Diethylene Glycol (DEG)
DEG is an organic compound with the formula (HOCH2CH2)2O. It is a colorless, practically odorless, poisonous, hygroscopic liquid with a sweetish taste. It is miscible in water, alcohol, ether, acetone, and ethylene glycol. DEG is a widely used as solvent.
Diethylene glycol, CH2OHCH2OCH2CH2OH, is similar in properties to MEG (mono ethylene glycol), but DEG has a higher boiling point, viscosity, and specific gravity.
MEG is the raw material used in the production of polyester fiber, PET resins, alkyds, and unsaturated polyesters.
Diethylene Glycol (DEG) is used in the manufacture of unsaturated polyester resins, polyurethanes and plasticizers. It is a water-soluble liquid; boiling point 245 C, and is soluble in many organic solvents.
DEG is produced by the partial hydrolysis of ethylene oxide.
Depending on the conditions, varying amounts of DEG and related glycols are produced. The resulting product is two ethylene glycol molecules joined by an ether bond, Diethylene glycol is derived as a co-product with ethylene glycol and triethylene glycol.
Diethylene glycol, commonly referred to as DEG, is similar in properties to ethylene glycol, but with a higher boiling point, viscosity and specific gravity.
DEG is straight-chain dihydric alcohol which is aliphatic terminated on both ends by a hydroxyl group.
It is a clear, water-white, practically odorless, hygroscopic liquid at room temperature. It is also soluble in many organic solvents.
Diethylene glycol is used as a dehydrating agent for natural gas, a raw material for the production of plasticizers and polyester resin, and a widely used solvent.
It is also used as a humectant in the tobacco industry and in the treatment of corks, glue, paper and cellophane as well as in the synthesis of morpholine and 1,4-dioxane.
Availability of DEG depends on the demand for derivatives of the primary product, ethylene glycol, rather than on DEG market requirements.
Di Ethelene Glycol (also known as DEG,oxydiethanol, and glycol ether glycol) is a clear, colorless, odourless liquid with the molecular formula C4H10O3, CAS: 111-46-6.
It has a specific gravity of 1.118 and a flashpoint of 154 °C.
It is soluble both in water and in many organic compounds and has hygroscopic properties which makes it a useful industrial chemical. it has also been involved in a number of prominent mass poisonings spanning back to 1937. Despite DEG’s toxicity and associated epidemics of fatal poisonings, a comprehensive review has not been published.
Di Ethelene Glycol Chemical Structure Composition.
Methods
A summary of the literature on DEG was compiled by systematically searching OVID MEDLINE and ISI Web of Science. Further information was obtained from book chapters, relevant news reports, and web material.
Aim
The aim of this review is to summarize all main aspects of DEG poisoning including epidemiology, toxicokinetics, mechanisms of toxicity, clinical features, the toxicity of DEG, diagnosis, and management.
Epidemiology
Most of the documented cases of DEG poisoning have been epidemics (numbering over a dozen) where DEG was substituted in pharmaceutical preparations. More often, these epidemics have occurred in developing and impoverished nations where there is limited access to intensive medical care and quality control procedures are substandard.
Toxicokinetics
Following ingestion, DEG is rapidly absorbed and distributed within the body, predominantly to regions that are well perfused. Metabolism occurs principally in the liver and both the parent and the metabolite, 2-hydroxyethoxyacetic acid (HEAA), are really eliminated rapidly.
Mechanisms of toxicity
Although the mechanism of toxicity is not clearly elucidated, research suggests that the DEG metabolite, HEAA, is the major contributor to renal and neurological toxicities.
Clinical features
The clinical effects of DEG poisoning can be divided into three stages: The first phase consists of gastrointestinal symptoms with evidence of inebriation and developing metabolic acidosis.
If poisoning is pronounced, patients can progress to a second phase with more severe metabolic acidosis and evidence of emerging renal injury, which, in the absence of appropriate supportive care, can lead to death. If patients are stabilized, they may then enter the final phase with various delayed neuropathies and other neurological effects, sometimes fatal.
