生物降解材料聚乳酸-聚乙二醇的直接熔融共聚法合成与表征

Direct synthesis of biodegradable material polylactic acid-polyethylene glycol via melt copolymerization and its characterization

直接以外消旋乳酸(D,L LA)单体为原料,使其与数均相对分子质量(Mn)为1000的聚乙二醇(PEG)[m(LA)∶m(PEG)=9]共聚,通过直接熔融共聚法合成了生物降解材料聚乳酸 聚乙二醇(PELG),用特性黏数[η]、凝胶渗透色谱(GPC)、傅立叶红外光谱(FTIR)、核磁共振氢谱(1HNMR)、差热分析(DSC)、X 射线衍射、接触角测试等手段,对其相对分子质量、结构、性能等进行了系统的表征。相同合成条件下,PELG与聚乳酸相比,其相对分子质量高,亲水性能也有所改善。在相近的合成条件下,D,L LA与PEG直接熔融共聚能获得比D,L 丙交酯开环共聚高的相对分子质量,并达到与L 丙交酯开环共聚相当的相对分子质量。

Directly starting from D,L-lactic acid (D,L-LA) and polyethylene glycol (PEG),[Mn=1000, and m(LA)∶m(PEG)=9], biodegradable material polylactic acid-polyethylene glycol (PLEG) was synthesized via melt copolycondensation under 165℃ and 70Pa. The relative molecular weight, structure and properties of PLEG were systematically characterized with intrinsic viscosity [η], GPC, FTIR, ~1H NMR, DSC, X-ray diffraction and contact angle testing. Under same synthetic conditions, PLEG has higher molecular weight and better hydrophility than poly(D,L-lactic acid) (PDLLA). Under similar conditions, the Mw of PLEG directly synthesized can reach or surpass that synthesized through the opening polymerization of lactide.