| Wood plastic composite (WPC) was widely used as a novel environmental protection material in recent years and had the features of both wood and polymer material. The antibacterial property of polymer material was excellent, so WPC was more resistant to corrosion than wood, manufactures also took this as one of the selling points. But during the pratical application, people found WPC still affected by mold corrosion at a certain temperature and humidity, plaque formed on the surface of the composite and mechanical properties declined. These led the service life of WPC shorted greatly. So study on the corrosion resistance of WPC was very necessary.In this paper, the WPC added with or without zinc borate、chlorothalonil and SD-36M fungicide were prepared by mixing and hot press molding method, and used coupling agent(KH550)modification wheat straw as filling material and PP as matrix. The wheat straw/PP composites with or without fungicide were done the accelerating corrosion test according to ASTMG21-96.After the test, comprehensive property and microstructure surface of the samples were tested to learn how much fungicides improve the corrosion resistance of wheat straw/PP composites. And the improvements of different surface treatments to the corrosion resistance of wheat straw/PP composites were studied in the same way. The main conclusions can be drawn as follows:(1)Researches about accelerating corrosion of wheat straw/PP composite without fungicides showed that as the corrosion time increased, mould on the surface of wheat straw/PP composite only treated with silane coupling agent increased, and comprehensive properties become more and more bad. After4weeks corrosion, the surface of wheat straw/PP composite was full of mould, and had more holes and cracks. It’s bending strength reduced by17.25%, the bending modulus of elasticity reduced by60%, the tensile strength reduced by20.97%, the impact strength reduced by26.15%.(2)Researches about the corrosion resistance of wheat straw/PP composite added with different kinds and contents of fungicides showed that both zinc borate and chlorothalonil could improve the corrosion resistance of WPC while SD-36M could not. The optimum contents of zinc borate and chlorothalonil were respectively1%and1.25%,the samples had the best comprehensive property:Compared with sample without any fungicides, when the content of zinc borate was1%,bending strength increased by15.67%, the bending modulus of elasticity increased by75.32%, the tensile strength increased by22.34%, the impact strength increased by7.18%while the bibulous rate reduced by31.33%, the color difference value reduced7.83.When the content of Chlorothalonil was1.25%,the bending strength increased by13.71%, the bending modulus of elasticity increased by54.91%,the bending elastic modulus increased by54.91%, the tensile strength increased by10.46%, the impact strength increased by47.53%while the bibulous rate reduced23.69%, the color difference value reduced11.56.(3)Researches about the corrosion resistance of wheat straw/PP composite with different surface treatments of wheat straw showed that NaOH treatment、acetic acid treatment and hydrothermal treatment could improve the corrosion resistance of WPC while microwave treatment could not. When concentration of NaOH was5%,concentration of acetic acid was1%and hydrothermal time was60min,the samples had the best comprehensive property:Compared with sample without any fungicides, when the concentration of NaOH was5%, the tensile strength increased by3.32%, the impact strength increased by75.34%while the bibulous rate reduced by12.23%, the color difference value reduced11.1. When the concentration of acetic acid was1%,the bending elastic modulus increased by27.74%, the tensile strength increased by3.45%, the impact strength increased by26.43%while the bibulous rate reduced1.31%, the color difference value reduced14.8. When the hydrothermal time was60min,the bending elastic modulus increased by5.26%, the tensile strength increased by3.03%, the impact strength increased by20.72%while the bibulous rate reduced by20.99%, the color difference value reduced... |
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