BTDA is important monomer of polyimide, and used for production of polyimide material.
일반 설명
Benzophenone-3,3′,4,4′-tetracarboxylic acid is formed by hydrolysis, it can be converted to the dianhydride by treating with Ac2O (molar ratio 4 to 1 of acid).The dianhydride is used to synthesize polyimides, which are highly flexible in nature due to the presence of keto and carbonyl groups in the dianhydride molecule. The keto and carbonyl groups subsequently increase the spacing between the imide rings enhancing the solubility and processibility.
Purification Methods
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.]
