Abstract
Phase separation and fractionation experiments were carried out for o-cresol resin (o-CR) -acetone-cyclohexane, acetylated o-CR (Ac-o-CR) -acetone-cyclohexane, poly (p-hydroxystyrene) (PHS) -acetone-cyclohexane and acetylated PHS (Ac-PHS) -acetone-cyclohexane systems and the fractionation efficiency of the first fraction was discussed. The partition coefficient σ was adopted as a fractionation efficiency parameter. It was confirmed that the efficiency increased more as σ was greater. The fractionation efficiency was affected by the initial polymer concentration and the amount of polymer partitioned in polymer-rich phase. By comparison of σ values for o-CR and Ac-o-CR systems, or PHS and Ac-PHS systems, it became apparent that the fractionation efficiency was influenced significantly by the hydrogen bonds among the phenolic hydroxyl groups. It was suggested that the fractionation efficiency was closely related to the molecular conformation as well as to the viscosity measured in solutions.
