聚乳酸熔体中缠结网络的形成  

Formation of Entanglements in Partially Disentangled Poly(L-lactide)Melt

作　　者：刘小亭[1] 包睿莹[1] 李艳梅[1] 杨伟[1] 杨鸣波[1] 

机构地区：[1]四川大学高分子科学与工程学院高分子材料工程国家重点实验室,四川成都610065

出　　处：《高分子材料科学与工程》2016年第7期107-111,共5页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(51303113)

摘　　要：采用冷冻萃取法制备了不同相对分子质量的部分解缠结聚乳酸试样。通过流变学的方法实时检测了聚乳酸熔体中缠结网络的形成和发展演变过程。结果表明,部分解缠结聚乳酸分子链的缠结过程分为快速穿插阶段和慢速穿插阶段。同时考察了在可控外场作用下缠结网络的形成,结果表明,预剪切和快速熔融会促进分子链缠结网络的形成,而检测频率则对缠结形成没有影响。Partially disentangled poly（L-lactide）（PLLA）samples with different molecular weights were obtained via a freeze extraction method from the dilute solution of PLLA.The kinetics of entanglement recovery process of freeze-extracted PLLA samples was monitored by dynamic rheology approach.The changes of the storage modulus G′and the normal force show that the re-entangling progress can be divided into two stages,a fast interpenetration process and a slow interpenetration process.The formation of entanglements under controlled fields was investigated and the results show that the re-entangling progress can be accelerated by preshear and fast-melting through changing the molecular chain conformation and entanglement distribution.The testing frequency study shows no effect on the re-entangling progress.

关 键 词：聚乳酸 缠结网络 可控外场 

分 类 号：O631.21[理学—高分子化学]