| 摘要 |
Polyacrolein of very high molecular weight is prepared from acrolein in the presence of water and a catalyst which is an aqueous solution of a polymer that contains sulphur dioxide and/or bisulphite in combined form and which is either soluble in water or becomes so on combination with sulphur dioxide and/or bisulphite. Specified polymers are polyvinyl carbazole, polyvinyl amine, polyvinyl alcohol, polyvinyl pyrrolidone, polyglycol, gelatine, cellulose polyethers, polyguanidine and particularly polyacrolein. The molecular weight of the product may be reduced by polymerizing in the presence of aliphatic alcohols and sugars, and may be increased by polymerising in the presence of polyformaldehyde. Examples describe the polymerization of acrolein in the presence of (1 and 3-6) polyacrolein /sulphur dioxide adducts, (2) a hexamethylene polyguanidine hydrochloride/sulphur dioxide adduct, and polyacrolein/sulphur dioxide adducts together with (7) methanol, (8) ethanol, (9) ethylene glycol and glycerol and (10) polyformaldehyde. Specifications 855,889 also is referred to. |
