DMTDA (E-300 EQUIVALENT)

DMTDA (E-300 equivalent), or dimethylthiotoluenediamine, is a liquid aromatic diamine isomer mixture used as a curative and chain extender in polyurethane-urea and polyurea systems. Its liquid form supports metering and mixing without the melting step required for some solid aromatic diamine curatives. The primary amine groups react with isocyanate groups to form urea linkages, extending chains and contributing to the hard-segment structure of the cured material.

CAS No: 106264-79-3
EC No: 403-240-8
Molecular formula: C9H14N2S2
Molecular weight: approximately 214.35 g/mol for the principal isomers
Appearance: clear yellow to amber liquid
Chemical class: aromatic diamine isomer mixture
Typical isocyanate equivalent weight: approximately 107 g/eq
Typical epoxy active-hydrogen equivalent weight: approximately 53.5 g/eq
Principal functions: curing and chain extension

WHAT IS DMTDA (E-300 EQUIVALENT)?

DMTDA (E-300 equivalent) is an aromatic diamine curative based mainly on dimethylthiotoluenediamine isomers, CAS 106264-79-3, used in cast elastomers and other reactive polymer systems. Its commercial description combines liquid handling with a cure response that must be matched to the selected prepolymer or resin.

The registered identity covers a mixture of 3,5-dimethylthio-2,4-toluenediamine and 3,5-dimethylthio-2,6-toluenediamine. Both principal isomers have the same molecular formula. Commercial products may also contain related diamines, so a high total-diamine value does not mean an equally high content of only the principal DMTDA isomers.

This material is a reactive ingredient, not an inert additive or a complete casting resin. Its performance depends on the isocyanate or epoxy component, reactive equivalents, mixing, temperature and cure schedule. A liquid at room temperature is not necessarily a low-viscosity liquid under every processing condition.

The E-300 comparison identifies a candidate replacement category. It does not prove identical composition, reaction profile or finished properties. Confirm the actual grade and validate any substitution in the intended system before treating it as interchangeable.

COMMON PRODUCT & CHEMICAL NAMES OF DMTDA (E-300 EQUIVALENT)

DMTDA (E-300 equivalent)
DMTDA
Dimethylthiotoluenediamine
Dimethylthio-toluenediamine
Mixture of 3,5-dimethylthio-2,4-toluenediamine and 3,5-dimethylthio-2,6-toluenediamine

ETHACURE 300 is a commercial reference associated with this chemistry, and E-300 equivalent is a replacement description. A trademarked reference is not the generic chemical name or proof of the origin of an offered material.

DETDA is diethyltoluenediamine, a different aromatic diamine. MOCA is another chemically different curative. Neither should be listed as a synonym for DMTDA, even when products are compared for the same application.

CAS, EC AND CHEMICAL IDENTIFICATION OF DMTDA (E-300 EQUIVALENT)

Product name: DMTDA (E-300 equivalent)
Common abbreviation: DMTDA
Chemical identity: dimethylthiotoluenediamine isomer mixture
CAS No: 106264-79-3
EC No: 403-240-8
Principal-isomer formula: C9H14N2S2
Principal-isomer molar mass: approximately 214.35 g/mol
Functional groups: two aromatic primary amines and two methylthio substituents
Main uses: curative and chain extender

The formula describes the principal isomers rather than every component in a commercial grade. Isomer distribution, related amines, moisture and reactive equivalent weight belong in the product specification. The CAS number alone does not establish a particular cure rate.

No cosmetic, food-additive or medicinal identity is assigned here. Industrial curative use and the suitability of a finished polymer are separate questions.

STRUCTURE AND REACTION OF DMTDA (E-300 EQUIVALENT)

The aromatic ring carries primary amine groups, a methyl group and methylthio substituents. Substitution around the amines influences their reaction environment. The two principal positional isomers can therefore contribute to a grade-dependent curing response.

In an isocyanate-terminated prepolymer, the primary amines form urea linkages. The resulting material can contain both pre-existing urethane segments and newly formed urea segments. Calling the reaction simply a catalyst effect misses the fact that the diamine is consumed in the polymer structure.

Nominally difunctional chain extension does not by itself guarantee a crosslinked network. Network formation depends on the functionality of the other components and the complete reaction system. Hardness, strength and elongation likewise cannot be predicted from the curative name alone.

