Chemical equilibrium study in the reacting system of (1-alkoxyethyl)benzene synthesis from isoalkanols and styrene

Abstract

The chemical equilibrium of the reactive systems isoalkanol + styrene ⇌ (1-alkoxyethyl)benzene (alkyl is isopropyl, sec-butyl, and cyclohexyl) was studied in the liquid phase in the temperature range 343 to 433 K using a cation exchanger as heterogeneous catalyst. Enthalpies of reactions, Δ_rH^o_m, of (1-alkoxyethyl)benzene synthesis in the liquid phase were obtained from the temperature dependence of equilibrium constants measured in reactive mixtures with an excess of alkanol and showed a good agreement with reaction enthalpies derived from values of the enthalpy of formation Δ_fH^o_m(l) of the participants in the reaction for the synthesis of (1-isopropoxyethyl)benzene, measured by combustion calorimetry. The standard molar enthalpies of vaporization of (1-alkoxyethyl)benzenes were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. Resulting values of Δ_fH^o_m(g) were used to prove the consistency of the experimental data and to derive strain enthalpies of (1-alkoxyethyl)benzenes. The strain effects were discussed in terms of deviations of Δ_fH^o_m(g) from the group additivity rules.