Grafting of amino groups on polybutadiene by hydrosilylation

Hydrosilylation catalyzed by hexachloroplatinic acid was used to introduce tertiary amino groups in an hydroxytelechelic polybutadiene. Kinetics and mechanisms were investigated. At low silane concentration, the reaction is first-order in Pt, second-order in silane and zero-order in vinylic double bonds. The apparent rate constant is inversely proportional to the concentration of amino groups (inhibitory effect). At high silane concentration, very sharp acceleration periods are observed and explained by a transformation of a weakly active Pt(II) catalyst into a more active Pt(O) compound.