A method for the preparation of polymers of hexa fluorine cyclo penta diene and / or perfluoro dicyclo penta diene

摘要

Octafluorocyclopentene may be hydrogenated in the presence of an alumina supported palladium catalyst at 175 DEG to 200 DEG C. to give a mixture of 1,2-dihydrooctafluorocyclopentane and a minor proportion of 1,1,2-trihydroheptafluorocyclopentane. The product may be treated with potassium hydroxide at 155 DEG to 160 DEG C. to give a mixture of hexafluorocyclopentadiene, 1-hydroheptafluorocyclopentene and 3-hydroheptafluorocyclopenteneALSO:Polymers of hexafluorocyclopentadiene may be prepared by subjecting hexafluorocyclopenta diene to polymerization conditions in the presence of a free radical forming catalyst and optionally one or more polymerizable ethylenically unsaturated compounds. Specified comonomers are ethylene, propylene, isobutylene, styrene, vinyl chloride, vinyl fluoride, vinylidene chloride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropene, acrylic and methacrylic acids, esters and nitriles, vinyl esters, vinyl ethers and conjugated dienes. Polymerization may be effected in bulk, solution or dispersion, to give liquid polymers suitable as plasticizers and hydraulic fluids and solid polymers suitable for moulding articles and pressing into films. The polymers heat cured or vulcanized. Examples describe (1) the bulk polymerization of hexafluorocyclopentadiene in the presence of nitrogen difluoride or azobisisobutyronitrile; (2) the copolymerization of hexafluorocyclopentadiene and tetrafluoroethylene in perfluoro-(dimethylcyclobutane) in the presence of nitrogen difluoride; the bulk copolymerization of hexafluorocyclopentadiene with (3) methyl methacrylate and (4) acrylonitrile in the presence of azobisisobutyronitrile; and (5) the copolymerization of hexafluorocyclopentadiene with hexafluoropropene and vinylidene fluoride in aqueous dispersion in the presence of ammonium persulphate, ammonium perfluorooctanoate and disodium phosphate.