Ti[O(CH2)(4)OCH=CH2](4), used for the ring-opening polymerization (ROP) of epsilon-caprolactone, was synthesized through the ester-exchange reaction of titanium n-propoxide and 1,4-butanediol vinyl ether, and its chemical structure was confirmed by nuclear magnetic resonance (H-1 NMR) and thermogravimetric analysis (TGA). The mechanism and kinetics of Ti[O(CH2)(4)OCH=CH2](4)-initiated bulk polymerization of e-caprolactone were investigated. The results demonstrate that Ti[O (CH2)(4)OCH=CH2](4)-initiated polymerization of epsilon-caprolactone proceeds through the coordination-insertion mechanism, and all the four alkoxide arms in Ti[O (CH2)(4)OCH=CH2](4) share a similar activity in initiating ROP of epsilon-caprolactone. The polymerization process can be well predicted by the obtained kinetic parameters, and the activation energy is 106 KJ/mol. Then, the rheological method was employed to investigate the feasibility of producing the crosslinked poly(epsilon-caprolactone)-poly (n-butyl acrylate) network by using Ti[O(CH2)(4)OCH=CH2](4) as the ROP initiator. The tensile test demonstrates that the in situ generated crosslinked PCL-PBA network in PMMA matrix provides the possibility of ameliorating the tensile properties of PMMA. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46:7773-7784,2008