Simultaneously improving stiffness, toughness, and heat deflection resistance of polylactide using the strategy of orientation crystallization amplified by interfacial interactions

A core-shell toughening agent was incorporated Polylactide (PLA) to prepare the high-PLA-content (>= 85 wt%) blends with high impact strength due to good interfacial adhesion. Interestingly, the synergistic effect of strong interfacial adhesion and intense shear flow on crystallization of PLA is proved whereas retarded crystallization occurs in the presence of impact modifier solely in this work. Moreover, by introducing intense shear flow in injection molding, thickness of oriented crystal layer and crystallinity of the PLA parts improve compared with conventional injection molding. Accordingly, oriented crystal and well dispersed second phase particles induced by intense shear flow result in promising balance of thermomechanical peoperties, i.e., modulus, strength, impact toughness and heat resistance can be achieved to 1890 MPa, 64.5 MPa, 29.6 kJ/m(2), 145.58 degrees C by adding 15 wt% of impact modifier, respectively, compared with those (1875 MPa, 64.5 MPa, 1.7 kJ/m(2), 59.0 degrees C) of conventional injection molded PLA parts.