Patent GB-793212-A (GB)
Title: A method of producing anion permselective membranes
IPC: C08J5/22
Filed: 1956-01-31
Abstract: Anion permselective membranes are prepared by chloroalkylating and aminating films of vulcanized or cyclised copolymers of aromatic vinyl compounds, e.g. styrene, vinyl toluene, vinyl xylene, ethyl styrene, diethyl styrene, methyl styrene and methylvinyl pyridine, with aliphatic conjugated polyene compounds, e.g. butadiene, isoprene and 1,3,5-hexatriene.  Mixtures of such copolymers or mixtures thereof with butadiene-acrylonitrile copolymers, polyethylene or natural rubber may be employed. Films may be prepared by rolling, calendering or solvent casting. They may be vulcanized by incorporating sulphur and accelerators, e.g. mercaptobenzothiazole, stearic acid and zinc oxide, in the copolymers, and heating the films produced therefrom, or by treating the films with sulphur chloride or its solution in tetrachlorethane.  Cyclisation may be induced by aluminium chloride, aluminium bromide, boron trifluoride, boron trichloride, titanium tetrachloride, titanium tetrabromide, or stannic chloride, or complexes thereof with ethers, e.g. ethyl ether, esters, e.g. ethyl acetate, phenol or acetic acid, or by g -radiation.  The cyclizing agents may be employed in solution or, if gaseous, mixed with the vapour of a volatile solvent. Chloroalkylation may be effected by immersing the films in a chloroalkyl ether, e.g. chloromethyl ether, chloroethyl ether, chloromethylethyl ether, dichloromethyl ether, and chloromethylpropyl ether, in the presence of a catalyst, e.g. aluminium chloride, stannic chloride and boron trifluoride, and optionally a solvent, e.g. tetrachloroethane, ethylene dichloride and carbon disulphide. The chloroalkylation and cyclization may be conducted simultaneously. The films may then be swollen with benzene, alcohol or acetone and aminated with methylamine, dimethylamine, trimethylamine, pyridine or diethylenetriamine.ALSO:Anion permselective membranes are prepared by chloroalkylating and aminating vulcanized or cyclised films comprising natural rubber and copolymer of aromatic vinyl compounds, e.g., styrene, vinyl toluene, vinyl xylene, methyl styrene, ethyl styrene, diethyl styrene and methyl vinyl pyridine, with aliphatic conjugated polyene compounds, e.g., butadiene, isoprene and 1,3,5-hexatriene.  Films may be prepared by rolling, calendering or solvent casting.  They may be vulcanized by incorporating p vulcanizing ingredients, e.g. sulphur, mercaptobenzothiazole, stearic acid and zinc oxide, and heating or by treating the films with sulphur chloride or its solution in tetrachlorethane. Cyclisation may be induced by aluminium chloride, aluminium bromide, boron trifluoride, boron trichloride, titanium tetrachloride, titanium tetrabromide and stannic chloride, or complexes thereof with ethers, e.g. ethyl ether, esters, e.g., ethyl acetate, phenol or acetic acid, or by g -radiation.  The cyclising agents may be employed in solution or, if gaseous, mixed with the vapour of a volatile solvent. Chloroalkylation may be effected by immersing the films in a chloroalkyl ether, e.g., chloromethyl ether, chloroethyl ether, chloromethylethyl ether, dichloromethyl ether and chloromethyl propyl ether, in the presence of a catalyst, e.g., aluminium chloride, stannic chloride and boron trifluoride, and optionally a solvent, e.g., tetrachloroethane, ethylene dichloride and carbon disulphide. The chloroalkylation and cyclisation may be conducted simultaneously. The films may be swollen with benzene, alcohol or acetone and aminated with methylamine, dimethylamine, trimethylamine, pyridine or diethylenetriamine.