聚乙二醇_聚对二氧环己酮两亲性嵌段共聚物的合成及其自组装.docVIP

  聚乙二醇/聚对二氧环己酮两亲性嵌段共聚 物的合成及其自组装# 吴刚，刘菖蕾，陈思翀，王玉忠** 5 10 15 20 25 30 35 40 （四川大学化学学院，四川省降解与阻燃高分子材料高校重点实验室，环保型高分子材料国 家地方联合实验室，成都 610064） 摘要：本文以单羟基或双羟基的 PEG 为引发剂，在辛酸亚锡的催化下，引发对二氧环己酮 （PDO）开环聚合。通过调控 PEG 的分子量以及与单体投料比制备了一系列具有不同结构的 两亲性两嵌段或三嵌段共聚物。采用核磁共振（NMR）对共聚物的结构进行了表征，通过凝 胶渗透色谱（GPC）获得了共聚物的数均分子量、重均分子量和多分散系数等结构参数。采 用芘荧光探针法和动态激光光散射(DLS)对共聚物在水中的自组装进行了研究。荧光光谱的 分析结果表明，共聚物能够在水中自组装形成纳米或微米聚集体，其临界聚集浓度（CAC） 随疏水性的增强而减小，较小的 CAC 表明共聚物更容易自组装。DLS 结果显示当 PEG 分子量 一定时，聚集体粒径随 PPDO 分子量的增大而增大。 关键词：嵌段共聚物；开环聚合；两亲性；自组装；聚乙二醇；聚对二氧环己酮 中图分类号：O 631.5 Synthesis and self-assembly of Poly(ethylene glycol)/Poly(p-dioxane) Amphiphilic Block Copolymers Wu Gang, Liu Changlei, Chen Sichong, Wang Yuzhong (National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), State Key Laboratory of Degradable and Flame Retardant Polymer Materials, College of Chemistry, Sichuan University, ChengDu 610064) Abstract: Amphiphilic di- or tri-block copolymers were synthesized by bulk ring-opening polymerization of PDO using nomohydroxyl PEG or dihydroxyl PEG as macro-initiator, and SnOct2 as catalyst with different PEG molecuar weight and feed ratio. The structure of copolymers was characterized by 1H-NMR. GPC was used to determine molecular weight and molecular weight distribution of the copolymers. The self-assembling behavior of the copolymers were investigate by FS and DLS. The results of FS showed that the copolymers could form nano/microparticle aggregates in aquesous solution, and the CAC decreased with increasing the hydrophobicity of copolymers. The lower CAC indicated that the copolymers could self-assemble readily. The DLS results showed that the particle size, which increased with the hydrophobicity of the copolymer, was determined by the structure of copolymers. Keywords: block copolymer; ring-opening polymerization; amphiphilicity; self-assembly; Poly(ethylene glycol); Poly(p-dioxane) 0 引言 两亲性的嵌段共聚物自组装行为的研究现在已成为当今科学研究中的一个热门课题。其 组装机理主要是：嵌段共聚物的亲水链段溶于水中后，其疏水链段通过疏水作用自发的聚集 在一起，形成疏水的微环境。通过自组装两亲性嵌段共聚物