| 摘要 |
Fibre-forming acetone-soluble copolymers of acrylonitrile and vinylidene chloride are prepared by polymerising a mixture of from 30% to 65% of acrylonitrile and 70% to 35% vinylidene chloride in the presence of a water-soluble polymerisation initiator, both monomers and the initiator being dissolved in a solvent mixture containing (a) water, (b) a water-miscible alcohol and (c) acetone, acetic acid or a mixture of acetone and acetic acid, the solvent mixture containing at least 15% by volume of each of (a), (b) and (c). Specified alcohols are ethanol (preferred), methanol, propanol, isopropanol, and tertiary butanol. The preferred activator is a redox catalyst, e.g. ammoninium persulphate/potassium metabisulphite and sodium chlorate/potassium. metabisulphite although hydrogen peroxide, ammonium persulphate t-butylhydroperoxide and sodium perborate may also be used; metal compounds, e.g. cupric acetate or a solvent salt should also be present in the redox system. Specifications 569,182 and 643,198 are referred to.
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