Journal of Molecular Catalysis A-Chemical, Vol.301, No.1-2, 84-92, 2009
Environmentally benign process for bulk ring opening polymerization of lactones using iron and ruthenium chloride catalysts
FeCl3 center dot 6H(2)O, RuCl3 center dot H2O and FeCl2 center dot 4H(2)O are found to be bulk polymerization catalysts for the ring opening polymerization of epsilon-caprolactone, delta-valerolactone and beta-butyrolactone. These polymerizations can be significantly enhanced by conducting them in the presence of appropriate amounts of different alcohols. The major initiation pathway in the polymerization is found to proceed via the activated monomer mechanism and depending on the nature of the alcohol used, poly(lactones) with different end groups can be synthesized. Such polymerizations constitute an economical process, employing readily available inorganics as catalysts and do not necessitate solvents. The overall system is green and eco friendly. (C) 2008 Elsevier B.V. All rights reserved.