Hydrolytic and photoche mical aging studies of a Kevlar.pdf

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1、PolymerDegradationandStability96(2011)1411e1419ContentslistsavailableatScienceDirectPolymerDegradationandStabilityjournalhomepage:www.elsevier.com/locate/polydegstabÒHydrolyticandphotochemicalagingstudiesofaKevlar-PBIblendCarlosArrieta*,ÉricDavid,PatriciaD

2、olez,ToanVu-KhanhDepartmentofMechanicalEngineering,Écoledetechnologiesupérieure,1100rueNotre-DameOuest,MontrealQCH3C1K3,CanadaarticleinfoabstractArticlehistory:ThefocusofthisworkisthestudyofthehydrolyticandphotochemicalagingbehaviorofaKevlarÒ-PBIReceived13

3、October2010blendfabric.TensiletestscarriedoutonyarnsextractedfromthisfabricaftereitherirradiationwithUVReceivedinrevisedformlightorexposuretohighhumidityindicatedacontinuousdecreaseofthebreakingforcewithexposure11April2011time.ATR-FTIRanalysesofphoto-chemi

4、callyagedsamplesshowedevidenceofaphoto-oxidativeAccepted18May2011reactioninitiatedbythecleavageoftheamidebondofKevlar.Theoverlappingofthebreaking-forceAvailableonline25May2011curvesthatwasobservedastheirradiancelevelwasincreasedatconstanttemperatureisbelie

5、vedtobecausedbya“screen”effectproducedbyPhoto-Friesproducts.ThefactthatatconstanttemperatureKeywords:thebreakingforcewasunaffectedbythevariationoftherelativehumiditysuggeststhattheabsorptionKevlarPhotochemicalagingofwaterisnottherate-controllingstepinthede

6、gradationkinetics.ATR-FTIRanalysesrevealedtheHydrolysispresenceofanewabsorptionbandascribedtocarboxylicacidendgroupsproducedduringtheInfraredspectroscopyhydrolysisoftheamidelinkagethatoccurredafterhumidityaging.TherelativeintensityoftheeCOOHAttenuatedtotal

7、reflectancebandtendedtoaconstantvalueasexposuretimesincreased,suggestingthatinadditiontothehydrolysis,acompetingrecombinationreactiontakesplaceduringdegradation.Akineticmodelforthehydrolyticdegradationprocesswasformulatedandsolved.Ó2011ElsevierLtd.Allrights

8、reserved.1.Introduction[3,4].Thehydrolysisofpolyamides,itseffectonmolecularweight,andthemathematicalmodelsofthereactionhavebeenthoroughlyWithinthebroaderscopeofstudyingthedegradationofstudiedandarewelldocumen