Cyclization tendencies in the free radical polymerization of allyl acrylate derivatives: A computational study

In this study density functional theory (DFT) has been used to model the elementary steps and rationalize the free radical polymerization kinetics in allyl methacrylate (AMA), allyl 2-cyanoacrylate (ACA) and methyl α-[(allyloxy)methyl]acrylate. The models used in this study have revealed the fact that while methyl α-[(allyloxy)methyl]acrylate, cyclopolymerizes via 5-membered rings, AMA and ACA do not. The cyclization tendency of methyl α-[(allyloxy)methyl]acrylate is attributed to the similar hybridization (sp 3 ) of C3 and C5 favoring a quasi cyclic structure for the reactive rotamer. On the other hand, the presence of the cyano (CN) group in ACA facilitates the initiation step as compared to AMA. The chain transfer reaction does not seem to play a major role in the monomers of interest. This study highlights the usage of quantum chemistry in determining the cyclization tendencies of allyl acrylate derivatives in their free radical polymerization reactions.