Glycol Ethers, High-Purity Solvents

Ethylene Glycol Monobutyl Ether (Butyl Cellosolve) (EB)

Ethylene Glycol Monobutyl Ether (EB), widely known by the trade name Butyl Cellosolve and the IUPAC name 2-Butoxyethanol, is a high-performance, versatile organic solvent. This colorless liquid possesses a mild, pleasant ether-like odor and belongs to the glycol ether chemical family. Its unique molecular structure—incorporating both ether and hydroxyl functional groups—endows it with an “amphiphilic” nature, allowing it to bridge the gap between aqueous and organic phases. Consequently, EB is exceptionally effective as a coupling agent and cosolvent in systems where water and oils must remain miscible.

In industrial chemistry, EB is valued for its high solvency power against a diverse range of resins, including nitrocellulose, acrylics, and alkyds. It features a balanced evaporation rate that facilitates superior film formation and leveling in coatings. While it is readily biodegradable, it is classified as a combustible liquid and requires careful handling to prevent skin absorption and inhalation, adhering to established occupational exposure limits.

Attributes

Key Features and Benefits

Superior Solvency: Effectively dissolves both hydrophobic substances and hydrophilic resins, ensuring a homogeneous formulation.
Coupling Efficiency: Acts as a powerful stabilizer for immiscible liquids, preventing phase separation in complex mixtures.
Coalescing Agent: Promotes optimal film formation in water-reducible coatings, improving durability and finish quality.
Viscosity Reduction: Lowers the viscosity of high-solids resin systems, enhancing ease of application and sprayability.
Surface Tension Reduction: Improves wetting and leveling characteristics, reducing surface defects like “orange peel” or “blushing.”
Low Odor Profile: Suitable for use in formulations where minimal olfactory impact is required for end-users.

Specifications

Technical Highlights

Chemical Identity: CAS Number 111-76-2; Molecular Formula C₆H₁₄O₂.
Physical State: Low-viscosity liquid with a molecular weight of 118.17 g/mol.
Boiling Point: 171°C (340°F) at 760 mmHg, providing a medium-to-slow evaporation rate.
Flash Point: 67°C (153°F) (Closed Cup), classifying it as a combustible liquid (GHS Category 4).
Miscibility: Completely miscible in water and most common organic solvents (alcohols, ketones, ethers).
Specific Gravity: 0.900 at 20°C.
Vapor Pressure: Relatively low at 0.8 mmHg at 20°C, minimizing volatile organic compound (VOC) emissions during storage.
Environmental Profile: Readily biodegradable with a low potential for bioaccumulation.