In epoxy curing, amine hydrogens participate in epoxide ring-opening reactions. The equivalent basis differs from ordinary amine chain extension with isocyanates. Using the wrong equivalent weight can substantially misbalance a formulation.

PHYSICAL AND CHEMICAL PROFILE OF DMTDA (E-300 EQUIVALENT)

Reference commercial descriptions show a clear yellow liquid that can darken with air exposure and time. Color should be assessed against an agreed limit, not assumed to stay unchanged during storage. For the offered equivalent, request actual composition and batch values from Ataman Kimya.

One reviewed reference grade reports density approximately 1.208 g/ml at 20°C and kinematic viscosity approximately 690 cSt at 20°C. A centistoke value is not a centipoise value. With that density, the corresponding calculated dynamic viscosity is approximately 834 mPa·s, not 690 mPa·s.

Other reported reference values include a pour point near 4°C and a flash point near 176°C by the stated closed-cup method. A boiling value of 200°C at 16.8 torr is a reduced-pressure result and must not be presented as an atmospheric boiling point. These are reference-grade data, not guaranteed limits for every replacement product.

Water compatibility is limited, while miscibility with selected organic solvents does not imply compatibility with every resin. Moisture must be controlled in isocyanate formulations because water can consume NCO groups and generate carbon dioxide. The consequences can include bubbles and a changed reactive balance.

Total diamines, principal DMTDA content and amine equivalent weight answer different quality questions. Avoid treating them as interchangeable measures of purity. Typical values should be confirmed for the actual supply before production calculations.

EQUIVALENT CALCULATIONS FOR DMTDA (E-300 EQUIVALENT)

For ordinary isocyanate chain-extension calculations, the reference equivalent weight is approximately 107 g/eq. The epoxy active-hydrogen equivalent weight is approximately 53.5 g/eq. The latter counts a different reaction basis and should not be substituted into the NCO calculation.

For 100 parts by weight of a prepolymer, an illustrative calculation is:

Curative parts = NCO content in wt% × 107 / 42.02 × equivalent ratio

Enter 4.0 for a prepolymer containing 4.0% NCO. The factor 42.02 g/eq represents the NCO group, and the equivalent ratio is the targeted amine/NCO ratio on the stated basis. Additional reactive ingredients must also be included in the balance.

A nominal 4.0% NCO prepolymer at a ratio of 0.95 requires approximately 9.676 parts curative per 100 parts prepolymer. This arithmetic is not a universal recommended index. The actual equivalent weight, prepolymer assay and process requirements take precedence.

APPLICATION AREAS OF DMTDA (E-300 EQUIVALENT)

Cast elastomers
The diamine can be evaluated as a curative for suitable isocyanate-terminated prepolymers. Processing may involve heated or room-temperature stages depending on the system. Liquid handling does not guarantee that the complete formulation cures adequately at room temperature.

Polyurethane-urea and polyurea systems
Chain extension contributes urea-rich segments. Reaction speed, mixing quality and equivalent balance influence the developing material. Fast or slow behavior is relative to the particular formulation rather than a fixed number of minutes.

Reaction injection molding and coating development
The chemistry is used in suitable reactive molding and coating systems, including blends with other diamines. Equipment, pot life and leveling must be evaluated together. Spray suitability requires a designed system and exposure controls, not merely a liquid curative.

Epoxy formulation research
The amine can be evaluated for epoxy curing using the appropriate active-hydrogen basis. Cure temperature, conversion and resulting properties must be established independently. The polyurethane equivalent calculation does not transfer directly.

PRACTICAL BENEFITS AND LIMITS OF DMTDA (E-300 EQUIVALENT)

Avoiding a separate solid-curative melting step can simplify dosing in a compatible process. However, viscosity, temperature control and mixing still matter. A lower equivalent weight can reduce the mass needed for a given equivalent demand without proving lower total cost or better performance.

A slower chain extender can provide a useful processing window in some systems, but too slow a cure can delay demolding or leave inadequate early properties. Blending with another diamine changes both reaction behavior and the equivalent balance. Pot life must be measured at a stated temperature, mass and test method.

Color development can limit appearance-sensitive applications. Assess cured color and aging under relevant exposure rather than assuming that an initially yellow liquid will produce a color-stable article. No universal outdoor color-retention claim is made.

USE CONSIDERATIONS FOR DMTDA (E-300 EQUIVALENT)

Confirm the actual amine equivalent weight and prepolymer NCO assay.
Use separate equivalent bases for isocyanates and epoxies.
Include every reactive component in the formulation balance.
Control water, mixing temperature and entrained air.
Measure usable processing time and demolding behavior.
Test properties after the intended cure and conditioning period.
Evaluate replacement grades through matched-condition trials.

