Research, standardization and practice in accelerated ageing tests

sP sw.dish Nationil Tcshn8 rnd Rcscarch In*itutc Polymo Tcchnol%y
Box 3sZ sE-501 r5 BoRAs.sweden
e
nail ĘmĆy jakubowiŹ@sp's
Research, standardization and practice in accelerated ageing tests
sumnary_Thc ircrc in3 usc of PolymcE in vłiols fuchnolosicalcnvj
ronmcnś rcquns undeBtandiĘ oI ihe dcglJdaiion Pheńońena and uhl
m cly.onbolling ihcm Qucsio|s msmiat.d with płfońan€,.os, duB'
biljiy and environnental efi€e łre dosely relabd to each othq ind muśbe
aNwercd b.for. ihe indlsry ańd the .onsJmels .an adoPi new n .rials
olfu., d'r lse Óf a<elerar.d ageinE lesb .onśjfuhs the only pcsibility b
ploduĆ_Ansslrabl.degradation żn
evel, predi.tioń of selvice lifą 6PŃall], fo. ńatc a]s .xFeded t Periom
f' 'i d'""d ' I J oll nu'rr.h|uPńB.
'el'żbv ln this
PiłIalls.
PaPeł example ol ilE many yeaĘ' wo!* wilh ł.eletated
less
lii€iine PredicliolT Ćłrtied out at sP sw.dish Nationłl Te*
I'Etil!t. are uŚ.d tÓ demonstatc somc pmbl€ms ańd Pit'alli
thai .an b. n.r with iń Pn.iice sońc c$ ń Plcs arc also given Ón insu1ficjcnt
information in jnlelńational *andards lo! aleilrg &sb' sPsńl itcnhon E
giveń to PĘdiction orscrrc lifc with onc d a point olly a5 wcll is thc
ińfiuen.. Óf differ.nt Prcvious hisiorv differcnt enviloinents and dillcrnt
saruahon mcthods on lilctimc prc
hlgh shs lĆvc]s ind Physi.al dePl.liol of dabilizcls
Key Uords: acrlcnild a8eing tesś'nathemari.al nodclling' durabilily of
miicń]s' Anhenius lelation,serui..lif.PFdi.rion
i€eing
ing
]d
]d Res.arch
.oBhntly indeasi.! usc of polvmms ń v.rious
rednolosi.al cnviroMcnb prcsenb an impo aniclal
lcngc to ihe Polymer i€.hnol%isk
'I1'€
mentol.cwm eliakłndprodu.
Proiding r Yientifi.
basis for und
,lahon Phcnonena and ułimai.ly
QlsiioN aso.iakd with Płfotńane, .oś,du'ab
oihł and mu* be ańswded bcforc thc indusiry
Ćo6!nłs can adoPt ncw mrie s'
and
lly
ih.
L.ńgrm pmfoman.c oI durab
''Ability of a Ploduct and its Pmk io Peńorn i6 tequiled
fulction ovcl a Pdiod of tim. and Lndł the jnflueD€ of
teh.ologi.al environm€nh" Thł. are hlo lundamcn.
blly dilloenl apPtMĆhs b modelljng thc dlnbiliiy of
nahials: empiri.al apprMch rh ar.npb b dsdibc
nathenati.aly "what has happcncd,, d predi.iive
aPPrrĆh whnh n bascd on ł młih
Óf d'e efie.b of dcPcndĆnt and ildependent variabhŚ
ańd the subsc]]ucnt rnncneni of the PrediĆtion based
]rle naforal (mrmal) teŚh art a basic reIcr.!rc lor
any aPPbach b ih. dunbiliĘ of Polyńcncn cńJls
con.cption "norńal'' i5 Uscd to lndud. conditions,
whi.h oc.Ur iń a sPNlfic ic.hnoloEi.il environmeni
whil. "sińUlited" enviromental
that the
sińulat.d cnvironment k
as Ćlose as FÓrsiblc
lhe PraĆli.al condilions' Il these.a
rhe Gsts and ih€ pnĆti.al aPPli.a
b
hme Ńalcs' Howev.i rhe u5. of
Produce neaśurablc dcg'adation łnd thc
dcn.d
maie
AĆĆ.lĆrahd ig.n]8 isb and extaFÓlatna1 Ń tcs !c
sults ĆÓńshfut. the predi.tive appr
achicvcdusi$highersrssrevcrsoioncormorcdegm
dahon ticroB r.lativc ro thc scrvi.c lilc conditions.
