formaldehyde(redirected from Fermaldihyde)
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(also methanal), CH2O, the first member of the homologous series of aliphatic aldehydes. A colorless gas with a pungent odor, formaldehyde is freely soluble in water and alcohol. It has a boiling point of – 19°C.
Formaldehyde is prepared commercially by the oxidation of methanol (methyl alcohol) or methane with atmospheric oxygen. Because it polymerizes readily, especially at temperatures up to 100°C, it is stored, transported, and used mainly in the form of Formalin or in the form of solid low-molecular polymers— trioxane and paraformaldehyde.
Formaldehyde is highly reactive. Many of its reactions form the basis of numerous commercial methods for the preparation of important products. For example, on interaction with ammonia, formaldehyde yields urotropine (hexamethylenetetramine); with urea, urea-formaldehyde resins; with melamine, melamine resins; with phenols, phenol-formaldehyde resins; with phenol-sul-fonic and napthalene sulfonic acids, tanning agents; and with ket-ene, beta-propiolactone. Formaldehyde is used in the manufacture of polyvinyl formal, isoprene, pentaerythritol, pharmaceuticals, and dyes. It is also used in the tanning of leather and as a disinfectant and deodorizing agent. The polymerization of formaldehyde yields polyformaldehyde.
Formaldehyde is toxic; its maximum tolerable concentration in the air is 0.001 mg/liter.