▎ 摘　　要

In this study, the flexural strength and elastic modulus of polypropylene-based nanocomposites reinforced with graphene nanosheets, basalt, and kenaf fiber were investigated. Response surface methodology based on Box-Behnken design was used as the experimental design. The blends fabricated in three levels of parameters include 0, 0.75, and 1.5 wt% graphene nanosheets, 0, 7.5, and 15 wt% basalt fibers, and 0, 7.5, and 15 wt% kenaf, prepared by an internal mixer and a hot press machine. The fiber length was 5 mm and was being constant for all samples. Flexural and tensile tests were conducted to determine the blend properties. The addition of graphene nanosheets to 0.75 wt% increased the flexural strength by 12% and a graphene addition up to 1.5 wt% reduced flexural strength by 6%. The addition of graphene nanosheets to 1.5 wt% increased the elastic modulus by 37%. The addition of basalt fiber up to 15 wt% increased the flexural strength and elastic modulus by 13% and 61%, respectively. The addition of kenaf fiber up to 15 wt% increased the flexural strength by 18% and the elastic modulus by 46%. Finally, samples were studied by field emission scanning electron microscopy to check the dispersion of graphene nanosheets, basalt, and kenaf fibers in the polymeric matrix.