Azo polymerization initiators


CAS : 78-67-1

oil soluble

Plastics manufacturing


AIBN is the most common oil-soluble azo polymerization initiator, and is used for polymerization of versatile polymers.

V-601 is a nitrile-free oil-soluble azo polymerization initiator which was developed as alternative to AIBN.V-601 has similar polymerization activity to AIBN, and the by-products of decomposition have less toxicity.

Product name AIBN V-601
Structural formula Structural formula of AIBN Structural formula of V-601
Chemical name 2,2'-Azobis(isobutyronitrile) Dimethyl 2,2'-azobis(2-methylpropionate)
CAS RN® 78-67-1 2589-57-3
Molecular weight 164.21 230.26
Molecular formula C8H12N4 C10H18N2O4

Physical characteristics

  AIBN V-601
Color white slightly yellow or light yellow
Appearance crystalline powder crystals or oily liquid
Melting point/freezing point 100-103(dec.) °C 22-28°C
10hour half-life decomposition temperature 65°C(in toluene) 66°C(in toluene)
Activation energy 132.4 kJ/mol 131.2 kJ/mol
Frequency factor(ln A) 36.30 35.67
SADT 50°C 35°C

*SADT: Self-accelerating decomposition temperature


  AIBN V-601
(wt%, r.t.)
Toluene 7.0 >50
Methanol 7.5 >50
Ethyl acetate 14.0 >50
n-Hexane n.a. >50
Ethanol 2.7 >50
DMF 20.5 >50
DMSO 6.5 >50
Water 0.1 0.3
Acetone 29 >50
Chloroform 25 >50


  AIBN V-601
Acute oral toxicity
Product 100(Rat) >527(Rat)
Decomposition Product 25(Rat) 2369(Rat)

Packaging & Storage conditions

  AIBN V-601
Packaging 20kg 10kg / 500g
Storage conditions keep under 20°C keep under 10°C

Related laws and regulations

  AIBN V-601
TSCA Listed Listed under 5e Consent Order
EINECS Listed Listed
REACH 01-2119488882-21-xxxx 01-2120807902-57-0000

Here, you can calculate the ‘residue rate’, ‘decomposition reaction time’, and ‘temperature during the decomposition reaction’ of azo polymerization initiators.

Image of Azo Residue Rate Calculation Tool