| 摘要 |
1348420 Acrylonitrile polymers BAYER AG 23 June 1971 [1 July 1970] 29412/71 Heading C3P Novel acrylonitrile polymers contain more than 28% by weight of crystalline component(s) (as determined by X-ray photography in accordance with Hendus' method) and have a K value greater than 80 and a narrow molecular weight distribution with an inhomogeneity factor (according to Vollmert) of less than 0�2. The polymers are obtained by polymerizing acrylonitrile monomer optionally containing up to 2% by weight of a comonomer in a solvent comprising at least 50% by weight of ethylene glycol carbonate at a temperature of from - 10� to +39�5� C. (i.e. the glycol carbonate solvent is in the solid state) using a free radical catalyst system containing an oxidizing agent (other than an organic hydroperoxide), which is soluble in ethylene glycol carbonate, and either a 1,3-diketone or oxalic acid. The optional comonomer may be an acidic monomer or salt thereof, e.g. sodium methallyl sulphonate. The glycol carbonate solvent may additionally include another solvent for polyacrylonitrile, e.g. dimethyl formamide, dimethyl sulphoxide, propylene carbonate or butylene carbonate. Suitable catalyst oxidizing agents include persulphates such as ammonium peroxydisulphate. Solutions of the polymers can be formed into filaments, fibres, films or wires. |
