga ion 14 %, HVIT = 17, HIT, = 175 MPa; while o composi es a e
ageing: E = 0.48 GPa, UTS = 17 MPa, elonga ion 23 %, HVIT = 15, HIT, = 125 MPa;
•
o composi es wi h CS, o composi es wi hou ageing he alues we e E = 0.82 GPa,
UTS = 21 MPa, elonga ion 10 %, HVIT = 29, HIT, = 302 MPa; while o composi es a e
ageing: E = 0.68 GPa, UTS = 21 MPa, elonga ion 10 %, HVIT = 27, HIT, = 290 MPa;
Polyme s 2022,14, 3152 18 o 21
Hence, i can be concluded ha he composi e wi h CS is he mos suscep ible o
changes in p ope ies a e ageing. O all he composi e a ian s, i is in e es ing o no e
ha PA_12_CS did no change elonga ion in ension— o he o he s, a clea inc ease in
duc ili y is appa en . This is mos likely ela ed o he olume o he ce amic ille —wi h
an inc ease in olume, a dec ease in he composi e’s plas ici y and a dec ease in he alue
o Young’s Modulus is obse ed. The analysis o he e ec o ageing shows ha , in gene al,
E-modulus and ha dness dec ease and he composi e becomes mo e duc ile (PA_12_CS is
di e en due o he signi ican olume sha e o CS, making he composi e s i e ).
Mo phology changes we e obse ed in SEM mic og aphs (Figu es 12–15), which
co ela ed wi h he esul s om he mechanical es s. In uns e ilized EO composi es,
elonga ed PA-12 ibe s a he b eak h ough we e obse ed p o ing highe duc ili y o
NS samples in compa ison wi h S samples. This obse a ion was mos appa en o
PA12_Al2O3_NS samples in Figu e 14A. In con as , hese di e ences we e no obse ed
o composi es wi h CSs (Figu e 15). This can be explained by he ac ha CSs ha e a highe
deg ee o packing in he polyme ma ix and mo e andom dispe sion han zi conia and
alumina, which is also e iden om he dispe sion compa ison images
(Figu es 16 and 17)
.
This obse a ion co ela es wi h ou obse a ions om he g anula e p epa a ion p ocess
o he ilamen . CSs agglome a e and do no mix e y well in he ex ude wi h PA-12. In
ou ea lie wo k we poin ed ou ha he maximum weigh pe cen we could add was 20%
CS o 80% PA-12 [
32
]. The e o e, his could also be he di ec eason o his beha io o he
PA12_CS_NS/S samples. We can guess ha his is mainly due o p oblems wi h we ing o
he CS su ace by he liquid polyme and poo adhesion o he ce amic o he polyme .
Polyme s2022,14,xFORPEERREVIEW18o 21


alsoe iden  om hedispe sioncompa isonimages(Figu es16and17).Thisobse a ion
co ela eswi hou obse a ions om heg anula ep epa a ionp ocess o  he ilamen .
CSsagglome a eanddono mix e ywellin heex ude wi hPA‐12.Inou ea lie wo k
wepoin edou  ha  hemaximumweigh pe cen wecouldaddwas20%CS o80%PA‐12
[32].The e o e, hiscouldalsobe hedi ec  eason o  hisbeha io o  hePA12_CS_NS/S
samples.Wecanguess ha  hisismainlydue op oblemswi hwe ingo  heCSsu ace
by heliquidpolyme andpoo adhesiono  hece amic o hepolyme .

Figu e16.Dispe siono ce amic ille sin hepolyme ma ix o (A)PA12_NSand(B)PA12_CS_S
samples.Visibleimpu i ies om hezi coniainjec ionmouldingp ocesswe e oundinPA12samples.

Figu e17.Dispe siono ce amic ille sin hepolyme ma ix o (A)PA12_Al
2
O
3
_Sand(B)
PA12_Z O
2
NSsamples.
Wi h ega d owa e abso p ion,wewe eno su p isedby he esul s.Pu ePA‐12
p o ed obe hemos abso ben , ollowedbyPA12_Al
2
O
3
,PA12_Z O
2
,and hen
PA12_CSsamples.Theabso babili yismainlya unc iono  hedensi yo  hece amic
ille .Aninc easein ille densi yinc eases heabso babili y(in e sely oi s olume).
Figu e 16.
Dispe sion o ce amic ille s in he polyme ma ix o (
A
) PA12_NS and (
B
) PA12_CS_S
samples. Visible impu i ies om he zi conia injec ion moulding p ocess we e ound in PA12 samples.
Wi h ega d o wa e abso p ion, we we e no su p ised by he esul s. Pu e PA-
12 p o ed o be he mos abso ben , ollowed by PA12_Al
2
O
3
, PA12_Z O
2
, and hen
PA12_CS samples. The abso babili y is mainly a unc ion o he densi y o he ce amic
ille . An inc ease in ille densi y inc eases he abso babili y (in e sely o i s olume). The
densi ies o he ce amic ille s a e 5.70 g
·
cm
−3
, 3.95 g
·
cm
−3
, and 0.84 g
·
cm
−3
o Z O
2
[
35
],
Al
2
O
3
[
36
], and CS [
32
], espec i ely. Tou is e al. epo an abso babili y alue o 0.693%
o he PA-12 ca he e jacke composed o G ilamid L25 (PA-12 by EMS-G i o y) a e 48 h
o soaking [
37
]. He e, we epo an abso babili y alue o 5.71% o PA-12. This can be
explained by imp ope d ying o PA-12 be o e g anula e p epa a ion and he p esence o
esidual mois u e in bulk PA-12.
Polyme s 2022,14, 3152 19 o 21
Polyme s2022,14,xFORPEERREVIEW18o 21


alsoe iden  om hedispe sioncompa isonimages(Figu es16and17).Thisobse a ion
co ela eswi hou obse a ions om heg anula ep epa a ionp ocess o  he ilamen .
CSsagglome a eanddono mix e ywellin heex ude wi hPA‐12.Inou ea lie wo k
wepoin edou  ha  hemaximumweigh pe cen wecouldaddwas20%CS o80%PA‐12
[32].The e o e, hiscouldalsobe hedi ec  eason o  hisbeha io o  hePA12_CS_NS/S
samples.Wecanguess ha  hisismainlydue op oblemswi hwe ingo  heCSsu ace
by heliquidpolyme andpoo adhesiono  hece amic o hepolyme .

