Considerations and restrictions on the theoretical validity of the linearized cloudpoint correlation

The linearized cloudpoint curve correlation presented by Boom et al. [Polymer, 1993, 34, 2348] is revised. Boundaries for the validity of the linearized cloudpoint correlation are given for which an interpretation from the Flory-Huggins theory is possible. The distinction between liquid-liquid and solid-liquid demixing by this correlation must also be subjected to some constraints, although the slope in the correlation still offers a good way to distinguish between solid-liquid and liquid-liquid demixing. The statement, however, that concentration-dependent interaction parameters can be derived from this correlation must be rejected. The empirical rule found by Li et al. [Desalination, 1987, 62, 7955] can be rationalized on the basis of the LCC correlation.