Terephthalic acid Terephthalic acid Terephthalic acid is an organic compound with formula CH(COH). This white solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several million tonnes are produced annually. The common name is derived from the turpentine-producing tree "Pistacia terebinthus" and phthalic acid. Terephthalic acid was first isolated (from turpentine) by the French chemist Amédée Cailliot (1805–1884) in 1846. Terephthalic acid became industrially important after World War II. Terephthalic acid was produced by oxidation of "p"-xylene with dilute nitric acid. Air oxidation of "p"-xylene gives "p"-toluic acid, which resists
Crotonic acid of plastics, it may be copolymerized with vinyl acetate. Crotonyl chloride reacts with "N"-ethyl-2-methylaniline ("N"-ethyl-o-toluidine) to provide crotamiton, which is used as an agent against scabies. Crotonic acid Crotonic acid ((2"E")-but-2-enoic acid) or is a short-chain unsaturated carboxylic acid, described by the formula CHCH=CHCOH. It is also called crotonic acid because it was erroneously thought to be a saponification product of croton oil. It crystallizes as needles from hot water. The "cis"-isomer of crotonic acid is called isocrotonic acid. Crotonic acid may be obtained by several methods: Crotonic acid crystallizes in long needles or as large panels in the monoclinic