提高聚乳酸熔体强度的研究进展  

Progress in the Improvement of Melt Strength of Poly(lactic acid)

作　　者：苏思玲[1] 赵吉洁[1] 柏大伟[1] 杨斌[1] 

机构地区：[1]上海交通大学化学化工学院,上海200240

出　　处：《中国塑料》2007年第8期7-12,共6页China Plastics

摘　　要：主要综述了提高聚乳酸(PLA)熔体强度的4种方法:共聚技术、反应挤出技术、射线辐照技术以及纳米技术。研究表明,共聚技术存在许多问题,例如共聚单体价格很高、反应过程比较难控制等;反应挤出技术目前常用的支化剂主要是包括带有3个或多个官能团的异氰酸酯、酸酐、环氧化合物、有机过氧化合物等,这种方法关键在于支化剂的选取和用量的控制;射线辐照技术目前使用最多的是电子辐射和γ射线,交联剂一般选用含有两个或多个双键的低分子化合物,其中具有丙烯酸类交联助剂最为有效;通过纳米技术制备 PLA 纳米复合材料在剪切流动中表现出流凝性,在拉伸中呈现应力硬化性质,具有高熔体强度,可制备高倍率挤出发泡片材。In this paper, four methods to improve the melt strength of PLA were introduced： copolymerization, reaction extrusion, radiation crosslinking, and nano-particle blending. Through copolymerization branching structure was introduced, however, the main problem was the high price of monomers and the uncontrollable reaction process. During the reactive extrusion branching agents were used, including isocyanic acid, acid anhydride, epoxy compound, and organic peroxide. The key points of this method were the selection of branching agents and the control of their dosage. In the radiation crosslinking PLA was subjected to irradiation of electronic or γ-ray in presence of cross-linking agents, which were compounds containing two or more double-bond with acrylic acid being the most effective. PLA nanocomposite showed rheopexy at shear flow and stress hardening at extensional flow, and had high melt strength, thus could be used in the production of high volume expension ratio extrusion foam sheet.

关 键 词：聚乳酸 熔体强度 共聚技术 反应挤出 射线辐照 纳米技术 

分 类 号：TQ320[化学工程—合成树脂塑料工业]