Triethanolamine is available in three concentrations: 85%, 97%, and 99%.
Domestic products from Fushun Jiahua and Jinyuan do not offer 99%, with the highest being 97%.
Triethanolamine 85% is divided into two types:
Commercial grade specifications: Triethanolamine content 70%, total amine content 85%, moisture below 15%.
Industrial grade specifications: Triethanolamine content 85%, total amine content 97%, moisture below 3%.
The quality of triethanolamine depends on the monoethanolamine content; the lower the monoethanolamine content, the better the quality.
Also known as tris(2-hydroxyethyl)amine, it can be regarded as the trihydroxy derivative of triethylamine. Similar to other amine compounds, due to the lone pair of electrons on the nitrogen atom, triethanolamine is weakly alkaline and can react with inorganic or organic acids to form salts.
Physical and chemical properties
Chemical formula: (HOCH?CH?)?N
Molecular formula: C?H??NO?
Molecular weight: 149.1882
Boiling point (°C, 101.3 kPa): 360
Melting point (°C): 21.2
CAS: 102-71-6
Relative density (g/mL, 20/4°C): 1.1242
Relative density (g/mL, 20/20°C): 1.1258
Appearance: Colorless to pale yellow transparent viscous liquid with a slight ammonia odor; becomes colorless to pale yellow cubic crystals at low temperatures. Color gradually darkens when exposed to air.
Preparation
Method 1:
Ethylene oxide and ammonia water are fed into a reactor, where a condensation reaction occurs at 30-40°C and 70.9-304 kPa pressure, producing a mixture of monoethanolamine, diethanolamine, and triethanolamine. After dehydration and concentration at 90-120°C, the mixture is sent to three vacuum distillation columns for fractional distillation. Fractions are collected based on different boiling points to obtain monoethanolamine, diethanolamine, and triethanolamine products with purities up to 99%. Increasing the proportion of ethylene oxide during the reaction increases the yield of diethanolamine and triethanolamine.
Purification method: Industrial-grade triethanolamine contains over 80% triethanolamine, with the remainder consisting of less than 1.0% water, less than 2.5% ethanolamine, 15% diethanolamine, and small amounts of impurities like polyethylene glycol. Purification involves steam distillation to remove ethanolamine, adding sodium hydroxide to precipitate triethanolamine as an alkali metal salt, followed by separation, neutralization, and vacuum distillation to obtain the pure product.
Method 2:
Purification is achieved by vacuum distillation of industrial-grade triethanolamine.
Storage and Transportation
Ensure packaging is intact; handle with care during loading and unloading.
Store in a cool, well-ventilated warehouse. Protect from moisture, light, and seal tightly. Keep away from fire and heat sources.
Store separately from oxidizers, acids, copper, and aluminum. Avoid mixed storage.
Equip with appropriate types and quantities of fire-fighting equipment. The storage area should have leak emergency handling equipment and suitable containment materials.