4,4'-Methylenedianiline
Encyclopedia
4,4'-Methylenedianiline (MDA) is a suspected carcinogen
.
It is included in the "substances of very high concern" list of the European Chemicals Agency (ECHA). The compound was involved in an accidental mass poisoning in the vicinity of Epping
, Essex
, United Kingdom during 1965 during which 84 individuals were poisoned through accidental contamination of flour used to make bread.
foams in which case it is first reacted with phosgene
to create 4,4 ́-methylene diphenyl diisocyanate
(MDI) prior to polymerization with a polyol
. Lower quantities are used as hardeners in epoxy resins and adhesives, as well as in the production of high-performance polymers.
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...
.
It is included in the "substances of very high concern" list of the European Chemicals Agency (ECHA). The compound was involved in an accidental mass poisoning in the vicinity of Epping
Epping
Epping is a small market town and civil parish in the Epping Forest district of the County of Essex, England. It is located north-east of Loughton, south of Harlow and north-west of Brentwood....
, Essex
Essex
Essex is a ceremonial and non-metropolitan county in the East region of England, and one of the home counties. It is located to the northeast of Greater London. It borders with Cambridgeshire and Suffolk to the north, Hertfordshire to the west, Kent to the South and London to the south west...
, United Kingdom during 1965 during which 84 individuals were poisoned through accidental contamination of flour used to make bread.
Synthesis
In the industrial production, MDA is synthesised by reaction of formaldehyde and aniline in the presence of hydrochloric acid.Uses
MDA is used primarily for making polyurethanePolyurethane
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 in which case it is first reacted with phosgene
Phosgene
Phosgene is the chemical compound with the formula COCl2. This colorless gas gained infamy as a chemical weapon during World War I. It is also a valued industrial reagent and building block in synthesis of pharmaceuticals and other organic compounds. In low concentrations, its odor resembles...
to create 4,4 ́-methylene diphenyl diisocyanate
Methylene diphenyl diisocyanate
Methylene diphenyl diisocyanate, most often abbreviated as MDI, is an aromatic diisocyanate. It exists in three isomers, 2,2'-MDI, 2,4'-MDI, and 4,4'-MDI, but the 4,4' isomer is most widely used. This isomer is also known as Pure MDI. MDI reacts with polyols in the manufacture of polyurethane...
(MDI) prior to polymerization with a polyol
Polyol
A polyol is an alcohol containing multiple hydroxyl groups. In two technological disciplines the term "polyol" has a special meaning: food science and polymer chemistry.- Polyols in food science :...
. Lower quantities are used as hardeners in epoxy resins and adhesives, as well as in the production of high-performance polymers.
External links
- International Labor Organisation icsc1111
- European Union Risk Assessment Report
- J.H. Petersen, S.K. Mortensen, G.A. Pedersen, Memorandum for the Danish Veterinary and Food Administration on An acute case of primary aromatic amines migrating from cooking utensils, Danish Institute for Food and Veterinary Research, 12 October 2004