L-丙交酯与蚕蛹蛋白共聚物的合成与表征

以L-丙交酯和蚕蛹蛋白为原料，在辛酸亚锡的催化作用下，采用熔融聚合法合成了聚乳酸和蚕蛹蛋白的共聚物（PLLA-co-SCP），研究了投料比对共聚物特性粘数的影响，结果表明：L-丙交酯与蚕蛹蛋白投料比为34∶1时得到特性粘数最大为0.2446 dL/g的共聚物．用傅里叶红外光谱（FTIR）、热重分析（TGA）、差示扫描量热法（DSC）和 X 射线衍射（XRD）对PLLA-co-SCP共聚物的结构、热性能及结晶性能进行了表征．FTIR谱图分析结果表明：合成的PLLA-co-SCP共聚酯兼具了PLLA链段的酯基和蚕蛹蛋白的酰胺基；TGA测试结果显示PLLA-co-SCP特性粘数越大热稳定性越高， SCP含量越高热分解残留率越大；DSC和XRD结果表明PLLA-co-SCP结晶主要由PLLA链段产生，聚乳酸链段越长共聚物结晶度越高，晶体也越完善．另外，XRD结果还表明PLLA-co-SCP共聚物含PLLA 的α和β两种晶体．

Preparation and characterization of L-lactide-silkworm chrysalis protein copolymer

Poly（L-lactide-co-silkworm chrysalis protein）copolymer （PLLA-co-SCP）was prepared by melt con-densation polymerization of L-lactide with silkworm chrysalis protein.Stannous octoate （Sn（Oct）2 ）was used as a catalyst.The influence of the reactant ratio on the intrinsic viscosity of the products was studied.The intrinsic viscosity results revealed that the largest intrinsic viscosity was 0.244 6 dL/g when the reactant ratio mL-LA：mSCP was 34∶1 .Their chemical structure,thermal properties and crystal structure were confirmed by FTIR,TGA, DSC and XRD.The FTIR showed that the copolymer included both ester groups of PLLA segments and amide groups of SCP segments.The TGA analysis indicated that the lager intrinsic viscosity could improve the thermo-stability of the copolymer,and thermal decomposition residue of copolymers increased with increasing SCP con-tent.The results of XRD and the DSC suggested that the crystallization of PLLA-co-SCP was mainly caused by PLLA segments,and the longer PLLA segments were,the higher crystallinity and the better crystal the PLLA-co-SCP got.The XRD analysis confirmed that the crystal unit cells of PLLA-co-SCP contained both αand βcrystal form.