Modification Of PVC Based Wood-Plastic Composites

Wood-plastic composites are prepared using wood fiber, agents andpolymer, which not only have the advantages of wood fiber and plastic,but also have good mechanical properties and processability.Wood-plastic composites can replace wood and plastic products to acertain extent. However, due to wood-plastic composite materials haveseveral defects, such as poor heat resistance, low mechanical propertiesand high density, which also limit the further application to some extent.The thesis focus on modification of the polyvinyl chloride （PVC）wood-plastic composites and aims to improve heat resistance andmechanical properties of wood-plastic composites. The results show asfollowing.(1) PVC matrix modified by chlorinated polyvinyl chloride (CPVC).CPVC has better heat resistance and mechanical properties. The resultsshow that tensile strength and flexural strength increase, flexural modulusand tensile modulus improve and heat distortion temperature ofcomposite materials increase with the CPVC contents increased; whenthe PVC/CPVC blend ratio is50/50, its heat distortion temperature increased by15℃, the heat resistance of PVC and mechanical propertieswere improved.(2) PVC/CPVC wood-plastic composites modified by inorganicparticle were prepared through two process methods. The results showthat the mechanical and thermal properties of PVC wood-plasticcomposites were significantly improved after the mixing andplasticization. The microstructure analysis show that clubbed inorganicrigid particles were easily oriented after compounding, thus this particlesare effective in the improvement of modulus of elasticity.(3) The PVC wood-plastic composite materials modified by threedifferent performances inorganic particle were made. There are highertensile properties and flexural properties when PVC wood-plasticcomposite materials are modified by muscovite; there are better modulusand thermal properties when PVC wood-plastic composites are modifiedby the attapulgit, especially thermal performance. And there is the bestimpact strength when PVC wood-plastic composites are modified bynano-barium sulfate.