A DIFFERENTIAL SCANNING CALORIMETRY STUDY OF A BINARY-SYSTEM .1. INTERPRETATION OF DSC CURVES FOR ISOTHERMAL AND NONISOTHERMAL PHASE-TRANSITIONS IN BINARY-SYSTEMS

Thermodynamic relations for the heat capacity of heterogeneous systems and for the heat capacity jumps are applied in analysis of DSC data for binary systems. It is shown that it is possible to distinguish between invariant (isothermal) and univariant (nonisothermal) phase processes using DSC at low scanning rates. The behavior of the system's heat capacity in the case of a three-phase transition is considered; DSC curves for the eutectic transformation are given. Theoretical statements are illustrated by experimental results for the dimethyldecylphosphine oxide-water system. © 1991.