Dynamic mechanical and thermal properties of fire‐retardant high‐impact polystyrene

Abstract

AbstractThe interaction of a series of fire‐retardant additives with high‐impact polystyrene (HIPS) has been inferred from their dynamic mechanical and thermal properties. High‐melting additives phase separate and act as inert filler in both the rubber and polystyrene phases, while low‐melting additives raise the Tg of the rubber phase and plasticize the polystyrene phase. Antimony oxide antiplasticizes the grafted rubber phase but acts as inert filler in the polystyrene phase. The impact strength of these fire‐retardant HIPS's shows good correlation with the integrated loss tangent of the rubber Tg peak indicative of large energy dissipation in the rubbery region during impact causing the matrix to craze or flow. It is also suggested that additives which are compatible with, and localized in, the polystyrene phase help retain the impact strength of HIPS.