环氧化天然橡胶对聚乳酸性能的影响

通过溶液共混的方法制备了左旋聚乳酸（PLLA）/环氧化天然橡胶（ENR-50）共混物，研究了ENR-50对PLLA的热稳定性、结晶性、力学性能和降解性能的影响。结果表明，ENR-50因环氧基团的存在，其引入可以显著提高PLLA的热稳定性。同时，分子运动性较高的弹性体虽不利于PLLA的成核，但可以提高其晶体生长速率。脆断面扫描电镜（SEM）结果表明，ENR-50呈椭球状均匀分散于PLLA中，作为应力集中物，经退火处理一定时间后ENR-50可以显著提高PLLA的韧性。此外，10%（质量分数）以内ENR-50的引入并不影响PLLA的酶降解速率。

The effect of epoxidized natural rubber on the properties of poly(lactic acid)

Poly(L-lactic acid) (PLLA)/epoxidized natural rubber (ENR-50) blends were prepared by solution casting, and the effects of ENR-50 on the thermal stability, crystallinity, mechanical properties and degradation properties of PLLA were studied. The results indicated that the introduction of ENR-50 significantly improved the thermal stability of PLLA due to the presence of its epoxy groups. In addition, although elastomers with higher molecular mobility are not conducive to the nucleation of PLLA, addition of ENR-50 did increase its crystal growth rate. Scanning electron microscope (SEM) micrographs of the fracture surface showed that ENR-50 was uniformly dispersed in PLLA with an ellipsoidal shape. As a stress concentrator, ENR-50 can significantly improve the toughness of PLLA after annealing for a certain time. In addition, the introduction of ENR-50 up to a mass fraction of 10% does not affect the enzymatic degradation rate of PLLA.