The cationic sudactant trimerhyloctadecylammonium chloride (OTAC) and the reactive cationic surfactant allyldimethyloctadecylammonium chloride (ADAC) were used for the intercalation of MMT．PS/C18MMT and PS/AC18 MMT nanocomposites were synthesized by in situ emulsion polymerization The results of XRD and TEM showed that MMT was exfoliated into sheets of individual layers or few layers during polymerization and randomiy dispersed in the PS matrix．TGA curves indicated that the degradation temperature of the nanocomposites was enhanced by the addition of MMT

moreover

the degradation temperature of PS/AC18 MMT was higher than that of PS/C18MMT due to the existence of chemical links between PS and the layers of organ-MMT．The results of dynamic mechanical analysis showed that the storage modulus G’and loss factor tanδ of PS were increased and decreased respectively with the addition of MMT．The glass transition temperature of PS/AC18 MMT is higher than that of the pure PS while the glass transition temporature of PS/C18 MMT is slightly lower than that of the pure PS．