E-MA-GMA三嵌段共聚物对聚乳酸的增韧改性

Toughening PLA with E-MA-GMA

在聚乳酸(PLA)中加入不同比例的乙烯-丙烯酸乙酯-甲基丙烯酸缩水甘油酯三嵌段共聚物(E-MA-GMA)对其进行增韧改性。用傅立叶变换红外光谱仪和旋转流变仪分别对体系的反应进行表征;用熔融指数测量仪和旋转流变仪对体系的流变性能进行表征;同时测试材料力学性能并观察样条微观结构以考察E-MA-GMA对PLA的增韧效果。结果表明:E-MA-GMA的环氧官能团与PLA的端羧基和端羟基发生反应,使得共聚物与PLA有一定的相容性,PLA的冲击性能得到了明显的提高,含20%E-MA-GMA(质量分数)的共混物冲击强度较纯PLA提高了329.7%。

E-MA-GMA was introduced to toughen PLA and the contents of E-MA-GMA were 5 %, 10%, 15%, 20%, respectively. The infrared spectroscopy （IR） and rheometer were used to characterize the reaction occurring in the blend. The melt index and rheological behaviors of blend were investigated. Mechanical properties were also investigated to view the toughening of different contents of E-MA-GMA. With the addition of E-MA-GMA, the failure＇mode changed from brittle fracture of the neat PLA to ductile fracture of the blend as demonstrated by scanning electron microcopy （SEM）. It is found that the epoxy functional group of E-MA-GMA can react with the end group of PLA, which makes PLA partial compatible with E-MA-GMA. Therefore, the impact strength PLA is improved. When adding 20% E-MA-GMA, the Izod impact strength increases by 329.7%.