Binary phase diagram of the system: n-docosane- n-tricosane

• Published in: Journal of molecular structure 1998-02, Vol.443 (1), p.197-204
• Main Authors: Nouar, H., Petitjean, D., Bouroukba, M., Dirand, M.
• Format: Article
• Language: English
• Subjects: Binary mixtures; DSC; Intermediate solid phases; n-docosane; n-tricosane; Phase diagram; Rotator phases; Terminal solid solutions; XRD
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/S0022-2860(97)00385-2

The binary phase diagram of the system: n-docosane- n-tricosane has been established by means of calorimetric and structural analyses. These technical methods have made it possible to show the existence of seven solid single-phase domains of equilibrium: three terminal solid solutions denoted γ 0(C 22), β 0(C 23), β 0′(C 23); and two intermediate solid-solutions noted β 1′, β 1″ of orthorhombic structures. All these phases are stable at 298K. On increasing temperature, a limited miscibility field has been shown in which the orthorhombic phase β(Fmmm), with appearance of the rotator state called RI, is stable. At the highest temperature, this latter phase changes into the rotator phase α-RII (R 3̄m), which has been detected on the whole concentration field. Moreover, several eutectoid and/or peritectoid decompositions were proposed in order to explain the experimental results and to respect thermodynamic rules.