Experimental analysis of mechanical properties of graphene/kenaf/basalt reinforced hybrid nanocomposites using response surface methodology

Abstract

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.