Abstract
An original synthesis of 8-bromo-1H,1H,2H-perfluorooct-1-ene (BDFO) and its radical copolymerization with vinylidene fluoride (VDF), initiated by 2,5-bis(tert-butylperoxy)-2, 5-dimethylhexane at 134 8C, are presented. The fluorinated bromoalkene was obtained by dehydrobromination of 1,8-dibromo-1H,1H,2H,2H-perfluorooctane in a satisfactory yield. Although BDFO did not homopolymerize under radical initiation, it did copolymerize with VDF. The compositions of the resulting random type copolymers were calculated by means of 19F NMR spectroscopy and allowed the quantification of the respective amounts of both comonomers in the copolymers, showing good incorporation of the brominated monomer. Nevertheless, obtaining PVDF copolymers containing a high molar percentage of BDFO in good yields was difficult to achieve from initial molar ratios of BDFO higher than 9.2 mol-%. Radical terpolymerization of VDF, BDFO and hexafluoropropene (HFP) was also successfully achieved. BDFO contents in these co- or terpolymers ranged from 3.6 to 12.2 mol-%. The bromoalkene acted as a cure site monomer and the resulting poly(VDF-co-BDFO) copolymers were crosslinked via the bromine atom in the presence of a triallyl isocyanurate/peroxide system. The materials obtained led to more thermally stable copolymers than the uncured ones and their thermostabilities were compared to those of commercially available poly(VDFco- HFP) copolymers crosslinked using diamines.