Abstract: Thermodynamics of phenol alkylation with tert-butyl alcohol (TBA) was studied. The result showed that phenol alkylation with TBA was spontaneous exothermic reaction. The heat effect and equilibrium constant decreased with the increase of temperature. Compared with the ether reaction on the hydroxyl group of phenol at the same temperature，the alkylation reaction on the carbon of phenol occurred more spontaneously，and the reaction equilibrium constant was higher. In the alkylation reactions on the carbons of phenol，the tribasic reaction occurred most spontaneously and the reaction equilibrium constant was the maximum，the dibasic one was in the middle and the monobasic got the lowest. Compared with the gas-phase reaction，the output of alkylation heat in liquid phase was higher than that in gas phase，and the reaction occurred more spontaneously and owned the greater reaction equilibrium constant. Therefore，the reaction was favored in liquid phase.

Key words: alkylation, thermodynamics, equilibrium, chemical reaction, heat effect

摘要： 采用热力学计算方法研究了苯酚与叔丁醇烷基化反应热力学，研究结果表明，苯酚与叔丁醇烷基化反应是自发进行的放热反应，反应热效应和反应平衡常数均随着温度升高而减小。在相同的温度下，与苯酚羟基上成醚反应相比，苯酚C上烷基化反应的自发进行趋势和反应平衡常数均较大。苯酚C上烷基化反应中，三取代反应的自发进行趋势和反应平衡常数均最大，二取代反应居中，一取代反应最小。与气相反应相比，液相烷基化反应放热量较大，其自发进行趋势和反应平衡常数均较大，反应以液相进行更有利。

关键词: 烷基化, 热力学, 平衡, 化学反应, 热效应