Novel Fluorinated Hybrid Polymer by Radical Polyaddition of Bis(α‐trifluoromethyl‐β,β‐difluorovinyl) Terephthalate onto Dialkoxydialkylsilanes

Abstract

To develop the radical polyaddition of bisperfluoroisopropenyl esters, the reactions of bis(α‐trifluoromethyl‐β,β‐difluorovinyl) terephthalate [CF2C(CF3)OCOC6H4COOC(CF3)CF2] (BFP) with dialkoxydialkylsilane were examined to prepare fluorinated hybrid polymers bearing dialkylsilyl groups in the main chain. Prior to polyaddition, the radical addition reaction of 2‐benzoyloxypentafluoropropene [CF2C(CF3)OCOC6H5] (BPFP) has been investigated to afford the results that diethoxydimethylsilane (DEOMS) or dimethoxydimethylsilane with BPFP initiated by oxo radical are the best combination for the preparation of polymers. The mechanism of the addition reaction was proposed. Radical polyaddition of BFP with DEOMS initiated by benzoyl peroxide or di‐tert‐butyl peroxide has yielded polymers of up to molecular weight 1 × 106 with rather broad molecular weight distribution. A mechanism for the polyaddition reaction is proposed based on the radical addition reaction between BPFP and DEOMS. The step‐growth polymerization is initiated by hydrogen abstraction of DEOMS to add a perfluoroisopropenyl group, followed by a 1,7‐shift of the radical in the intermediate. The relationship between addition reaction mechanism and polyaddition mechanism was also discussed.

Radical polyaddition reaction of bis(α-trifluoromethyl-β,β-difluorovinyl) 2,3,5,6-tetrafluoroterephthalate

“…The reaction was ceased by bubbling oxygen and the concentration of PFBP was measured by vapor-phase chromatography (GC) by means of tridecane as an external standard. The reaction system was concentrated by removing lowboiling materials under reduced pressure, and the reaction products were roughly separated by the chromatography of silica gel 60 column with hexane: diethyl ether (20:1 to d ¼ À71:4to À 72:3 (3F, m, CF 3 ), À115:7to À 120:2 (2F, m, CF 2 ), À136:1to À 136:7 (2F, m, C 6 F 5 (o)), À145:1toÀ 145:5 (1F, m, C 6 F 5 (p)), À159:4to À 159:8 (2F, m, C 6 , À119:2to À 120:0, À122:2to À 123:6, À127:8to À 128:9 (2F, m, CF 2 ), À138.4 (2F, s, C 6 F 5 (o)), À147.5, À147.7 (2F, t, J ¼ 23:0 Hz, C 6 F 5 (p)), À161.6, À161.8 (1F, t, J ¼ 23:0 Hz, C 6 F 5 (m)).…”

“…(1) [1]; which suggests that a wide variety of organic compounds possessing carbon-hydrogen bonds might be incorporated into polymer main chains. The 2,5-diaddition on DOX was demonstrated by X-ray crystallographic analysis of the reaction product of 2-benzoxypentafluoropropene [CF 2 ¼C(CF 3 )OCOC 6 H 5 ] (BPFP) with DOX [2]. The development of radical addition reaction of perfluoroisopropenyl group (CF 2 ¼CðCF 3 ÞÀ) with the organic compounds possessing carbonÀhydrogen bonds enables to prepare a wide variety of fluorinated polymers from the compounds which have never been supposed as starting materials for preparation of polymers.…”

“…The development of radical addition reaction of perfluoroisopropenyl group (CF 2 ¼CðCF 3 ÞÀ) with the organic compounds possessing carbonÀhydrogen bonds enables to prepare a wide variety of fluorinated polymers from the compounds which have never been supposed as starting materials for preparation of polymers. The reaction has been developed to preparation of polymers with 1,2-dimethoxyethane [3], diformylalkane [4], triethylamine [5] and dialkoxydialkylsilanes [6].…”

“…In this report, the preparation of polymers by radical polyaddition of bis(a-trifluoromethyl-b,b-difluorovinyl) 2,3,5,6-tetrafluoroterephthalate [CF 2 ¼C(CF 3 )OCOC 6 F 4 -COOC(CF 3 )¼CF 2 ] (TFT) with DOX and diethoxydimethylsilane (DEOMS) is discussed in order to obtain polymers of higher fluorine content compared to those from BFP with Journal of Fluorine Chemistry 125 (2004) 381-389 (1) DOX and DEOMS since the results of detailed study on the high reactivity of DOX [1] and DEOMS [6] has previously been reported. The reactivity difference between TFT and BFP was also examined by the ternary polyaddition of TFT, BFP and DOX.…”

Novel fluorinated polymer from 18-crown-6 by radical polyaddition

“…To develop the radical addition reaction of perfluoroisopropenyl esters with cyclic ethers, radical polyadditions of bifunctional bis(a-trifluoromethyl-b,b-difluorovinyl) dicarboxylates [CF 2 ¼C(CF 3 )OCO-R-COOC(CF 3 )¼CF 2 ] with compounds possessing carbon-hydrogen bonds, such as 1,4-dioxane (Eq. (1)) [3], diethyl ether [4], 1,2-dimethoxyethane [4], dimethyldiethoxysilane [5], diformylalkane [6] and triethylamine [7] have previously been reported to yield the corresponding polymer bearing a molecular weight of as high as 10 4 . To grow up the addition reaction, the present paper is concerned with the production of the polymers from a bifunctional perfluoroisopropenyl ester, bis(a-trifluoromethyl-b,b-difluorovinyl) terephthalate [CF 2 ¼ C(CF 3 )OCOC 6 H 4 COOC(CF 3 )¼CF 2 ] (BFP), with 18-crown-6.…”