GB821093A - Polymerisation of unsaturated organic compounds - Google Patents

Abstract

Aqueous dispersions of polymers, of average molecular weight of at least 3000, of allyl esters of carboxylic acids of formula XCOOH where X represents an aryl or substituted aryl radical, HOOC(CH2)n or R(CH2)n where n is 1 to 16 and R is a hydrogen atom or an alkyl, alkenyl, alkoxy, epoxy or hydroxyl radical or any combination thereof, are prepared by polymerizing the ester in the presence of water, a dispersion stabilizer and a polymerization catalyst, the feed ratio of monomer to water being from 10/90 to 70/30 parts by weight. The dispersion may be an emulsion or a granular or bead suspension. The allyl ester may be diallyl sebacate, diallyl phthalate or allyl caproate. Comonomers, when employed, may be vinyl or allyl esters of carboxylic acids, e.g. vinyl acetate, allyl acetate and diallyl phthalate, styrene, a -methyl styrene, acrylonitrile, methacrylic acid esters, e.g. methyl methacrylate, vinyl chloride or vinylidene chloride. Specified dispersion stabilizers are polyvinyl alcohol, partially hydrolysed polyvinyl acetate, acrylic and methacrylic acid polymers and salts thereof, alkali metal salts of styrene-maleic acid resins, potassium palmitate, sodium oleate, triethanolamine soaps, rosin soaps, sulphonated oils, alcohols and esters, sulphated compounds, salts of sulphosuccinic acid esters, cetyl trimethyl ammonium chloride, cetyl pyridinium bromide, alkali metal phosphonium halides, alkali metal sulphonium halides, ethylene oxide condensates with fatty alcohols, fatty acids, alkylphenols and castor oil, gum arabic, gum tragacanth, casein, lecithin, gelatin, alginates, calcium, barium and magnesium carbonates, silicates, sulphates and phosphates, alumina, fuller's earth, milk of magnesia, talc and bentonite. The catalyst may be diazaminobenzene, hydrogen peroxide, sodium peroxide, ammonium persulphate, sodium perborate, tertiary butyl hydroperoxide, cumene hydroperoxide and benzoyl peroxide, optionally together with activators, e.g. alkali metal thiosulphates, sulphites, bisulphites, metabisulphites, hydrosulphites and sulphoxylates, hydroxylamine and its salts, hydrazine, dextrose, ferrous ammonium sulphate and copper sulphate. Electrolytes and thickeners may be added and the density of the medium adjusted by adding ethylene glycol or glycerol. Polymerization may be effected by heat or ultra-violet light, preferably under an inert atmosphere, e.g. of nitrogen, by batch or continuous processes. The reactants may be added, mixed or separately, portionwise as the reaction proceeds.