Polymerization of conjugated diolefines

1:3-Dienes are polymerized by contact with a catalyst obtained by reacting a halogenated hydrocarbon in the presence of a graphitic form of carbon with an alkali metal (preferably Li) and/or compound thereof capable of reacting with the halogenated hydrocarbon forming the corresponding metal halide. Monomers specified are butadiene and 1-and 2-methyl-, 2:3-dimethyl-, 2-ethyl-, 2-phenyl- and 2-chloro-butadienes, butadiene/isoprene mixtures and as comonomers for the specified dienes, styrene and vinyl toluenes, e.g. a -methyl styrene. The following ingredients are specified: (a) reactive alkali metal compounds -NaH, LiH, LiAlH4, Na2O, LiOH, NaNH2, Li methyl, ethyl, butyl, hexyl, n-octadecyl, phenyl, tolyl and allyl and the corresponding Na and K compounds, sodium dibutylamide and lithium diphenyl-amide; (b) halogenated hydrocarbons-EtBr, i-PrBr, n-BuCl, i-amyl and stearyl bromide and iodide, stearyl, vinyl, allyl, cyclohexyl, benzyl and benzal chlorides, 1:4-dibromobutane, bromo-, iodo- and chloro-benzene, 1:4-dibromobenzene and 1-bromonaphthalene; (c) graphitic forms of carbon-wood, animal, bone, blood and sugar charcoals, thermal, gas, oil, furnace, channel, acetylene and naphthalene blacks, coke, lustrous carbon and retort, synthetic or natural graphites. Polymerization may take place in bulk or in presence of a solvent, the usual solvents being mentioned. It is preferred, when working up the products to use stabilizers and antioxidants such as phenyl-b -naphthylamine, N:N1-diphenyl-p-phenylenediamine, di-t-Bu-p-cresol, di-t-Bu hydroquinone, t-Bu-pyrocatechol and tris (nonylphenyl) phosphite.