Investigation on molar heat capacity, standard molar enthalpy of combustion for guaiacol and acetyl guaiacol ester

Abstract

The molar heat capacities (Cp) of guaiacol (CAS 90-50-1) and acetyl guaiacol ester (AGE, CAS 613-70-7) were determinated from 290K to 350K by differential scanning calorimetry (DSC), and expressed as a function of temperature. Two kinds of group contribution models were used to estimate the molar heat capacities of both guaiacol and AGE, the average relative deviation is less than 10%. The standard molar enthalpies of combustion of guaiacol and AGE were −3590.0kJ·mol−1 and −4522.1kJ·mol−1 by a precise thermal isolation Oxygen Bomb Calorimeter. The standard molar enthalpies of formation of guaiacol and AGE in a liquid state at 298.15K were calculated to be −307.95kJ·mol−1 and −448.72kJ·mol−1, respectively, based on the standard molar enthalpies of combustion. The thermodynamic properties are useful for exploiting the new synthesis method, engineering design and industry production of AGE using guaiacol as a raw material.