酚类在芳烃溶剂中的缔合溶液热力学

用凝固点降低法测量了对甲酚、间甲酚、邻甲酚、2,4-二甲酚、2,6-二甲酚以及对甲酚+间甲酚、对甲酚+邻甲酚、间甲酚+邻甲酚、2,4-二甲酚+2,6-二甲酚的1:1摩尔比混合物等为溶质, 溶剂为苯或对二甲苯的活度系数, 用Wiehe-Bagley型的连续缔合模型对数据进行了处理, 得到了各种酚的自缔合常效K_A. 在同一溶剂中, K_A依下列顺序减小: 对甲酚>间甲酚>邻甲酚; 2,4-二甲酚>2,6-二甲酚. 各混合酚的表观K_A 介于两种纯酚的K_A之间.

A THERMODYNAMIC STUDY ON THE SELF-ASSOCIATION OF PHENOLS IN AROMATICS BY FREEZING POINT DEPRESSION

The activity coefficients of solvent for some phenols,i.e.p-cresol,m-cresol,o-cresol,2,4-dimethyiphenol,2,6-dimethylphenol and phenol mixtures p-cresol+m-cresol,p-cresol+o-cresol,m-cresol+o-cresol,2,4-dimethylphenol+2,6-dimethylph-enol(1:1 mole ratio)in benzene and in p-xylene have been measured by freezing pointdepression.The data was treated with Wiehe-Bagley association model combining witha Hildebrand-Scatchard term to evaluate the association constants K_A of phenols.Itis found that the K_A of phenols in each solvent follows the order:p-cresol>m-cresol>o-cresol;2,4-dimethylphenol>2,6-dimethylphenol.The association constants ofbinary solute mixtures are all situated between the respective two pure components.