Chapter 17 Pyrolysis of Carboxylic Acids

Carboxylic acids are characterized by the presence in their structure of one or more carboxyl groups (–COOH), which bring to the molecule a proton donor character (acidic character). Carboxylic acids have the capability to form anions and salts (carboxylates). Thermal decomposition of organic acids with two or more COOH groups in the molecule may take place at a single carboxyl group or with simultaneous participation in the decomposition process of both groups. This chapter presents the pyrolysis of di- and polycarboxylic acids such as oxalic acid; malonic and malonic type acids; succinic and glutaric type acids; maleic, fumaric, and glutaconic acids; adipic and pimelic type acids; aromatic dicarboxylic acids; and polycarboxylic acids. Hydroxy acids are compounds containing in their structure both carboxyl and hydroxyl groups. Depending on the position of the two groups (OH and COOH), hydroxyl acids are classified as α-hydroxy acids (the COOH and OH attached on the same carbon), β-hydroxy acids, γ-hydroxy acids, etc. The chapter describes the pyrolysis of carboxylic acids with other additional functionalities or groups such as halogeno acids; cyclic ether acids; aldehyde acids and keto acids; lactonic acids; and acids with the carboxyl group attached to an aromatic heterocycle. The chapter explores the pyrolysis of organic acid salts that is utilized in organic synthesis as well as for the preparation of specific inorganic combinations such as oxides or even metals or superconducting materials.