Polyaniline and graphene nanocomposites for enhancing the interlaminar fracture toughness and thermo-mechanical properties of carbon fiber/epoxy composites

Abstract: Delamination is one of the major concerns for carbon fiber reinforced polymer (CFRP) composites. Improving fracture toughness reduces delamination and allows for the creation of multifunctional CFRP. In this study, polyaniline (PANI) coated graphene nanoplatelets (GNP) are introduced in the interlaminar region of CFRP pre-preg with the aid of environmentally friendly thermoplastic polymer, polyvinylpyrrolidone (PVP). The GNP content is varied as 1, 3, and 5% by weight with respect to PVP. The improvements in the fracture toughness are investigated using a double cantilever beam test. An improvement of approximately 79% in mode-I fracture toughness is observed with the addition of 5 wt% GNP with respect to PVP. Dynamic mechanical analysis results confirmed the improvements in storage modulus but showed a decrease in glass transition temperature with the addition of nanofiller. Various spectroscopic analysis and imaging techniques were used to understand and evaluate the interactions of nanocomposites with CFRP pre-preg.