DMT DIMETHYL TEREPHTHALATE

DMT Dimethyl Terephthalate, also called terephthalic acid dimethyl ester, is an aromatic diester with formula C10H10O4 used as a raw material for PET, PBT and other polyester systems. Its two methyl ester groups provide a defined terephthalate source for ester-interchange routes, while its meltable crystalline form offers solid or molten-feed options. Reaction with diols replaces the methyl groups with glycol-derived groups, releases methanol and enables subsequent polyester chain growth.

CAS No: 120-61-6
EC No: 204-411-8
Molecular formula: C10H10O4
Molecular weight: 194.18 g/mol
Appearance: white crystalline solid, flakes or powder
Chemical class: aromatic dicarboxylic acid diester
Melting region: approximately 139-142°C
Water solubility: very low
Commercial physical forms: solid and, for suitable supply arrangements, molten liquid

WHAT IS DMT DIMETHYL TEREPHTHALATE?

DMT Dimethyl Terephthalate is the dimethyl ester of terephthalic acid, CAS 120-61-6, used mainly as a reactive intermediate in polyester production. It supplies the para-substituted aromatic terephthalate structure for ester-interchange routes to polymers such as polyethylene terephthalate and polybutylene terephthalate.

At ordinary temperatures, the material is a crystalline solid rather than a ready-to-use polyester resin. Heating melts it, but melting alone does not polymerize it. Its methyl ester groups must react with suitable hydroxyl-containing materials in a designed chemical process.

Purity, moisture, acid value, color and trace contaminants distinguish grades that may share the same CAS number. Material recovered through chemical recycling also requires purification and qualification for its intended reuse. Neither a high assay nor a recycled origin alone establishes suitability for demanding polymer applications.

Industrial preparation can involve oxidation and methyl esterification of para-xylene-derived intermediates, followed by purification. Esterification of terephthalic acid with methanol provides another chemical route. The actual production route and feedstock origin of an offered batch must be confirmed rather than inferred from the molecular formula.

One practical distinction is its role as a monomer precursor, not a polymerization initiator or general catalyst. It is also different from a finished terephthalate plasticizer. Similar chemical-family names do not make these materials interchangeable.

COMMON PRODUCT & CHEMICAL NAMES OF DMT DIMETHYL TEREPHTHALATE

DMT Dimethyl Terephthalate
Dimethyl terephthalate
DMT
Terephthalic acid dimethyl ester
Dimethyl benzene-1,4-dicarboxylate
Dimethyl 1,4-benzenedicarboxylate
1,4-Benzenedicarboxylic acid, dimethyl ester
Dimethyl p-phthalate

DMT is the common abbreviation, and the other chemical names describe the same para-substituted dimethyl ester. Database identifiers, catalog numbers and analytical-grade labels are not additional chemical synonyms.

The historical name dimethyl p-phthalate should not be confused with dimethyl phthalate, commonly DMP, which has the ortho substitution pattern. Dimethyl isophthalate has the meta pattern. These positional isomers can share a molecular formula while producing different material behavior.

CAS, EC AND CHEMICAL IDENTIFICATION OF DMT DIMETHYL TEREPHTHALATE

Product name: DMT Dimethyl Terephthalate
Common abbreviation: DMT
Chemical name: dimethyl benzene-1,4-dicarboxylate
CAS No: 120-61-6
EC No: 204-411-8
Molecular formula: C10H10O4
Molar mass: 194.18 g/mol
Condensed formula: C6H4(COOCH3)2
Functional groups: two methyl ester groups on a para-substituted benzene ring
Principal role: reactive terephthalate intermediate

The identity describes the molecular compound, not a particular purity or polymer grade. Confirm whether the offer is a solid product, a molten feed or a formulated solution. A solution requires its solvent and actual concentration to be included in the purchase specification.

No cosmetic INCI or food-additive number is assigned here. The use of a resulting polyester in packaging does not establish that the raw monomer is an edible ingredient or that every derived polymer meets food-contact requirements.

CHEMICAL STRUCTURE OF DMT DIMETHYL TEREPHTHALATE

The benzene ring bears two ester groups opposite one another in the 1,4 positions. Each ester contains a carbonyl oxygen and an alkoxy oxygen. This arrangement provides two reactive sites for exchange with hydroxyl-containing compounds while retaining the aromatic terephthalate framework.

The two methyl groups are displaced during the ester-interchange route. Their fate matters in the process balance because methanol must be managed. DMT is therefore incorporated through chemical reaction rather than simply dispersed as an inert filler.

A neutral ester structure should not be described as a universally neutral pH. pH applies to an appropriate solution or aqueous phase under defined conditions. The solid itself has no directly assignable aqueous pH, and its very low water solubility further limits such a shorthand description.

