Comparison Between Effects of Two Different Cationic Surfactants on Structure and Properties of HIPS/OMT Nanocomposites

The high impact polystyrene (HIPS)/organophilic montmorillonite (OMT) nanocomposites were prepared by melt-mixing. The hexadecyl triphenyl phosphonium bromide (P16) and cetyl pyridium chloride (CPC) were used to modify montmorillonite (MMT). The structure and thermal stability property of the OMT were respectively characterized by Fourier transfer infrared (FTIR) spectra, X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The results indicated that the cationic surfactants intercalated into the gallery of the MMT and the OMT had higher thermal stability. The influences of two different OMT on the structures and properties of the HIPS nanocomposites were characterized by XRD, TGA, Cone calorimeter and dynamic mechanical analysis (DMA), respectively. The increased basal spacing showed that HIPS intercalated into the gallery of the OMT. The TGA showed that onset temperature of thermal degradation, temperature of maximal weight loss and char residue at 700°C of the HIPS nanocomposites had remarkable enhancements compared to pure HIPS. The Cone calorimeter tests showed that the peak of heat release rate (PHRR) decreased significantly. The DMA indicated that the loading of silicate clays improved the storage modulus of HIPS.