Kinetic study of anionic polymerization of butadiene in a polar solvent

Abstract

The kinetics of the propagation reaction for the polymerization of butadiene initiated by cumyl potassium in tetrahydrofuran solution at several temperatures have been studied. Kinetic data and electrolytic behaviour indicate that polybutadienyl free ions assume the whole of the propagation reaction. At 0°C, the respective rate constants for ion-pairs and free ions are 1 l mol −1 s −1 and 4.8 × 10 4 l mol −1 s −1 respectively. The ionic dissociation constant is 7.8 × 10 −9 mol/l. The activation energy of the propagation reaction for free ions is 6.5 kcal/mol.