预览加载中,请您耐心等待几秒...
1/6
2/6
3/6
4/6
5/6
6/6

在线预览结束,喜欢就下载吧,查找使用更方便

如果您无法下载资料,请参考说明:

1、部分资料下载需要金币,请确保您的账户上有足够的金币

2、已购买过的文档,再次下载不重复扣费

3、资料包下载后请先用软件解压,在使用对应软件打开

http://www.paper.edu.cn Amethodofenhancmentcrosslinkingeffciencyof ethylene-vinylalcoholcopolymer(EVOH)1 LiuMeihua1,ZhangWanxi1,LiHaihong1,DengPengyang2 1DepartmentofMaterialScience,JilinUniversity,Changchun(130025) 2ChangchunInstituteofAppliedchemistry,ChineseAcademyofScience,Changchun(130022) E-mail:Zhangwanxi0626@sina.com Abstract Preparationandphysicalpropertiesofethylene-vinylalcoholcopolymer(EVOH)crosslinkedby enhancedradiationhavebeenstudiedthroughvariousmethods.Itwasfoundthatthemosteffective agentforirradiationcrosslinkingwastriallylisocyanurate(TAIC)amongfourkindsofpolyfunctional monomers.65.6%gelcontentwereformedforEVOH-44(contentofethyleneis44mol%)at200kGy with5%TAIC,butforEVOH-32(contentofethyleneis32mol%),only37.4%gelcontentwereformed underthesameconditions.Thisresultshowedthatthemorethecontentofethyleneunitscomprisedin EVOH,theeasierthechemicalbondscouldbeformedbetweendifferentmolecularchains.Tensile strengthandelasticmodulusincreasedaftercrosslinkingathightesttemperature. Keywords:EVOH;Polyfunctionalmonomers;Radiation-crosslinking 1.Introduction Ethylene-vinylalcoholcopolymers(EVOH)areconstructedbyrandomsequencing hydrophobicethylene(E)andhydrophilicvinylalcohol(V)monomericunits.Thepropertiesof EVOHvarydrasticallywiththecopolymercomposition[1].WhenthecontentofEunitsisbelow 50mol%,EVOHhasoutstandinggas-barrierpropertiesunderdryconditionscomparedtoother polymericmaterials[2].SoEVOHisusedwidelyinvariousfieldssuchasfoodpacking,gasoline tanks[3].Anditisexpectedtoworkwellasoneofsoftmaterialsforecologybecauseofno emissionofpoisonousgasuponincineration. However,EVOHishygroscopicandtheabsorbedwaterinitlowersitsglasstransition temperature[4].Consequently,EVOHlosesmuchofitsabilitytoinhibitoxygendiffusion,which isundesirableinfoodpackaging.Introducingcrosslinkingbondsbetweenpolymermoleculesby chemicalorradiationtreatmentsisapowerfulmethodtoreducethehygroscopicity.Butfew studieshavebeenonthissubject.Inourpreviousstudy[5],wefoundthatneatEVOHwas difficulttoradiati