Melamine

Melamine has the IUPAC name of 1,3,5-Triazine-2,4,6-triamine. Melamine is white solid with the formula C₃H₆N₆. Melamine is soluble in water, glycol, glycerin and pyridine; slightly soluble in ethanol; insoluble in diethyl ether, benzene and carbon tetrachloride. In addition, Melamine is incompatible with strong oxidizing agents and strong acids. Melamine will sublime when gently heated. It has the CAS register number of 108-78-1 and EINECS register number of 203-615-4. What's more, you should protect Melamine from moisture, heat, ignition sources, and incompatible substances. On the other hand, Melamine should be protected from direct light.

Preparation: You can use urea to produce Melamine as the following reaction which is very common in most industrial manufacturers. This reaction can be carried out by either of two methods: catalyzed gas-phase production or high pressure liquid-phase production. Currently, China is the world's largest exporter of melamine, while its domestic consumption still grows by 10% per year.

6 (NH₂)₂CO → C₃H₆N₆ + 6 NH₃ + 3 CO₂

Melamine can also be prepared by dicyandiamide and ammonia in solvent of methanol at temperature of 200 °C. Per ton of product will consume 1180Kg dicyandiamide (98% ), 30 Kg liquid ammonia in this method.

H₄C₂N₄ + NH₃ [CH₃OH] → C₃H₆N₆

Uses: Both the Melamine and formaldehyde can be used to produce melamine resin which is a very durable thermosetting plastic used in Formica, and Melamine foam, a polymeric cleaning product. As superplasticizer, Melamine can also enter the fabrication of Melamine poly-sulfonate for making high-resistance concrete. As fertilizer, Melamine had been envisaged for crops because of its high nitrogen content. However, Melamine is much more expensive to produce than other common nitrogen fertilizers, such as urea. Melamine and its salts are used as fire-retardant additives in paints, plastics and paper. Melamine is sometimes illegally added to food products in order to increase the apparent protein content.

Regulation: The United Nations' food standards body, Codex Alimentarius Commission, has set the maximum amount of Melamine allowed in powdered infant formula to 1 mg/kg and the amount of Melamine allowed in other foods and animal feed to 2.5 mg/kg. While not legally binding, the levels allow countries to ban importation of products with excessive levels of melamine.

When using the Melamine, you should be very cautious because it is irritant and harmful. Melamine is harmful by inhalation and in contact with skin. Melamine may cause sensitisation by skin contact. There will be a risk of explosion if heated Melamine under confinement. Whenever you will use Melamine, you should wear suitable protective clothing and gloves.

Descriptors computed from structure of Melamine:
(1)Canonical SMILES: C1(=NC(=NC(=N1)N)N)N
(2)InChI: InChI=1S/C3H6N6/c4-1-7-2(5)9-3(6)8-1/h(H6,4,5,6,7,8,9)
(3)InChIKey: JDSHMPZPIAZGSV-UHFFFAOYSA-N

Toxicity of Melamine: