Heterogeneously catalyzed living cationic polymerization of isobutyl vinyl ether using iron(III) oxide

Heterogeneously catalyzed living cationic polymerization of isobutyl vinyl ether (IBVE) with Fe2O3 in the presence of an added base is described. Cationic polymerization of IBVE using Fe2O3 in conjunction with ethyl acetate or 1,4-dioxane and IBVE-HCl, a suitable cationogen, proceeded smoothly in a heterogeneous system to produce polymers with very narrow molecular weight distributions (M-W/M-n <= 1.1). The living polymerization was also achieved under unfavorable conditions: at higher temperature (30 degrees C) or in the presence of a small amount of water. Furthermore, Fe2O3 was readily separable from product polymers according to simple procedures. The reused Fe2O3 was very similar in catalytic activity to the virgin counterpart even after multiple use, producing nearly monodisperse polymers.