Kinetics and mechanism of the polymerization of t-butyl methacrylate in presence of butyllithium

Abstract

1. The kinetics of the polymerization of t-butyl methacrylate (t-BMA) in toluene in presence of butyllithium were investigated, and the apparent constants, activation energies, and preexponential factors of the elementary reactions were calculated. 2. The high values of the preexponential factors in the Arrhenius equation for the elementary reactions have given rise to the considerable values of the apparent constants of the elementary reactions. 3. The complex compounds formed as intermediate products in the elementary reactions are less stable than in the case of methyl methacrylate (MMA) and butyl methacrylate (n-BMA). 4. The higher ratio of the constant for the generation of active centers to the constant for chain propagation has determined the absence of an induction period in the polymerization and the formation of polymers of lower molecular weight than in the case of MMA and n-BMA. 5. In the polymerization of alkyl methacrylates,butyllithium is consumed to the extent of 0.5–6% in the generation of active centers, but most of it is consumed by reaction at the C=O bond.