Papers by Author: Wen Lei

Abstract: Wood-plastic composites (WPC) were prepared by compression molding process using high density polyethylene and wood fiber as the main raw materials. The influence of nanozinc oxide, nanosilver antimicrobial powder and rosin amid treatment on WPC was investigated respectively by testing the mass loss, flexural strength, color change, surface tension, as well as surface images of the composites before and after the corrosion test. The results indicate that nanozinc oxide has little antimicrobial effect on WPC. While nanosilver antimicrobial powder and rosin amid both have effects on the anti-corrosion properties of WPC. It is also suggested that the WPC with the mass fraction of 6% rosin amid is the most antimicrobial, and its mass loss and flexural strength only decrease by 0.0788% and 2.24% respectively. These cost-efficient WPC can be practical to industrial application.

Abstract: In this study,silvergrass (SV) reinforced high density polyethylene (HDPE) composites (WPCs) were prepared by injection molding. The effects of maleated polyethylene (MAPE), Slivergrass fibers (SV) content on the thermal, crystalline properties of WPCs were investigated. It was found that compared with the untreated WPCs, the thermal stability of the composites after incorporation of MAPE was significantly improved. Moreover, the results show that with MAPE adding, SV was an effective heterogeneous nucleating agent.

Abstract: In this study, alfalfa protein modified by sodium hydroxide was used to prepare adhesive. The effect on the bonding property by adding different amount of sodium hydroxide was discussed. The upper limit using temperature of alfalfa protein-based adhesive was increased and its bonding property was improved after the protein modified by sodium hydroxide. The adhesive prepared by alfalfa protein modified by 6% sodium hydroxide had the best bonding strength of 2.5MPa.

Abstract: Phosphoric acid, pentaerythritol and aniline were used to synthesize a novel intumescent flame retardant agent(IFR), then IFR was added into high density polyethylene based wood plastic composites(WPC) by three different ways. Thermal degradation behavior, combustion properties and mechanical properties of WPC were evaluated by means of limiting oxygen index(LOI), thermogravimetric analysis(TGA), universal testing and scanning electron microscope(SEM) images of char formed after LOI tests. The results show that when IFR was added directly into WPC, the composite has the best flame resistant property, but the worst mechanical properties; when IFR is dissolved into solution, and the immersion method is adopted, the WPC has the best mechanical properties and better fire retardant property.

Abstract: Polypropylene and wood flour were used as raw materials,maleic anhydride grafted polypropylene(MAPP) as compatibilizing agent, wood-plastic composite(WPC) was prepared by compression molding process. The effects of the content of MAPP on the mechanical and thermal properties of WPC were investigated. The results show that, with the increase of the content of MAPP, both the tensile and flexural strengths of WPC will increase, and the impact strength of WPC increases first, then decreases, and the impact strength reaches the maximum of 1.18kJ/m2 when the content of MAPP is 4%,which is 76.7% increased from that of the composite without MAPP. Each composite has an obvious heat-absorption peak when melted during 140-170 and the melting enthalpy of WPC increases with the content of MAPP, the melting procedures of all the composites are quite similar with one another. Application of MAPP can improve the thermal stability of WPC

Abstract: On the investigations on the flexural properties,color stability and melting properties,the effects of treating ramie fiber with silane coupling agent on the anti-thermo-oxidative aging properties of high density polyethylene(HDPE)/ ramie fiber composites were studied.The results show that,treating the fiber with 3% coupling agent can improve the flexural strength and modulus of the composites before the aging test by 15.9% and 21.7% respectively,and also it can improve the flexural properties of the composites after the aging test;the modified composites will be more color stable,less color difference,and less disminish of the color during the aging test;the peak melting temperatures of the modified composites when aged for 0,500,1000,1500 and 3000h will be increased by 0.6，0.2， 0.5,2.3 and 3.8 oC from those of the unmodified composites;the flexural properties,color stability and melting properties of HDPE / ramie fiber composites during thermo-oxidative aging tests all indicate that treating ramie fiber with coupling agent can improve the anti-thermo-oxidative properties of the composites.