HowNcr, rhe liabiriry oi thc mcth
formation on detgioĘhon ratc .
Plope ies as rhc tundions or studure, .onpNition and
sh$ses The lack of inform.tion nakcs ilr. de!.loPńĆnt
ol exPleŚbn5 that .ompleiPly pre'liĆt perlorńanĆ.
, pror of actuar cxP6urc data diff
modll ńav ńorbc.ońP
ina 10Ę tem theńodynańi.scns!_
uij]it-a t]ris
Rabs ordeterioLaiion or many rmpo int pmpcrhcs
o' Pol],ńeń. ńaleialŚ ńł), be dcsdib&l b}, s_shapcd
fuPgł iśPlotĆd in
rom of dcpcndcnt vanibl. as a iun
lariablc' Induction is ł dcsnptor ol thc vihc "i" th
represents
ively the maSrih'dc oI ihc ind..
'lraniii
PńP.*]r chańge' lńdudiotr lhel .le
rcquĘdfurhcPn]dudn !nas '!
quantity
dcfo.s, or "obselvablc" Ćhan8Ćs, d'at
.onhouins stcP rs thai
pit
oI
*t.Ś
ł. ne6Mry
i''
of rhc d
0)
s
'!hłc]
ó l' udilr
'r
.r]łxo2
l/'
rl]rsł'l
ł/sl,
'l
P l}tl lv
sjołL, 1l
.JńlJr
'!ś
'llł.9l ''
RclationsoltheAheniusi([ńń
popeńies of somc m oHls ovcr l]nntcd tcmpcnfu.
nnEcs. Thcv ncitho aPPly io all m cń]s' noL io a]l
lroPgńcs ind may bc diflerent difieilnt tcmpdahm
ranscs Fu hemore, dqradarior i
bcr oI difloclt med[|isńs fu a
sonc or ill nuy lorlorv flP AnlEn
Iom' Dcspite of thł, th! Atrhcn
pmbably ttr only plo.ed ur. .u Fcnily
raPolarion of ac.crsarcd rscins r
.va, Labl.
ru ce
Óds to i llow .xhłPolation oI shońłimc dała t,
PĘdd lon8ł.In pelfornan.e, an aPPrÓptiato .Jlv.
In
nud
bc drcwn
.lcv
dmrEh thc sho
ed hńFclaforcs
tionlorth.Ćhcńi.al rcichon.nd tik lgloginthm 3n s
r/rrB
]/r thcn g]vcs i ł'iiEht linc
l'\t=(E/R)
wh.l.i i: ll/ll ,ll
d] tlr nl)Yń łŁł ;J ,]]l
i1rdi'| t1nna nl ń 'łł..l,/
tu nB r| lh! inllPdrldr !ńrbl!
Equabon (2) pcmib pr.,lrtion or thc,lunbiLity ol
Plot of
^ E/n md is knowD
sloPc
boninsporion Thcindcpcndcntlariablc,vhi.h idsis
rrrc drvins forcc ror ilrc dcgr.darion readion, may be
liFht (U!', x{iy' ), t.mP.ratłe' .hemi. s or physi.al
śres.sln moł o*s, tlrc ind.p
śńjghr lnre The sloP! of rhc lińc
idjYation energy of the dqżdahon Prorcss Exti},o]i-
thcPQPsty"'"jntmsofth.cxF
ro
synĆrgi*ic dfcc6. lI n
ij\Uńs
śN|
gcneralfuńWithNquiho|s
bc
wl'er.i i- ] .N,ŁlrT] ,ńdlrr if 1 hII
tnn^ furt),'l rhanlk fu,rtr,n.'
}'c$nt.d
l!
h!
d
nr
Ar
Ę1 sil]nłd
I]ddli,'.I./ui.ol m.'i]ń q,rs.Jis fJ l]|]' hdJł.
\ ifuJn^dns lh ĘK,i\! wdn dM lr tl0ni l n], ir trcI:lln
i),q |Udill a| llt ot ||!lkn a| dnndłisli: 3) ar
łt ) i1| di\1 llrśwń ,o hr ilfutrlnlij an tł|pnrn)
For
('4)
i sinPl.
