Glycol Ethers, High-Purity Solvents

Ethylene Glycol Monohexyl Ether (EGH)

Ethylene Glycol Monohexyl Ether (EGH), also frequently identified by the trade name Hexyl Cellosolve (CAS: 112-25-4), is a high-performance, slow-evaporating solvent belonging to the ethylene glycol ether family. Structurally, it consists of a six-carbon hexyl chain linked to an ethylene glycol unit, providing a distinct amphiphilic character. This molecular structure allows EGH to bridge the gap between water-soluble and oil-soluble components, making it an exceptional coupling agent and surfactant-like solvent.

Physically, EGH is a clear, colorless liquid with a mild, characteristic ether-like odor. Compared to its shorter-chain analogs (such as EB or EM), EGH features a much higher boiling point and lower vapor pressure. These properties are highly valued in industrial applications where controlled evaporation, high solvency for hydrophobic substances, and reduced volatile organic compound (VOC) emissions are critical. While it is only sparingly soluble in water, its ability to reduce surface tension and promote the coalescence of resins makes it indispensable in advanced coatings and heavy-duty cleaning formulations.

Attributes

Key Features and Benefits

Superior Solvency: Exhibits powerful dissolving capabilities for hydrophobic materials, including greases, oils, waxes, and complex resins.
Slow Evaporation Rate: Provides extended “open time” in coatings, significantly improving flow and leveling while preventing surface defects like pinholing.
High Coalescing Efficiency: Effectively reduces the Minimum Film Forming Temperature (MFFT) of polymer dispersions, ensuring a smooth, continuous film.
Surface Tension Reduction: Acts as a powerful wetting agent, improving the penetration of cleaners and the adhesion of coatings on contaminated substrates.
Phase Stabilization: Functions as a robust coupling agent to stabilize immiscible aqueous and organic phases in concentrated liquid formulations.
Safety Profile: Offers a high flash point and low volatility, enhancing workplace safety compared to more volatile solvents.

Specifications

Technical Highlights

Chemical Formula: C₈H₁₈O₂ / CH₃(CH₂)₅OCH₂CH₂OH
Molecular Weight: 146.23 g/mol
Boiling Point: 208°C (406°F) at 760 mmHg, indicating its status as a high-boiling solvent.
Vapor Pressure: Very low (approximately 0.05 mmHg at 20°C), minimizing atmospheric loss.
Specific Gravity: 0.888 at 20°C.
Water Solubility: Approximately 0.99% by weight at 20°C; however, it is highly miscible with most organic solvents.
Flash Point: 91°C (195°F) (Closed Cup), classifying it as a combustible liquid rather than highly flammable.
Viscosity: 5.2 cP at 20°C, facilitating easy blending and pumping in industrial processes.