Dinitrotoluene
Encyclopedia
2,4-Dinitrotoluene or Dinitro is an organic compound
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

 with the formula C6H3(CH3)(NO2)2. This pale yellow crystalline solid is well known as a precursor to trinitrotoluene (TNT) but is mainly used in the polymer industry.

Isomers of dinitrotoluene

Six isomers are possible for dinitrotoluene. The most common one is 2,4-dinitrotoluene.

The nitration of toluene gives sequentially mononitrotoluene
Mononitrotoluene
Mononitrotoluene, or methylnitrobenzene or nitrotoluene , is a group of 3 organic compounds, a nitro derivative of toluene...

, DNT, and finally TNT. 2,4-DNT is the principal product from dinitration, the other main product being about 30% 2,6-DNT. The nitration of 4-nitrotoluene gives 2,4-DNT.

Applications

Most DNT is used in the production of toluene diisocyanate
Toluene diisocyanate
Toluene diisocyanate is an aromatic diisocyanate. It is produced for reaction with polyols to form polyurethanes. It exists in two isomers, 2,4-TDI and 2,6-TDI . 2,4-TDI is produced in the pure state, but TDI is often marketed as 80/20 and 65/35 mixtures of the 2,4 and 2,6 isomers respectively...

 which is used to produce flexible polyurethane
Polyurethane
A polyurethane is any polymer composed of a chain of organic units joined by carbamate links. Polyurethane polymers are formed through step-growth polymerization, by reacting a monomer with another monomer in the presence of a catalyst.Polyurethanes are...

 foams. DNT is hydrogenated
Hydrogenation
Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...

 to produce toluenediamine, which in turn is phosgenated to form toluene diisocyanate
Toluene diisocyanate
Toluene diisocyanate is an aromatic diisocyanate. It is produced for reaction with polyols to form polyurethanes. It exists in two isomers, 2,4-TDI and 2,6-TDI . 2,4-TDI is produced in the pure state, but TDI is often marketed as 80/20 and 65/35 mixtures of the 2,4 and 2,6 isomers respectively...

. Other uses include the explosives industry. It is not used by itself as an explosive, but some of the production is converted to TNT.

Dinitrotoluene is frequently used as a plasticizer
Plasticizer
Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effects and results are...

, deterrent coating, and burn rate modifier in propellant
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...

s (e.g., smokeless gunpowders). As it is carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...

ic and toxic, modern formulations tend to avoid its use. In this application it is often used together with dibutyl phthalate
Dibutyl phthalate
Dibutyl phthalate is a commonly used plasticizer. It is also used as an additive to adhesives or printing inks. It is soluble in various organic solvents, e.g. in alcohol, ether and benzene...

.

Toxicity

Dinitrotoluenes are highly toxic with a TLV
Threshold Limit Value
The threshold limit value of a chemical substance is a level to which it is believed a worker can be exposed day after day for a working lifetime without adverse health effects. Strictly speaking, TLV is a reserved term of the American Conference of Governmental Industrial Hygienists...

 of 1.5 mg/m3. It converts hemoglobin
Hemoglobin
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...

 into methemoglobin.

2,4 Dinitrotoluene is also a listed hazardous waste under 40 CFR 261.30. Its United States Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...

(EPA) hazardous waste Number is D030. The maximum concentration that may be contained to not have toxic characteristics is 0.13 mg/L.
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