Role of graphene nanoplatelets and carbon fiber on mechanical properties of PA66/thermoplastic copolyester elastomer composites

In this work, the effect of graphene nanoplatelets (GNPs) on the physico-mechnaical properties of short carbon fiber (SCF) reinforced polyamide 66/thermoplastic copolyester elastomer composites was investigated. The composites were fabricated with extrusion followed by injection molding method. The host matrix, fiber plus host matrix and graphene nanoplatelets loaded hybrid composites were examined for density, hardness, tensile, flexural and impact properties according to the governing ASTM standard. Fiber reinforcement decreased void content to < 1 % but GNPs were able to keep void content under limits. Hardness and impact strength augmented with 2 wt. % graphene nanoplatelets loading, owing to superficial dispersion developing the relationship between the hardness and impact strength. Graphene nanoplatelets loading benefitted the tensile property. However, the same has a deteriorating effect on flexural strength. Flexural modulus increases until 2 wt. %. Improvement in mechanical properties upon GNPs loading is very feeble when compared to the enhancement with SCFs loading to the host. Upon comparing the properties, it was observed that 2 wt. % of graphene nanoplatelets performed admirably and was recognized as an optimum filler loading. Morphology of fractured surfaces was studied by analyzing the scanning electron microscope images to understand the various features and mechanisms.