Evaluation of the effect of nanomaterials and fibers on the mechanical behavior of polymer-based nanocomposites using Box–Behnken response surface methodology.

This study aims to investigate the mechanical properties of hybrid polypropylene and ethylene-propylene-monomer (EPDM)-based nanocomposites reinforced with graphene nanosheets, nanoclay, and glass fibers. The response surface methodology was the study design. An internal mixer and a hot press machine were used to prepare the samples, including 0, 1, and 2 wt% of graphene nanosheets, 0, 3, and 6 wt% of nanoclay, 0, 10, and 20 wt% of glass fiber, and 0, 5, and 10 wt% of EPDM. To determine the tensile strength, tensile tests were conducted, and tensile modulus and impact tests were run to assess the impact strength of the compounds. Scanning electron microscopy images were taken to investigate the dispersion of nanoparticles and glass fibers in the polymer. The results showed the formation of agglomeration at high percentages of graphene nanosheets and nanoclay. The addition of lower weights of graphene nanosheets improved the impact strength, tensile strength, and tensile modulus by 23, 46 and 16%, respectively. Also, the use of low weight percentages of nanoclay increased the tensile strength by 21%, and its use at high weight percentages weakened the mechanical properties. The use of glass fibers increased the impact strength and tensile modulus by 18 and 24%, respectively. Its use first increased and then decreased the tensile strength. While the incorporation of EPDM increased the impact strength by 57%, it negatively affected the tensile behavior. [ABSTRACT FROM AUTHOR]