Figu e16.Dispe siono ce amic ille sin hepolyme ma ix o (A)PA12_NSand(B)PA12_CS_S
samples.Visibleimpu i ies om hezi coniainjec ionmouldingp ocesswe e oundinPA12samples.

Figu e17.Dispe siono ce amic ille sin hepolyme ma ix o (A)PA12_Al
2
O
3
_Sand(B)
PA12_Z O
2
NSsamples.
Wi h ega d owa e abso p ion,wewe eno su p isedby he esul s.Pu ePA‐12
p o ed obe hemos abso ben , ollowedbyPA12_Al
2
O
3
,PA12_Z O
2
,and hen
PA12_CSsamples.Theabso babili yismainlya unc iono  hedensi yo  hece amic
ille .Aninc easein ille densi yinc eases heabso babili y(in e sely oi s olume).
Figu e 17.
Dispe sion o ce amic ille s in he polyme ma ix o (
A
) PA12_Al
2
O
3
_S and
(B) PA12_Z O2NS samples.
4. Conclusions
In his s udy, we e alua ed he e ec o a i icial ageing in SBF o PA-12 composi es
wi h zi conia, alumina and CSs. The ageing model was calcula ed acco ding o Hamme -
lich’s modi ied A henius kine ic equa ion. The a i icial ageing es was calcula ed so ha
he en i e deg ada ion p ocess co esponds app oxima ely o he exposu e o human sali a
a 37
◦
C o 365 days. The ollowing conclusions we e d awn om conduc ed in es iga ions:
1. in all o he p epa ed composi es, changes in he alues o mechanical p ope ies
2.
as a esul o a i icial ageing ha e been obse ed; in compa ison o ea lie
s udies [22,32],
a dec ease in he alue o he Young’s Modulus as well as comp ession se and UTS
ha e been obse ed; in con as , he UTS o non-s e ilised PA-12 samples inc eased
a e ageing; i is di icul o disce n any co ela ion be ween he ageing p ocess and
changes in mic oha dness and ha dness due o la ge a iabili y; he e o e, u he
s udies a e equi ed;
3.
EO s e ilisa ion ended o cause de e io a ion o mechanical p ope ies. Howe e ,
in he case o ha dness changes he e is a la ge a iabili y, hence u he esea ch is
needed on his opic;
4.
sligh in e ac ion wi h a i icial sali a was ound du ing ageing in PA-12 and compos-
i e samples as e idenced by he p esence o K and Cl ions obse ed using EDS;
5.
a i icial sali a es ing wi h MS a e ageing did no e eal he p esence o PA-12
b eakdown p oduc s o any composi e componen s;
6.
in he case o PA-12 wi h ce amic ille s, he abso babili y is a unc ion o he ille den-
si y. The sample abso babili y is g ea e wi h inc eased densi y and
dec eased olume.
Au ho Con ibu ions:
Concep ualiza ion, D.S.N.; me hodology, D.S.N.; so wa e, L.P., K.E. and
M.H.; alida ion, D.S.N. and F.K.; o mal analysis, D.S.N. and G.S.; in es iga ion, D.S.N., G.S., M.A.,
F.K., L.P., K.E. and M.H.; esou ces, D.S.N.; da a cu a ion, D.S.N., G.S., M.A. and F.K.; w i ing—
o iginal d a p epa a ion, D.S.N. and G.S., w i ing— e iew and edi ing, D.S.N. and M.A.; isualiza-
ion, D.S.N. and M.A.; supe ision, D.S.N.; p ojec adminis a ion, D.S.N.; unding acquisi ion, D.S.N.
All au ho s ha e ead and ag eed o he published e sion o he manusc ip .
Polyme s 2022,14, 3152 20 o 21
Funding:
The esea ch was pa ially suppo ed by he Rec o ’s o The Silesian Uni e si y o Technol-
ogy Habili a ion G an 07/020/RGH20/0062 and G an o Polish Minis y o Science and Highe
Educa ion 07/020/BK_22/0073. This wo k was also pa ially suppo ed by he p ojec IT4Inno a ions
na ional supe compu ing cen e—pa h o exascale p ojec (CZ.02.1.01/0.0/0.0/16-013/0001791) and
“Science wi hou bo de s” p ojec s CZ.02.2.69/0.0./0.0./16_027/0008463 wi hin he Ope a ional
P og amme Resea ch, De elopmen and Educa ion, Minis y o Educa ion, You h and Spo o he
Czech Republic SP2021/106 and SP2022/31.
Da a A ailabili y S a emen : No applicable.
Acknowledgmen s:
The au ho s would also like o hank EVONIK and Philip Engel o p o iding
he polyamide (VESTAMID PA12 E onik) samples o es ing.
Con lic s o In e es : The au ho s decla e no con lic o in e es .
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