Melamine

Melamine is an organic compound that responds to the chemical formula C₃H₆N₆, and whose IUPAC name is 2,4,6-triamino-1,3,5-triazine. It is slightly soluble in water, and naturally forms a white solid.

Chemical constitution

Melamine is a trimer (consists of three equal molecules) of cyanamide, forming an aromatic heterocycle that can react with formaldehyde, giving the melamine-formaldehyde resin.

Both urea-formaldehyde and melamine-formaldehyde have very similar general properties, although there is much difference in their applications. Both resins are known as amino resins. Aminoresins are mainly used as adhesives for making particleboard and plywood, used in residential construction, furniture manufacturing (decorative laminates).

Melamine resins

Melamine vanilla

They are formed by polycondensation of phenylamine and formaldehyde. There are solid resins with the general characteristics and properties of powdered resins. These characteristics are the following:

• Red or brown colour.
• They are presented in the form of crystals.
• High point of reblation.
• Little fluency.
• Insoluble in common solvents.
• Resistance to the bases.
• Low high-frequency loss factor.
• Excellent isolation resistance.
• High synthetic frequency of added value.
• Dielectrical rigidity.
• Thermostable.
• It's not recyclable.

These resins are used in molding compounds. On the other hand, there are many applications for liquid resins from the reaction of melamine and formaldehyde that are soluble in water. Also, base resins for automotive paints are methylated (reacted with methanol) and butylated or isobutylated (reacted with butanol or isobutanol) resins. These resins are colorless, crystalline and with a high solids content (more than 95%). This reaction is carried out in two stages, first methylation and then methylation or butylation.

Food alteration

3D melamine molecule

Due to their high nitrogen content, they have been fraudulently used to adulterate pet and human foods. In this way they simulate having a higher protein content of the product, although making it toxic.

In 2007, this adulteration was detected in pet food exported from China to the United States. The following year, the same alteration was detected in baby milk products in China. This adulteration was detected in milk, ice cream, yogurt and pizza dough.

'White Rabbit' brand sweets have been recalled in the UK as a precautionary measure. given the risk that these candies contain melamine; Chile similarly withdrew Chinese products contaminated with melamine from circulation.

The manufacturer of candies that sells, among others, the White Rabbit brand, announced on September 26, 2008, the suspension of the sale of its candies, suspected of containing melamine, after having withdrawn all its exports from the market. These candies, very popular in China, were exported to Ecuador and Mexico, among other countries, where the day before customs were ordered to veto entry and remove from the market any dairy product from China.[1]