ASSOCIATION OF (POLYBUTADIENYL)SODIUM IN HYDROCARBON MEDIUM

Concentration dependences of the viscosity of living and deactivated ( polybutadienyl)sodium in cyclohexane solutions at 30 degrees C were st udied using vacuum viscometry. When the living polymer is deactivated, its intrinsic viscosity decreases by 2.5 times. This unambiguously in dicates that in a polar medium active (polybutadienyl)sodium centers a re in the associated state. Linearity of the concentration dependence of the viscosity of living polymer in coordinates of the Huggins equat ion, which is observed as the concentration of active centers decrease s from 1.4 x 10(-3) to 1.3 x 10(-4) mol/l, indicates that the associat es are rather stable. The obtained data, in combination with previousl y found first reaction order of chain propagation with respect to init iator when the concentration of the latter is higher than 10(-3) mol/l , support the view that, for the specified concentration range, it in the associated forms of active (polybutadienyl)sodium centers that pla y the dominating role when polymerization in conducted in a nonpolar m edium