SOLUBILITY BEHAVIOR OF AN ORGANIC SOLUBLE POLYIMIDE

The solubility behavior of an organic soluble polyimide synthesized from 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride and 2,3,5,6‐tetramethyl‐p‐phenylene diamine in about 60 liquids was investigated via solubility experiments. These results were put into a computer program to obtain a three‐dimensional representation of the polymer solubility region in the hansen space; the values of dispersion, hydrogen bonding, and polar components of the total solubility parameter were 10.6, 5.3, and 5.3 cal 1/2/cm3/2, respectively, and the total solubility parameter was 12.96 cal1/2/cm3/2 after calculation. The total solubility parameter determined from an equilibrium swelling method was between 12.9 cal1/2/cm3/2and 13.1 cal1/2/cm3/2. Both experimental results were in very good agreement. The calculated dispersion solubility parameter obtained from its correlation with the refractive index of the polymer was 10.56 cal1/2/cm3/2 and was in accordance with the result obtained from the polymer solubility region in the Hansen space. However, the total solubility parameter of the organic soluble polyimide calculated from the Fedors method was 12.1 cal1/2/cm3/2 and was low in comparison to the experimental results. Copyright © 1990 John Wiley & Sons, Inc.