Nano-TiO2 Modified Wheat Straw/Polylactic Acid Composites Based on Synergistic Effect Between Interfacial Bridging and Heterogeneous Nucleation

To improve the interfacial compatibility of wheat straw/polylactic acid (WS/PLA) composites, nano-TiO2 with different particle sizes was blended with molten PLA to modify straw fiber to obtain a nano-TiO2 modified WS/PLA composite. This study explored the effect of the nano-TiO2 particle size on the properties of the WS/PLA composites using mechanical property tests, contact angle measurements, water absorption tests, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The tensile strength and flexural strength of the modified composite improved to 44.9 MPa and 95 MPa, respectively. Mechanistic studies showed that nano-TiO2 played modified the interface and improved the interfacial compatibility of the composites by promoting the heterogeneous nucleation and rapid crystallization of PLA, which formed a stable crystal structure between the straw fiber and the PLA matrix. This study provides a method to develop biomass composites to solve environmental problems. [GRAPHICS] .