Do not infer harmlessness from comparisons with another curative. Prevent skin contact and aerosol exposure, and assess the hazards of the isocyanate or epoxy component as part of the complete operation.

INITIAL FORMULATION APPROACHES FOR DMTDA (E-300 EQUIVALENT)

The following binary blends are proposed calculation examples for laboratory development, not validated commercial casting recipes. All percentages are by weight of the total initial blend. They assume curative equivalent weight 107 g/eq, an amine/NCO equivalent ratio of 0.95 and the stated hypothetical prepolymer assays.

EXAMPLE 1: DMTDA (E-300 EQUIVALENT) WITH A 4.0% NCO PREPOLYMER

Components:

Compatible isocyanate-terminated prepolymer, 4.0% NCO: 91.177%
DMTDA curative: 8.823%
Total: 100.000%

The normalized blend corresponds to approximately 9.676 parts curative per 100 parts prepolymer. It does not specify prepolymer backbone, catalyst or a cure schedule, so those must be designed before a practical trial.

Evaluation criteria:

Mixing consistency and working time
Temperature rise and bubble formation
Conversion, demolding and post-cure response
Hardness, tensile properties and elongation after conditioning
Color and application-specific durability

Use suitable reactive-chemical equipment and prevent uncontrolled bulk exotherm. The example is not a recommendation to mix an arbitrary prepolymer with the curative.

EXAMPLE 2: DMTDA (E-300 EQUIVALENT) WITH A 6.0% NCO PREPOLYMER

Components:

Compatible isocyanate-terminated prepolymer, 6.0% NCO: 87.325%
DMTDA curative: 12.675%
Total: 100.000%

This corresponds to approximately 14.515 parts curative per 100 parts prepolymer. The higher curative demand follows the greater NCO equivalent content, not a universal prescription for a harder elastomer.

Evaluation criteria:

Verified raw-material equivalents and blend homogeneity
Working time under defined mixing conditions
Cure development and residual reactivity
Mechanical properties and dimensional stability
Comparison with the required application specification

Any addition of polyol, another diamine, water-bearing filler or reactive additive requires a recalculated balance. Establish curing and safe handling for the complete mixture before scale-up.

ALTERNATIVES TO DMTDA (E-300 EQUIVALENT)

DETDA offers a different aromatic diamine structure and reaction response. A faster response can suit some equipment while shortening the processing window in another system. Equal masses do not provide equal reactive equivalents.

MOCA is a chemically different solid aromatic diamine comparator with different handling and hazard considerations. Replacing it requires more than eliminating a melting step. Equivalent demand, cure development and final properties must be reassessed.

Other diamines or polyol chain extenders change the resulting linkage pattern and processing behavior. A hydroxyl extender forms urethane rather than the same amine-derived urea structure. Select the alternative against the complete material requirement.

QUALITY CONTROL AND PURCHASING OF DMTDA (E-300 EQUIVALENT)

Specify the intended prepolymer or resin, required processing window and performance targets. Request composition, related-amine information, equivalent weight and test method, water content, color and viscosity with both temperature and units. A generic E-300 comparison is not an acceptance specification.

Review the batch COA, current TDS and regional SDS together. The COA records batch values, typical technical data describe expected behavior and the SDS addresses hazards. Qualification should include application testing rather than relying on paperwork alone.

Compare price per usable equivalent and the actual processing outcome. Availability, packaging, shelf life and supporting information for the offered grade should be confirmed with Ataman Kimya.

STORAGE AND HANDLING OF DMTDA (E-300 EQUIVALENT)

Keep the material in clean, closed, compatible containers in a dry, ventilated location. Limit air exposure and contamination, and segregate reactive isocyanates, strong oxidants and other incompatible materials. Avoid unnecessary heating.

Color can darken during storage, but appearance alone does not establish the reactive quality. After prolonged storage or cold exposure, obtain grade-specific assessment and rehomogenization guidance. Confirm temperature limits and shelf life with Ataman Kimya instead of assigning one reference product's guarantee to every equivalent.

Contain spills, collect with suitable absorbent and prevent entry into drains or watercourses. Treat contaminated material as chemical waste under applicable requirements. Do not wash a spill into the drainage system.

