Synthesis and Radical Polymerization of Bio-based New Cyclic Ketene Acetal, 2-Methylene-4-methyl-1,3-dioxepane

A methyl-substituted new cyclic ketene acetal, 2-methylene-4-methyl-1,3-dioxepane (MMD) was synthesized from 1,4-pentanediol made from levulinic acid as a biomass based material. MMD was shown to undergo free radical ring-opening polymerization with the introduction of an ester group into the backbone. Polymerization of MMD in bulk at 60 degrees proceeded by quantitative ring-opening which was divided into 90% of the intermediate secondary free radical and 10% of the intermediate primary radical. Furthermore, 1H and 13C-NMR spectra suggested that back-bite reaction occurred during polymerization of MMD.