Electron-Poor Butenolides: The Missing Link between Acrylates and Maleic Anhydride in Radical Polymerization
Mathieu L. Lepage, Georgios Alachouzos, Johannes G. H. Hermens, Niels Elders, Keimpe J. van den Berg, Ben L. Feringa
Abstract
Butenolides are a class of 5-membered lactones that hold great potential as bio-based monomers to replace oil-derived acrylates, of which they are cyclic analogues. Despite this structural resemblance, the reactivity of the unsaturated ester moiety of electron-poor butenolides leans toward that of maleic anhydride, another essential monomer that does not homopolymerize but copolymerizes in a highly alternating fashion with polarized electron-rich comonomers. By studying the reactivity of 5-methoxy and 5-acyloxy butenolides through a combination of kinetics and density functional theory (DFT) experiments, we explain why electron-poor butenolides constitute a missing link between acrylates and maleic anhydride in radical polymerization.