Glycol Ethers, High-Purity Solvents

Ethylene Glycol Monoethyl Ether (EE)

Ethylene Glycol Monoethyl Ether (EE), also known by the IUPAC name 2-ethoxyethanol and the commercial trade name Cellosolve™, is a clear, colorless, and nearly odorless liquid. As a member of the ethylene glycol ether family (E-series), it possesses a bifunctional chemical structure containing both an ether and a hydroxyl group. This dual functionality grants it exceptional solvency power, allowing it to remain miscible with water as well as a vast array of organic solvents, including alcohols, ketones, and aliphatic/aromatic hydrocarbons.

Historically, EE has been a staple in the chemical industry due to its high boiling point, low volatility at room temperature, and ability to dissolve a wide variety of resins, oils, and waxes. However, in contemporary practice, its use is strictly monitored. It is classified as a reproductive toxicant, leading to stringent regulatory oversight by bodies such as OSHA and REACH. In many consumer applications, it has been phased out in favor of less toxic propylene glycol ethers (P-series), though it remains a critical intermediate in specialized industrial synthesis and controlled manufacturing processes.

Attributes

Key Features and Benefits

Exceptional Solvency: Acts as a powerful solvent for nitrocellulose, lacquers, and various natural and synthetic resins.
High Boiling Point: Its high boiling point (135°C) ensures stability in high-temperature applications and controlled evaporation rates.
Miscibility Profile: Completely miscible with water and most organic solvents, making it an ideal coupling agent for immiscible phases.
Improved Leveling: In coating applications, it prevents “blushing” and improves the flow and gloss of the finished film by regulating drying times.
Chemical Stability: It is chemically stable under standard storage conditions and non-corrosive to most metals and industrial equipment.
Low Odor: Provides a mild, non-intrusive ether-like odor compared to harsher aromatic solvents.

Specifications

Technical Highlights

Molecular Identification: CAS Registry Number 110-80-5; Molecular Formula C₄H₁₀O₂ (Molar Mass: 90.12 g/mol).
Thermal Properties: Boiling Point of 135°C (275°F) and a Freezing Point of -70°C (-94°F).
Flammability: Flash Point is 43°C (109°F) (Closed Cup), classifying it as a Flammable Liquid (GHS Category 3).
Vapor Pressure: Low vapor pressure of 3.8 mmHg at 20°C, which minimizes evaporative loss during handling.
Specific Gravity: 0.930 at 20°C, slightly less dense than water.
Safety Profile: Known reproductive toxicant with a significant rate of dermal absorption; requires rigorous PPE and engineering controls (OSHA PEL: 200 ppm).