Blends of polystryene, polyvinyl chloride and cross-linkable monomers were studied. The networks were based either on styrene with divinylbenzene or on ethyl acrylate with hexane diol diacrylate. Parameters governing the obtaining of macroscopically homogeneous plates were optimized. The tensile and impact resistance of such materials were tested. A preliminary approach to their structure was also carried out.