!żsc oI N homo8dr,uŚ lqlatn,nsand
naybc.ak!laled łr hvo difiE
r.,/r r
i /Jr)
nÓn
.qljlibriun pnss.s,
/ (..r
rli:
l s
\'ith
is rhc
pon]6 c oblłijrcd by sclc.tin8 an ]ppiopriat!
end_poi'{ d cnon oI a diii!żl Ptop.frl At l.ł* Ioll
mc
cxt.mcly l.n3 iim.s, bur.onsldcrihof nnEt Lrc gtun to
t]t risl d olhc. liłoN rvlich might.iuse deviłtj.n
łon th! Po]cd.d {railht 1i!e' Iti
whd'.h(x,ns cl.v ed hmleraru
dEglad3hon medłnisms.th& tha
rordihon in thc usc
oIthE tchIiL]U! ]s a(óo|iblc knowh!]gc ofboih ihc
u|dulyinE .heńiśly and thc ń
Thc ploćedllc dcscrib.d ibovcis valid 1or ńes|m
plĆ$ (jd.il) siiuatiol, \vhi.h oft!
rare dl ch rsc of a imporani d
el!ńbd śrcs jcv.k
hysi.il chin*cs arc
sPedcd uP e']ualL' Ź5 the tcnPcĘ
other .ontmveĘv lnvolvcs ihc łsumPIion dmt ihc ell!.
iive adi!łtbn cncrgv of the degradatiotr plm*s is ijk]!
PeM.nr of tnPcaturc and ag.jĘ timc
/ lr r !r/
so.\(
y nitur. jnvolv.s
wiih sonc Padical
Ił..ddion of seivi..liIi eśPoriany fu n3brials
P{bd to perlom rcliablv 1or ńan
ex
iinuiĘ
all.ngą wliĆn ÓnbiN nany Pit1al]5. one of
tlen js Lse of ae.leraEd aEeińg lesb at one sbes lcvcl
EńkinA o io' pas/fail dmision on difIoent mih.
The kcy to seled ań activati,n en
]Ęaldcd as .oNeNative j5a knovlcdgc łbout th. dis
bibuhon of a.tivJtjon cncĘles of thc speilicd type ol
'o!als without corejdoaiion ol adivation enł8y' In Plać. mabdals. In Fi8ure 2 lhe IrequenĆy dktibLrion of adi
of e*ablishi$ ihe Arrh€nius diagram {'m a8.ing ei
Varion encĘis ol225 diffarent maĘrńLs js P!ścntcn
ai
diIlerent
Mp.iafores,
ii
i9
often
]n thc
Paimen6
Pra.tiśed lrj kis cvideni ńat lhg nośfrquent valucs
nry an,l an ffiumcd
Fn8e 90 120 k'lfrolc but thc {holc Ił|8c'rc
iNlud€s
sloPe (óĆbvation eneĘy). lf the sloPc is selRhd rnseF
values fion 20 b 200 *j/nolc Many engineere aM
vatively (low acńvadon cnggy) thc nsk lhat thc he s.icntishar.usinga "ruleof ihumb" inselcdion of tiń.
adivation encrgy is lows is ninimal and the expeded
d tmp.ralut irr acccleratld a8ciĘ iesb nlis tllc
klls thł if thc tmPenfure n in.resed by ]0 K, $Ć laic
rełdions is doubled (the tino halved)
ll is indicated in Fig' 2 when ttis aŚlmPtion i! hc of
.Ó!6c thc rNl.iłtiÓn fa.br (1) dePcnds on Jchlaiion
eńelgy and on the emperafure rang. fu shovn b]' ihc
hńc baBformatioń fuńciions (Tablc l )
Ó1de8radadon
rig 1 ' Lł.Irt aal'Lial !siń| aE drk Prnł
qrow alwbts lcrinati dwsi]s u 7a
100 k]kolt,3 130 k]knk); lłl ti1n d ,a
ya's,2 33va6,3
193
rdt
Fi8uIP 1 shows the cons€qu.m€
of variÓJs a.tivation
enłgi€s (Eł) on li1etińe PtediĆtion' U5in3 tińc bansfoF
70 oc
onsponds b
6
thał onc month
ihc lifchmc oI5.s yeaE
ar 20
t
for
**'Ę""'..,lł
ńak wiih Ei = 70 k]lmoh, it corsponds b33
'l mbial wiih ad = r0o kllmole and io 193
ycaB for the
r]gas lol a maerial wiilt Ę = 13o k]/nole
the
ł is generłlly le.oEnizcd thai thc seŃi.c lifeiinc Pr*
diction k varid fo! a givcn Poly
8iven serviĆe onditiolB o$. ln lhe lollowing enmPlrŚ
rhe various I6uhs' which ako al. ol signifi.łle, are
Th.sańe n.l.!id, difigrenipreviDuŚhistÓry
r
New ndoor Profiles ńadc of rigid Pvc hivc becn
dudied aftd vanous numbeN of repeated extusions
(me.hańi.al !R]'din8) in oder to g n knowl.dBĆ abÓlr
rhe chan8c of pmpeńi€s and durability łItlr ą'1vd'
riotur procesins t2t
Fk' 2' F,.q!.ncy dishfuub'| a| r.lifrliDn ł|i!s (EA) oi The a.hvłiion .fuĘi6 Ó1the
.ss in darł włe dde!ńjncd io!
