Photoinitiated polymerization of N-vinylcarbazole in presence of benzoyl peroxide. Part 1.—Kinetics and mechanism of polymerization

Abstract

Benzoyl peroxide is a photosensitizer of the polymerization of N-vinylcarbazole at λ= 365 nm. In benzene solution, polymer is formed mainly by a radical mechanism at low concentrations of benzoyl peroxide, but its formation by a cationic mechanism becomes increasingly dominant as the concentration of peroxide is raised. In dichloromethane solution the polymer is formed exclusively through cationic intermediates. Absorption and emission spectrophotometric studies indicate the formation of a ground state charge transfer complex between N-vinylcarbazole and benzoyl peroxide and it is proposed that the cationic polymerization is initiated by its excitation.

Kinetic mechanisms compatible with the experimental observations are proposed.