Abstract
The present invention concerns the synthesis of new fluoroelastomers having very low glass transition temperatures (Tg), a good resistance to acids, to oils and fuels, as well as good workability properties. The elastomers of this invention contain, by way of a non limiting example, from 60 to 80 mole % of vinylidene fluoride (henceforth "VDF") and 20 to 40 mole % of perfluoro(4-methyl-3,6-dioxaoct-7-ene)sulfonyl fluoride (henceforth "PFSO2F"). The present invention also pertains to the preparation of these elastomers by radical copolymerisation of the comonomers in the presence of conventional organic initiators, such as peroxides, peresters, diazocompounds or alkyl peroxipivalates.