GB900523A - Polymerization of conjugated diolefins - Google Patents

Abstract

Conjugated diolefins are polymerized alone or with a comonomer by contacting at least one open chain 1;3-diene having from 4 to 10 carbon atoms with or without a comonomer with a catalyst consisting of (a) at least one alkali or alkaline earth metal, or alloy or organometallic compound thereof, and (b) one or more Lewis bases or with the complex compound formed by the reaction of (a) and (b), said Lewis bases being such that they neither react with the metal alloy or organometallic compound during the polymerization to form hetero polar compounds having positively charged metal atoms, nor react with the metal, alloy or organometallic compound to form complex compounds not capable of initiating the polymerization. The Lewis bases are tertiary amines having one or more tertiary nitrogen atoms which are not members of an aromatic ring system, tertiary phosphines, tertiary arsines, tertiary stilbines and thioethers not capable of forming metal salts. Specified diolefins are 1-methyl-, 2-methyl-, 2,3-dimethyl-, 2-ethyl-, 2-phenyl-, 2-chloro- and 1,3-butadiene. Styrene, vinyl toluene and alpha-methyl styrene are specified as comonomers. Oxygen and moisture are preferably absent and a solvent, e.g. aliphatic hydrocarbons, their mixtures, cycloaliphatic hydrocarbons, and aromatic hydrocarbons may be present. The polymerization may take place in the presence of halogenated hydrocarbons such as butyl chloride, allyl bromide, vinyl chloride, cyclohexyl chloride, bromobenzene and 1-chloronaphthalene. Specified Lewis bases are triethyl, tripropyl, tributyl and triallylamine, tricyclohexylamine, hexahydrodimethylaniline and hexahydrotoluidine, N-alkyl or N-cycloalkyl derivatives of piperidine, pyrrolidine and morpholine, endoethylenepiperidine, endomethylenepiperazine and endoethylpyrimidine, triethyl and triphenyl phosphine, methydiphenyl and dimethyl-phenyl phosphines, the equivalent arsines and stibines and diethyl-, dibutyl-, diphenyl and alpha-alpha-dinaphthyl sulphides. The polymer may be precipitated, when made using a solvent, using alcohols, acetone, alcohol/water and acetone/water mixtures. Specifications 884,699 and 895,607 are referred to.