【摘要】 采用开环聚合法合成了一系列具有不同组成的聚(乳酸乙醇酸)(PLLGA)共聚物,并通过红外光谱(FT-IR)、核磁共振氢谱(1HNMR)、凝胶渗透色谱(GPC)、差示扫描量热分析(DSC)、X射线衍射分析(XRD)和拉仲试验,对PLLGA共聚物的化学结构、相结构、热性能、力学性能和形状记忆性能进行了系统研究,并分析了其形状记忆效应的微观机理.研究表明,通过调整PLLGA共聚物的组成,可获得良好的力学性能和形状记忆效应.对PLLGA90/10和80/20,由结晶部分及大分子链之间的缠结点共同作为固定相,无定型部分作为可逆相.而对PLLGA70/30和60/40,仅由大分子链之间的缠结点作为固定相,其无定型部分均作为可逆相.综合而言,PLLGA80/20具有最好的形状记忆效应.更多还原

【Abstract】 A series of poly(l-lactic-co-glycolic acid) (PLLGA) with different compositions was synthesized by ring opening copolymerization.The chemical structure,phase structure,thermal property,mechanical property and shape memory property of PLLGA were investigated through FT-IR,1H NMR,GPC,DSC,XRD and tensile tests,and the shape memory microscopic mechanisms were analyzed.The results showed that good mechanical and shape memory properties can be obtained through changing of PLLGA compositions.For PLLGA90/10 and 80/20,the fixed phase was acted by their crystals and the entanglements of molecular chains,while the reversible phase was acted by their amorphous phase.However,for PLLGA 70/30 and 60/40,the fixed phase was only acted by the entanglements of molecular chains.In general,the best shape memory properties were showed by PLLGA 80/20.更多还原