摘要 |
In a process for destroying residual catalyst in polymerization processes employing alkali metal catalysts by the addition of acetic acid, at least two molar equivalents of acetic acid per molar equivalent of alkali metal are used. Specified polymerization processes are those used in preparing butadiene-styrene copolymers of the drying oil type. The butadiene may be replaced, wholly or in part, by isoprene, piperylene, 2, 3-dimethyl-butadiene-1:3, or 2-methylpentadiene-1:3, and the styrene by such ring substituted styrenes as p-methyl or p-ethyl or dimethyl styrenes. Specified catalysts are sodium and potassium. It is preferred that the molar equivalent of acetic acid is between 2.2 and 3, and that it is employed as glacial acetic acid. The invention is particularly applicable to the polymerization of from 60-95 parts of butadiene with 40 to 5 parts of styrene using a sodium catalyst, in an inert diluent such as naphtha, mineral spirits pentane, xylene, toluene, benzenecyclohexane, diethyl ether, diisopropyl ether, dioxane, vinyl ethyl ether, vinyl isobutyl ether, anisole and phenetole, in the presence of a C1 to C5 aliphatic alcohol, e.g. isopropanol. |