Isothermal Sections of Ternary Mixtures: n-docosane + n-tricosane + n-tetracosane

Abstract

The crystallographic long c parameter of the binary and ternary β′₁, β′₂, β″₁, intermediate solid solutions (n-C₂₂H₄₆ + n-C₂₃H₄₈ + n-C₂₄H₅₀) is approximately equal to the average c parameter of mixture equivalent orthorhombic pure n-alkanes: this finding shows that the longer n-alkane chain is not straight in unit cell of the mixture, but flexible near the chain end, as earlier observed from spectroscopy analyses by other authors. Four ternary isothermal sections were determined at 305 K, 308 K, 311 K and 313 K from binary diagram data and differential scanning calorimetry and X-ray diffraction analyses of thirty ternary mixtures: the ternary intermediate solid solutions undergo the same first-order solid-solid equilibrium transitions as those of binary alloys with the observation of β(Fmmm)-RI and α(R3m)-RII Rotator states below the solidus point.

Key Words:

• n-docosane
• n-tricosane
• n-tetracosane
• solid solutions
• Rotator states