225 dł.i|em. palańtn ltabtk) A k1ldtinnrldt
rh
Thc oxid ive degrad ion or PE N oftcn rollo$.d
$ing IR spĆdrt,koPy measltem
r. \Pcdlm
Th.. bo
rabsorbi
F4 3 E||-l ł NrdŻr ttakn a| Ńn PvC rl Klńr, l
olłxv G) a| !L.|R1dr!|t1rljrt
r
r
re
iÓ de.rease łith infleaJn8
Fi8
mber ofethnsions Gc.
3) The adivatiÓn elc8y
lxtusion
rd
wsc louńd
aatc! five
a5 rzB kj/nolebut
Ćiłusions ih. concsPoIding val!c !vas
The sane
ńł.!ial, dirfgrentenvnonmcnb
99k|/ńole ThiśinvoNes lh. ovm
hmcby ; facroruPb3'óiilve sumclh.tlh.ńĘivalue
isvalid indcpcndcntorrhe n!mbdor.xtnsions.
ildiĘs
alkaline .nviromenr
m Vaponr
.rc cdbyv
wcrcinv*tisakd wiih iespc.t
.oncrclc
!
rd nr nrojśail' Th!
to
thcrducbil ybr';c
rłe ol degia'lation
in thc
aranbi.nttumpen
iulewmnuchhrghcrth rĘńoiltairl3]'Butahothe
łdivation enel8), wis highcr ln W
ńrńt(]3ó kJ/ molc comParcd io rr3 kl/ńol.) lnlp eof
hR! rŚ.il| r| PE.I'D ll dlll!|1Śn,nn) rl
lbol!] l|l.l (lr))ldrp rł. ] ga''c,
.łrbonyl jide! Fi8Ule 5 shows that onitol
iiB or thc d.8(c of dcs'adation b
bonyl ord i hon producb dos not
surts oI thc clong ion at brcak nmsurclrcnis l1l Thn
r(.nfuats ihe inpołance of th..oiIcdchojc.of cjń
cl PoPct], 1or the eval!łion oI a3!n]3
leired
!
5
Fi! ,1 L1IldŚ lt ud
klanlrliń rl bnnb i
ihc
lid th
thc
rrt x |l1 t
|E 9a'c
hf.bńc (clongatiotr
lildinc in noist ań (Flg
10't giv* a liletime or 66 yc
Óncrebbul5] ye s i'rmoisl air
ule
s
to as
PrrdiĆtion ol !ubbcls ljfcńńĆs js
at break >400
?J of
inFo antlorfic
Flctcd to pcrlon rchably lor ń
p.ldcnton a..elerakd a8eing tcsis ind cxhaPohtńn
oi tc* rcsulls Ac.e]eniion is łch]cvcd usjng hi8hq
śrc$lcvPls ofone or more de€ndrtion fa.toś Ęla
tivc to the scrvkc lifc .onditions. whcf choo5inE
o1vitrljnpo arccló] Aftc! PcdÓds of ageilg, lhe elon'
garion ai brak rtr measumd The Esulb cl.arlv dG
ńoBbai. tlai forc€d{ir ovcB (hc tyFc usdd Predoni
nańdy).an Ćalse a sigńili.ant
a
an tiox
idin l loss by eVł
Anothc! imponant physiol tanspo Plmss rh
on innucn.e lifetinc Pcdiction of Polyńeric mai.riak
EĘ 6 cń!,Ęskl łl 0|,l1ryhrthlwl.tldi,Ę kryru
,ht (EPDM) łLh. A ha1ils plat
j. a (clera
leśs i t ń ińPhysi..l łnd
cheni.al PtÓ.€ses o.cu. sinultanćolsly vh.n i co|.
