GB777248A - Improvements in or relating to ion exchange substances - Google Patents

Abstract

Ion-exchange resins are made by partial hydrolysis of a polymeric diallyl-lower alkyl or triallyl phosphate. The lower alkyl group contains up to 5 carbon atoms, e.g. methyl and ethyl. Hydrolysis may be effected by refluxing with aqueous or alcoholic alkali metal hydroxide, washing with water and drying. The product may be repeatedly washed with sulphuric acid and then with water until the wash-water is free from sulphate ions to convert the resin to the acid form. In examples: (1) triallyl phosphate is polymerized in the presence of benzoyl peroxide at 100 DEG C. in a sealed vessel and the product crushed to 30 to 70 mesh size and washed with acetone; (2) triallyl phosphate containing benzoyl peroxide is heated with water under reflux with vigorous stirring to form polymer beads which are similarly washed. The resin absorb ferric more strongly than uranyl ions, which may be eluted from the resin with aqueous ammonium carbonate solution, leaving ferric ions which may be subsequently eluted with dilute sulphuric acid containing sulphur dioxide. U.S.A. Specification 2,394,829 is referred to.ALSO:Ion-exchange resins made by partial hydrolysis of polymeric diallyllower alkyl or trialkyl phosphates absorb ferric more strongly than uranyl ions, which may be eluted from the resin with aqueous ammonium carbonate solution, leaving ferric ions which may be subsequently eluted with dilute sulphuric acid containing sulphur dioxide.