Macromolecules, Vol.42, No.5, 1634-1639, 2009
N-Heterocyclic Carbenes for the Organocatalytic Ring-Opening Polymerization of epsilon-Caprolactone
We report the synthesis of poly(epsilon-caprolactone) utilizing N-heterocyclic carbene (NHC) organocatalysts. Sterically unencumbered NHCs were found to be highly effective for the living ring-opening polymerization of E-caprolactone under mild conditions. The NHCs were able to produce poly (epsilon-caprolactone)s with controlled molecular weights, low polydispersities, and well-defined end groups derived from the alcohol initiator. Star-shaped poly(epsilon-caprolactone)s with three and four arms were prepared using NHC organocatalysts and characterized. by H-1 NMR and GPC.