Thermodynamic study of alkyl-cyclohexanes in liquid, glassy, and crystalline states

The specific heat of some alkyl-cyclohexanes in their liquid, supercooled liquid, crystalline, and (for the first time) glassy states has been measured by quasiadiabatic calorimetry. Thermodynamic properties as well as the glass forming ability have been studied as a function of systematic changes of the molecular structure. Only one stable crystalline phase is observed experimentally for ethylcyclohexane, propylcyclohexane, and butylcyclohexane. In the case of methylcyclohexane, experimental evidence is provided of a crystal-to-crystal transition at temperatures just below the melting.