Characteristics and Kinetics of Ring-opening Polymerization of ε-Caprolactone Initiated by Lanthanide Tris(2,4,6-trimethylphenolate)s

Abstract

Novel single-component rare earth phenolate catalyst—lanthanide tris(2,4,6-trimethylphenolate)s [Ln(OTMP)3] initiated ring-opening polymerization of e-Caprolactone (CL). The effects of polymerization conditions, such as rare earth element, solvent, ligand, monomer and catalyst concentration, as well as reaction temperature and time on the polymerization have been investigated. Kinetics study indicates that the polymerization is of first order with respect to monomer and to initiator concentration, and the overall activation energy amounts to 58.7 kJ/mol. 1H NMR spectrum analyses of PCL demonstrates that the polymerization of CL proceeds through acyl–oxygen bond cleavage.