Abstract
θ Temperatures for o-cresol resin in o-dichlorobenzene and for acetylated o-cresol resin in 2-ethoxyethanol were determined as 119. 2°C and 92. 0°C, respectively, from the experiments of phase equilibrium using Shultz-Flory equation.
The values of the exponent a in Mark-Houwink-Sakurada viscosity equation for acetylated o-cresol resin in the θ solvent was obtained to be 0. 50. From the result, it becomes obvious that the molecules of acetylated o-cresol resin behave as an unperturbed chain in the θ solvent since there is no branching and no intramolecular hydrogen bonding by acetylation of phenolic OH groups. In the good solvent (THF) however, the value of a becomes larger (a = 0. 65) by the effect of the excluded volume. Before acetylation, the molecules becomes compact both in the good solvent and in the θ solvent by the effect of intramolecular hydrogen bonding.
