Image result for dicarboxylic acid A dicarboxylic acid is an organic compound containing two carboxyl functional groups (−COOH). The general molecular formula for dicarboxylic acids can be written as HO2C−R−CO2H, where R can be aliphatic or aromatic. ... Dicarboxylic acids are also used in the preparation of copolymers such as polyamides and polyesters.