丝素蛋白/聚D,L-乳酸共聚物的研究

摘要

以D,L-丙交酯和蚕丝丝素蛋白(SF)为原料,在氯化亚锡/对甲苯磺酸体系的催化作用下聚合得到丝素蛋白改性聚D,L-乳酸的共聚物(PSFLA).该共聚物的结构与性能采用红外光谱法、1H NMR、热重分析、差示扫描量热法、粘度法、旋光度法和扫描电镜等方法进行研究.所得的PSFLA均不具有光学活性,但原料配比对共聚物的微结构与结晶性能有重要的影响.当D,L-丙交酯与丝素蛋白的质量比为6:1时,共聚物中可能形成了络合结晶,结晶的熔点为128℃,且随着D,L-丙交酯用量的增加,结晶的熔点略微增加.PSFLA的热分解温度大于220℃.PSFLA中的SF与聚乳酸(PLA)链段间可能存在着氢键相互作用,SF与乳酸链段可自组装形成片层结构.%The copolymers of silk fibroin and poly(D,L-laetide) (PSFLA) were prepared from D,L-lactide and silk fibroin (SF)through ring-opening polymerization catalyzed by SnCl2/TSA. Viscometiy, polarimetry, 1H nuclear magnetic resonance;FT-lR,thermo-gravimetry, differential scanning calorimetry and scanning electron microscopy were employed to detect the obtained copolymers. Racemic copolymers were obtained at all D,L-lactide/SF mass ratios. When D,L-lactide/SF mass ratio was 6:1,complex crystal could be formed, and the melt point of copolymers increased with increasing D,L- lactide/SF ratios. The thermodecomposition temperature of PSFLA was over 220 ℃. The obtained copolymers may form lamellas through self-assembly of lactide units and SF units.