ATRP法合成弹性蛋白接枝共聚物及其性能研究

弹性蛋白经α-溴异丁酰溴化制备了大分子ATRP引发剂溴化弹性蛋白(E-Br), 再以E-Br作为引发剂, 在CuCl/2,2-联吡啶催化体系下, 用原子转移自由基聚合方法合成了弹性蛋白-g-聚甲基丙烯酸-β-羟乙酯接枝聚合物. 用红外光谱(FTIR)、X射线光电子能谱(XPS)、热重分析(TGA)、扫描电镜(SEM)、离子色谱和动态接触角对接枝聚合物进行了表征. 结果表明, PHEMA键接到了弹性蛋白表面; SEM显示接枝改性后弹性蛋白的表面比未改性前光滑, 但改性后样品的热性能均比未改性样品的低, 起始热分解温度由改性前的307 ℃变为265 ℃; 动态接触角实验结果表明, 接枝改性后的样品具有良好的亲水性, 反应72 h后, 其前进角由接枝前的130.45°下降到29.80°.

Synthesis of Elastin Graft Copolymer via ATRP and Its Properties

Elastin was modified with 2-bromoisobutyryl bromide to prepare macro-initiator and subsequently poly(2-hydroxyethyl methacrylate) was synthesized by atom transfer radical polymerization(ATRP) method initiated by the macro-initiator. The graft copolymers were examined by using FTIR, XPS, TGA, SEM, ion chromatography and dynamic contact angle test. The results show that PHEMA has been covalently bound to the elastin. Although SEM suggested the surface of ATRP-modified elastin was much smoother than that of the unmodified samples, the thermal stability of modified samples was slightly lower than that of unmodified samples, and the initial temperature of thermal decomposition changed from 307 ℃ to 265 ℃. The dynamic contact angle test shows that the modified elastin was hydrophilic and after polymerization for 72 h, the advancing angle of elastin decreased from 130.45° to 29.80° and contact angle hysteresis reduced from 70.42° to 29.80°.