Lanthanum isopropoxide (La(OiPr)(3)) has been synthesized and employed for ring-opening polymerization of 1,4-dioxan-2-one in bulk as a single-component initiator. The influences of reaction conditions such as initiator concentration, reaction time, and reaction temperature on the polymerization were investigated. The kinetics indicated that the polymerization is first-order with respect to the monomer concentration. The Mechanistic investigations according to H-1 NMR spectrum analysis demonstrated that the polymerization of PDO proceeded through a coordination-insertion mechanism with a rupture of the acyl-oxygen bond of the monomer rather than the alkyl-oxygen bond cleavage. (C) 2008 Wiley Periodicals, Inc.