| 摘要 |
A method of stabilizing solutions of acrylonitrile polymers in strong sulphuric acid is characterized in that, for the purpose of delaying saponification of the cyano groups, there is added to the solution an inhibitor selected from a monocarboxylic acid other than glycolic acid, a carboxylic acid amide other than benzamide or urea, a carboxylic acid ester other than phenolphthalein, an ammonium salt of a carboxylic acid, a nitrile, a beta-diketone, a dicyano diethyl sulphide, a butyl titanate or orthophosphoric acid. Specified inhibitors are formamide, acetamide, cyanoacetamide, trichloro-acetamide, n-caproamide, urethane, acetyl urea, ethyl formate, ethyl acetoacetate, ammonium formate, ammonium acetate, acetylacetone, b ,b 1-dicyanodiethylsulphide and n-butyl titanate. Examples describe the stabilization of sulphuric acid solutions of (1) an acrylonitrile-methyl methacrylate copolymer with formamide; and of polyacrylonitrile with (2) formamide, (3) acetylacetone, (4) ammonium acetate, (5) ethyl formate and (6) n-butyl titanate. The solutions may be used in the manufacture of films, filaments and fibres. |
