GB696723A - Solutions of acrylonitrile polymers containing an inorganic acid - Google Patents

Abstract

Acrylonitrile polymers containing at least 80 per cent of acrylonitrile are dissolved in an organic solvent, e.g. dimethyl formamide, dimethyl acetamide and sulpholane, containing from 0.09 to 5 per cent of nitric acid of at least 70 per cent strength, hydrochloric acid of 35 to 38 per cent strength, or sulphamic acid of at least 99 per cent purity, to form a solution containing at least 5 per cent of polymeric material. The acrylonitrile polymers may contain up to 20 per cent of one or more ethylenically unsaturated substances such as acrylic, methacrylic, and haloacrylic acids, methyl, butyl, octyl, methoxymethyl and chlorethyl acrylates, methacrylates, and alpha-chloracrylates, methacrylonitrile, vinyl and vinylidene fluorides and chlorides, 1 - fluoro - 1 - chloroethylene, vinyl acetate, chloracetate, propionate, and stearate, styrene, vinyl naphthalene, N-vinyl phthalimide and succinimide, N-vinyl caprolactam and butyrolactam, 2-vinyl pyridine, N-allylformamide, N - methallylformamide, N - ethallylformamide, N - vinyl - N - methylformamide, allyl urea, and N-allyl sulphonamides. The acrylonitrile polymer may be blended with other polymeric materials such as a dye-receptive copolymer containing 10 to 70 per cent of acrylonitrile and 30 to 90 per cent of a vinyl-substituted heterocyclic amine. The solutions produced are of reduced viscosity and may be formed into films, fibres, sheets, casings, tubings, or rods.