PROCESS FOR PREPARING A POLYMER OF A CONJUGATED DIENO OR VINYL-AROMATIC HYDROCARBONIDE OR A COPOLYMER OF A CONJUGATED DIENO AND VINYL-AROMATIC HYDROCARBONIDE

摘要

A method for preparing essentially color-free, stabilized polymers of conjugated dienes or vinyl aromatic hydrocarbons or copolymers of conjugated dienes and vinyl aromatic hydrocarbons involves a first stage in which a living polymer of a conjugated diene or vinyl aromatic hydrocarbon or copolymer of a conjugated diene and a vinyl aromatic hydrocarbon is prepared by anionically polymerizing the conjugated diene or vinyl aromatic hydrocarbon, or copolymerizing the conjugated diene and the vinyl aromatic hydrocarbon using a lithium-based catalyst and an inert hydrocarbon diluent. Then, the living polymer or copolymer is terminated by the addition of a suitable terminating agent. Following the termination procedure, boric acid is added to the polymer of copolymer in a sufficient amount to prevent or substantially reduce color formation. Then, stabilizing agents are added to the polymer or copolymer and the polymer or copolymer is recovered from the diluent.