Products Description of 2,2'-Azobis(2-methylpropionitrile) CAS#78-67-1
2,2'-Azobis(2-methylpropionitrile), abbreviated as AIBN, is a white crystalline powder with a molecular formula of C₈H₁₂N₄ and a molecular weight of 164.21. It is characterized by a melting point of about 102–104 °C, which is accompanied by decomposition, and it dissolves easily in common organic solvents including methanol, ethanol, ether and benzene, while being practically insoluble in water. As a representative azo compound, AIBN is highly sensitive to heat and undergoes homolytic cleavage to release nitrogen gas and generate free radicals. Because of its self-reactive and thermally unstable nature, the product must be kept in tightly sealed containers under refrigeration, protected from light, moisture, friction and impact. Proper temperature-controlled storage is essential to prevent premature decomposition and to guarantee consistent quality during warehousing and shipment.
2,2'-Azobis(2-methylpropionitrile) Chemical Properties
| Melting point | 102-104 °C (dec.)(lit.) |
| Boiling point | 281.68°C (rough estimate) |
| density | 1.11 |
| vapor pressure | 0.81Pa at 24.85℃ |
| refractive index | n20/D1.495 |
| Fp | 4℃ |
| storage temp. | 2-8°C |
| solubility | Chloroform (Slightly), Methanol (Slightly) |
| form | Solid |
| color | Crystals from EtOH |
| Odor | Odorless |
| Water Solubility | Insoluble |
| Merck | 13920 |
| BRN | 1708400 |
| Stability: | Stability Flammable solid. Shock sensitive. Thermally unstable. May be explosive in combination with acetone or heptane. Incompatible with oxidizing agents. |
| InChIKey | OZAIFHULBGXAKX-VAWYXSNFSA-N |
| LogP | 1.1 at 25℃ |
| CAS DataBase Reference | 78-67-1(CAS DataBase Reference) |
| NIST Chemistry Reference | 2,2'-Azo-bis-isobutyronitrile(78-67-1) |
| EPA Substance Registry System | Azobis(isobutyronitrile) (78-67-1) |
| Hazard Codes | E,Xn,F,Xi |
| Risk Statements | 2-11-20/22-52/53-67-65-48/20-38-63-66-36 |
| Safety Statements | 39-41-47-61-62-36/37-16-26 |
| RIDADR | UN 3234 4.1 |
| WGK Germany | 2 |
| RTECS | UG0800000 |
| F | 4.4 |
| HazardClass | 4.1 |
| PackingGroup | II |
| HS Code | 29269090 |
| Hazardous Substances Data | 78-67-1(Hazardous Substances Data) |
| Toxicity | LDLo orl-rat: 670 mg/kg 34ZIAG 0,117,69 |
Product Application of 2,2'-Azobis(2-methylpropionitrile) CAS#78-67-1
AIBN is one of the most extensively used azo-type free-radical initiators in polymer science and organic synthesis. Upon thermal decomposition, it generates free radicals and nitrogen gas, which makes it a highly reliable initiator for the polymerization of vinyl monomers, including styrene, acrylonitrile, vinyl chloride, acrylic esters and methacrylic esters, in bulk, suspension and solution polymerization processes. These polymerizations are fundamental to the production of plastics, synthetic rubbers, acrylic fibers, coatings and adhesives.
Beyond polymerization, AIBN is employed as a chemical blowing agent in the manufacture of foamed plastics and serves as a convenient radical source for various synthetic transformations. Its well-controlled decomposition behavior and moderate reaction temperature make it a preferred choice for both industrial manufacturing and laboratory-scale radical reactions.
