Improving the stereocomplexation and toughness of poly(L-lactic acid)/poly(D-lactic acid) blends via melt blending with ethylene/methyl acrylate/glycidyl methacrylate terpolymer

Abstract

In this study, the ethylene/methyl acrylate/glycidyl methacrylate (EGA) terpolymer was performed to improve the stereocomplexation and toughness of poly(L-lactic acid)/poly(D-lactic acid) (PLLA/PDLA). The effects of EGA presence on the competing formations and crystallization kinetics of homocrystallites (HCs) and stereocomplexes (SCs), phase morphology and mechanical properties of PLLA/PDLA blends were investigated. For non-isothermal melt crystallization, the degree of SC crystallinity of PLLA/PDLA blends increased after PLLA/PDLA blending with EGA. For both isothermal and non-isothermal cold crystallization, the crystallization rate of PLLA/PDLA blends increased as the mass fraction of EGA in the blends grew from 10% to 30%. The incorporation of EGA was observed to facilitate the HC-to-SC melt reorganization of PLLA/PDLA blends; moreover, a significant enhancement in the toughness of the PLLA/PDLA matrix was achieved by incorporating the EGA elastomer. When EGA was added to produce a blend containing 30 wt%, the blend’s impact strength increased from 6.0 (for PLLA/PDLA) to 44.9 kJ/m2. Overall, this study provides effective guidance for achieving the melt-processability of PLLA/PDLA blends characterized by improved stereocomplexation ability and toughness.