完全生物降解塑料PLA/PPC合金的结构与性能研究

利用机械共混法,将聚乳酸(PLA)与聚丙撑碳酸亚丙酯(PPC)熔融共混,制备了完全生物降解塑料PLA/PPC合金,并用FTIR、流变仪等手段研究了其结构、力学性能和流变性能。结果表明该共混体系具有良好的相容性、力学性能和熔体流动性,PLA与PPC之间存在着较强的相互作用,PPC的加入使体系拉伸强度下降幅度不大,断裂伸长率升高到23.8%,比纯PLA提高近20倍。共混体系的黏度亦随着PPC的加入逐渐增大,PLA/PPC(50/50)体系的黏流活化能为37.1kJ/mol,同时在一定的温度范围内,提高切应力也会使体系黏度下降。

Structure and Property of Fully Biodegradable PLA/PPC Alloy

Fully biodegradable poly(lactic acid)/poly(propylene carbonate) (PLA/PPC) alloy was prepared via melt mixing method, and the structure, mechanical properties and rheological behavior of the alloy were studied by means of FTIR analysis and rheometer. The results indicated that the blend system had favorable compatibility, mechanical properties and melt flowability, the certain interaction between the two macromolecules was confirmed, and the tesile strength of PLA/PPC decreased little with the addition of PPC, while the elongation at break increased to 2.38%, 20 times higher than that of pure PLA. The viscosity of the blend system increased with the addition of PPC. The viscous flow activation energy of PLA/PPC(50/50) was 37.1KJ/mol. In addition the viscosity of the blend system could be decreased by increasing the shear stress within a certain range of temperature.