借助ATRP法合成两亲性星状多臂h-PCMS-g-mPEG接枝共聚物

Synthesis of amphiphilic star-shaped grafted copolymer h-PCMS-g-mPEG by atom transfer radical polymerization

以对氯甲基苯乙烯(CMS)为活性单体,CuCl/2,2'-联吡啶(bpy)为催化体系,通过原子转移自由基聚合反应(ATRP)合成具有不同结构特征的超支化聚对氯甲基苯乙烯(h-PCMS),分别考查了反应温度、反应时间对所合成的h-PCMS的组成结构、相对分子质量分布指数和转化率的影响。在NaH催化下,以不同支化度的h-PCMS与单甲氧基封端聚乙二醇(mPEG)进行醚化反应,制得以超支化大分子h-PCMS为疏水性核,以单甲氧基封端聚乙二醇(mPEG)为亲水性臂的两亲性星状多臂接枝共聚物h-PCMS-g-mPEG。采用红外光谱(IR)、凝胶色谱(GPC)、核磁共振氢谱(1H-NMR)及差示扫描量热仪(DSC)等技术对聚合物的结构和性能进行表征。

A series of hyperbranched polychloromethylstyrene（ h-PCMS） with different branching degrees are synthesized by atom transfer radical polymerization（ ATRP） at 120℃ under nitrogen in the presence of CuCl /2,2＇-bipyridine（ bpy）,using chloromethylstyrene（ CMS） as both a reactive monomer and a high efficient initiator. The influences of reaction temperature and reaction time on the molecular characteristic features,i. e.,composition,structure, molar mass and polydispersity index as well as conversion,are investigated. Then,the obtained h-PCMS is used to react with monomethyl polyethylene glycol（ mPEG） in the presence of sodium hydride to prepare an amphiphilic star-shaped dobby grafted copolymers,h-PCMS-g-mPEG,where the core is h-PCMS and the arm is mPEG. The resulting（ co） polymers are characterized by infrared spectroscopy（ IR）,gel permeation chromatography（ GPC）,proton nuclear magnetic resonance spectroscopy（1H-NMR） and differential scanning calorimetry（ DSC） technologies.