Vazo™ Free Radical Initiators

Vazo™ Free Radical Initiators are substituted azonitrile compounds (including AIBN) that are used as initiators for polymerization.  Vazo™  initiators decompose when exposed to heat or light to form one mole of nitrogen gas and two free radical intermediates per molecule of Vazo™.  These free radicals can then be used to abstract an electron from the monomers present in a polymerization reaction and kick off a free radical polymerization process. Polymerizations that are possible with Vazo™ radical initiators include bulk, solution, suspension, and emulsion polymerizations. 

Azo Initiators like azobisisobutyronitrile (AIBN) are much more stable than organic peroxides and allow for more control over the final polymer structure making them more useful for specialty polymer development.  Unlike free radical generation using peroxides, decomposition of AIBN and other azo compounds is unaffected by solvent type or even the presence of inhibitors.  In addition, azo initiators will not abstract hydrogen from growing polymer chains.  This prevents unwanted branching and cross-linking during polymerization and allows for better control over final polymer structure.  This makes them significantly more useful in specialty polymerizations than peroxides.

Other than their use as initiators in free radical polymerizations, azonitrile compounds like AIBN can be used as chemical blowing agents, in halogenation reactions, and to cross-link polymers.

Vazo™ Initiators are commercially available in oil soluble and water soluble grades and are classified by thermal decomposition temperature. For example Vazo™ 64, also known as AIBN, has a 10 hour half life in solution at 64°C.  To learn more about a particular Vazo™ initiator select a grade page below or contact us to speak directly to one of our dedicated product experts

Unpredictability of polymerization reactions.
Excessive side reactions leading to decreased yield.
Difficult reaction conditions.