Azobisisobutylonitrile
Encyclopedia
Azobisisobutyronitrile is a compound often used as a foamer in plastics and rubber
and as a radical initiator
. It is commonly known as AIBN. Its most common chemical reaction is one of decomposition
, eliminating a molecule of nitrogen
gas to form two 2-cyanoprop-2-yl radicals:
These radicals can be used to initiate free radical polymerizations and other radical reactions. For instance a mixture of styrene and maleic anhydride
in toluene
will react if heated, forming the polystyrene
polymer
, only very slowly unless an initiator such an AIBN is present. Another example of a radical reaction that can be initiated by AIBN is the anti-Markovnikov
hydrohalogenation of alkenes.
(another radical initiator
) because the risk of explosion is far smaller. However, it is considered a flammable solid.
It is soluble in methanol and ethanol, but is insoluble in water. It can explode if dissolved in acetone.
AIBN is highly toxic. A respirator/dust mask, protective gloves, & safety glasses should be worn when handling AIBN.
Several water-soluble azo initiators similar to AIBN are manufactured by DuPont
and Wako.
Rubber
Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...
and as a radical initiator
Radical initiator
In chemistry, radical initiators are substances that can produce radical species under mild conditions and promote radical reactions . These substances generally possess weak bonds—bonds that have small bond dissociation energies. Radical initiators are utilized in industrial processes such...
. It is commonly known as AIBN. Its most common chemical reaction is one of decomposition
Chemical decomposition
Chemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction...
, eliminating a molecule of nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
gas to form two 2-cyanoprop-2-yl radicals:
These radicals can be used to initiate free radical polymerizations and other radical reactions. For instance a mixture of styrene and maleic anhydride
Maleic anhydride
Maleic anhydride is an organic compound with the formula C2H22O. It is the acid anhydride of maleic acid and in its pure state it is a colourless or white solid with an acrid odour....
in toluene
Toluene
Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3.It is an aromatic...
will react if heated, forming the polystyrene
Polystyrene
Polystyrene ) also known as Thermocole, abbreviated following ISO Standard PS, is an aromatic polymer made from the monomer styrene, a liquid hydrocarbon that is manufactured from petroleum by the chemical industry...
polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
, only very slowly unless an initiator such an AIBN is present. Another example of a radical reaction that can be initiated by AIBN is the anti-Markovnikov
Markovnikov's rule
In organic chemistry, Markovnikov's rule or Markownikoff's rule is an observation based on Zaitsev's rule. It was formulated by the Russian chemist Vladimir Vasilevich Markovnikov in 1870....
hydrohalogenation of alkenes.
Safety
AIBN is safer to use than benzoyl peroxideBenzoyl peroxide
Benzoyl peroxide is an organic compound in the peroxide family. It consists of two benzoyl groups bridged by a peroxide link. Its structural formula is [C6H5C]2O2. It is one of the most important organic peroxides in terms of applications and the scale of its production...
(another radical initiator
Radical initiator
In chemistry, radical initiators are substances that can produce radical species under mild conditions and promote radical reactions . These substances generally possess weak bonds—bonds that have small bond dissociation energies. Radical initiators are utilized in industrial processes such...
) because the risk of explosion is far smaller. However, it is considered a flammable solid.
It is soluble in methanol and ethanol, but is insoluble in water. It can explode if dissolved in acetone.
AIBN is highly toxic. A respirator/dust mask, protective gloves, & safety glasses should be worn when handling AIBN.
Several water-soluble azo initiators similar to AIBN are manufactured by DuPont
DuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
and Wako.