Polybutadiene or polybutadiene-styrene! polymer used for tyre treads - is formed by polymerising using organo-lithium catalyst then reacting living polymer with carbo-di:imide and multifunctional coupler

摘要

A rubbery polybutadiene or butadiene/styrene copolymer is obtained by polymerisation in a hydrocarbon solvent in the presence of an organolithium compound as catalyst; and reacting the living site on the polymer with a carbodiimide and if required a tri- or higher functional coupling agent, to give a product having a weight average/number average mol. wt. ratio of 1.2 to 3, and Mooney viscosity 20-150. An amino compound may be added to minimise changes in viscosity.