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Zhai, M.; Hasegawa, Shin; Chen, J.; Maekawa, Yasunari
Journal of Fluorine Chemistry, 129(12), p.1146 - 1149, 2008/12
Times Cited Count:16 Percentile:53.12(Chemistry, Inorganic & Nuclear)We report herein the first successful grafting of perfluorinated vinyl ether monomer into base polymer films by simultaneous radiation method. 2-Bromotetrafluoroethyl trifluorovinyl ether (BrTFF) could be grafted into poly(ethylene-co-tetrafluoroethylene) (ETFE) films by -rays irradiation at room temperature. The grafting yield increased linearly with an increase in the dose up to 1400 kGy. The required dose for a satisfactory grafting yield, such as 20%, was as high as ca. 400 kGy probably due to low polymerization reactivity of fluorinated monomers. The thermal analysis of the grafted films indicated no phase separation between poly (BrTFF) grafts and ETFE films, probably owing to high compatibility of the fluorinated grafts and base polymers.
Narita, Tadashi*; Enomoto, Kazuyuki*; Maekawa, Yasunari; Yoshida, Masaru; Ichikawa, Mitsuru*; Hamana, Hiroshi*
Journal of Fluorine Chemistry, 128(1), p.52 - 54, 2007/01
Times Cited Count:5 Percentile:19.25(Chemistry, Inorganic & Nuclear)Perfluorinated polymers have expected to be the key materials for fuel cell membranes owing to the high chemical stability, thermo-durability and optical property. However, a homopolymer of FVPE has never yielded under usual polymerization conditions and alternating copolymers with several non-fluorinated vinyl monomers have only been reported. Thus, using radiation-induced polymerization, in which initiating species (radicals) can be continuously produced, the polymerization of trifluorovinyl heptafluoropropyl ether (FVPE) was examined to afford high molecular weight polymers of FVPE. The formation of FVPE homopolymers was confirmed by NMR and IR spectroscopy.
Enomoto, Kazuyuki*; Narita, Tadashi*; Maekawa, Yasunari; Yoshida, Masaru; Hamana, Hiroshi*
Journal of Fluorine Chemistry, 125(7), p.1153 - 1158, 2004/07
Times Cited Count:3 Percentile:10.64(Chemistry, Inorganic & Nuclear)Radical polyaddition of bis(-trifluoromethyl-
,
-difluorovinyl) terephthalate (BFP) with 1,4-dioxane (DOX) afforded higher molecular weight polymers under
-rays compared to those yielded by benzoyl peroxide initiation. More detailed study on the radiation-induced polyaddition of BFP with DOX and optimization of the reaction conditions were carried out. It was necessary to irradiate with doses of 2000, 1500, and 750 kGy, to obtain quantitative conversion of BFP at the feed molar ratio DOX/BFP of 8.0, 16, and 32, respectively. Step-growth polymerization mechanism was suggested by the measurements of molecular weights of the polymers obtained with several irradiation doses. It was concluded that the molecular weight of the polymer could be controlled by the feed molar ratio of DOX/BFP and irradiation doses. The reaction between polymers might take place after the quantitative conversion of BFP. Radiation-induced radical polyaddition mechanism of BFP with DOX was proposed.