POLYAMIC ACIDS AND METHODS TO CONVERT POLYAMIC ACIDS INTO POLYIMIDEBENZOXAZOLE FILMS

摘要

This invention relates to polyamic acids and to methods for converting polyamic acid into polyimidebenzoxazole polymers. The polyamic acids are prepared by reacting a dianhydride with a diaminobenzoxazole under conditions sufficient to form polyamic acid with an inherent viscosity of greater than 2.0 dL/gram, as measured at 0.2 g/dL in N-methyl-pyrrolidinone at 25 ·C. The polyamic acids are converted to polyimidebenzoxazole in the form of films, fiber and coatings using thermal and chemical processes.