Systèmes à tension de vapeur non négligeable : diagrammes T-v et p-T de l'adamantane

Abstract
A DSC method, designed to determine the melting enthalpy of compounds with non-negligible vapour pressure, is applied to adamantane. This method, based upon the linear dependence of the melting-related thermal effect with the specific volume v, is used to construct the T-v diagram of adamantane through which a melting enthalpy, at the triple point conditions, Δ_fusH (+12,4 ± 0,3) kT.mol^-1 at T_fus = (543 ± 2) K of is obtained. Also, the specific volume of the vapour phase is extrapolated to (52,7 ± 1,5) cm³.g^-1 With this information, a more general description of the p-T diagram for adamantane is put forward.