HC30 (DMTDA)
| HARTCURE 30 (DMTDA) | |
| Trade Name: | DMTDA |
| Similar Name: | DimethylthioToluene Diamie; DiMethylthiotoluenediaMine (DMTDA, E-300); 2,4-Diamino-3,5-dimethylthiotoluene |
| Molecular Formula: | C9H12N2 S2 |
| CASNumber: | 106264-79-3 |
HARTCURE 30 (DimethylthioToluene Diamie / DMTDA), CAS number. 106264-79-3, is a diamines curative for both TDI and MDI systems. Being a viscous liquid at room temperature results in significant processing advantages, i.e. easy transferring, ready to use without melting down the solids like MOCA does. DMTDA is an ideal curing agent used to make durable and flexible polyurethane/polyurea elastomers.
DMTDA can be both a curing agent and a chain extender for diisocyanate pre-polymers, especially for polyurea system providing with good mechanical and dynamic properties. DMTDA is an universal curing agent to combined with other liquid diamines, for example DETDA, to vary curing rates and mechanical properties to meet different requirements. Therefore, there is a wide application of DMTDA on polyurethane wheels, tires, casters, rollers, elastomeric coatings and so on. You can find DMTDA-base finished products everywhere, including construction, mining, automotive, electronics, textiles and printing areas.
Unlike MOCA, 4,4'-Methylenebis(2-chloroaniline), DMTDA is not suspected carcinogens. It’s eco-friendly, non-toxic and safe for workers to handle with during the processing. Benefits with being in liquid form, DMTDA won’t cause any toxic dust, fumes nor vapors while operation. Therefore, workers won’t be exposed to the danger while handling with DMTDA. In early times, the EU polyurethane producers use MOCA as the main curing agent for TDI-based polyurethane systems due to it’s low-price, excellent performance on tensile strength, durability, resiliency and abrasion resistance. In order to protect workers and the environment, more and more countries forbidden the usage of MOCA, thus, it forces polyurethane producers to find the MOCA substitute, the DMTDA, also called liquid MOCA. DMTDA eliminates most of the health hazards associated with handling MOCA and provide excellent physical properties in comparison of MOCA-based polyurethanes/polyureas elastomers.
There is another crucial advantage of DMTDA comparing with MOCA. Since DMTDA is in liquid form, it allows operation at lower temperature than MOCA does. Without melting process which is a must on MOCA, you can save much energy cost during manufacturing. The possibility of solidification does not occur in mixing containers or mixing machines. Additionally, it can be handled at lower temperatures than MOCA for its liquid state. The equivalent weight of HARTCURE 30 (DMTDA) is 107 comparing with MOCA is 133.5. This means a 20% reduction in weight of prepolymer at the same stoichiometr
Shelf life
12 months since production date.
Packing
25 kg/iron drum
200 kg/iron drum
It can be packaged on demand. Please inquire.
DMTDA is used as PU curing agent. It can slow down the activity of "NH2" group, thus, to extend the pot life while casting.
Processing
DMTDA (Hartcure 30), being a liquid at room temperature result in a significant processing advantage in comparison of MOCA, melting down of solids is unnecessary. Also, its liquid form allows to process prepolymer at lower temperature than that of MOCA and without solidification during the mixing. DMTDA (Hartcure 30) has an equivalent weight of 107 compared to 133.5 of MOCA. This means that about 20% less by weight is required for a given prepolymer at the same stoichiometry.
e.g.：
Prepolymer (%NCO 4.1) | 100 Pts | 100 Pts |
MOCA (stoichiometry*95%) | 12.4 Pts | — |
DMTDA(stoichiometry*95%) | — | 9.9 Pts |
Total | 112.4 Pts | 109.9 Pts |
Comparing of Physical Properties of Prepolymer Cured with DMTDA & MOCA
The physical properties of prepolymer, both ether and ester types, when cured with DMTDA (Hartcure 30) curing agent, are comparable to those based with MOCA. As in MOCA curing system, physical properties are sensitive to the ration (stoichiometry) of curative to prepolymer. DMTDA (Hartcure 30) curative exhibition tolerance to stoichiomety variations similar to that of MOCA.
Low stoichiomety (80~90%) generally tends to maximize compression set resistance, while high stoichiomety (100-105%) tends to maximize tear strength and flex life. The best results for most application are obtained at about 95% stoichiometry. While cure conditions (temperature and times) are similar to those used with MOCA, DMTDA (Hartcure 30) curative requires closer attention to post cure conditions to obtain maximum physical properties, particularly for compression set and dynamic properties.
| Equivalent Weight | 107 |
| Appearance | Light yellow liquid |
| Odor | Slight Amine |
| Boiling Point | 353℃/667℉ (decompose) |
| 1.18 g/cm3 at 60℃/140℉ | |
| 1.15 g/cm3 at 100℃/212℉ | |
| Viscosity, cPs | 690 at 20℃/68℉ |
| 22 at 60℃/140℉ | |
| 5 at 100℃/212℉ | |
| Vapor Pressure, mmHg | 0.6 mmHg at 20℃/65℉ |
| Amine Value | 536 mg KOH/g |
| TDA content (%) | ≤1.0% |
| Moisture | ≤0.1% |
Note: The specific gravity of DMTDA (Hartcure 30) is about 1.20g/cm3 at 21℃-33℃, whereas that of molten MOCA is 1.26 at 116℃. When delivering these two materials by volumetric pumps, we need to change the formula weight of MOCA to that of DMTDA (Hartcure 30) without changing meter-mixing machines.
DMTDA is widely used in coating systems in architectural, automotive, marine and industrial maintenance fields. DMTDA-based polyurethanes coating is with high performance, such as toughness and elasticity, high strength, waterproof, weather resistance, abrasion resistance, scratch and corrosion resistance. DMTDA-based polyurethanes can be applied through different coating techniques to substrates, i.e. metals, wood, concrete, masonry and plastic surfaces.
DMTDA also can be used as the epoxy resin curing agent/insulation material and PU elastomers, such as polyurethane and polyurea used for everything from high durable coatings to flexible foam seals, even wheels and tires. In addition, DMTDA can applied on automobile, building, mining, textile, printing rollers, trolley wheels, adhesives and electronic industries.