Polymerization initiators are used for polymer synthesis.
We have azo polymerization initiators with different structures which are soluble in organic solvents or soluble in water in our lineup.
Please select appropriate product for your applications.

Azo polymerization initiator

Radical polymerization is mainly used for the polymerization of vinyl monomer and so on. It is a chain reaction including initiation reaction, propagation reaction and termination reaction as elementary reaction, and azo compounds and peroxides are used as the initiator. Azo polymerization initiator is a compound having an azo group (R-N=N-R) generating free radical which decomposes with heat and/or light. The formed radical is excellent in reactivity, therefore azo polymerization initiator is used for the polymerization of vinylic monomers or helogenation of organic compounds.

Characteristics (compared with peroxide)

・Decomposes at first-order reaction.
・Not decompose by metallic contact, etc.
・Decomposes at a constant rate regardless of the solvent used
・Generates carbon radical. (Shows mild reactivity.)

Mechanism of radical formation

・Azo polymerization initiator decomposes with heat or light, and forms nitrogen gas and carbon radicals.*1
(The decomposition rate in solution follows first-order reaction rate kinetics and decomposition temperature varies depending on the structure of initiator.)
・The carbon radical addition-polymerizes with vinyl monomers and forms a polymer.*2
・Since the azo polymerization initiator is introduced at the end of polymer, the effect of end group is expected.
・The efficiency of common azo polymerization initiators is approximately 0.5-0.7, and the remaining results in recombination3 or disproportionation4.

How to select

Bulk polymerization : Initiator soluble in monomers
→ Oil-soluble type, Water-soluble type
Solution polymerization : Initiator soluble in monomers and solvents
→ Oil-soluble type, Water-soluble type
Emulsion polymerization : Initiator soluble In water and insoluble in monomers
→ Water-soluble type
Suspension polymerization : Initiator soluble in monomers and insoluble in water
→ Oil-soluble type

Oil-soluble Water-soluble Type Structural formula
V-70、V-65、V-60(AIBN)、V-59、V-40 V-501

Azo Nitrile


Azo Ester

VF-096、VAm-110 VA-086

Azo Amide

 – V-50、VA-057

Azo Amidine

 – VA-044、VA-046B、VA-061

Azo Imidazoline


<10-hour half-life temperature>

A temperature at which the concentration (amount) of azo group becomes a half in the solvent.
Please select the initiator suitable for the polymerization temperature.