4,4'-Azobis(4-cyanovaleric acid)
[CAS# 2638-94-0]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives
• Name: 4,4'-Azobis(4-cyanovaleric acid)
• Synonyms: 4,4'-Azobis(4-cyanopentanoic acid); ACVA
• Molecular Formula: C₁₂H₁₆N₄O₄
• Molecular Weight: 280.28
• CAS Registry Number: 2638-94-0
• EC Number: 220-135-0
• SMILES: CC(CCC(=O)O)(C#N)N=NC(C)(CCC(=O)O)C#N

Properties

• Density: 1.2±0.1 g/cm³ Calc.^*
• Melting point: 118 - 125 ºC (Decomposes) (Expl.)
• Boiling point: 503.6±50.0 ºC 760 mmHg (Calc.)^*
• Flash point: 258.3±30.1 ºC (Calc.)^*
• Index of refraction: 1.546 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS02 DangerGHS02
• Hazard Statements: H228-H242
• Precautionary Statements: P210-P234-P235-P240-P241-P280-P370+P378-P403-P410-P411-P420-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Self-reactive substances or mixtures	Self-react.	D	H242
Flammable solids	Flam. Sol.	1	H228
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Acute toxicity	Acute Tox.	4	H302
Self-reactive substances or mixtures	Self-react.	E	H242
Skin irritation	Skin Irrit.	2	H315
Self-reactive substances or mixtures	Self-react.	C	H242
Eye irritation	Eye Irrit.	2	H319
Flammable solids	Flam. Sol.	2	H228

• Transport Information: UN 1325

Discovory and Applicatios

4,4'-Azobis(4-cyanovaleric acid) is a chemical compound widely recognized for its role in the field of polymer chemistry, particularly as a radical initiator. It is an azo compound, characterized by the presence of a central azobisisobutyronitrile (AIBN) backbone, where each side of the azo bond is connected to a 4-cyanovaleric acid moiety. This compound plays a significant role in the initiation of polymerization reactions, which are crucial in the synthesis of a wide variety of polymers and copolymers.

The discovery of 4,4'-Azobis(4-cyanovaleric acid) stems from ongoing research into the use of azo-based compounds as polymerization initiators. Azo compounds are known for their ability to generate free radicals when exposed to heat or light, making them invaluable in initiating polymerization reactions. These free radicals are key to the growth of polymer chains, enabling the polymerization of monomers into longer polymer chains. This reaction is crucial for the production of materials used in numerous applications, including plastics, coatings, adhesives, and more.

4,4'-Azobis(4-cyanovaleric acid) operates by decomposing into two free radicals when heated, each capable of initiating the polymerization of monomers such as acrylates, methacrylates, and styrene. The reaction mechanism typically involves the decomposition of the azo bond under heat, producing two radicals that attack the monomers, causing them to link together and form a polymer chain. This process is known as free radical polymerization.

The specific advantage of using 4,4'-Azobis(4-cyanovaleric acid) over other azo initiators is related to its structure and decomposition temperature. The presence of the 4-cyanovaleric acid group allows for the fine-tuning of its thermal decomposition characteristics, making it suitable for use in a wide range of polymerization reactions that require precise control over initiation conditions. The compound is particularly effective in applications where a controlled polymerization process is required, as it offers predictable behavior in terms of both the rate of radical generation and the temperature conditions needed to activate the polymerization process.

In addition to its use in free radical polymerization, 4,4'-Azobis(4-cyanovaleric acid) has also found applications in the preparation of functionalized polymers and copolymers. By incorporating this initiator into the polymerization process, researchers can create polymers with specific chemical functionalities that are useful for creating specialized materials. These include polymers with enhanced properties such as increased solubility, improved mechanical strength, or responsiveness to environmental stimuli. Such materials are used in industries ranging from pharmaceuticals to environmental applications, where tailored materials are needed.

Furthermore, the compound has applications beyond polymerization. It is used in the production of crosslinked networks, a vital component in the creation of materials such as hydrogels and other advanced materials used in biotechnology, sensors, and drug delivery systems. Crosslinking, the process of connecting polymer chains into a three-dimensional network, enhances the mechanical properties and stability of the resulting materials, making them suitable for a wide range of uses, including biomedical applications.

While 4,4'-Azobis(4-cyanovaleric acid) is generally considered safe for use in controlled industrial environments, it does require careful handling due to its ability to generate free radicals. These free radicals can be highly reactive and, if not properly controlled, may lead to undesired side reactions or hazards. As such, proper safety precautions must be observed during its handling and storage. Additionally, the compound is typically used in specialized manufacturing settings, where temperature control and reaction monitoring are essential to ensure that the polymerization process proceeds as intended.

In conclusion, 4,4'-Azobis(4-cyanovaleric acid) plays a crucial role as a radical initiator in polymer chemistry, enabling the efficient and controlled polymerization of monomers into a wide range of functional materials. Its ability to generate free radicals under controlled conditions has made it indispensable in the production of polymers and copolymers for various industrial applications. As research in polymer chemistry continues to evolve, compounds like 4,4'-Azobis(4-cyanovaleric acid) remain essential tools for creating new materials with unique properties suited to a broad spectrum of uses.

References

1984. Thermal decomposition of 4,4'-azobis(4-cyanopentanol). Polymer Bulletin, 11(2).
DOI: 10.1007/bf00258025

2022. Thermal analysis and pyrolysis products analysis of 4,4'-azobis (4-cyanovaleric acid) by using thermal analysis methods and combination technology. Journal of Thermal Analysis and Calorimetry, 148(4).
DOI: 10.1007/s10973-022-11571-6

2024. Synthesis Techniques in Molecular Imprinting: From MIP Monoliths to MIP Films and Nanoparticles. Springer Series on Polymer and Composite Materials.
DOI: 10.1007/978-3-031-67368-9_4