śantstess iŚ inposed on rubber Generally, ph]rsj.al
cffcds ale doninantatsho rimcs rnd low hnpen
iules Jnd cheńical eIf{ts ar€ molc aPp cńl ar IonB
iimes and high tenP.ratlr.s If ac.€leEtcd condi
iions s uch .s glgvatcd tcńpeB turą are used i t follows
'
thal resu1bcould be ńiśleading' 1n FĘure 6, a dcvla
drłied is a rcsultof
oo
(>r25
too hiSh iemPPmturc
l5l.
h
igher *reŚ levels
ted ag.ing
l Ievek '
[i!a
lc
5a
Mi.!|Li"n
rh.
a| l t^'nfu łlźdfun1a76) i) PErl
f\trs lrna lot tht txttti,
ltp łnl lhÓltltrl sohłj'6 { .nł'śao'd
solin .wUts
is deplerion of *abilters by nigr.tion or difiusion. In
one of &e nośfrequendy uscd a
ovcn ageing ai Śelebd fumP.nfu
exańination of 6\e naterials' ch
ProP hes irc o'tcn lsed to fÓllow iI. .onBe
o1
dcgra'
FĘUt.3 lh. Ón.entation Prolil6 oian łniio\idintini
danr which Ms oc
iadc.yl stc! (lĘanol r 076) was Pres
themiddleof thc*ackarthe.one
lilm sb.k wis then hcłłcdat 50'c ind the.on..nba
tiof or the iniioxidanr in padr rilm in th. stick was
measurcd łnel various periods 17] li is dcmonst cd
lhat the .on.enkation nr ih. doPeLl films i5 r.du€d to
haU or the onginal value aner 72 houE onlysholviv th.
.rucialmpo in( of ihis Plo.css fol rhc Iifdtińc predi.
ln lhc
dsiln
of lifchn. hs6ng' Idlowins Ćliti.al
_consilcntiol
tibutc
FiŚ'7
anl rŚńlxa|PE.ĘŃ,I rń fu!
u h] !(a2 lnnn rń hkh
nl Rbirds
1aa n|nnn 0n
to thc
of all ihc lacton Nh(h ńlght co|
of thc PEdUct Ę lhc ińbńd*l
deAlad ion
D€sriPtion
Óf the
At.lerated teŚti'u
accclc.ihon coeańdenl
Consbudion ol modcls and h,lurc {undions rir
lhc rśPons. of thematoiil io ihc
on rhc r.celerated rest r?sulb and thc cnvrcnmcniil
the achvaijon cncr8y or
dation Tnc in Potancc oI a proPe! sclecńon o1 rhe nÓ*
ŚigniIidnt Ia.bE.ausing d€8ladahon is deff oŃkabd
in Fis. Z wn.r. orc air speed in thc
ne.haniJm of ihe dcgRd (n
in Ótdł tÓ dofine ihc mo* sig:
326
3B
Dixon R.. "Corsbu(rils .n arhaius plor hth
onry ore D'b poinr', w$bnqhrue EkEn cd@o
Y&annidl N'' JallboĘje l , G€tl T' Pobn' DŹ
sńr gń'm0l'?3'93'
]alQbo{c l' "lnnuenc oJ MoiśrcomĘ on the
Dmb iy of Polyns", s.nlMr ar ch']Ęs !.!_
vmity
of
T.Ćh&lq)" Gothg.bfĘ (sw.den), Mddr
tahbowie r,: "tnJlla.e orw.t cmeb m OrDunbilirt of polylur FinE", vrn rntufio.ar con,
on Polyńgs in col@Ę oGĘld€ celquhJ
{thJuł 1995'
l.kubołie I' Lhdgrs A': ,Theb!łafue Lj_
mib ot Rubbffi h cobprsim", pcr; Disenbli@}ubbfu Ę Goń.r'buĘ (s$€dmt, r]th May
g
l',
johlBń
U''
-rh@l Afue
wind
'.LuloPbteuon Laym", Sp
<mlł16|or'
Móllą
'99a'
k'cidr'.
!' A?p]'
Tehnnl"Re;
Po]!
o.
sci'1g94,5L,s95'