Thermodynamics Research Center / ThermoML | Thermochimica Acta

ABSTRACT

A mathematical model for the prediction of phase change temperatures and crystallization paths for mixtures consisting of palmitic (P), stearic (S), oleic (O), linoleic (L) and linolenic acid (Ll) in any distribution is presented in this paper. This model is based on the information gathered from modelled ternary phase diagrams, namely PSO, PSL, PSLl and OLLl, that were based on experimental binary phase diagrams of all possible combinations of these fatty acids. These experimental binary phase diagrams were obtained by means of differential scanning calorimetry and mathematical function fitting, within which the eutectic region of binary palmitic/stearic with oleic/linoleic/linolenic acid was investigated in detail. The basic mathematical model used was previously shown in literature which delivered good results for such systems. The importance of the developed model was then justified by investigations on real and composed synthetic fatty acid mixtures, where a high accuracy of the predicted temperatures could be shown for the technically relevant liquidus and solidus temperatures. A satisfying prediction for thermal events below the first solidus line could be reached as well. This work directly contributes to an enhanced understanding of the thermodynamic and kinetic background of such important mixtures applied in diverse products and industries, thereby showing a large optimization potential for crystallization technologies.