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

Abstract

The effect of solvents on radiation‐induced grafting of styrene onto commercial fluorinated polymer films such as poly(tetrafluoroethylene) (PTFE), poly(tetrafluoroethylene‐co‐hexafluoropropylene) (FEP) and poly(tetrafluoroethylene‐co‐perfluorovinyl ether) (PFA) was investigated by a simultaneous irradiation technique. Three solvents, ie methanol, benzene and dichloromethane, 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 also studied. The degree of grafting was found to be strongly dependent upon the type of solvent and composition of the monomer/solvent mixture. Dilution of styrene with dichloromethane in various grafting conditions was found to enhance dramatically the degree of grafting compared with other solvents, and the maximum degree of grafting was achieved at a monomer/solvent mixture having a composition of 60:40 (v/v). The formation of polystyrene grafts in the three fluorinated films was verified using FTIR spectrometry. © 2001 Society of Chemical Industry

Pre‐Irradiation Grafting of Styrene/Divinylbenzene onto Poly(tetrafluoroethylene‐co‐hexafluoropropylene) from Non‐Solvents

“…This applies to simultaneous-irradiation grafting at high dose rates [20] as well as to grafting systems with base materials or graft polymers that are incompatible with the monomer but swell in monomer/solvent mixtures [21 ± 24]. In partially just seeming agreement with these observations, benzene, toluene, and CH 2 Cl 2 have been repeatedly used as solvents for radiation grafting of styrene and styrene derivatives [19] [20] [28 ± 32].…”

A review of radiation-grafted polymer electrolyte membranes for alkaline polymer electrolyte membrane fuel cells

“…In general, grafting starts from the surface then proceeds inward through the swollen grafted layers [205,231]. Diffusion of the monomer affects chain growth and chain termination in the internal structures of the membrane.…”

Preparation of crosslinked polystyrene-grafted PFA films by a simultaneous irradiation method

“…60% styrene/DVB solution irradiated at a 10 kGy dose also became a brittle solid due to a homopolymer formation and the grafted film from the solution was not recovered because this condition was not useful for a simultaneous grafting. Dichloromethane was chosen as the solvent for the grafting of styrene/DVB since it is known to increase the swelling rate of fluoropolymer films and to reduce the homopolymerization of styrene during a simultaneous irradiation process, compared to other solvents such as benzene and methanol [14][15][16].…”