Effect of solvents on radiation-induced grafting of styrene onto fluorinated polymer films

The effect of solvents on radiation-induced grafting of styrene onto commer cial fluorinated polymer films such as poly(tetrafluoroethylene) (PTFE), po ly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) and poly(tetrafluoroet hylene-co-perfluorovinyl ether) (PFA) was investigated by a simultaneous ir radiation technique. Three solvents, ie methanol, benzene and dichlorometha ne, were used to dilute styrene under various irradiation doses, dose rates and monomer concentrations. The effect of addition of mineral and organic acids on the degree of grafting in the presence of the three solvents was a lso studied. The degree of grafting was found to be strongly dependent upon the type of solvent and composition of the monomer/solvent mixture. Diluti on of styrene with dichloromethane in various grafting conditions was found to enhance dramatically the degree of grafting compared with other solvent s, and the maximum degree of grafting was achieved at a monomer/solvent mix ture having a composition of 60:40 (v/v). The formation of polystyrene graf ts in the three fluorinated films was verified using FTIR spectrometry. (C) 2001 Society of Chemical Industry.