HOW DOES DMT DIMETHYL TEREPHTHALATE WORK IN POLYESTER PRODUCTION?

With ethylene glycol, ester interchange forms hydroxyethyl terephthalate species and methanol. Subsequent reactions of the intermediates build PET chains, with control of volatile removal and functional-group balance. The intermediate mixture can contain partly exchanged species and oligomers, not just one isolated compound.

Using 1,4-butanediol instead provides the glycol-derived segment relevant to a PBT route. Other diols and comonomers can change the polyester structure. A raw-material name alone does not determine the final resin's molecular weight, crystallinity or processing behavior.

Catalyst selection, temperature history, oxygen exposure, reaction time and removal of volatile products all matter. Moisture and impurities can change the reaction balance or product quality. No universal reactor cycle follows from the melting point alone.

PHYSICAL AND CHEMICAL PROPERTIES OF DMT DIMETHYL TEREPHTHALATE

Representative technical profile:

Physical state at room temperature: crystalline solid
Molten appearance: typically colorless liquid for suitably pure material
Melting region: approximately 139-142°C
Reported water solubility: approximately 0.019 g/l at 25°C
Boiling behavior: reported near 288°C at atmospheric pressure
Chemical functionality: difunctional methyl ester

These values describe the substance and are not a binding sales specification. A reported boiling point is not an instruction to operate a reactor or storage system at that temperature. Thermal handling requires its own design and fire assessment.

The low aqueous solubility rules out treating DMT as a convenient water-soluble formulation ingredient. Solubility in an organic solvent depends on solvent identity, temperature and concentration. A claim that it dissolves easily in all common solvents, or in methanol under every condition, is too broad.

Melting range and color can help assess consistency, but neither replaces an assay and impurity profile. Acidic residuals, including monomethyl terephthalate, can influence acid value. Methyl p-formylbenzoate and other process-related contaminants may also matter in polymer-grade evaluation.

Density and bulk density are different measurements, and a solid-state value should not be used as a molten-liquid value. Likewise, a laboratory purity specification should not be copied into an industrial offer. Obtain missing grade-specific parameters from Ataman Kimya.

DMT DIMETHYL TEREPHTHALATE AND POLYESTER RECYCLING

Methanolysis can cleave PET ester bonds to recover DMT and ethylene glycol. This is different from glycolysis, which commonly targets hydroxyethyl terephthalate products, and from hydrolysis, which can recover terephthalic acid or its salts. The choice of route changes the recovered chemical form.

Recovered DMT needs separation from residual solvents, catalysts, oligomers and contaminants from the waste stream. Its ability to serve as new feedstock depends on the specification and the next polymerization process. Recycling origin does not remove the need to test color, assay, moisture and trace impurities.

No universal yield, energy saving or environmental advantage is assigned to every methanolysis route. Such comparisons depend on the complete process, purification needs and the feedstock considered.

SECTORS AND INDUSTRIAL APPLICATIONS OF DMT DIMETHYL TEREPHTHALATE

PET fibers and films
The ester provides an aromatic building block for appropriate PET synthesis routes. Fiber spinning and film manufacture then depend on the finished polymer's quality and processing. The monomer itself does not guarantee strength, transparency or dimensional stability.

Polyester container and specialty-plastic systems
DMT-derived PET can be used in relevant container and specialty applications once the polymer is appropriately produced and qualified. Residual substances and migration requirements belong to the final application assessment, not to a blanket raw-material claim.

PBT engineering polymers
Reaction with butanediol-based feeds provides a route to PBT. Resin performance also depends on molecular weight, additives, compounding and processing. DMT is a precursor rather than a ready-made engineering plastic.

Specialty esters and chemical intermediates
Ester exchange can provide other terephthalate derivatives, including suitable plasticizer intermediates. The selected alcohol and subsequent purification define the product. A precursor must not be marketed as though it already has the properties of its final ester derivative.

PROBLEMS DMT DIMETHYL TEREPHTHALATE CAN HELP ADDRESS

A polyester process needing a methyl-ester terephthalate feed can use DMT as its defined reactive component. Equipment, catalyst and volatile-handling arrangements must match that route.

A chemical-recycling process seeking an isolable terephthalate intermediate can target recovery and purification of DMT. The final specification still determines whether the recovered material can replace an existing feed.

Inconsistent polymer quality calls for examination of feed purity, water, acid value and reaction balance. Increasing the amount of monomer is not a general correction for poor catalyst control, contamination or inadequate volatile removal.

