Pervaporation membranes endowed with catalytic properties, based on polymer blends*

Membranes endowed with both catalytic and separative properties were designed by using the polymer blend concept Two polymer blend systems were studled the poly (acrylonltnle)(PAN)-poly (styrene sulfonlc acid)(PSSA)and the poly (vinyl alcohol)(PVA)-PSSA blend From mlsclblhty and extraction studies, it appeared that PAN-PSSA could not be employed due to polymer segregation and extraction of PSSA m the liquid mixture In the case of PVA-PSSA, mlsclblhty was observed at high PVA content but, whatever relative polymer concentration m the blend, PSSA extractlon occurred To circumvent this extraction problem, PVA crosshnkmg was carried out by heat treatment The catalytic and separative properties of the membranes were tested with an estenflcatlon reaction mixture Good catalytic properties were observed A rather good selectlvlty was also obtained, but not sufficient for the combined process By castmg the PVA-PSSA blend onto a hydrophlhc GFT membrane and by subsequently crosshnkmg the blend, a composite membrane with both good catalytic and separative propertles was obtained