低分子量级分对熔体拉伸聚乳酸流延膜结构和性能的影响  

Effect of the Content of Low Molecular Weight Component on the Structure and Properties of Melt-Stretched Polylactic Acid Casting Film

作　　者：梁烨琳 田子钦 黄恒辉 谢嘉宜 徐睿杰[1] 雷彩红[1] Yelin Liang;Ziqin Tian;Henghui Huang;Jiayi Xie;Ruijie Xu;Caihong Lei(Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter,Guangdong Provincial Engineering Laboratory of Energy Storage Materials and Devices,School of Materials and Energy,Guangdong University of Technology,Guangzhou 510000,China)

机构地区：[1]广东省功能软凝聚态物质重点实验室广东省储能材料与器件工程实验室广东工业大学材料与能源学院,广东广州510000

出　　处：《高分子材料科学与工程》2021年第12期98-102,110,共6页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(52173033,51603047);广东省自然科学基金资助项目(2021A1515011914);广州市科技计划(2021020952)。

摘　　要：选取低分子量级分有较大差异的2种左旋聚乳酸(PLLA),比较了采用熔体拉伸工艺制备的聚乳酸流延膜的结构与性能的差异。实验结果显示,较少低分子量级分的存在有利于熔体拉伸场下聚乳酸分子链的解缠结,在低熔体拉伸比下更易形成类取向纤维结构,带来聚乳酸流延膜常温韧性和结晶性能的改善;解缠结后,在高熔体拉伸比下,形成的类Shish-kebab结构明显,带来流延膜高的断裂应力。通过对原料中低分子量级分及熔体拉伸流动场的调控可以实现聚乳酸流延膜的高强高韧。Two kinds of poly(L-lactic acid)(PLLA)with large difference in low molecular weight component content were selected.The structure and properties of polylactic acid(PLA)films prepared by melt-stretching process were compared.The low content of low molecular weight component is beneficial for the disentanglement of PLA molecular chains in the melt-stretching flow field and formation of oriented fiber-like structure under low melt-drawing ratio,which is conducive to improving the crystalline ability and toughness of PLA under room temperature.Under high melt-drawing ratio,the formed shish-like structure is more apparent,resulting in the higher stress at break.Through the control of low molecular weight component content in PLA and melt-stetching flow field,the high strength and high toughness of PLA would be obtained.

关 键 词：聚乳酸 熔体拉伸 类取向纤维 类Shish-kebab结构 

分 类 号：TQ323.4[化学工程—合成树脂塑料工业]