Polymerization of higher aldehydes. VI. Mechanism of aldehyde polymerization

Abstract On the basis of results presented in previous papers possible mechanisms of polymerization of higher aldehydes are considered. The influence of solvents, temperature, initiator, and monomer upon the polymerization is discussed with particular emphasis on the stereoregularity of the resulting polymer. It is proposed that more than one monomer unit is involved in the propagation step. Both the stereoselective addition of monomer to the growing chain and the chain transfer reaction are thought to take place in a concerted manner. Chain transfer results in termination with the formation of hydroxyl, ester and probably ether end groups; growing chains which do not undergo transfer remain as “living” ends after the monomer supply is exhausted. Some thermodynamic values for carbonyl polymerizations are estimated.