Utilization of decayed wood for polyvinyl chloride/wood flour composites

Although applications of wood-plastic composites (WPC) have rapidly increased, the raw materials used for producing WPC are still sound wood until now. The decayed wood usually is discarded or used as fire wood, which causes a serious waste of resources and environmental pollution. However, the decayed wood contains high lignin content which can be used for producing polymeric materials. In this study, decayed wood plastic composites (DWPC) with nano calcium carbonate (NCC), activated carbon (AC) and chitosan (CS) were fabricated and sound wood plastic composites (SWPC) without any additive were prepared. Compared to the results of physical and chemical properties of DPWCs with SWPCs, it was found that the mechanical properties, chemical structure, thermal stability, degree of crystallinity (Cr) and flame retardancy of DWPC with CS were better than DWPC without any additive, and even better than SWPC. The addition of CS (4%) to decayed wood powder (about 30%) and PVC (about 70%) could improve the physical, chemical, and bonding properties of DWPC, which could reach the level of sound wood plastic composites. The results of this work proposed a novel green strategy for utilizing decayed wood for making polyvinyl chloride/wood flour composites.