Research On Preparation And Properties Of Plasticized And Toughened Wood Flour/PP Composite

Wood flour is produced from remaining scrap of wood working. Wood-plastic composite(WPC), with high rigidity, strong heat resistance and replacement of wood in many occasions, can be produced by melt blending of wood flour with polypropylene(PP). Therefore WPC is developing rapidly in recent years. With the promotion of wood flour content, property of wood flour/PP composite will be similar to that of solid wood, while its processing flow and impact toughness will decline sharply. Therefore, it’s valuable to investigate how to enhance the processing flow and impact toughness of WPC.Firstly, PP-g-MAH and KH550 were used as the compatibilizer and interface modifier for compatibilized WPC respectively, which was produced via melt blending of wood flour with PP. Then, liquid paraffin(LP) was added as plasticizer to prepare the plasticized WPC. On the above basis, nano-SiO2 was pre-dispersed in LP to produce the nano-sol, which was used to produce the plasticized and toughened WPC. The effect of compatibilizer, coupling agent, LP, nano-SiO2, as well as content of wood flour on properties of WPC was investigated.The experiment results showed that compatibility between wood flour and PP could be improved through the addition of PP-g-MAH and coupling agent together. LP could enhance the impact strength of WPC and processing flow greatly. The fine dispersion of nano-SiO2 could be solved through the method of nano-sol, therefore the impact strength of WPC could be improved further. For the plasticized and toughened WPC produced via extrusion and injection molding process, in which the content of wood flour reached 70%, its impact strength, flexural strength, moisture rate and water absorption were 7.2kJ/m2,42.2MPa,6.6% and 1.86% respectively.