The influence of complexing agents on the polymerization of vinyl and allyl monomers

Acceleration of photo‐induced polymerization of methyl methacrylate (MMA) has been found in the presence of AlCl3 and AlBr3. On the basis of the kinetic data it has been supposed that at lower concentrations of AlX3 ([AlX3]/[MMA] ≤ 0.1) the role of the complexing agent is reduced to acceleration of propagation with complexed radicals. The peculiar behavior of these radicals has been revealed by ESR. We have proposed that the mechanism of activation of propagation by the complexing agent consists of electron transfer from the radical to the adding monomer molecule through the metal atom of the complexing agent. At higher concentrations of the complexing agent its role is also reduced to ordering of the monomer molecules into mobile organized arrays. Acceleration of radical polymerization of allyl acetate and allyl alcohol has also been found in the presence of ZnCl2. The mechanism of acceleration involves activation of allyl radicals of chain transfer and formation of mobile, organized arrays of the monomer molecules.