Cresylic soluble polyimides

摘要

AbstractPolyimides are prepared by reaction of dianhydrides with aromatic diamines under dehydrating conditions to insure conversion of the polyamic acids to polyimides. Cresylic acid solubility is observed only for cyclopentane dianhydride and benzophenone dianhydride. Most of the batches are made from BPDA, since it is the preferred dianhydride for thermal stability. Of 19 aromatic diamines only 2,4‐ and 2,6‐diaminotoluene, 2,4‐diaminoanisole, 4,5‐dimethyl‐1,2‐phenylene diamine and 1,5‐diamino‐4,8‐dihydroxyanthraquinone contribute a great deal toward making soluble polyimides of BPDA. 2,4‐Diamino‐acetanilide when used as the only diamine also gives a soluble polyimide with BPDA. The solubility of polyimides can be correlated with their solubility parameters, their symmetry, and their tend