Abstract: | The surfaces of kenaf fibers were treated with three different silane coupling agents. 3-glycidoxypropyltrimethoxy silane (GPS), 3-aminopropyltriethoxy silane (APS), and 3-methacryloxypropyltrimethoxy silane (MPS). Among them, the most effective one for the property improvement was GPS when it was applied to the kenaf fiber surfaces at 0.5 wt%. Thermoplastic polypropylene (PP) and thermosetting unsaturated polyester (UPE) matrix composites with chopped kenaf fibers untreated and treated at different GPS concentrations from 0.1 wt% to 5 wt% were fabricated using compression molding technique. The present study demonstrates that the interfacial, flexural, tensile, and dynamic mechanical properties of both kenaf/PP and kenaf/UPE composites importantly depend on the GPS treatments done at different concentrations. The greatest property improvement of both thermoplastic and thermosetting polymer composites was obtained with the silane treatment at 0.5 wt% and the mechanical properties were comparable with E-glass composites prepared the same polymer matrix under the corresponding fiber length and fiber loading. The results also agreed with each other with regard to their interfacial shear strength, flexural properties, tensile properties, storage modulus, with support of fracture surfaces of the composites. |