Diacyl peroxides and the use thereof as polymerization catalysts

摘要

Ethylenically unsaturated compounds containing at least one CH2=C< group are polymerized in the presence of a diacyl peroxide catalyst having the formula wherein R represents an alkyl, cycloalkyl or aralkyl radical, preferably containing 1 to 12 carbon atoms, or a halogen atom, and n is 0, 1 or 2, the catalyst being present in an amount of 5 parts per million to 5% by weight, based on the total weight of the polymerizable compounds. Suitable polymerizable compounds mentioned are ethylene, propylene, butene, decene, styrene, acrylic acid, methyl methacrylate, methyl acrylate, vinyl acetate, vinyl chloride, vinylidene chloride, butadiene and isoprene. The polymerization reaction may be carried out batchwise at 30 DEG to 70 DEG C. or continuously at 100 DEG to 150 DEG C., desirably under a pressure in excess of 10,000 p.s.i. Chain transfer agents, e.g. hydrogen and aliphatic hydrocarbons, or catalyst activators, e.g. sulphites, aromatic amines, sulphur dioxide and dimethyl aniline, may be present in the reaction mixture. An example illustrates the polymerization of ethylene using as catalyst (a) bis-cyclohexane carbonyl) peroxide, (b) bis - (3 - methylcyclohexane carbonyl) peroxide, and (c) bis-(2,3-dibromocyclohexanecarbonyl) peroxide.ALSO:The invention comprises diacyl peroxides of the formula: wherein R is an alkyl, cycloalkyl or aralkyl radical, preferably containing 1 to 12 carbon atoms, or a halogen atom, and n is 0, 1 or 2, and a process for their preparation comprising reacting an acyl halide of the formula: wherein R and n are as defined above and X is a halogen atom, with an alkali or alkaline earth metal peroxide at a temperature not in excess of 25 DEG C., preferably from -40 DEG C. to +15 DEG C. The peroxides may be used as catalysts in the polymerization of ethylenically unsaturated compounds (see Division C3P).