Sulfonated polystyrene (SPS) is a polyelectrolyte solid that is widely used in many applications. In this study, the sulfonation reaction of food packages polystyrene (PS) waste was done using sulfuric acid as a sulfonation agent, with the variation of concentration and times. The degree of sulphonation was determined. Composite from SPS and two types of fillers (carbon black and Nano silica) were synthesized, and new IPNs between SPS and phenolic resin type novolac was prepared. The characterization of the sulfonated product and its IPNs have covered functional groups' analysis using FTIR spectrophotometers. On the other hand, tensile and modulus of the SPS composites were determined, and the results showed that the tensile strength and modulus was increase with increasing filler content ( 0.48 Map for SPS alone to 1.051 Map when the percentage of Nano silica 7% ) while the modulus was increase from 0.527 Map for SPS alone to 1.272 Map when the percentage of Nano silica 7% , The same results obtained in the case of carbon black as filler .Water absorption of the prepared thin films for SPS was more than PS alone due to the effect of the presence of polar sulphonic group in their polymer chains . Thermal behavior of SPS and their IPNs also studied and evaluated using TGA and DSC techniques; the results show that the decomposition temperature was more than 300 oC