Verbessertes Verfahren zur Herstellung von ionisch polymerisiertem wachstumsfaehigem Polybutadien

摘要

Butadiene polymers are made by adding a hydrocarbon fraction consisting of butadiene, C4 paraffins, C, olefins and other minor constituents such as C3 and C5 hydrocarbons and acetylenics, to a mixture of an alkali metal, in a form having a large surface area, a stoichiometrically insufficient amount of an activator such as a condensed ring aromatic hydrocarbon, a polynuclear aromatic hydrocarbon with a bonded non-condensed ring, a polynuclear aromatic hydrocarbon with a bonded condensed ring, a conjugated unsaturated heterocyclic compound or a diarylketone, and a Lewis base at a temperature of from -100 DEG to 30 DEG C. in an inert atmosphere and terminating the reaction by adding a terminating reagent. Comonomers selected from compounds of the formula where X is a hydrogen atom or an organic substituent and Y is an organic substituent, and the sum of Hammett's values of para substituents for X and Y is in a range from -0.2 to 0.7, to the reaction mixture, may be added to the hydrocarbon fraction or prior to adding the terminating agent to form a block copolymer. The comonomer may be selected from alphamethylstyrene, isoprene, styrene, methoxystyrene, methacrylates, acrylates, and methacrylonitrile. The terminating agent may be water, alcohol, or a Lewis acid, or a reagent capable of introducing a functional group to the anionic end of the living polymer such as CO2, O2, CH2O, ethylene oxide, propylene oxide or carbon bisulphide. The Lewis base may be selected from ethers, acetals, and tertiary amines. In Examples 5 and 6, a butadiene hydrocarbon fraction was polymerized in tetrahydrofurane in the presence of a sodium dispersion and o-terphenyl and the reaction terminated with methanol and propylene oxide respectively. In Example 7, a butadiene hydrocarbon fraction was polymerized in 1,2-dimethoxyethane in the presence of a lithium dispersion and o-terphenyl and the reaction terminated with alcohol. In Example 8, a block copolymer is formed with styrene using the procedure of Example 5, by adding the styrene prior to the terminating agent. Example 9 as Example 8 except CO2 used as terminating agent. Example 10 as Example 5 except CO2 used as terminating agent. Example 11 as Example 10, except benzophenone replaced o-terphenyl. Example 12 as Example 10 except 1.4-dioxane replaced tetrahydrofurane. In Example 13, a block copolymer with styrene was formed in presence of tetrahydrofuran, sodium and biphenyl. In Example 14, the hydrocarbon fraction is polymerized in presence of tetrahydrofuran, and a potassium-naphthlene complex whilst Example 15 was similar to Example 5.