n-Alkane Binary Molecular Alloys

The experimental systems considered in this paper are normal alkanes, in the range from octane to octacosane; and their binary mixtures {(1− x ) mol of C n H2 n +2 + x mol of C n ‘H2 n ‘+2}, with n ‘ > n, and Δ n = n ‘ − n taking the values 1 and 2. The alkanes and their mixtures have a rich, complex polymorphic nature, for the description of which a distinction is made between a high-temperature and a low-temperature domain. The high-temperature domain is occupied by rotator phases, and the low-temperature domain by a variety of mixed crystalline phases, referred to as the “ordered” phases. Experimental phase diagram data for 19 binaries including 11 binaries for which original data are presented are used to give a uniform and coherent description of the phase relationships for the ensemble of alkane alloys.