Study On Compatibility Of Wheat Straw Fiber, Waste Plastics And Polypropylene

Replacing timber with agricultural residues and replacing resins with waste plastics, to explore a green plant-fiber/wasted-plastics composite of industrial application, will not only open up a new application field for the abundant agricultural residues and improve the use rate of waste plastics, but also reduce the environmental impacts caused by burning agricultural residues and waste plastics. According with the Sustainable Development Strategy of reducing energy emission and protecting environment, it is one of a focus in new material field.Wheat straw and waste polypropylene as raw materials, which are rich and obtained easily, were used to research compatibility of wheat straw fiber and polypropylene plastic. According to the program design, first, the extraction of wheat straw fiber (acid-base extraction and thermal-mechanical extraction) and its surface treatment process were explored. Second, the pretreated wheat straw fiber was compounded with polypropylene resin and wasted-polypropylene respectively. Finally, the effect of wheat straw fiber content, coupling agent types and MAPP content on the compatibility between wheat straw fiber and polypropylene plastic was researched by the mechanical properties testing and microstructure analysis.The results show that after treated by the acid socking, wheat straw fiber which was subjected to treat with 10% NaOH at 90℃for 1h is pure. Surface structure with more functional group content of wheat straw fiber obtained by thermal-mechanical extraction is similar to the inner surface of wheat straw. When wheat straw fibers are treated by 3%KH550 and their amount are about 20~25%wt in polypropylene plastics, the mechanical properties of composites with 6~8%wt MAPP are the best because of the good dispersion and interfacial adhesion. Compared with the acid-base extraction, thermal-mechanical extraction is simpler and the mechanical properties of the corresponding composites with attractive macro-morphology are improved significantly. The above results will be of great theoretical and practical reference value in the industry application of wheat straw fiber/plastic composites.