Research On Comprehensive Performance Of Polvethvlenc/natural Fiber Composites

Natural fiber reinforced polyolefin is a hot research topic in recent years, andapplication field of composites are also more and more widely, corresponding to theperformance requirements of composites also more and more rigorous. The effect onadding stripped the natural fiber with organic molecules inserting pretreatment toreclaim polyethylene was researched. Organic molecules inserting wood fiber haslayered hollow structure by single screw or twin screw extruder and silane couplingagent molecules can insert into hollow fibers hollow position. Part silane moleculebegan to polymerization in hollow position, then adding SEBS/LAC (acrylate monomer)solution into wood fibers, mixing, getting organic fiber. Finally, adding treated naturalfiber to recycling high density polyethylene, obtained the composites. The results showthat:1. Adding treated natural fiber to HDPE had a significant influence on mechanicalof composites. By comparing the alkali treatment and extrusion stripping processing,extrusion stripping had a better effect on improve the performance of the fiber. This ismainly because alkali treatment fiber only removed lignin and hemicellulose. It did notform the hollow layer structure in axial direction. Extrusion stripping not only can makecircumvolute lignin, cellulose and hemicellulose for solution of tangled role, but alsocan form layer structure. Therefore, extrusion stripping can greatly improve naturalfibers of surface area, and enhance the performance of the composites.When use4wt%of the silane coupling agent,9wt%of SEBS/LAC solution and3wt%DCP, thecomprehensive of RHDPE/WF composites performance is best, tensile strength31.8MPa, impact strength6.4kJ/m2, bending strength to39MPa, bending modulus reach2240MPa.2. Recycling high density polyethylene/natural fiber composites was a typicalpseudo plastic fluid, and200℃is more significant than190℃. The relationshipbetween lgηaand lgγωshows that several natural fiber composites were typical pseudoplastic fluid, the Newton index were less than1, Not only sensitive to shear rate, butalso sensitive to temperature in the Test temperature range. The balance torque of thecomposites increase and torque balance time also growth when add wood flour.3. Adding three different fiber respectively to RHDPE compared with pureRHDPE，molten curve indicated that molten peak, ΔH, XCwere all reduced. Comparingwith the other composite, the ΔH，XCof composites was increased after4wt%silanecoupling agent powder of wood processing. Composites have high melting peak, ΔHand XCwhen content of the SEBS is6wt%~12wt%.4. The hollow structure of fiber is observed though the microscope and scanningelectron microscope (SEM). Extrusion stripping formed the hollow layer structure inaxial direction and was proved by microscope and scanning electron microscope (SEM).When silane content at3wt%~5wt%the interface was blurry. After SEBS/LAC intercalation treatment, the interface was also fuzzy. The two treatments could improvecompatibility of polyethylene/natural fiber composites.