Isopleth section of the system: n-eicosane and a multi-paraffinic wax

This paper displays a study of the system associating a commercial multi-paraffinic sample and pure n-eicosane: (C20H42). It has been studied by means of calorimetric and structural analyses. The X-ray analysis of the commercial product performed at room temperature has shown that it forms a single solid-solution of orthorhombic structure isostructural to that previously observed with binary or ternary alkane mixtures. The structural characterizations carried out on molecular alloys whose concentration in C20 is in range from 0 to 100% have allowed to determine the following phase appearance sequence: β′/β′+γ0/γ0 where β′ is the solid solution of the wax and γ0 is the triclinic structure of C20. lid–solid transitions of the molecular alloys have been highlighted by DTA and characterized by X-ray diffraction. Compilation of the results led to the proposal of the isopleth section of the system: multi-alkane product-eicosane. In this system, the crystallization is of ‘eutectic’ type and several ‘invariant’ transformations (‘eutectoid’ or ‘peritectoid’ reactions) are reported.