GB1255764A - A process for the preparation of living polymers - Google Patents

Abstract

1,255,764. Polymerization. NIPPON SODA CO. Ltd. 6 March, 1970 [11 March, 1969; 27 March, 1969], No. 10907/70. Heading C3P. A process for the preparation of living polymers employing a tubular reactor having an initiator inlet, reactant outlet and a plurality of monomer inlets and equipped with cooling means, the reactor being such as to provide a residence time of 20 minutes to 2 hours, a heat transfer surface to maintain the reactants at -20 to -80‹ C. and a rate of reactant flow of 0.1 to 3 metres per second, comprises continuously feeding initiator solution containing a Lewis base and dispersed alkali metal or complex thereof with conjugated diolefins, polynuclear or condensed ring aromatic compounds, styrene, α-methyl styrene or mixtures thereof through the initiator inlet, feeding diluted monomer containing at most 70 weight per cent of conjugated diolefins and aliphatic or cycloaliphatic liquid hydrocarbon diluent through the monomer inlets while keeping the reactants at a temperature of -20 to -80‹ C. The monomer may comprise butadiene or butadiene containing fractions from cracked petroleum, optionally in admixture with comonomers such as styrene, α-methyl styrene, methoxystyrene, methacrylates, acrylates and acrylonitrile. The diluent may be C 4-8 alkanes and alkenes, C 5 and C 6 cycloalkanes and cycloalkenes, petroleum ether, gasoline, naphtha, kerosene or mineral spirits. The initiator may comprise an ether, acetal or t-amine, together with lithium, sodium, potassium, rubidium or caesium which may be complexed with or activated by condensed or non-condensed ring polynuclear hydrocarbons, diaryl ketones, conjugated vinyl heterocyclic compounds, conjugated diolefins, styrene or α- methyl styrene. The living polymer products may be treated to introduce terminal functional groups by reacting with electrophilic reagents, e.g. oxygen, alkylene oxides, formaldehyde, carbon dioxide, alkylene sulphides or carbon disulphide. Block copolymers may be prepared by introducing different monomers at successive inlets. Many examples are given describing the polymerization of (1, 3, 4 and 10) butadiene, mixtures thereof with (2, 7 and 10) styrene, butadiene followed by (5) α-methyl styrene, (6 and 7) cracked petroleum C 4 fractions together with (8) styrene, and (10) isoprene in hydrocarbon diluents in the presence of initiators formed from tetrahydrofuran, sodium and (1, 3, 4 and 6) butadiene, (2) o-diphenyl benzene together with (8) butadiene (5 and 7) α-methyl styrene and (9) biphenyl; from sodium and (10) tetrahydrofuran and dimethyl ether or dioxane and biphenyl; and from tetrahydro furan and (10) lithium and o-diphenyl benzene or potassium and naphthalene; and the treatment of the products with water, ethylene oxide, propylene oxide, methanol or carbon dioxide.