Installing lactone chain termini during photoinduced polymerization

We exploit the Thorpe–Ingold effect as a spontaneous end group transformation method during photo-induced polymerization of methacrylates using the functional (2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone) species as radical photoinitiator. Herein, the isopropyl hydroxyl function endows the polymer with geminal methyl groups inducing an angular compression, enabling through close proximity a ring-closing reaction between the hydroxyl group and the ester motif.