tereftalat

Tereftalat, also spelled terephthalate, refers to the dianion of terephthalic acid (1,4-benzenedicarboxylic acid) as well as the esters and salts derived from it. The core structure is a benzene ring with two carboxylate groups in the para position, giving rigidity and a high potential for polymerization.

In industry, tereftalat is encountered as terephthalic acid, its esters such as dimethyl terephthalate (DMT), and as the repeating unit in polyesters like polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). Terephthalic acid is produced mainly by oxidation of p-xylene, followed by purification. DMT can be produced from the acid or via oxidation products; PET is formed by condensation or transesterification of DMT or terephthalic acid with glycols such as ethylene glycol or propylene glycol.

Applications of tereftalat compounds are most prominent in polymer chemistry, where they serve as monomers or precursors for resins, fibers, films, and bottles. In addition to the major polyesters, various terephthalate esters and salts are used in specialty polymers, plasticizers, and processing aids. Salts such as sodium terephthalate may appear in processing formulations and detergents.

Safety and environmental aspects: terephthalic compounds generally have low vapor pressure and are handled under standard chemical-safety protocols. They can cause skin and eye irritation and should be managed to minimize exposure and environmental release. Early to mid-20th century development of PET and related polyesters greatly expanded the commercial use of tereftalat derivatives.