terephthalate are consumed as precursors to polyethylene terephthalate (PET). World production in 1970 was around 1.75 million tonnes. By 2006, global purified terephthalic acid (PTA) demand had exceeded 30 million tonnes. A smaller, but nevertheless significant, demand for terephthalic acid exists in the production of polybutylene terephthalate and several other engineering polymers. Other uses Polyester fibers based on PTA provide easy fabric care, both alone and in blends with natural and other synthetic fibers. Polyester films are used widely in audio and video recording tapes, data storage tapes, photographic films, labels and other sheet material requiring both dimensional stability and toughness. Terephthalic acid is used in paint as a carrier. Terephthalic acid is used as a raw material to make terephthalate plasticizers such as dioctyl terephthalate and dibutyl terephthalate. It is used in the pharmaceutical industry as a raw material for certain drugs. In addition to these end uses, Terephthalic acid based polyesters and polyamides are also used in hot melt adhesives. PTA is an important raw material for lower molecular weight saturated polyesters for powder and water-soluble coatings. In the research laboratory, terephthalic acid has been popularized as a component for the synthesis of metal-organic frameworks. The analgesic drug oxycodone occasionally comes as a terephthalate salt; however, the more usual salt of oxycodone is the hydrochloride. Pharmacologically, one milligram of hydrochloridum oxycodonae is equivalent to 1.13 mg of terephthalas oxycodonae. Terephthalic acid is used as a filler in some military smoke grenades, most notably the American M83 smoke grenade and M90 vehicle-employed smoke grenade, producing a thick white smoke that acts as an obscurant in the visual and near-infrared spectrum when burned. Solubility Terephthalic acid is poorly soluble in water and alcohols; consequently, until about 1970 terephthalic acid was purified as its dimethyl ester. It sublimes when heated. |} Toxicity Terephthalic acid and its dimethyl ester have very low toxicity, with >1 g/kg (oral, mouse). Biodegradation In Comamonas thiooxydans strain E6, terephthalic acid is biodegraded to protocatechuic acid, a common natural product, via a reaction pathway initiated by terephthalate 1,2-dioxygenase. Combined with the previously known PETase and MHETase, a full pathway for PET plastic degradation can be engineered. See also Polycyclohexylenedimethylene terephthalate a thermoplastic polyester formed from terephthalic acid References Cited sources External links and further reading International Chemical Safety Card 0330 Dicarboxylic acids Monomers Benzoic acids Commodity chemicals