Kinetic study has been made on the hydration of isobutylene with two types of macroreticular cation exchange resin catalysts, Amberlyst 15 and Amberlyst XN-1010. The hydration reaction was found to be diffusion-limited, and experimental results were interpreted by the two-phase model. Effectiveness factors and the apparent reaction rate constants were calculated from the reaction rate data over the two catalysts with different particle sizes.
The apparent reaction rate constant per unit equivalent on Amberlyst 15 was found unexpectedly higher than that on Amberlyst XN-1010, which has been explained by the hypothesis that the activity of -$SO_3H$ groups within the microparticles was higher than that on the surface of the microparticles.
