Triethanolamine is a sticky organic compound that is both a tertiary amine and a triol (a molecule with three alcohol groups). It is produced by the reaction of ethylene oxide with aqueous ammonia. In this reaction, ethanolamine and diethanolamine are also produced. Triethanolamine is soluble in water and some organic solvents. It is a colorless compound but may appear yellow due to impurities. It has a slight ammonia odor and solidifies below 20°C.
Chemical and Physical Properties of Triethanolamine:
- Chemical Formula: C6H15NO3
- Molecular Weight: 149.19 g/mol
- Melting Point: 20.5°C
- Boiling Point: 335°C
- Density: 1.124 g/mL
- Vapor Pressure: 0.01 mmHg (at 25°C)
- Flash Point: 185°C
- Octanol/Water Partition Coefficient (log Kow): -1.28
- Acidity (pKa): 7.8
- pH: 10.5 (1% solution)
- Solubility: Highly soluble in water and some organic solvents; low solubility in hydrocarbons.
Triethanolamine has numerous applications. It is most commonly used as an emulsifier in the production of surfactants. Surfactants reduce surface tension and increase the interaction between oil and water. It is a common component in formulations used for both industrial and consumer products. Triethanolamine neutralizes fatty acids, adjusts pH, and dissolves other components that are completely insoluble in oils and water.
Common Products Containing Triethanolamine:
- Sunscreen Lotions: Triethanolamine enhances the solubility of UV filters in sunscreen lotions and prevents leaving a white residue on the skin.
- Liquid Laundry Detergents: It is used as a scale inhibitor and softener in liquid laundry detergents. It also helps adjust the viscosity of the detergent and control foam formation.
- Dishwashing Liquids: Triethanolamine is used as a degreaser and scale inhibitor in dishwashing liquids. It also helps in shining dishes and preventing stains.
- General Cleaners: It serves as a degreaser and scale inhibitor in general cleaners and helps adjust the pH and control foam formation.
- Hand Sanitizers: Triethanolamine is used as a moisturizer to reduce the drying effect of alcohol in hand sanitizers. It also helps in adjusting the viscosity of the sanitizer and preventing foam formation.
- Polishes: It is used to neutralize fatty acids in the production of polishes and helps adjust the viscosity of the polish and dissolve glossing agents.
- Metalworking Fluids: Triethanolamine serves as a corrosion inhibitor and lubricant in metalworking fluids, helping remove rust from metal surfaces and improving the efficiency of metalworking processes.
- Paints: It is used as a pH regulator and buffer in paint production, helping adjust viscosity and disperse pigments.
- Shaving Cream: Triethanolamine functions as a foam stabilizer and moisturizer in shaving creams, ensuring smooth application on the skin and easy glide of the razor.Ink Printing: Triethanolamine is used as a pH regulator and buffer in ink printing, helping adjust viscosity and enhance the efficiency of inkjet printing.
Triethanolamine is also used in cement clinker grinding, pharmaceuticals, cosmetic products, and complexometric titrations. It is a versatile chemical compound used across multiple industries for various purposes.