Research On Preparation And Mechanical Properties Of PP Based Wpc

Wood plastic composite (WPC) is a new kind of environment-friendly material. Due to the lack of wood and petroleum resources,"wood replaced by WPC"was aroused great attention among the public. WPC got significantly developed since 1990s.This article is based on the PP/ poplar wood flour composites. Samples were prepared by compression molding. The molding craft was optimized. The effects of wood flour content of WPC on the density, mechanical strength, Vicat softening temperature, rheology, matrix crystal property and interface compatibility were investigated by some tests, such as mechanical test, VST test, SEM and XRD etc. The optimized content of Aluminic ester coupling agent was obtained through those investigations. Meanwhile, the proper thermoplastic elastomer and its modification were also evaluated.PP is selected for experimental use, its major ingredient isα-PP, and with 9.97% content ofβ-PP crystal, which was restrained by wood flour according to the results of wide-angle X-ray diffraction, and peak (300) was disappeared. Contrast with the WAXD result of AE0.5, EA10, SS05, the EA10 shows the highest values of the main peaks of (110), (040) and (130), then SS05, the least is AE0.5. For EA10, the special peak, (130), its wave crest is sharper, the value is higher, crystal property is better than other samples used in the test.By increasing the content of WF from 0 to 30wt% of WPC, the density, tensile strength tends to increase linearly, while the notched impact strength shows a sharp decrease. The tensile strength of WF30 is 25.4MPa, and the notched impact strength is 5.06KJ/㎡, respectively 23.62% higher and 56.92% lower than PP. The tensile strength of AE0.5 is 26.8MPa, and the notched impact strength is 6.25KJ/㎡.The tensile strength of EA10 is 31.4MPa, and the notched impact strength is 7.94KJ/㎡, respectively 23.62% and 56.92% higher than WF30. The molding property decreased when adding WF to PP matrix. The VST of WPC with 30wt% WF is 120℃, 17℃higher than PP.The fracture structure of WPC with 30wt% WF and 0.5wt% AE gained by SEM shows that more wood fiber were ruptured in PP matrix. Based on AE0.5 system, when adding 10wt% EVA or SBS, mass of wood fiber were ruptured in consecutive matrix. With a number of tearing regions represented, the toughness of WPC with 30w% wood flour was well enhanced.