GB854385A - The polymerisation of ethylene - Google Patents

Abstract

Ethylene is polymerized using as a catalyst a mixture of an alkyl or aralkyl chloride or bromide with an alloy containing at least 20% by weight of aluminium and at least 20% by weight of copper. The polymerization is preferably performed at elevated temperature, e.g. 50-100 DEG C. and pressure, e.g. above 100 p.s.i.g. in the absence of air or moisture. The catalysts, e.g. an alloy of 50% copper 45% aluminium and 5% zinc with ethyl bromide, are preferably prepared by grinding the alloy with a solution of the halide in an inert solvent at a slightly elevated temperature. p Preferably aliphatic hydrocarbons e.g. petroleum ether are used as solvents and an amount of halogen approximately chemically equivalent to the amount of aluminium is economical. The solid products are purified by decomposing the catalyst with water, steam, or alcohol, and the polymer is washed with an acid solution, e.g. ethanolic hydrochloric acid, water or a hydroxyl containing compound, and dried.ALSO:Catalysts comprising mixtures of an alkyl or aralkyl chloride or bromide with an alloy containing at least 20% by weight of aluminium and at least 20% by weight of copper are used in the polymerization of ethylene. An alloy of 50% copper, 45% aluminium and 5% zinc with ethyl bromide is specified, and the mixtures are prepared by grinding the alloy with a solution of the halide in an inert solvent at a slightly elevated temperature. Preferably aliphatic hydrocarbons, e.g. petroleum ether, are used as solvents, and an amount of halogen approximately chemically equivalent to the amount of aluminium is economical. The solid polymerization products are purified by decomposing the catalyst with water, steam or alcohol and the polymer is washed with an acid solution, e.g. ethanolic hydrochloric acid, water or a hydronyl-containing compound and dried.