| 摘要 |
Acrylonitrile is polymerized alone, or together with a copolymerizable monomer in an aqueous medium at pH values of from 2 to 6 with the aid of per-compounds and sulphur compounds of lower oxidation stage, in the presence of (a) 0.1 to 10 millimol of oxalic and/or malonic acid per mol of monomer(s), and (b) 0.5 to 20 p.p.m. of Cu11 ions, and/or 0.1 to 40 p.p.m. of Su11 ions and or 0.2 to 80 p.p.m. of Hg11 ions (based on the quantity of monomer in each case). Comonomers specified for use with acrylonitrile are acrylic and methacrylc esters, e.g. methyl acrylate, vinyl and vinylidene chlorides, vinyl acetate, acrylic and methacrylic acids and amides, styrene, vinyl sulphonic acid and styrene sulphonic acid. Also present during the polymerization may be thioglycol or an aliphatic mercaptan. Monomer and catalyst may be added to the reaction vessel as polymerisation proceeds. The acrylonitrile polymers produced are stated to have good thermostability. |
