| 摘要 |
1,139,120. Polymerizing acrylonitrile. CRYLOR. 1 May, 1967 [3 May, 1966], No. 20032/67. Heading C3P. [Also in Division C7] Polymers containing 50-100% by weight of acrylonitrile units and 0-50% by weight of comonomer units are prepared by polymerizing the corresponding monomer or monomers in aqueous medium in a polymerizer made of ferrous metal and in the presence of at least one electrode which is in contact with the polymerization medium and is connected electrically to the body of the polymerizer solely by a circuit outside this medium, the electrode being formed of a metal whose potential, in the medium, is positive with respect to the metal of the polymerizer, which metal is sufficiently electro-positive to dissolve in the medium, releasing hydrogen, immediately after it has been deposited on the wall of the polymerizer, and which exists in only a single oxidation state. Suitable comonomers include vinyl chloride, vinylidene chloride, vinyl acetate, acrylic or methacrylic acid and esters, amides and nitriles thereof, styrene - sulphonic acid, vinyl - oxyarylene sulphonic acids, acryloxyalkoxyarylene sulphonic acids and salts thereof, vinyl pyridine and its alkyl derivatives, and vinyl aminoalkyl ethers. Polymerization is generally effected with a redox catalyst, e.g. a mixture of a persulphate, chlorate, chlorite or hydrogen peroxide with sulphurous or hydrosulphurous acid. a bisulphite or hydrosulphite, or sulphur dioxide. The polymerization can be carried out continuously. The metal of the electrode(s) may be zinc, aluminium or magnesium or alloys thereof, e.g. with one or more of tin, titanium, copper and nickel. |
