Correlation Between Thermodynamic Characteristics of Glass-Forming Substances

Background. Thermodynamics of the glass transition of the bulk samples of glass-forming substances. Objective. The aim of the paper is analytical description of the correlations between thermodynamic characteristics of substance in the glass transition point and prediction of thermodynamic properties of organic and polymeric glass-forming substances. Methods. Thermodynamic analysis of the glass transition in view of the formal consideration of the melt in the glass transition as the second-order phase transition. Results. The applicability ranges of Ehrenfest-type relations for description of the correlation between thermodynamic cha??racteristics of substance in the glass transition point are determined. The increments of the isobaric heat capacity and the thermal expansion coefficient at the glass transition point, as well as the pressure coefficient of the glass transition tem?pe??rapture are predicted with the “entropic” correlation ratio for a number of organic and polymeric glass-forming substances. Conclusions. “Entropic” correlation ratio is obtained and successfully tested. “Volumetric” correlation ratio is inapplicable to glass transition process.