Super-Tough and Highly-Ductile Poly(l-lactic acid)/Thermoplastic Polyurethane/Epoxide-Containing Ethylene Copolymer Blends Prepared by Reactive Blending

Ethylene-methyl acrylate-glycidyl methacrylate copolymer (E-MA-GMA) is employed to improve the impact toughness of poly(l-lactic acid) (PLLA)/thermoplastic polyurethane (TPU) blends by reactive melt-blending. The reaction and miscibility between the components are confirmed by Fourier transform infrared spectroscopy, dynamic mechanical analysis, and differential scanning calorimetry. A super-tough PLLA/TPU/E-MA-GMA multiphase blend (75/10/15) exhibits a significantly improved impact strength of 77.77 kJ m(-2), which is more than 17 times higher than that of PLLA/TPU (90/10) blend. A co-continuous-like TPU phase structure involving E-MA-GMA phase at the etched cryo-fractured surface and the high-orientated matrix deformation at the impact-fractured surface are observed by scanning electron microscopy. The high-orientated matrix deformation induced by the co-continuous TPU phase structure is responsible for the super toughness of PLLA/TPU/E-MA-GMA blends.