Reduced graphene oxide-reinforced unsaturated polyester resin nanocomposites with improved thermal stability, mechanical modulus, and electromagnetic interference shielding performance

This article aims to investigate the impact of reduced graphene oxide (RGO) nanofillers on the curing kinetics, thermal stability, mechanical modulus, electrical conductivity, and EMI shielding effectiveness of unsaturated polyester resin (UPR). The curing rates of UPR/styrene (60/40 by wt%) mixtures with small amounts of RGO (0.1-0.3 wt%) exhibit slight delays owing to the barrier and scavenger roles of 2-dimensional RGO sheets. Nonetheless, it is observed that within the cured nanocomposites, RGOs are effectively dispersed and firmly bonded to the UPR matrix at interfaces through hydrogen bonding and pi-pi interactions. Consequently, the nanocomposites display heightened thermal decomposition temperatures and increased residue at 800 degrees C with higher RGO loading content. The addition of RGO notably improves the elastic storage modulus and increases the temperature associated with glass transition-related relaxation. The electrical percolation threshold is attained at a specific RGO loading between 0.2 and 0.3 wt%. Thus, the nanocomposite with 0.3 wt% RGO is characterized to have an electrical conductivity of 1.9 x 10(-6) S/cm and an EMI shielding effectiveness of similar to 9 dB at 8 GHz, for a thickness of 1 mm.