SAFETY AND TRANSPORT OF DMTDA (E-300 EQUIVALENT)

Reviewed hazard information for this chemistry includes H302, harmful if swallowed, H317, may cause an allergic skin reaction, and H410, very toxic to aquatic life with long lasting effects. Regional labels can differ, so confirm the classification and composition of the exact offer through Ataman Kimya. A comparative low-toxicity description is not a statement that exposure is safe.

Wear suitable chemical-resistant gloves, protective clothing and splash goggles. Avoid breathing mist or spray and provide task-appropriate ventilation. Prevent contaminated clothing from spreading exposure and maintain good handling hygiene.

After skin contact, remove contaminated clothing and wash thoroughly with soap and water. Seek medical advice for rash or persistent symptoms. After eye contact, rinse with clean water, remove lenses if easy and obtain medical advice. After swallowing, rinse the mouth, do not induce vomiting without medical advice and seek prompt professional help.

Environmental classification, shipment quantity, packaging and transport rules must be checked for the actual consignment. Historical reference documents are not a basis for promising universal transport exemption. Contact Ataman Kimya for current shipping information.

SUPPLY OF DMTDA (E-300 EQUIVALENT) FROM ATAMAN KIMYA

ATAMAN KİMYA can be contacted for DMTDA (E-300 equivalent) inquiries. Confirm the offered composition, equivalent weight, specification, documentation and availability.

Provide the prepolymer NCO content or resin equivalent basis, trial quantity, desired processing window, curing equipment and final property requirements. Include the delivery destination and any replacement-qualification criteria.

FREQUENTLY ASKED QUESTIONS ABOUT DMTDA (E-300 EQUIVALENT)

What does DMTDA mean?
Dimethylthiotoluenediamine, an aromatic diamine curative chemistry.

What is its CAS number?
106264-79-3.

What is its EC number?
403-240-8.

What is the principal-isomer formula?
C9H14N2S2, with molar mass approximately 214.35 g/mol.

Is the commercial material a single isomer?
No, it is based on an isomer mixture and can contain related diamines.

Does E-300 equivalent guarantee identical performance?
No, composition and application performance need confirmation.

What equivalent weight is used with isocyanates?
Approximately 107 g/eq for the reviewed reference basis.

What equivalent weight is used with epoxy resins?
Approximately 53.5 g/eq on the active-hydrogen basis.

Can the epoxy value be used in the NCO calculation?
No, it represents a different reactive basis.

Is 690 cSt the same as 690 cP?
No, kinematic and dynamic viscosity differ and conversion requires density.

Does a liquid curative guarantee room-temperature cure?
No, the complete system and cure schedule determine the result.

Does every diamine automatically create a crosslinked network?
No, network formation depends on the functionality of the full system.

Why control moisture?
Water can consume isocyanate and produce carbon dioxide and bubbles.

Can it be blended with another diamine?
Yes, in a designed system with recalculated equivalents and verified reaction behavior.

Is color unchanged during storage?
Not necessarily, reference descriptions report darkening with air exposure and time.

Is it harmless because a marketing description says low toxicity?
No, ingestion, sensitization and environmental hazards still require control.

Are the two example mixtures commercial recipes?
No, they are illustrative equivalent-balance starting points.

What should be requested before purchase?
The actual grade specification, batch COA, current SDS, equivalent-weight information and application qualification data.

DMTDA (E-300 EQUIVALENT) - TECHNICAL SUMMARY

DMTDA is a liquid aromatic diamine isomer mixture identified by CAS 106264-79-3 and EC 403-240-8. Its principal isomers have formula C9H14N2S2 and molar mass approximately 214.35 g/mol.

Amine reaction with isocyanates forms urea linkages and supports chain extension in suitable elastomer systems. The resulting network and properties depend on the whole formulation.

The reference isocyanate equivalent weight of approximately 107 g/eq differs from the epoxy active-hydrogen value of approximately 53.5 g/eq. Correct reaction basis and batch data are essential for dosing.

Liquid handling can simplify processing, but viscosity units, moisture, color and cure behavior still need control. An E-300 replacement description does not prove grade equivalence.

Ingestion, sensitization and aquatic hazards must be considered alongside the hazards of the other reactive components. Quality, storage and transport information should cover the exact offered material.

DMTDA (E-300 equivalent) can be sourced from ATAMAN KİMYA. For further information and supply inquiries about DMTDA (E-300 equivalent), please contact ATAMAN KİMYA.