Optimization of the mechanical behavior of polymer composites reinforced with fibers, nanoparticles, and rubbers

Mechanical behavior of polypropylene-based nanocomposites reinforced with graphene, basalt, and ethylene propylene diene monomer (EPDM) was investigated in this study. The experimental design was based on the response surface methodology (RSM) and the Box-Behnken design (BBD). Graphene at 0.5, 1, and 1.5 wt%, basalt at 5, 15, and 25 wt%, and EPDM at 10, 20, and 30 wt% were manufactured and added to the matrix. The aim of this research was to achieve the maximum impact strength, tensile strength, and modulus of elasticity. The addition of 1 wt% graphene increased tensile and impact strength by 21% and 15%, respectively, while adding it up at 1.5 wt% decreased these properties. The modulus of elasticity increased to 58% when graphene was added at a concentration of 1.5 wt%. The addition of up to 25% basalt improved the modulus of elasticity, tensile strength, and impact strength by 47%, 19%, and 14%, respectively. The incorporation of EPDM decreased tensile strength and modulus of elasticity, but its addition by 30 wt% increased the impact strength by 62%. Finally, the dispersion of graphene and basalt in the polymeric matrix was examined using FE-SEM. The values obtained by this experiment for the mechanical properties were roughly close to the data yielded from desirability optimization.