Super Toughened Poly(L-lactide)/Thermoplastic Polyurethane Blends Achieved by Adding Dicumyl Peroxide

Dicumyl peroxide (DCP) was introduced into thermoplastic polyurethane (TPU) toughened poly(L-lactide) (PLLA) blends. The results showed that the presence of DCP at relatively high concentration (0.2–0.5 wt.%) not only resulted in the homogeneous distribution of TPU particles with largely decreased particle size but also improved the interfacial interaction between PLLA and TPU components. Consequently, super toughened PLLA/TPU blends with largely enhanced impact strength were achieved successfully. The toughening mechanism was analyzed based on the impact-fractured surface morphologies of samples. Further enhanced impact toughness could be achieved by introducing crystalline structure to PLLA matrix, which was realized by annealing treatment.