Preparation and characterization of permanently anti-static packaging composites composed of high impact polystyrene and ion-conductive polyamide elastomer

Antistatic composites composed of high impact polystyrene (HIPS) and NaSCN doped poly(ether-block-amide) (PEBA) solid-polymer-electrolyte (SPE) were successfully prepared in a Haake torque rheometer. The influence of PEBA component on the surface resistivity of PEBA-based SPE was extensively studied by surface resistivity test. The dependence of the surface resistivity of HIPS/SPE composites on both temperature and relative humidity (RH) was also investigated. Thermal decomposition behaviors, mechanical properties, and surface morphology of the HIPS/SPE composites were evaluated by thermal gravimetric analysis (TGA), tensile test, and scanning electron microscopy (SEM), respectively. The results show that the surface resistivity of the HIPS/SPE composites can be effectively reduced to 10⁹ Ω cm⁻² orders of magnitude when the SPE content reaches 20 phr. TGA result reveals that the antistatic HIPS/SPE (70/30 by wt.) composite can be fabricated by traditional thermoplastic processing method without any decomposition once the processing temperature is lower than 320 °C. SEM results show that the antistatic ability of HIPS/SPE composites is originated from the formation of continuous PEBA-based ion-conductive channels or networks.