THINGS TO CONSIDER WHEN USING DMT DIMETHYL TEREPHTHALATE

Keep solid and molten handling requirements distinct.
Specify assay, moisture, acid value and relevant impurity limits.
Express glycol-to-DMT ratios in moles as well as feed mass.
Account for methanol and other process volatiles.
Avoid treating initial feed percentages as final polymer composition.
Check catalyst compatibility and the required polymer properties.
Control powder dust and ignition sources during transfer.

Heated equipment introduces burn hazards, while the ester-interchange route generates methanol with its own toxicity and flammability concerns. These are process requirements even where a supplied solid grade has no GHS hazard classification.

INITIAL FEED APPROACHES FOR DMT DIMETHYL TEREPHTHALATE

The following binary feeds illustrate mass and molar calculations for laboratory development. They are not validated commercial resin formulations or complete polymerization instructions. Percentages are by weight of the initial monomer blend, with nominally pure components, and exclude any separately designed catalyst or additive package.

EXAMPLE 1: DMT DIMETHYL TEREPHTHALATE AND ETHYLENE GLYCOL

Components:

Dimethyl terephthalate: 60.00%
Ethylene glycol: 40.00%
Total: 100.00%

Using 194.18 g/mol for DMT and 62.07 g/mol for ethylene glycol gives approximately 2.09 mol glycol per mol DMT. This is an initial glycol-rich feed, not the repeat-unit ratio in finished PET. Excess glycol and methanol removal change the later mass balance.

Evaluation criteria:

Feed assay and moisture
Ester-interchange progress and residual methyl ester
Methanol recovery and material-balance closure
Color and oligomer distribution
Final intrinsic viscosity and other properties in a separately developed polymerization

A qualified process must define the catalyst, thermal cycle and vapor-handling system before heating. The percentages alone are not sufficient to run a reaction safely or obtain a specified resin.

EXAMPLE 2: DMT DIMETHYL TEREPHTHALATE AND 1,4-BUTANEDIOL

Components:

Dimethyl terephthalate: 50.00%
1,4-Butanediol: 50.00%
Total: 100.00%

Using 90.12 g/mol for 1,4-butanediol gives approximately 2.15 mol diol per mol DMT. The ratio is an illustrative starting balance rather than a recommended optimum for PBT manufacture. Actual development must account for volatile removal and side reactions as well as ester exchange.

Evaluation criteria:

Feed homogeneity under the designed process conditions
Conversion and recovered methanol
Residual diol and other volatile products
Polymer color and molecular-weight development
Thermal and processing properties of the resulting resin

Do not transfer a PET catalyst or operating cycle automatically to this feed. Equipment suitability, condensation capacity and process safety need a separate assessment.

ALTERNATIVES TO DMT DIMETHYL TEREPHTHALATE

Purified terephthalic acid is the principal chemical comparison for many polyester routes. It reacts through direct esterification with glycol, producing water rather than the methanol associated with methyl-ester interchange. Feed handling, catalyst strategy and equipment requirements therefore differ.

Bis(2-hydroxyethyl) terephthalate and suitable oligomers can serve as more advanced intermediates in particular PET processes. Their purity, end groups and water content must be matched to the intended route. They are not equal-mass replacements for the methyl ester.

Other aromatic dicarboxylates or diacids can modify polyester structure. A change from para to meta substitution is a change in backbone design rather than a simple purity substitution. Select alternatives against both process feasibility and the finished material specification.

QUALITY CONTROL AND PURCHASING CRITERIA FOR DMT DIMETHYL TEREPHTHALATE

Define the intended polymer or derivative before comparing offers. Review assay method, moisture, acid value, color, melting range, residual solvents and relevant organic impurities. For sensitive applications, specify the required metals and catalyst-residue controls rather than assuming a high headline purity covers them.

For solid supply, also clarify particle form, dust, packaging and handling behavior. For molten supply, confirm the delivery arrangement and the properties needed for transfer and storage. The two forms require different logistical preparations even when the chemical identity is unchanged.

Request the batch COA, current TDS and regional SDS for the offered grade. The COA describes batch results, while typical technical data and hazard information serve other purposes. Contact Ataman Kimya for unverified specification values, availability, origin claims and shipment conditions.

STORAGE AND HANDLING OF DMT DIMETHYL TEREPHTHALATE

Store the solid in closed, compatible packaging in a dry, ventilated location away from ignition sources and incompatible reactive materials. Prevent contamination and accumulation of fine dust. Use transfer equipment and cleaning methods suitable for combustible organic powders.

Molten material requires engineered heated storage, temperature control and suitable lines and seals. A general solid-storage recommendation does not define a safe molten operating range. Ask Ataman Kimya for the supplied form's current temperature, packaging and shelf-life requirements.

