A method for the preparation of stabilized, not coloured rubber

摘要

A process for the recovery of an initially living polymer from a cement produced in a polymerization process. The living polymer cement is shortstopped, washed, stabilised, coagulated and dried. The recovery process comprises adding a short stop to the polymer in the cement, washing catalyst residue from the polymer with water, adding an antioxidant Irganox 1520 to the cement to stabilise the polymer, adding epoxidised soya bean oil to the polymer to stabilise the polymer against colour degradation, and coagulating and drying the polymer. The pH of the cement is regulated in the range of from about 3 to about 7, and preferably from about 6 to about 7, during the catalyst wash and the coagulation steps of the recovery process. A product of the process is also described. The product and process provide for use of a preferred anti-oxidant system, which overcomes health concerns associated with existing anti-oxidant systems used in anionic polymerization processes, while providing a polymer product that has excellent colour and stability characteristics suitable for use in high impact polystyrene applications.