The main impurity is the free acid formed by hydrolysis (check for OH bands in the IR). This can be converted to the dianhydride by treating with Ac2O (molar ratio of 4 to 1 of acid), heating at 110-120o for 1.5 to 2hours, cooling to 0—5o and collecting the dianhydride. This is then dissolved in hot dioxane or Me2CO, filtered and cooled to 10—15o. The moisture sensitive solid is collected and dried at 120—130o in vacuo. It has been sublimed at high vacuum. [Faberov et al. J Org Chem USSR 4 153 (English translation) 1968.]
white crystall powder
Used in the synthesis of polyimides.
BTDA is important monomer of polyimide, and used for production of polyimide material. The material has high temperature resistance, low temperature resistance, corrosion resistance, radiation resistance, insulation, shock resistance, excellent performance. Can be made into structure parts, laminates, films, adhesives, coatings, insulation materials and reinforcing material, etc., can be widely used in the field of aerospace, electrical / electronics, shipbuilding, automobile, precision machinery.