Mechanical properties and phase morphology of super-tough PLA/PBAT/EMA-GMA multicomponent blends

Poly(lactide) (PLA)/poly(butylene-adipate-co-terephtalate) (PBAT) blends containing varying amounts of ethylene-methyl acrylate-glycidyl methacrylate copolymer (EMA-GMA) are prepared through reactive melt-blending to improve toughness. A super-tough PLA/PBAT/EMA-GMA multicomponent blend (75 wt%:10 wt%:15 wt%) exhibits a significantly improved notched impact strength of 61.9 ± 2.7 kJ/m2, nearly 13 times higher than those of PLA/10 wt%PBAT binary blend, respectively. A special core-shell like dispersed phase microstructure involving PBAT particles and EMA-GMA phase at the cryofractured surface of the PLA blends is observed by Scanning Electron Microscopy (SEM). The strong interfacial adhesion and enormous shear-yielding deformation of the PLA matrix with the dispersed phases are responsible for the super-toughened effect exhibited by the PLA/PBAT/EMA-GMA blends.