Slightly Cross-Linked Polyrotaxanes Made by Linking α-Cyclodextrins Entrapped in Polyrotaxanes Using Hexamethylene Diisocyanate  

作　　者：李硕 王锦 姜岚 叶霖 张爱英 冯增国 

机构地区：[1]School of Materials Science and Engineering,Beijing Institute of Technology,Beijing 100081,China

出　　处：《Chinese Journal of Chemistry》2012年第10期2453-2460,共8页中国化学（英文版）

基　　金：This work was supported by the Natural Science Foundation of China （No. 20974015） and the Doctoral Program Foundation of Ministry of Education of China （No. 20091101110029）. Wang Jin also thanks the sup- port from YUMIAO foundation of Beijing Institute of Technology.

摘　　要：In this study polyrotaxane （PR）-based triblock copolymers were first synthesized via the atom transfer radical polymerization （ATRP） of N-isopropylacrylamide initiated with the self-assembly of a distal 2-bromoisobutyryl end-capped Pluronie 17R4 with a varying amount of a-cyclodextrins （a-CDs） in the presence of CuCI/PMDETA at 25 ℃ in aqueous solution. The a-CDs entrapped on the copolymer chain were then linked with hexamethylene diisocyanate to give rise to novel slightly cross-linked polyrotaxanes （SCPRs） in DMF at 45 ℃. The structures of the PR-based triblock copolymers and SCPRs were characterized by 1H NMR, 13C CP/MAS, GPC and TGA analy- ses. The number-average molecular weight of the resulting SCPRs was nearly three and five times of their precursor after linking with a low polydispersity index range of 1.08--1.28. The thermo-responsive transition of both PR-based supramolecular polymers in aqueous solution was demonstrated by turbidity measurements and the self-aggregated morphologies were also evidenced by TEM observations.In this study polyrotaxane （PR）-based triblock copolymers were first synthesized via the atom transfer radical polymerization （ATRP） of N-isopropylacrylamide initiated with the self-assembly of a distal 2-bromoisobutyryl end-capped Pluronie 17R4 with a varying amount of a-cyclodextrins （a-CDs） in the presence of CuCI/PMDETA at 25 ℃ in aqueous solution. The a-CDs entrapped on the copolymer chain were then linked with hexamethylene diisocyanate to give rise to novel slightly cross-linked polyrotaxanes （SCPRs） in DMF at 45 ℃. The structures of the PR-based triblock copolymers and SCPRs were characterized by 1H NMR, 13C CP/MAS, GPC and TGA analy- ses. The number-average molecular weight of the resulting SCPRs was nearly three and five times of their precursor after linking with a low polydispersity index range of 1.08--1.28. The thermo-responsive transition of both PR-based supramolecular polymers in aqueous solution was demonstrated by turbidity measurements and the self-aggregated morphologies were also evidenced by TEM observations.

关 键 词：Α-CYCLODEXTRIN POLYROTAXANE ATRP poly（N-isopropylacrylamide） hexamethylene diisocyanate 

分 类 号：O636.12[理学—高分子化学] TQ633[理学—化学]