摘要
以O-溴化壳聚糖(CS-Br)为大分子引发剂,Cu(I)Br为催化剂,通过单电子转移-活性自由基聚合(SET-LRP),合成了壳聚糖-O-寡聚乙二醇甲基丙烯酸酯(CS-O-POEGMA),用原位核磁研究了寡聚乙二醇甲基丙烯酸酯(OEGMA)在不同聚合条件下的聚合反应动力学。结果表明:随着介质pH的降低,配体发生质子化,导致聚合速率下降;在缓冲溶液中,随着CS-Br浓度的升高,反应过程中体系发生凝胶化;pH=5.0的介质中,CS-Br中溴代异丁酸的取代度对反应动力学基本无影响,表明该介质中壳聚糖分子链较舒展,反应可控性最佳。
Chitosan through single electro C O[poly(oligo ( ethylene n transfer living radical (CS-Br) as an initiator and Cu(I)Br glycol ) polyme as the methacrylate) (CS-O-POEGMA) was synthesized rlzatlon catalyst. conditions was studied using insitu ^1H-NMR. Results showe (SET-LRP) of OEGMA, using O-brominated The polymerization kinetics under different d that with the decreasing of medium pH, the polymerization rate declined. When CS Br concentration was raised to a certain extent, gelation took place during polymerization. The degree of substitution of bromobutyrate groups in CS-Br had little effect on the polymerization kinetics in pH 5.0 buffer solution, suggesting the conformation of chitosan backbone was in an extended state and the controllability of the polymerization was the best.
出处
《功能高分子学报》
CAS
CSCD
北大核心
2012年第4期342-347,共6页
Journal of Functional Polymers
基金
国家自然科学基金(21174125
20974097)