Preparation and properties of flame retardant high impact polystyrene

Flame retardant high impact polystyrene (HIPS) was prepared by melt blending HIPS with nano-modified aluminum trihydrate (nano-CG-ATH) and red phosphorus masterbatch (RPM). Styrene–butadiene–styrene (SBS) was used as a strengthener in this research. The effects of the nano-CG-ATH, RPM, and SBS on properties of HIPS composites were studied using mechanical and combustion tests, and thermogravimetric analysis. The morphologies of fracture surfaces and char layers were characterized through scanning electron microscopy (SEM). The HIPS/nano-CG-ATH/RPM (68/20/12) composite and its combustion residues at various temperatures were characterized by Fourier transform infrared (FTIR) spectra analysis. The results show that the UL-94 rating of the HIPS/nano-CG-ATH/RPM (68/20/12) composite reached V–0 and that its char layer after flame test was well-developed and robust, but that its impact performance was poor. The addition of the SBS improved its impact performance but did not influence its thermal and flame retardant properties, but lowered its tensile strength and flexural modulus to some extent. The FTIR spectra confirm that both P–O–P and P–O–C groups were present in the char.