An improved method for the treatment of high molecular weight polymers of ª--olefinsand their derivatives

A method of treating high molecular weight polymers of alpha-olefins and their derivatives consists in placing the polymers in contact with a chromyl halide at a temperature below the temperature of decomposition of the polymer. Specified polymers are polyethylene, polypropylene, polyisobutylene, polyvinyl chloride, polyvinyl acetate, polyvinyl formal, polyvinyl acetal, polyvinyl butyral, polytetrafluoroethylene, polyvinylidene chloride, polyacrylonitrile and polymethacrylonitrile. The chromyl halide may be chromyl chloride, chromyl fluoride, chromyl bromide or chromyl iodide, and may be in solution, e.g. in methylene chloride, chloroform, carbon tetrachloride, tetrachlorethane, dichlorethane, dibromethane, chlorobenzenes, acetyl chloride, tin tetrachloride, thionyl chloride, silicones, acetic acid or anhydride, benzene, cyclohexane, carbon disulphide, nitrobenzene or nitric acid; or may be formed in situ, e.g. by the reaction of an alkali or alkaline earth metal chromate or bichromate or chromium trioxide with hydrochloric acid or a chloride and sulphuric acid, or chromium trioxide or a bichromate with an acid chloride such as oxalyl, acetyl or pyrosulphuryl chloride or phosphorus pentachloride. The treated polymers may be dyed. Examples describe the treatment of (1 to 4) polyethylene flasks, (5 and 6) polyethylene sheet, (7, 9, 10 and 11) polypropylene fabric, (8) polyethylene fabric and (12) a skein of polypropylene fibres, the products in examples 7 to 12 being subsequently dyed.ALSO:The dye affinity of polymers of alpha-olefins and their substitution derivatives is improved by contacting the polymer with a chromyl halide at a temperature below the decomposition temperature of the polymer. Specified polymers are polyethylene, polypropylene, polyisobutylene, polyvinyl chloride, polyvinyl acetate, polyvinyl formal, polyvinyl acetal, polyvinyl butyral, polytetrafluoroethylene, polyvinylidene chloride, polyacrylonitrile and polymethacrylonitrile. The chromyl halide may be chromyl fluoride, chloride (preferred), bromide or iodide, and may be in solution, e.g. in methylene chloride, chloroform, carbon tetrachloride, tetrachlorethane, dichlorethane, dibromethane, chlorobenzenes, acetyl chloride, tin tetrachloride, thionyl chloride, silicones, acetic acid or anhydride, benzene, cyclohexane, carbon disulphide, nitrobenzene or nitric acid; or may be formed in situ, e.g. by the reaction of an alkali or alkaline earth metal chromate or bichromate or chromium triox