Crystallization behavior, rheology, mechanical properties, and enzymatic degradation of poly(L-lactide)/poly(D-lactide)/glycidyl methacrylate grafted poly(ethylene octane) blends

Abstract

Poly(L-lactide) (PLLA)/poly(D-lactide) (PDLA)/poly(ethylene octene) grafted with glycidyl methacrylate (GPOE) were prepared by simple melt blending method at PDLA loadings from 1 to 5 wt%. Differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) demonstrated the formation of the stereocomplex in the blends. The addition of PDLA led to the increase of nucleation density from polarized microscope (POM) observations. Rheological measurements indicated that the blends exhibited a rheological fluid-solid transition and an enhanced elastic behavior in that ternary system as the PDLA loadings reached up to 5 wt%. By adding 1-2 wt% PDLA, the ternary system has better tensile and impact properties. Dynamic Mechanical Analysis (DMA) results showed that SC crystal formation and its effect on the enhancement of thermal stability at higher temperature. It is interesting that the enzymatic degradation rates have been enhanced clearly in the PLLA/PDLA/GPOE blends than in the PLLA/GPOE blend, which may be of great use and significance for the wider practical application of PLLA/GPOE blends.