DETERMINATION OF SOLID LIQUID-PHASE EQUILIBRIUM OF ORGANIC TERNARY EUTECTIC MIXTURES BY DIFFERENTIAL SCANNING CALORIMETER - THE ORTHO-NITROANILINE, META-NITROANILINE AND PARA-NITROANILINE SYSTEM

The solid-liquid phase equilibrium (SLE) determination system originally developed for binary systems has been improved and applied to a ternary eutectic forming system. The determination system comprises a differential scanning calorimeter (DSC) and a personal computer. The SLE providing simulated DSC curves which are in agreement with the measured DSC curves is defined as the true SLE for the system. The ternary system of ortho-, meta-, and para-nitroaniline (NA) was studied and was found to form a simple eutectic mixture at 43.3°C with the composition 0.667 o-NA, 0.199 m-NA and 0.134 p-NA. This is in good agreement with the literature data. The system could produce pseudo-binary phase diagrams cut from the ternary diagram, hence precise analysis of the ternary SLE was made possible in a short time.