FRIEDEL-CRAFTS REACTION GRAFTING OF PVC AND PS THROUGH MICROWAVE IRRADIATION: FRIEDEL-CRAFTS REACTION GRAFTING OF PVC AND PS THROUGH MICROWAVE IRRADIATION

With tetrahydrofuran or cyclohexanone as dissolvent, Friedel-Crafts reaction grafting of polyvinyl chloride and polystyrene was realized through microwave irradiation. Graft of PVC-g-PS was successfully prepared. Influence of heating method, reaction temperature, type and mass fraction of catalyst on grafting reaction and grafting ratio was investigated. Graft structure of PVC-g-PS was characterized through FTIR, the mechanism and features were discussed. Results showed that Friedel-Crafts reaction grafting of polyvinyl chloride and polystyrene can carry out through heating by oil bath or microwave irradiation. Under heating with oil bath the graft of PVC-g-PS occurs at the meta position of the benzene ring, and the graft ratio is only 0. 27%; while in the case of microwave irradiation,the graft of PVC-g-PS occurs at ortho-para positions of the benzene ring, and the graft ratio reaches up to 23%. Anhydrous AlCl3, FeCl3 or SnCl4 can all catalyze Friedel-Crafts reaction grafting of polyvinyl chloride and polystyrene, but the best catalytic activity is observed for anhydrous AlCl3. When the mass fraction of anhydrous AlCl3 is 3%, the highest graft ratio reaches up to 29%, but when mass fraction of anhydrous AlCl3 is over 3%, the graft ratio declines, PVC begins degradation and produces olefinic bonds. Research results demonstrate that microwave irradiation is an effective way of realizing Friedel-Crafts reaction grafting of polyvinyl chloride and polystyrene.