Synthesis and characterization of 4-vinyl pyridine-crafted Teflon-PFA filmfor water technologies

To get highly reactive polymeric materials for selective studies of enzyme immobilization, water purification, separation, and enrichment technologies , we attempted to graft 4-vinyl pyridine (4-VP) onto Teflon-PFA by simultan eous gamma -ray initiation. The resulting graft copolymers were quaternized by treatment with some alkylating agents. Optimum conditions for grafting were evaluated through the variation of the total dose of radiation, the am ount of water, and the monomer concentration. The effect of the solvent com position (H2O/MeOH) was also studied. In the presence of MeOH, grafting occ urred less often and was nonselective as 4-VP was incorporated on both side s in comparison with highly selective grafting in an aqueous medium. The pe rcentages of the grafting, total conversion, and grafting efficiency and th e rates of the polymerization, grafting, and homopolymerization were also e valuated. Some other monomers such as methacrylic acid, methyl methacrylate , maleic acid, acrylonitrile, and vinyl imidazole were not incorporated ont o the backbone film under the optimum grafting reaction conditions evaluate d for the grafting of 4-VP. Although some grafting occurred, the graft yiel d was too low to be considered of any significance. The grafted films were quaternized with benzyl chloride, and quaternized and unquaternized films w ere used for the immobilization of lipase. The former showed high activity with lipase and has potential for development as a bioreactor. (C) 2000 Joh n Wiley & Sons, Inc.