The use of crosslinking promoters in the gamma-radiolysis of poly(tetrafluoroethylene-co-perfluoromethylvinyl ether). II

Incorporation of 0.5 mol % of nitrile and bromine functionalities was found to enhance the radiation crosslinking of the copolymer of tetrafluoroethyl ene-co-perfluoro(methylvinyl ether) (TFE/PMVE) by a factor of 2 for gamma-i rradiations carried out at room temperature to doses in the range 0-50 kGy. The functional groups, nitrile, perfluorophenyl, and hydrogen were found t o greatly enhance crosslinking well below the glass transition temperature of TFE/PMVE (276 K). Increased amounts of gel formation as well as improved tensile properties were obtained for irradiations carried out below the T- g of the polymers containing functionalized monomers. These functional grou ps appear to be acting as catalysts for the radiation crosslinking of TFE/P MVE but they do not get incorporated into the crosslink. (C) 2000 John Wile y & Sons, Inc.