硫代-iniferters法改性弹性蛋白的研究

弹性蛋白经对氯甲基苯甲酰氯氯化、二乙基二硫代氨基甲酸钠(NaSD)硫化制备了大分子iniferter剂(E-S), 再以E-S为引发剂, 在紫外光(UV)照射下引发甲基丙烯酸-β-羟乙酯(HEMA)聚合, 合成了聚甲基丙烯酸-β-羟乙酯(E-PHEMA)改性的弹性蛋白聚合物. 用红外(FTIR)和X射线光电子能谱(XPS)、热重分析(TGA)、扫描电镜(SEM)和动态接触角对改性弹性蛋白进行了表征. 结果表明: PHEMA键接到了弹性蛋白上; SEM显示改性后弹性蛋白的表面比未改性前变得光滑, 但改性后样品的热性能均低于未改性样品, 起始热分解温度由改性前的307.0 ℃变为260.2 ℃, 最大失重速率温度由347 ℃降到316.3 ℃; 动态接触角实验表明改性后样品具有良好的亲水性, 反应72 h后前进角由改性前的130.45°下降到35.40°, 接触角滞后由70.42°变为35.40°.

Modification of Elastin via Thio-iniferters

Elastin was firstly modified by reacting the amino-groups on the elastin with para chloro-methylbenzoyl chloride and sodium diethyldithiocarbamate to prepare the macro-iniferters and subsequently modified by UV-induced polymerization to attach poly(2-hydroxyethyl methacrylate). These modified elastin were examined using FTIR, XPS, TGA, SEM, ion chromatography and dynamic contact angle test. Results showed that PHEMA had been covalently bound to the elastin. Although SEM examination sug-gested that the surface of thio-iniferters-modified elastin was much smoother than that of unmodified sam-ples, the thermal stability of modified samples was slightly lower, that is to say, the initial temperature of thermal decomposition reduced from 307 to 260.2 ℃ and the temperature of maximum weight loss rate changed from 347 to 316.3 ℃. The dynamic contact angle test showed that the modified elastin was hydrophilic compared with the high hydrophobicity of elastin itself and after photopolymerization for 72 h, the advancing angle of elastin decreased from 130.45° to 35.40° and contact angle hysteresis reduced from 70.42° to 35.40°.