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In this research, we mainly study the solid-liquid equilibria
of 2,6-xylenol+m-cresol, 2,6-xylenol+tert-butanol and m-cresol+
tert-butanol binary systems at the atmospheric pressure. We
applied solid disappearance method to measurethe melting points
of the above binary systems. We obtained experimental data of
2,6-xylenol+tert-butanol mixture different from those of Jadhav
et al.(1991). Our experimental data show, the eutectic point
occurs at 0.321 mole fraction of 2,6-xylenol and eutectic
temperature at 253.68K, but Jadhav et al.(1991)showed the
eutectic composition of 0.271 and the eutectic temperature at
251.35 K. To ensure the reliability of our data,Differential
Scanning Calorimeter(DSC), was used to measure the melting
point. The result is far from that of Jadhav et al.(1991). We
found that there are two eutectic points (x1=0.489 and x1=0.772)
and one congruent point (x1=0.689) for the system of m-
cresol(1)+tert-butanol(2). We found that the mixture of
2,6-xylenol and m-cresol exhibited an unusual behavior of
thermal minimum that was very different from eutectic point.But
this needs to be examined carefully. Finally, we correlated the
experimental data for systems containing one eutectic point by
Wilson Model, van Larr Theory, NRTL Model and Regular Solution
Theory to predict the behavior of the solid-liquid equilibrium
and find the NRTL is better than others. We correlated the
system containing one congruent point by Ideal Chemical Model(
ICM).Unfortunately, the experimental data and correlation
results do not agree each other very well at the two ends of the
phase diagram.
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