Effect of surface treatment of carbon fiber on the electrical and mechanical properties of high-impact polystyrene composite

Carbon fiber (CF), PU(polyurethane)-coated carbon fiber (CF-PU) and Ni-coated fiber (NCF) treated with a coupling agent (CA) were used to prepare composites for high impact polystyrene (HIPS) by melt blending. The optimum concentration of the titanate CA is 1.5 phf (per hundred parts of filler) when coupled with the carbon fibers. A composite prepared by adding a CA directly into the matrix which was then reinforced with fibers was investigated for comparison. These composites were evaluated for electromagnetic interference shielding effectiveness, dispersion, and adhesion between the polymer and the filler by means of scanning electron microscopy (SEM). The addition of CA generally improved the shielding effectiveness; this is especially apparent when the matrix was pretreated with CA before compounding with the fibers. The tensile properties were also improved upon CA addition.