GB827320A - Reactive thioether-terminated addition polymers - Google Patents

Abstract

Reactive thioether-terminated addition polymers of formula X-Ar-S-[M]n-S-Ar-X, when n is 3 to 2000, M is at least one monomer unit selected from conjugated diene hydrocarbons, 2-chlorobutadiene, styrene, ring halogenated, alkylated and alkoxylated styrenes, amino styrene, vinyl naphthalenes, acrylic acid, methacrylic acid, alkyl acrylic esters, acrylonitrile and vinyl pyridines; Ar is phenyl or naphthyl and X is a radical containing a reactive substituent selected from bromide, chloride, carbonyl, hydroxyl, amino, pyridyl, formyl, mercaptyl, alkoxycarbonyl, arylsulphonate and alkaryl sulphonate, X when chloride, bromide hydroxyl or mercaptyl being attached to Ar by means of at least one aliphatic carbon atom and the reactive radicals present being mutually unreactive under polymerization and processing conditions, may be prepared by polymerizing the corresponding monomers in the presence of the corresponding aromatic disulphides. Many suitable monomers are listed and the polymerization of butadiene, isoprene, styrene, ethyl acrylate and methyl methacrylate; and the copolymerization of butadiene with styrene, aminostyrene, paramethyl styrene, acrylonitrile, acrylic acid, methacrylic acid, ethyl acrylate, methyl methacrylate and glycidyl methacrylate; styrene with ethyl acrylate, methacrylic acid, glycidyl methacrylate, b -bromoethyl methacrylate, 2-vinyl pyridine, 4-vinyl pyridine and 2-methyl-4-vinyl pyridine; ethyl acrylate with 4-vinyl pyridine and 2-methyl-5-vinyl pyridine; butadiene and styrene with acrylic acid, methacrylic acid, 2-vinyl pyridine, 4-vinyl pyridine, 2-methyl-4-vinyl pyridine and 2-methyl-5-vinyl pyridine; butadiene with acrylonitrile and methacrylic acid; and styrene with 2,5-dichlorostyrene and 4-vinyl pyridine is described. Many suitable disulphides are listed and the use of bis-(2-aminophenyl)disulphide, bis-(4-aminophenyl)disulphide, bis - (4 - N - dodecylaminophenyl)disulphide, bis - (2 - hydroxymethylphenyl)disulphide, bis-(2-chloromethylphenyl)disulphide, bis - (2 - bromomethylphenyl)disulphide, bis - (4 - carboxymethylphenyl)disulphide, bis - (2 - isonicotinamidophenyl)disulphide, bis - (2 - chloroacetamidophenyl)-disulphide, bis - (2 - bromoacetamidophenyl)-disulphide, bis - (2 - b - bromopropionamidophenyl)disulphide, N - dichloroacetyl - N1 - chloroacetyl bis - (2 - aminophenyl)disulphide, bis - (4 - b - bromoethoxy - 2,6 - xylyl)disulphide, bis - (4 - b - dimethylaminoethoxycarbonyl - 2,6 - xylyl)disulphide, bis - (4 - carboethoxymethoxy - 2,6 - xylyl)disulphide, bis-(4-carboxymethoxy - 2,6 - xylyl)disulphide, bis-(4-b -hydroxyethyl, 1-naphthyl)disulphide, bis-(4-b -bromoethyl, 1-naphthyl)disulphide, bis-(4-carboxymethyl, 1-naphthyl)disulphide and bis-(5-amino, 1-naphthyl)disulphide described. Polymerization may be effected in the presence of catalysts, e.g. bisazoisobutyronitrile, diazoaminobenzene and potassium persulphate, inhibitors, e.g. hydroquinone, or by photo initiation, in aqueous media in the presence of dispersing agents, e.g. soap, sodium alkyl sulphonates and lauryl pyridinium chloride, and buffers, e.g. potassium acid phosphate and sodium hydroxide, or in bulk. The modifier may be added in the form of a dispersion or, when bulk processes are employed and the modifier is not readily soluble in the monomers, together with solvents, e.g. isopropanol, acetone and methyl ethyl ketone. When very reactive disulphides are employed the polymerization may be terminated at low conversion or the modifier added continuously or incrementally as the polymerization proceeds. The polymers may be purified by dissolving in methyl ethyl ketone or chloroform and reprecipitating with methyl or ethyl alcohol. The polymers may be cured by heating with polymers carrying reactive groups on the polymer chain, e.g. styrene-4-vinyl pyridine copolymers, ethyl acrylate-4-vinyl pyridine copolymers and styrene-methacrylic acid copolymers converted to potassium salt by reacting with alcoholic potassium hydroxide, or by heating with difunctional compounds, e.g. 1,5-dibromopentane. The thioether-terminated polymers may be selfcuring when the polymer chains carry reactive groups. The products may be used in the production of tyres.