Dimethyl terephthalate

  • Dimethyl-1 ,4 - benzenedicarboxylate
  • Dimethyl-p- phthalate
  • Dimethyl terephthalate
  • DMT

Colorless, almost odorless solid

Fixed

1.35 g · cm -3

140.64 ° C

282 ° C

< 0.13 hPa ( 30 ° C)

  • Practically insoluble in water and alcohols (36 mg · l-1 at 20 ° C)
  • Slightly soluble in chloroform and dioxane

> 3200 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Dimethyl terephthalate ( DMT) is an organic compound. It is the dimethyl ester of 1,4- benzenedicarboxylic acid ( terephthalic acid). DMT consists of a benzene ring to the first and fourth carbon atom is each a COOCH3 - group.

Production

Dimethyl terephthalate is prepared by oxidation of a mixture of p -xylene and methyl p-toluate with air and subsequent esterification with methanol - Katzschmann the method ( Ewald Katzschmann, the developer of the process ).

Also possible is the progressive oxidation of p -xylene to p- toluic acid, followed by esterification with methanol to form methyl p-toluate, oxidation to terephthalic acid monomethyl ester, and esterification with methanol to form dimethyl terephthalate.

Use

Dimethyl terephthalate is a raw material for the industrial production of polyesters, for example polyethylene terephthalate ( PET) or polybutylene terephthalate ( PBT). It is also used for the preparation of polyester resins for films, coatings and adhesives, and 1,4- dimethylolcyclohexane.

CAS registry number Vapor pressure 1,4-Dioxane Integrated Authority File
240380
de