Mechanical and Thermal Properties of Sugar Palm Fiber Reinforced Thermoplastic Polyurethane Composites:Effect of Silane Treatment and Fiber Loading

The aim of the present study was to develop sugar palm fiber(SPF)reinforced thermoplastic polyurethane(TPU)composites and to investigate the effects of fiber surface modification by 2%silane treatment and fiber loading(0,10,20,30,40 and 50 wt%)on the mechanical and thermal properties of the obtained composites.Surface treatment was employed to improve the fiber-matrix interface,which was expected to boost the mechanical strength of the composites,in terms of tensile,flexural and impact properties.Thermal properties were also investigated by thermal gravimetric analysis(TGA)and dynamic mechanical analysis(DMA)to assess the thermal stability of the developed composites.Furthermore,scanning electron microscopy(SEM)was used to study the tensile fracture samples of composites with a view towards evaluating the effects of fiber surface treatments on the fiber/matrix interfacial bonding.The findings of this study reveal that the silane treatment has determined good bonding and linkage of the cellulose fiber to the TPU matrix,hence contributing to enhanced mechanical and thermal properties of the composites.The composite formulation with 40 wt%sugar palm fiber loading showed optimum values such as 17.22 MPa for tensile,13.96 MPa for flexural,and 15.47 kJ/m^2 for impact strength.Moreover,the formulations with higher fiber content exhibited satisfactory values of storage modulus and thermal degradation,while their good interfacial adhesion was evidenced by SEM images.

Effect of silane and zirconia on the thermal property of cathodic electrophoretic coating on AZ31 magnesium alloy

Magnesium alloys,the lightest structural metal,are used in the field of aeronautics and astronautics more and more,however they are still limited for the poor corrosion resistant and high temperature property.In order to satisfy the need of long time store and short time operation at elevated temperature,coating with excellent corrosion resistance and thermal resistance was prepared on the surface of Mg alloy AZ31B.The cathodic electrophoretic deposition was applied for the preparation of coating.The bonding of organic electrophoretic deposition coating with substrate was improved using silane pretreatment.Nano-ZrO_(2) powder treated by silane was added into electrophoretic deposition solution.The corrosion resistance property of electrophoretic coating was evaluated using Machu test,and thermal characteristic using the thermal shock experiment and DTA respectively.The morphology of the coating was examined by SEM.It is found that both the corrosion resistant and thermal shock resistant properties can be improved by modifying the Mg specimen with APS silane,while adding nano-ZrO_(2)powder treated by GPS silane to the coating has the optimal effect.And the results also show that the main reason of the coating damage after thermal shock at 400°C or 500°C is mainly for the thermal stress.

Properties of Renewable Biocomposite from Poly（butylene succinate） and Teakwood Sawdust before and after Accelerated Weathering Condition

A new kind of renewable biocomposite was prepared by compounding bio-based poly（butylene succinate） （PBS） with teakwood sawdust which sieved sawdust were used as received or treated with 3-aminopropyltriethoxy silane （APS）. The PBS/teakwood composites were compounded in the weight ratio of 90/10 wt%, 80/20 wt%, 70/30 wt% and 60/40 wt%. Thermal properties and morphology of the composites were investigated. The accelerated weathering testing was carried out for 60 h under water spraying and cycle of UV ex- posure at 60 ~C. Tensile and flexural properties before and after the accelerated weathering condition were analyzed. It was found that teakwood sawdust did not effect on the melting temperatures of PBS but reduced the degree of crystallinity. The composites showed lower thermal stability due to the degradation ofhemicellulose and silane. Interfacial adhesion between PBS and APS-treated teakwood sawdust was achieved showing less pull-out of sawdust. Tensile and flexural modulus of composites increased with respect to sawdust content, in which the APS-treated composites had higher modulus. After passing the accelerated weathering condition, tensile modulus of the composites slightly increased while flexural properties decreased in the composites added sawdust content higher than 20 wt%. Loss of flexural properties was more pronounced than tensile properties due to the hydrolytic degradation introduced by hydrophilicity of lignocellulosic fillers.