Study On Modified Straw Fiber/PVC Wood Plastic Composite Materials

Plant fibers and the thermoplastic resins are used to prepare wood-plastic composites(WPC)through mould pressing,extrusion molding and injection molding process.The strength of WPC depends on the interaction between the surface of plant fiber and matrix resin.The chemical treatment of fiber surface plays an important influence on the strength of WPC.NaOH solution,KH550(silane coupling agent)solution,NaOH/KH550 were respectively used to modify corn straw fiber and cotton stalk fiber.Then,the modified fibers mixed with PVC and other assistant agents were compression-molded into WPC.Scanning electron microscope(SEM),contact angle measurement instrument,thermogravimetric analyzer,mechanical property tests,etc.were utilized for the characterization of WPC.1.The results showed that the WPC containing the fiber treatmented with Na OH/KH550 had the best interface bonding,mechanical properties,thermal stability,and the lowest water absorption.The tensile strength of cotton straw fiber and corn straw stalk fiber composites reached 26.03 MPa and 26.16 MPa,and the bending strength reached 57.90 MPa,53.9 MPa respectively.2.Joining the alkali treated corn straw stalk fiber with MBS resin(methyl methacrylate,butadiene and styrene terpolymer)improved the mechanics performance of WPC.3.When sodium bicarbonate was used as foaming agent,the minimum density of the WPC was 1.02 g/cm3 with 5 wt% loading.When AC/ZnO were adopted as foaming agents,the minimum density of the WPC was 1.02 g/cm3 with 5 wt% loading.It was reduced by 4.9% compared with sodium bicarbonate for foaming agent.4.When sodium bicarbonate was used as foaming agent,the diameter of holes on the cross section of WPC was uneven distribution.When AC/ZnO were adopted as foaming agents,the holes on the cross section appeared collapse phenomenon.