| 摘要 |
<p>Acrylonitrile is polymerized alone or in admixture with one or more polymerizable compounds, other than aliphatic olefines, which are soluble in water and in organic solvents, in an emulsifier-free aqueous solution in which a polymerization catalyst is dissolved, the concentration of the acrylonitrile monomer and other monomers, if present, being kept constant by vigorously stirring with one or more organic solvents for the monomer or monomers, which are immiscible with water, and in which the polymerization catalyst is insoluble. Solvents specified are pentane, isopentane, hexane, isohexane, heptane, isoheptane, cyclopentane, cyclohexane, cycloheptane, benzene, and toluene. Copolymerizable monomers specified are 2, 3-, and 4-vinyl pyridines, vinyl isopropyl ether, and methoxy ethyl vinyl ether. As a catalyst there may be used alkali and ammonium persulphates, which may be activated by water-soluble reducing agents such as sulphites, bisulphites, metabisulphites, polyhydroxy compounds and/or water-soluble compounds of heavy metals such as copper sulphate and silver nitrate. The aqueous polymerization medium may contain a salt dissolved therein, and preferably has a pH of between 2 and 5. Specification 586,796 is referred to.</p> |
