| 摘要 |
A method for preparing stable, epihalo hydrin-alkylenepolyamine condensation copolymers having a high molecular weight within the range of 10,000-20,000 comprises the steps of: slowly adding an epihalohydrin to an aqueous, concentrated, agitated solution of an alkylenepolyamine having a 25-60% concentration by weight to form an aqueous reaction mass thereof, the addition being at temperatures of 105 DEG to 185 DEG F. until the mol. ration of epihalohydrin to alkylenepolyamine is within the range of 1.4 : 1 to 2.2 : 1, further polymerizing the reaction mass, after the addition, within the range of 150-185 DEG F. while slowly simultaneously diluting the concentrated reaction mass to a final copolymer solids content of 10 to 30% by weight; and adding at least 0.2% by weight of the total reaction mass of a reducing agent to prevent further polymerization and gelation. High molecular weight condensation copolymeric compositions comprise aqueous solutions containing 10-30% by weight of an epihalohydrin-alkylenepolyamine condensation copolymer of molecular weight of 10,000 to 20,000 and at least a stabilizing amount of a reducing agent, the solution having a viscosity of at least 200 c.p.s., when measured as a 20% by weight aqueous solution of the copolymer at 75 DEG F. Epihalohydrins specified are epichlorohydrin, epibromohydrin and epi-iodohydrin; many alkylenepolyamines are specified which are alkylenediamines or polyalkylenepolyamines. Reducing agents specified are hydrogen sulphide, alkali metal sulphites, stannous chloride, hydriodic acid, ferrous chloride and sulphur dioxide. The copolymers are useful as precipitants for the clarification of water.ALSO:High molecular weight (10,000-20,000) epihalohydrin-alkylenepolyamine condensation copolymers are used as coagulants in the clarification of water. |
