Effect of solvents in radiation-induced grafting of 4-vinyl pyridine onto fluorinated ethylene propylene copolymer

A wide range of solvents have been examined to find their effect on radiation-induced grafting of 4-vinyl pyridine onto fluorinated ethylene propylene copolymer by simultaneous irradiation technique. The effect of solvent on percentage of grafting has been monitored by varying monomer concentration and total dose of radiation. Further grafting results have been correlated with the solubility parameter of the solvent and solvent mixtures. Evidence of grafting has been based on characterization of grafted samples in terms of FTIR, EDAX, X-ray mapping, thermogravimetric analysis, and dynamic mechanical analysis. Depth profiling of a few representative grafted films were studied by viewing the cross-sectional distribution of elemental nitrogen using SEM-EDAX. The results suggest that with increase in grafting the grafting front propagates from the surface toward bulk, thus establishing the frontal mechanism of radiation grafting. Furthermore, the grafted films were characterized for their surface properties using contact angle goniometry. (C) 2008 Wiley Periodicals, Inc.