GB779994A - Quaternary ammonium anion-exchange resins - Google Patents

Abstract

Anion exchange resins comprise a cross-linked polymer matrix containing aromatic nuclei, whose ring carbon atoms constitute a major proportion of the total number of carbon atoms in the matrix, to which are attached groups of the form <FORM:0779994/IV(a)/1> in which Y represents an anion, A the radical <FORM:0779994/IV(a)/2> or an alkylene radical of 2 to 6 carbon atoms, and R, R1 and R2 methyl, ethyl or b -hydroxyethyl radica. They may be prepared by reacting amines of the form <FORM:0779994/IV(a)/3> e.g. 2-dimethylamino-ethyltrimethylammonium iodide, with a chloromethylated copolymer of 98 to 99.5 per cent of a monovinyl aromatic hydrocarbon, e.g. styrene, vinyl toluene, vinyl naphthalene, vinyl anthracene or ethyl styrene, and 0.5 to 2 per cent of a polyvinylidene compound, e.g. divinyl benzene, divinyl xylenes, divinyl toluenes, divinyl ethyl benzenes, divinyl naphthalenes, trivinyl benzene, divinyl ether, divinyl "Cellosolve" (Registered Trade Mark), ethylene glycol diacrylate, ethylene glycol dimethacrylate or diallyl maleate. Alternatively, the chloromethylated polymer may be reacted with amines of the form <FORM:0779994/IV(a)/4> where R5 and R6 are methyl or ethyl radicals, e.g. N,N1-tetramethylethylenediamine, and the product quaternized, e.g. by reacting with methyl chloride, methyl iodide, methyl sulphate, ethyl sulphate, ethylene oxide, butyl chloride or butyl sulphate in the presence of sodium iodide and lime, limestone, zinc oxide or sodium hydroxide. The copolymers may be prepared by aqueous emulsion or suspension, e.g. in the presence of magnesium silicate, polymerization in the presence of catalyst, e.g. benzoyl peroxide, and chloromethylated by reacting with paraformaldehyde and hydrochloric acid or chloromethyl methyl ether in the presence of aluminium chloride and preferably petroleum ether. The animation is preferably conducted by refluxing the amine with the chloromethylated polymer in suspension in water, toluene or ethylene dichloride. Specifications 654,706 and 779,995 are referred to.