Synergistic reinforcement of polylactic acid/wood fiber composites by cellulase and reactive extrusion

Abstract

In order to overcome the consumption of non renewable resources and serious environmental pollution caused by traditional petroleum based polymers, blending and modifying renewable PLA and wood fibers to replace traditional petroleum based plastics has become a current research hotspot. However, due to the large polarity difference between PLA and wood fibers, the performance of the composite material prepared is not ideal. To improve the performance of polylactic acid/poplar fiber (PLA/PF) composites and simplify the process, this study used cellulase and 2,2 '- (1,3-phenylene) - dioxazoline (PBO) co modification, a safe, environmentally friendly and simple process, to prepare the composites. The results show that the crystallization properties of cellulase and PBO-modified composites will be appropriately reduced, the microstructure shows that the interface of PLA/CF-5.5/PBO is more tightly bonded, and the mechanical test results show that the modified material has excellent mechanical properties. Compared to the unmodified PLA/PF, PLA/CF-5.5/PBO has a 28.85% increase in tensile strength, reaching 63.65 MPa. while its flexural strength reaches 116.07 MPa, representing a 21.45% increase. Surprisingly, the tensile and strength of PLA/CF-5.5/PBO exceeds that of pure PLA, with the flexural modulus showing a significant increase of 43.96% compared to PLA. The above analysis shows that the effect of the two synergistic modification methods is significant, and the research results provide an environmental protection idea for the development of PLA matrix composites with high compatibility, good mechanical properties and good environmental adaptability, and broaden the application scope and value of the composites.