Radiation-induced radical polyaddition of Bis(-trifluoromethyl-, -difluorovinyl) terephthalate with excess of various ethers

Enomoto, Kazuyuki*; Maekawa, Yasunari; Katsumura, Yosuke*; Miyazaki, Toyoaki*; Yoshida, Masaru; Hamana, Hiroshi*; Narita, Tadashi*

Radiation-induced radical polyaddition of bis(-trifluoromethyl-,-difluorovinyl) terephthalate [CF=C(CF3)OCOCHCOOC(CF)=CF] (BFP) in the presence of an excess of cyclic and acyclic ethers in feed was examined at 0C using -rays irradiation. Irradiation of BFP with an 8-fold excess of 1,4-dioxane (DOX) and diethyl ether (EE) gave monomodal polymers consisting of the ernating unit of BFP and DOX moieties (poly(BFP--DOX), = 5.110) and of BFP and EE (poly(BFP--EE), =3.910), respectively. The irradiation of BFP with an 8-fold excess of tetrahydrofuran or tetrahydropyran provided only 1:2 addition products in high yields. Mono-functional 2-benzoxypentafluoropropene [CF=C(CF)OCOCH] (BPFP) as a model compound showed preferential formation of the 2:1 adduct to the 1:1 adduct with DOX and EE. The kinetic analysis of the model reactions revealed that the rate constants for the formation of the 2:1 adducts () of BPFP with DOX and EE were two orders of magnitude higher than those of the 1:1 adducts (). Poly(BFP--DOX) showed higher radiation resistance than poly(BFP--EE) in solid states as well as in solution. It was concluded that radiation-induced step-growth polymerization under the stoichiometric imbalance of the two compounds requires a high / value as well as high radiation resistance for the formation of high molecular weight polymers.