聚L-乳酸/丝素蛋白共聚物增容剂的结构表征及性能研究

摘要

Poly ( L-lactide-co-silk fibroin ) copolymers ( PSFLA ) were sythesized through ring-opening copolymerization of L-lactide prepared from L-lactic acid, and silk fibroin with Sn( Oct) 2/naphthalene disulfonic acid as the catalyst system. PSFLA was acted as the compatibilizer for the blends of poly( L-lactide) ( PLLA) and silk fibroin ( SF) with hexafluoroisopropanol using as solvent. FT-IR, differential scaning calorimetry, thermogravimetry ( DSC) , scanning electron microscopy ( SEM) . Electronic universal testing machine were then employed for the characterization of these blends. The results showed that PSFLA chains contained PLLA units and SF units, while PLLA units probably possessed crystalline morphology. PSFLA had good thermal stability with initial thermal decomposition temperature at 220 ℃, and the maximum degradation rate at above 300 ℃. The compatibilities and mechanical properties of the blends were improved with the addition of PSFLA. When 8% PSFLA was added, the blend showed maximum mechanical property with tensile strength of 5. 24 MPa and breaking elongation of 117. 45%.%以L-丙交酯和蚕丝蛋白( SF)为原料、异辛酸亚锡/萘二磺酸为催化剂体系,开环聚合制备聚L-乳酸/丝素蛋白共聚物( PSFLA),该共聚物可以作为聚L-乳酸与丝素蛋白共混体系的增容剂。以六氟异丙醇为溶剂,分别制备PSFLA、聚L-乳酸( PLLA)和丝素蛋白的六氟异丙醇溶液,并采用溶液混合法制备含PSFLA增容剂的聚L-乳酸/丝素蛋白共混物。采用红外光谱、差示扫描量热法、热重法、扫描电子显微镜、电子万能试验机等对所得共聚物与共混物体系进行结构表征与性能测试。结果表明,所得的共聚物PSFLA分子链中含有PLLA链段和SF链段,且PLLA链段可能形成结晶形态。 PSFLA的热分解温度为220℃,且在300℃以上才大幅度分解。 PSFLA改善了PLLA与SF共混体系的相容性,提高了其力学性能。共混体系在PSFLA用量为8%时,力学性能最好,其拉伸强度为5.24 MPa,断裂伸长率为117.45%。