Dimethyl terephthalate, DMT, is a chemical substance used as a raw material for PET film, PET fiber, PBT, various chemical intermediates and others. Teijin began producing DMT in 1964 and has become the largest DMT supplier in Asia, with an annual production of 230,000 metric tons. Teijin supplies DMT for a wide range of applications around the world.
|IUPAC name ||DIMETHYL TEREPHTHALATE |
|Abbreviated name ||DMT |
|Synonyms ||1,4-Benzenedicarboxylicacid, |
|CAS No. ||120-61-6 |
|MF ||C10H10O4 |
|Structural formula || |
|MW (g/mol) ||194.186 |
|Tm (℃) ||140 |
|Tb (℃) ||288 |
|Purity (wt%) ||≧99.9 |
|Figure ||Flake, Briquette |
|Packing ||Paper bag, Flexible container bag |
Differences in chemical properties between DMT and terephthalic acid
(1) DMT has a low melting point and is dissolved easily in methanol and
⇒ DMT is an easy-to-handle raw material for various chemical reactions.
(2) The polymerization reaction of DMT starts at lower
temperatures than that of terephthalic acid.
⇒ DMT may react with chemical substances that are susceptible to
degradation at high temperatures.
(3) When DMT is used as a raw material in the production of polymers,
additives can be dispersed even at low temperatures; therefore, additive
aggregation is unlikely to occur.
⇒ When terephthalic acid is used, the reaction mixture needs to be heated to a high
temperature before the addition of additives; additive aggregation is likely to occur due
to heat shock.
(4) DMT has a neutral pH; terephthalic acid is acidic.
⇒ Terephthalic acid reacts with basic substances such as calcium carbonate, to form
sediments. DMT is neutral and is therefore unlikely to form sediments.
⇒ When terephthalic acid is used as a raw material to produce epoxy resins, the epoxy
groups of the product resin tend to be decomposed or become ring-opened.
When DMT is used, the epoxy groups are likely to remain intact.
⇒ When terephthalic acid is reacted with 1,4-butanediol (BDO), the latter is converted
into tetrahydrofuran (THF), resulting in the generation of a large amount of THF
Also, the reaction of terephthalic acid with ethylene glycol (EG) generates a large
amount of diethylene glycol byproduct (DEG). On the other hand, reaction of
DMT with either 1,4-BDO or EG is unlikely to generate these byproducts.
DMT may be used as a raw material for various polymers, including PET and PBT, as well as for insulating varnish, adhesive, plasticizer, paint resin and others.
Examples of the chemical products that can be made from DMT are as follows: