通过 RAFT 聚合制备的 N-邻苯二甲酰壳聚糖接枝-(聚（N-异丙基丙烯酰胺）嵌段-聚丙烯酸)两亲性嵌段共聚物。

Dual stimuli-responsive N-phthaloylchitosan-graft-(poly(N-isopropylacrylamide)-block-poly(acrylic acid)) copolymer prepared via RAFT polymerization.

机构信息

MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.

出版信息

Carbohydr Polym. 2013 Jan 30;92(1):662-7. doi: 10.1016/j.carbpol.2012.09.003. Epub 2012 Sep 7.

DOI:10.1016/j.carbpol.2012.09.003

PMID:23218351

Abstract

In order to develop stimuli-responsive hydrogel, chitosan graft copolymer with chitosan back-bone and poly(N-isopropylacrylamide)-block-poly(acrylic acid) (PNIPAAm-b-PAA) branch chains was prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization in DMF. The chain transfer agent was obtained by modification of chitosan with 3-benzylsulfanyl thiocarbonylsulfanyl propionic acid (BPATT) with 68% the degree of substitute. The graft polymerizations possessed controlled/living characteristics. The behavior of the graft copolymer in aqueous solution was investigated by dynamic light scattering, transmission electron microscopy, and UV-visible spectrophotometer. N-Phthaloylchitosan-graft-(poly(N-isopropylacrylamide)-block-poly(acrylic acid)) copolymer (N-phthaloylchitosan-g-(PNIPAAm-b-PAA)) could assemble to micelles in aqueous solution in range of 200-300 nm with narrow size distribution, and the hydrodynamic diameter could be controlled dependent on length of branch chains and temperature. The LCST values of micelle could be modulated from 34 to 40 °C by controlling the constitution of branch chains, pH, and concentration.

摘要

为了开发对刺激响应的水凝胶，通过可逆加成-断裂链转移（RAFT）聚合在 DMF 中制备了壳聚糖主链和聚（N-异丙基丙烯酰胺）-嵌段-聚（丙烯酸）（PNIPAAm-b-PAA）支链的壳聚糖接枝共聚物。链转移剂是通过壳聚糖与 3-苄基硫代羰基硫代丙酸（BPATT）的修饰得到的，取代度为 68%。接枝聚合具有可控/活性特征。通过动态光散射、透射电子显微镜和紫外可见分光光度计研究了接枝共聚物在水溶液中的行为。N-邻苯二甲酰壳聚糖-接枝-（聚（N-异丙基丙烯酰胺）-嵌段-聚（丙烯酸））共聚物（N-邻苯二甲酰壳聚糖-g-（PNIPAAm-b-PAA））可以在 200-300nm 的范围内在水溶液中组装成具有窄粒径分布的胶束，并且水动力直径可以通过支链的长度和温度来控制。通过控制支链的组成、pH 值和浓度，可以将胶束的 LCST 值从 34°C 调节到 40°C。