Carboxylic acids are organic acids with a carboxyl group, and are formulated as -COH. A carbon (C) atom is bonded to an oxygen (O) atom in double bonds, and bonded to a hydroxyl group (―OH) in a single bond.
The primary chemical properties of carboxylic acids arise from their acidic properties. Generally, they are more acidic than other organic compounds containing hydroxyl groups; however, they are weaker than the known mineral acids.
The solubility of carboxylic acids in water is similar to the solubility of alcohols, aldehydes and ketone. Acids with approximately five carbons are water-soluble; however, those with a higher molecular weight are not water-soluble.
Carboxylic acids have significantly higher boiling points than hydrocarbons, alcohols, ethers, aldehydes or ketons of similar molecular weight. Even formic acid, which is the simplest carboxylic acid, boils at 101°C.
Ftalic anhydride is of white crystal form and has a characteristic odor. It is also known as phthalic acid anhydride, 1.2-benzenedicarboxylic acid anhydride, and 2-benzofuran-1.3-dione. Its chemical formula is C8H4O3 . It has a melting point of 131.6°C and a boiling point of 295°C. Its molecular weight is 148.1 g/mol. It is used in manufacturing materials such as artificial resin, and in paint and polyester products.
Teraphthalic Acid (TPA) has a white, crystal appearance, and is in powder form. It is also known as Benzene-1.4-dicarboxylic acid and para-phthalic acid. Its chemical formula is C8H6O4. It has a melting point of 427°C. Its molecular weight is 166.132 g/mol. Terephthalic acid (TPA) is used for manufacturing polyester fiber, plastic bottles, synthetic perfumes and drugs.
Adipic acid has a white, crystal appearance. It is also known as Hexandionic acid, Butane-1.4-dicarboxylic acid, Hexane-1.6-dionic acid and 1.4-butandicarboxylic acid. Its chemical formula is C8H4O3. It has a melting point of 152.1°C and a boiling point of 337.5°C. Its molecular weight is 146,142 g/mol. It is one of the most important monomers in the polymer industry. It does not form a solution when mixed with water. It is used for manufacturing plastic and foam, and in other fields.