| 摘要 |
1283087 Sulphoxide and sulphone terminated oligomers; emulsion polymerization processes UNIROYAL Inc 7 Nov 1969 [19 Nov 1968] 54636/69 Heading C3P Oligomers having the formula are prepared by oxidizing an oligomer of the formula In the above formulµ R represents an alkyl group (primary, secondary or tertiary) having from 5-20 carbon atoms, R 1 and R 3 are each H, methyl, ethyl or -COOH, R 2 and R 4 are each H, methyl, ethyl, -COOH or -CH 2 COOH, Y is a strongly hydrophilic group selected from -COOH, -CONH 2 , -OCH 3 , -OC 2 H 5 , -CH 2 OH and X is either a group as defined for y or is a less hydrophilic group selected from -COOC 2 H 4 OH, a+b is from 2 to 50, and a/a+b is from 0 to 1 unless X is a said less hydrophilic group in which case a/a+b is less than 0À6, and n is 1 or 2. (Alkyl sulphide-terminated oligomers similar to those used as starting material are described in Specification 1,207,532.) Oxidation of the oligomers is suitably effected, generally in an aqueous medium, with hydrogen peroxide or ozone, e.g. at 30-90‹ C.; one mole equivalent of oxidizing agent yields the terminal sulphoxide derivative and two mole equivalents yields the corresponding sulphone. The new oligomers are soluble in water or can be rendered soluble in water (when they contain acidic groups) by conversion to salts, e.g. ammonium, substituted ammonium, alkali metal, alkaline earth metal and Group III metal salts. Monomers from which the oligomers are derived include acrylic acid, acrylonitrile, acrylamide, itaconic acid, methacrylic acid and methacrylamide. Oligomerization of the monomers is suitably effected in the presence of an appropriate mercaptan R-SH in an organic solvent, e.g. methanol or isopropanol, using as initiator ammonium persulphate, lauroyl peroxide or lauroyl peroxide/dimethyl aniline. The new oligomers are useful as emulsifiers in the emulsion polymerization of ethylenically unsaturated monomers, e.g. butadiene, butadiene-styrene, butadiene-acrylonitrile, butadiene vinylidene chloride, butadiene-methacrylonitrile (and corresponding monomer(s) in combination with a small amount of an unsaturated acid monomer, e.g. itaconic acid), styrene, styrene-acrylonitrile, styrene-methacrylonitrile, ethyl acrylate, ethyl acrylate-vinyl acetate, ethyl acrylate-methyl methacrylate, ethyl acrylate-styrene, ethyl acrylate-butyl acrylate, butyl acrylate-acrylonitrile, and combinations of an ester such as ethyl or butyl acrylate with a minor amount of a mixture of (a) styrene, methyl methacrylate, butyl acrylate or vinyl acetate with (b) acrylic, methacrylic or itaconic acid. In examples the monomers used are (a) butadiene, styrene and itaconic acid, and (b) styrene and acrylonitrile; in addition to the oligomeric emulsifiers used, other components present include potassium persulphate, tetrasodium salt of EDTA and t-dodecyl mercaptan. |
