Nitrogenous anion-exchange resins

Abstract

Abstract Insoluble anion-exchange resins are prepared by reacting with a primary or secondary amine or a mixture thereof or a tertiary amine an insoluble infusible copolymer of an aromatic monovinyl hydrocarbon and an aromatic divinyl hydrocarbon, the copolymer containing for every fifteen aromatic nuclei at least one haloalkyl group having the formula -CnH2nX, wherein n is an integer of from one to four, and X is chlorine or bromine, this haloalkyl group being preferably chloromethyl. Preferably the insoluble infusible copolymer contains 0.1 to 40 per cent on a molar basis of the divinyl hydrocarbon and is preferably prepared by copolymerizing a monovinyl hydrocarbon and a divinyl hydrocarbon and then introducing haloalkyl groups into the copolymer, which may be effected by reacting the polymer with a mixture of an aldehyde and hydrochloric acid or a mixture of a halide and a Friedel-Crafts catalyst. The monovinyl hydrocarbon may be styrene, ortho-, meta- or para-methyl styrene, ortho-, meta- or para-ethyl styrene, a vinyl naphthalene or vinyl anthracene, and the divinyl hydrocarbon may be divinyl benzene, divinyl toluene, divinyl naphthalene, divinyl ethyl benzene or divinyl xylene. The copolymer may be formed from a divinyl hydrocarbon and a mixture of two or more monovinyl hydrocarbons. Amination of the haloalkylated copolymer is preferably carried out by adding the amine to the haloalkylated copolymer while the latter is suspended or agitated in a liquid which is a solvent, such as benzene, for the amine. Amines referred to in specific examples are tetraethylene pentamine, diethylene triamine, dimethylamine and trimethylamine. The Specification as open to inspection under Sect. 91 refers also to the use of mixtures of primary, secondary and tertiary amines. This subject-matter does not appear in the Specification as accepted.ALSO:Insoluble anion-exchange resins are prepared by reacting with a primary or secondary amine or a mixture thereof or a tertiary amine an insoluble infusible copolymer of an aromatic monovinyl-hydrocarbon and an aromatic divinyl hydrocarbon, the copolymer containing for every fifteen aromatic nuclei at least one haloalkyl group having the formula-CnH2nX wherein n is an integer of from one to four and X is chlorine or bromine, this haloalkyl group being preferably chloromethyl (see Group IV(a)). The resins do not impart colour to fluids brought into contact with them, are resistant to attrition and have unusual stability at high temperatures. They may be regenerated by being washed with an alkaline solution such as a solution of potassium hydroxide or of sodium carbonate.

Inventors

• 👤 Charles H Mcburney

Bibliographic Details