Vinylcyclohexene Dioxide: Properties, Uses & Safety

Vinylcyclohexene dioxide is a bifunctional aliphatic epoxide compound bearing two reactive oxirane rings, making it a versatile building block in polymer crosslinking, epoxy resin formulation, and synthetic organic chemistry research.

Chemical Name

1,2-Epoxy-4-(epoxyethyl)cyclohexane (Vinylcyclohexene Dioxide)

CAS Number

106-87-6

Molecular Formula

C8H12O2

Molecular Weight

140.18 g/mol

Functionality

Bifunctional diepoxide (two oxirane rings)

Aladdin SKU

V420509

Physical State

Colorless to pale yellow liquid at room temperature

Chemical Structure and Reactivity

Vinylcyclohexene dioxide (VCD, CAS 106-87-6) is derived from the double epoxidation of 4-vinylcyclohexene. The resulting molecule contains two distinct oxirane (epoxide) rings: one integrated into the cyclohexane ring system (alicyclic epoxide) and one on the pendant vinyl-derived side chain (terminal epoxide). This bifunctional architecture confers a high degree of reactivity toward nucleophiles, including amines, thiols, carboxylic acids, and hydroxyl groups.

The alicyclic epoxide is generally considered more sterically hindered and somewhat less reactive than the terminal epoxide, providing a degree of selectivity that can be exploited in stepwise synthetic strategies. Both rings participate readily in cationic and anionic ring-opening polymerization, as well as in crosslinking reactions with polyfunctional hardeners.

Research and Industrial Applications

VCD serves multiple roles across research and applied chemistry:

• Epoxy Resin Crosslinker and Reactive Diluent: VCD is used to reduce the viscosity of high-molecular-weight epoxy formulations while contributing additional epoxide functionality to the cured network, thereby improving crosslink density and thermal stability.
• Polymer Synthesis: As a monomer or co-monomer, VCD participates in ring-opening polymerization to produce polyether networks or polyols for downstream applications.
• Synthetic Intermediate: The two differentially reactive epoxide groups allow stepwise functionalization, making VCD a useful intermediate for the preparation of diol derivatives, amino alcohols, and other bifunctional small molecules in medicinal and materials chemistry.
• Surface Modification: VCD has been explored for functionalization of inorganic substrates and nanoparticles, where ring-opening reactions with surface hydroxyl groups create covalent organic coatings.

Handling, Storage, and Safety Considerations

VCD is classified as a sensitizer and potential carcinogen and must be handled with strict engineering and administrative controls. Key precautions include:

• Personal Protective Equipment (PPE): Nitrile or neoprene gloves, chemical splash goggles, and a laboratory coat are required as a minimum. Work in a certified fume hood to minimize inhalation exposure.
• Skin and Eye Contact: VCD is a known skin sensitizer; even brief dermal contact may induce allergic responses upon subsequent exposure. In case of contact, flush immediately with copious water and seek medical advice.
• Storage: Store in a tightly sealed container in a cool, dry, well-ventilated area away from heat sources, oxidizers, and strong acids or bases. Refrigerated storage (2–8 °C) is recommended for long-term stability.
• Disposal: Dispose of as hazardous chemical waste in accordance with applicable local and national regulations. Do not pour down the drain.

Consult the current Safety Data Sheet (SDS) for complete hazard information before use. Regulatory status should be verified for each jurisdiction prior to purchase and use.

Formulation Tips and Compatibility

When incorporating VCD into epoxy formulations, the following practical considerations apply:

• Hardener Selection: VCD is compatible with a broad range of amine, anhydride, and Lewis acid hardeners. Cycloaliphatic epoxides such as the ring-integrated epoxide in VCD respond particularly well to cationic photocuring initiators, enabling UV-curable coating applications.
• Viscosity Adjustment: Because VCD is a low-viscosity liquid diepoxide, it functions effectively as a reactive diluent, reducing mix viscosity without sacrificing network functionality after cure.
• Pot Life: Formulations containing VCD with amine hardeners may exhibit shorter pot lives at elevated temperatures. Conduct small-scale trials to determine working time before scaling up.
• Compatibility Testing: Always verify compatibility with specific hardener systems, fillers, and substrates at the intended use concentration, as reactivity can vary with formulation pH and temperature.

Frequently asked questions

What makes vinylcyclohexene dioxide a bifunctional epoxide?

VCD contains two separate oxirane rings: one fused into the cyclohexane ring (alicyclic) and one on the pendant side chain (terminal). Both rings are capable of undergoing ring-opening reactions with nucleophiles or under cationic conditions, providing two sites for crosslinking or functionalization per molecule.

Can vinylcyclohexene dioxide be used as a reactive diluent in epoxy systems?

Yes. VCD is a low-viscosity liquid diepoxide that reduces the overall viscosity of epoxy formulations while remaining chemically reactive. Upon curing, both epoxide groups participate in network formation, so VCD does not act merely as an inert plasticizer but contributes to the final crosslinked structure.

What are the primary safety concerns when working with vinylcyclohexene dioxide?

VCD is classified as a skin sensitizer and a potential carcinogen. Researchers should use appropriate PPE (nitrile gloves, splash goggles, lab coat), work in a fume hood, and consult the current SDS before handling. Prolonged or repeated skin contact must be strictly avoided to prevent sensitization.

How should vinylcyclohexene dioxide be stored to maintain stability?

VCD should be stored in a tightly sealed container in a cool, dry, and well-ventilated location, away from heat, strong oxidizers, and acidic or basic conditions. Refrigerated storage at 2–8 °C is recommended for long-term stability. Always check the SDS for the most current storage guidance.

References

1. Aladdin Scientific. Vinylcyclohexene Dioxide, SKU V420509, product reference V113963.
2. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley: New York, 1992. (Epoxide ring-opening reactions, general textbook reference.)
3. Lee, H.; Neville, K. Handbook of Epoxy Resins; McGraw-Hill: New York, 1967. (Reactive diluents and bifunctional epoxides in formulation.)
4. International Agency for Research on Cancer (IARC). Monographs on the Evaluation of Carcinogenic Risks to Humans. (VCD carcinogenicity classification — specific volume and page to be verified.)

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.