Enhanced thermal and mechanical properties of lignin/polypropylene wood-plastic composite by using flexible segment-containing reactive compatibilizer

A reactive compatibilizer containing flexible segment (RCFS) was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). The RCFS was used as a compatibilizer for the preparation of lignin/polypropylene (PP) wood plastic composites, and the effect of the RCFS on the properties of composites (e.g., mechanical properties, thermal properties, crystal structure, and morphology) were investigated in detail. Experimental results indicated that the lignin/PP composite displayed the best performance with the addition of 2 wt% RCFS. Its impact strength, flexural strength, and modulus were 56.8%, 37.3%, and 20.6%, respectively, which are higher than those of the untreated composites. Moreover, RCFS treatment could also increase the thermal stability, crystallization rate, and degree of crystallinity of lignin/PP composites