Geometric analysis of the calorimetric glass transition and fragility using constant cooling rate cycles

Abstract

A novel calorimetric approach and analytic method were proposed to characterize the glass transition and fragility of glass-forming systems. Initial characterization of the glass transition temperatures (onset, inflection, and end) was performed by precisely defining these points based on derivative behavior of the total heat flow curve obtained through differential scanning calorimetry (DSC). Geometric representation allowed for consolidation of critical glass transition data into one matrix. This glass transition matrix can be used for automated characterization of the regime, including thermodynamics and kinetics, via programmed computation. Comparison of results to traditional methods revealed excellent agreement with results derived by the novel procedure proposed, and indeed was corroborated by literature values of glass transition temperature, liquid fragility index, and activation energy. The proposed analytic methods establish a significant metrological traceability by development of a robust confidence interval for all targeted measurands, and in so doing provide a highly reproducible and efficient analysis via DSC. K E Y W O R D Scharacterization, calorimetry (or DSC), fragility (or liquid fragility index), glass transition, heat capacity How to cite this article: Mancini M, Sendova M, Mauro JC. Geometric analysis of the calorimetric glass transition and fragility using constant cooling rate cycles.

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