Kinetics and mechanism of acid catalyzed alkylation of phenol with cyclohexene in the presence of styrene divinylbenzene sulfonic resins

The kinetics of phenol cyclohexylation catalyzed by sulfonic resins is studied taking into account equilibria and side reactions observed in the reaction media. The influence of different sulfonic resins has been tested and only small variation of the catalyst activity, referred to the acid amount, has been observed. Besides, the selectivity is unaffected by varying the type of the catalyst. The effect of reagent concentration on the reaction rate has been also studied, together with the reactivity of the cyclohexyl phenyl ether as intermediate. The etherification equilibrium of cyclohexyl phenyl ether has been analyzed in the presence of methanesulfonic acid, and the adsorption equilibria on a sulfonic resin of reagents and intermediates are measured, too. Starting from the evidences obtained from these studies an Eley-Rideal type kinetic model has been proposed and the fitting of the experimental data allows obtaining the kinetic constant of each stage. Good reliability of the model with the experimental data has been observed, also at high conversion, and the values of the fitting parameters are substantially constant by varying the operative variable, which is a further proof of the goodness of the model. © 2011 Elsevier Ltd. All rights reserved.