Ring-opening polymerization of alpha-chloro-epsilon-caprolactone and chemical modification of poly(alpha-chloro-epsilon-caprolactone) by atom transfer radical processes

A highly versatile strategy was implemented in order to attach a range of polymer grafts and functional groups along the backbone of poly(epsilon-caprolactone). alpha-Chloro-epsilon-caprolactone (alphaClepsilonCL) was first prepared by the Baeyer-Villiger oxidation of alpha-chlorocyclohexanone. This monomer (alpha-Cl-epsilon-CL) was then copolymerized with epsilon-caprolactone in the presence of 2,2-dibutyl-2-stanna-1,3-dioxepane. Finally, the pendant activated chlorides of the copolymer were used to initiate (i) the "grafting from" of poly(methyl methacrylate) by atom transfer radical polymerization and (ii) the grafting of benzoate groups by atom transfer radical addition of 3-butenyl benzoate.