Contain spills and prevent entry into drains or surface water. Collect solid material without dispersing dust. For a molten spill, isolate the hot area and follow the site's trained response procedure rather than approaching it as an ordinary powder spill.

SAFETY AND TRANSPORT OF DMT DIMETHYL TEREPHTHALATE

Dust can form an explosive mixture with air, and molten product can cause severe thermal burns. Use suitable eye protection, gloves and clothing, with dust extraction or ventilation appropriate to the task. Prevent ignition and avoid uncontrolled dust deposits.

The supplied historical hazard assessment reports low acute toxicity in its reviewed studies, but also identifies urinary-tract effects after substantial repeated exposure in animals. Such findings do not establish a safe workplace exposure level or justify an unqualified harmless claim. Current classification must follow the offered grade and region.

Reviewed supplier SDS information includes grades not classified as hazardous under the applicable GHS framework. This does not remove dust, hot-liquid or process-methanol hazards. Solid and heated-liquid transport assignments may differ, so no single UN number is assigned to every DMT shipment here.

After eye contact, rinse with clean water, remove contact lenses if easy and obtain medical attention for persistent irritation or injury. Wash contaminated skin, and seek urgent care for thermal burns. Move to fresh air after significant dust or vapor exposure and obtain help if symptoms occur.

Confirm regional classification, transport temperature and shipment documentation with Ataman Kimya. Keep the raw-material assessment separate from the additional hazards introduced by the chosen reaction process.

SUPPLY OF DMT DIMETHYL TEREPHTHALATE FROM ATAMAN KIMYA

ATAMAN KİMYA can be contacted for DMT Dimethyl Terephthalate inquiries. Confirm the offered grade, physical form, specification, availability and delivery arrangement for the intended application.

Provide the target polymer or derivative, required quantity, destination, impurity limits and solid or molten handling capability. Include any recycled-content or end-use documentation requirements so that they can be evaluated for the actual offer.

FREQUENTLY ASKED QUESTIONS ABOUT DMT DIMETHYL TEREPHTHALATE

What is DMT?
The dimethyl ester of terephthalic acid used as a reactive polyester intermediate.

What is its CAS number?
120-61-6.

What is its EC number?
204-411-8.

What are its formula and molar mass?
C10H10O4 and 194.18 g/mol.

Is it the same as dimethyl phthalate?
No, DMT is the para isomer and dimethyl phthalate is the ortho isomer.

Is DMT already a polyester resin?
No, it is a reactive feedstock for suitable chemical routes.

What happens when it melts?
It becomes a liquid, but melting alone does not produce polymer.

Is it readily soluble in water?
No, its water solubility is very low.

Can the solid simply be assigned pH 7?
No, a meaningful pH requires an appropriate aqueous measurement under defined conditions.

Which glycol is associated with PET production?
Ethylene glycol.

Which diol is associated with a DMT-based PBT route?
1,4-Butanediol.

What volatile is released during methyl-ester interchange?
Methanol.

Is DMT a polymerization initiator?
No, its role is a reactive terephthalate building block.

Can it be recovered from PET?
Yes, appropriate methanolysis routes can recover DMT for subsequent purification.

Does recovered DMT automatically meet polymer-grade requirements?
No, its composition and performance must be qualified.

Are initial feed percentages the final resin composition?
No, reaction and removal of volatile materials change the balance.

Does absence of a GHS classification eliminate handling hazards?
No, dust combustion, molten-product burns and process hazards still require control.

What should be requested before purchasing?
The exact grade specification, batch COA, current SDS, physical-form details and application-relevant documentation.

DMT DIMETHYL TEREPHTHALATE - TECHNICAL SUMMARY

DMT Dimethyl Terephthalate is an aromatic dimethyl ester identified by CAS 120-61-6 and EC 204-411-8. Its formula is C10H10O4 and its molar mass is 194.18 g/mol.

The material is a crystalline solid with a melting region near 140°C and very low water solubility. Physical form, assay, moisture and impurity profile must be specified for the intended feed arrangement.

Ester interchange with diols provides routes to PET, PBT and related polyesters, releasing methanol. Subsequent polymer development depends on the catalyst, volatile removal and full reaction balance.

Methanolysis of PET can recover the methyl ester, but purification and qualification determine whether it is suitable as new feedstock. Molecular identity alone does not establish recycled content or final application compliance.

Solid dust, molten handling and reaction byproducts create distinct process considerations. Quality, storage, safety and transport decisions must follow the exact supplied form and current documentation.

DMT Dimethyl Terephthalate can be sourced from ATAMAN KİMYA. For further information and supply inquiries about DMT Dimethyl Terephthalate, please contact ATAMAN KİMYA.