Quasi-chemical approximation for nonrandomness in the hole theory of polymeric fluids. 2. Miscibility behavior of binary systems: polystyrene in cyclohexane or methyl acetate

The nonrandom mixing version of the Holey Huggins theory for pure components, presented in a previous paper, is extended to binary mixts. and is applied to the miscibility behavior of polystyrene (I)-Me acetate (II) and I-cyclohexane (III) systems.. Comparison with the exptl. data shows that the present theory is successful in predicting the miscibility behavior and its pressure dependence for these systems. For I-III the results of the random mixing and nonrandom mixing theory are comparable. For I-II system the agreement between theory and expt. improves by applying the nonrandom mixing theory, indicating that nonrandom effects are of importance. [on SciFinder (R)]