Effect of graphene on mechanical properties and flame retardancy of polycarbonate/ acrylonitrile butadiene styrene nanocomposites

Abstract

Polycarbonate/acrylonitrile butadiene styrene (PC/ABS) nanocomposite containing graphene nanoplatelets (GNPs) as a nanofiller and bisphenol A bis(diphenyl phosphate) (BDP) as a flame retardant was prepared using a counter-rotating twin-screw extruder followed by injection molding. The mechanical properties of the nanocomposites were studied through the tensile, flexural and impact testing. The thermal characteristics of the nanocomposites were evaluated through thermogravimetric analysis (TGA). The morphological behavior of the samples was observed via Field Emission Scanning Electron Microscopy (FESEM). The chemical structural of the PC/ABS nanocomposites were investigated by Fourier trans-form infrared (FTIR). Flammability of the nanocomposite has been measured using the Limiting Oxygen Index (LOI) and UL94. The tensile strength, Young's modulus and flexural properties of PC/ABS blend improved when GNPs and BDP was incorporated. The maximum tensile strength, Young's modulus and flexural properties have been observed for the nanocomposite with 3wt.% GNPs content. The thermal stability of PC/ABS/BDP and its nanocomposite were significantly improved compared with pure one, when the GNPs loading was only 1wt.% the 20% weight loss temperature (T10) increased 23 oC. The char residual of PC/ABS/GNPs3 dramatically increased by 64 % with incorporation of 10 wt.% BDP. A synergism in LOI and UL94 were observed for PC/ABS/GNPs3/ BDP10 compared to PC/ABS + BDP. FESEM results showed well dispersion of GNPs in PC/ABS blend. Besides the intercalation of GNPs was observed when BDP added to the nanocomposite. The FTIR spectra showed that the addition of GNPs in PC/ABS matrix did not result in any significant change in its chemical structure however some hydrogen bonding reactions between GNPs and PC/ABS blend is proposed.