Study of phase equilibria in the two-component organic system biphenyl – n-docosane

Abstract

The fusibility diagram of the diphenyl – n-docosane system was calculated by Schroeder, UNIFAC and UNIFAC Dortmund methods, and it was shown that it belongs to the eutectic type. Individual substances and their mixtures were studied experimentally using a differential scanning microcalorimeter. The endo-effect corresponding to the melting of the eutectic was noted on the DTA heating curve of the eutectic alloy. A comparison of the eutectic coordinates calculated by these methods with experimental data is presented. Specific fusion enthalpy, molar values of entropy and enthalpy of fusion, volumetric specific fusion enthalpy and density for standard conditions were calculated for an eutectic alloy. The eutectic mixture can be used as a heat carrier, as well as a working fluid of a heat accumulator.