Straightforward synthesis of well-defined poly(vinyl acetate) and its block copolymers by atom transfer radical polymerization

A facile Atom Transfer Radical Polymerization (ATRP) method based on the use of the complex obtained with CuCl, CuCl2 and the very active ligand 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (Me6CyClam) as catalytic system, was successfully employed for the first time to polymerize vinyl acetate (VAc) with a good control over the polymerization, which showed a living character and monomer conversion up to 90%. The use of such an active ligand allows to maintain a particularly low concentration of propagating species once very reactive radicals, from such monomers, are formed, hence establishing a fast and dynamic ATRP equilibrium. Several kinetic studies on the ATRP of VAc were carried out with the aim to identify the optimized conditions allowing a good control over the process attaining materials with well-defined structure and low polydispersity. The livingness of the macromolecular system was confirmed, among the others, by using the obtained PVAc as ATRP macroinitiator for the synthesis of several block copolymers. Furthermore, the possibility to hydrolyse the VAc block thus attaining amphiphilic materials was studied.