PLA_PBAT共混物的降解性能研究

第30卷第8期2016年8月中国塑料CHINAPLASTICSVol.30,No.8Aug.，2016PLA/PBAT共混物的降解性能研究张敏，孟庆阳，刁晓倩，翁云宣**(北京工商大学材料与机械工程学院，北京100048)摘要：通过双螺杆挤出机和吹膜机组制备不同比例的聚乳酸/聚对苯二甲酸-己二酸-丁二酯(PLA/PMD共混物薄膜，测量共混物的热性能、力学性能，并观察其相形貌，计算共混物在堆肥条件下的生物降解率，研究共混物降解前后的结构、热力学行为和元素的变化。结果表明，PLA与PMT是不相容体系，加入PBAT后PLA的韧性得到改善;PLA的生物降解率高于PBAT，共混物的生物降解率随着PBAT含量的增加而降低，且在降解初期，PLA的降解产物会促进的水解;PLA、PBAT及其共混物在堆肥降解前期只是大分子链水解为小分子链的过程，不发生分子链的结构变化;PLA及PBAT的降解会先发生在无定形区，共混物中PLA在无定形区的降解速度受到PMT的影响而变慢，且共混物中PLA、PBAT的降解行为发生变化，无定形区与结晶区的降解同时发生;共混物在堆肥试验初期的降解以水解为主。关键词：聚乳酸;聚对苯二甲酸-己二酸-丁二酯;生物降解率中图分类号：TQ321文献标识码:B文章编号:1001-9278(2016)08-0079-08BiodegradationBehaviorofPLA/PBATBlendsZHANGMin,MENGQingyang,DIAOXiaoqian,WENGYunxuan*(SchoolofMaterialScienceandMechanicalEngineering,BeijingTechnologyandBusinessUniversity,Beijing100048,China)Abstract：Inthisstudy,blendedfilmofpolydacticadd)(PLA)/poly(butyleneadipate-coterephthalate)(PEAT)waspreparedbyatwin-screwextruderandasinglescrewextruder.Thethermal，mechanicalpropertiesandmicrostructurehadbeeninvestigatedThebiodegradationrateoftheblendsundercompostingconditionwasmeasured?andthestructure?elanentcontent,andthannomechanicalbehaviorbeforeandafterdegradationwascharacterized.ItindicatedthatPLA/PBATblendwasanimmiscibles^tan,andtheadditionofPBATiriprovedtheflexibilityofPLA.Italsofoxondthat,thebiodegradationrateofneatPLAwasgreaterthanthatofneatPBAT,andthebiodegradationrateofPLA/PBATblendswasdecreasedwithincreasingPBATcontentFurthermore,thedegradationproductsmayacceleratethehydrolysisofPBATatthebeginningofdegradatioaAttheearlierstageofdegradationundercompostingcondition,thelongpolymerchainsofPLA,PBATandtheirblendshydrolyzedtoshortchainswithoutchemicalstructurechangeofthemonomers.ThedegradationofneatPLAandPBATinitiallyoccurredatamorphousphase,howeverthedegradationofPLA/PBATblendsoccurredatbothamorphousandcrystallinephasessimultaneously.Moreover9thedegradationofPLAchainsinamorphousphaseinblendswasdecreasedaffectedbytheadditionofPBAT.ThedegradationofPLA/PBATblendswasmainlystartedwithahydrolysis.Keywords：polydacticacid)；p