Hydrophilic-hydrophobic IPN materials of poly(acrylic acid)poly(styrene-co-acrylonitrile) were synthesized and the pervaporation characteristics of the IPN membranes were evaluated for the separation of ethanol/water mixture. Hydrophilic-hydrophobic IPN materials of polyurethane-polystyrene were synthesized and the blood compatibility of the IPN's were measured for the biomedical application. Dicyanate-engineering plastics semi-IPN's were prepared and the morphology and mechanical properties were evaluated for the high temperature composite matrix materials.