Effects of tension rates and filler size on tensile properties of polypropylene/graphene nano-platelets composites

The influence of tension rates and filler size on the tensile properties of polypropylene (PP) composites separately reinforced with graphene nano-platelets (GNPs) were investigated at room temperature within a tension rate range from 20 to 300 mm/min using a universal materials tester. The results showed that the Young's modulus, the tensile yield strength and the tensile fracture strength of these three PP composite systems increased obviously when tension rate was lower than 100 mm/min, and then increased slightly with increasing tension rate. The tensile elongation at break of these three composite systems decreased obviously when tension rate was lower than 100 mm/min, and then decreased slightly with increasing tension rate. The morphology of the tensile specimens of the composite was observed after tensile tests. Finally, the reinforcement mechanisms of the composites under different tension rates were discussed.