TOXICITY OF DEG: Doses of DEG necessary to cause human morbidity and mortality are not well established. They are based predominantly on reports following some epidemics of mass poisonings, which may underestimate toxicity.
The mean estimated fatal dose in an adult has been defined as approximately 1 mL/kg of pure DEG.
Management:
Initial treatment consists of appropriate airway management and attention to acid-base abnormalities. Prompt use of fomepizole or ethanol is important in preventing the formation of the toxic metabolite HEAA; hemodialysis can also be critical, and assisted ventilation may be required.
Conclusions:
DEG ingestion can lead to serious complications that may prove fatal. Prognosis may be improved, however, with prompt supportive care and timely use of fomepizole or ethanol.
Application:
TCC’s Diethylene Glycol is used as a dehydrating agent for natural gas; a raw material for the production of plasticizers and polyester resins; a humectant; a textile lubricant and coupling agent; a solvent in textile dyeing and printing; a constituent of hydraulic fluids; a plasticizer for paper, cork and synthetic sponges; a solvent in printing inks; a raw material for the production of esters used as emulsifiers, demulsifiers, and lubricants; and a selective solvent for aromatics in petroleum refining.
Examples of applications:
DEG is primarily used as a feedstock in the manufacturing process of unsaturated polyester resins, polyol, polyurethane, and plasticizers.
It serves as a solvent in the production of industrial resins. Polyester resins are found mainly in textile products (sportswear, carpets, upholstery). Special types of fibers are also used in the automotive industry (seatbelts, airbags) and in the construction and transport sectors (ropes, tarpaulins).
Packing:
- Bulk in seagoing vessels/barges
- Bulk in flexitank cars
- Bulk in road tank cars
- Bulk in iso tank containers
- Other packaging solutions are possible by agreement.
How is it produced?
Production of diethylene glycol is generally based on the demand for, and production of, mono ethylene glycol as it is a by-product of this production process.
The process consists of the oxidation of ethylene at a high temperature in the presence of a silver oxide catalyst. The ethylene oxide is then hydrated to yield diethylene glycol with mono ethylene glycol and triethylene glycol as co-products.
The chemical industry tries to maximize the production of monoethylene glycol in this process but diethylene glycol is a very useful by-product.
How is it stored and distributed?
Diethylene glycol can be stored in stainless steel, aluminum, or lined drums, tank cars, or tank trucks. It has a specific gravity of 1.118 and a flashpoint of 154 °C (closed cup). It is not regulated for transport on road, rail, air, or sea but it is classified as harmful and is harmful if swallowed.
What is Di Ethylene used for?
Diethylene glycol has a variety of uses in the industry. The tobacco industry makes use of its hygroscopic properties and uses it as a humectant in tobacco production. This same property also makes it useful in the treatment of paper, cork, glue, and cellophane and it is utilized as a dehydrate in the natural gas industry where it removes the water from the gas pipelines.
Diethylene glycol is also used as a chemical intermediate in the manufacture of unsaturated polyester resins, plasticizers, acrylate and methacrylate resins, and urethanes. In the U.S. and Western Europe, 51% of DEG is consumed in this way.
However, in Japan, it is mostly utilized as a cement grinding aid. It can also be used in petroleum solvent extraction and can be found in the printing ink, and drywall joint compounds.
Diethylene glycol is now being displaced by tri ethylene glycol in some of its applications as the lower toxicity of tri ethylene glycol makes it more appealing to manufacturers.
Corrosionpedia Explains Diethylene Glycol (DEG)
- Diethylene glycol (DEG) is used in a wide range of industrial applications. Some of these include:
- To produce tobacco and tobacco products (such as additives, humectants, and inks)
- To produce artificial smoke/fog/mist
- As an ingredient in fuel to warm foods and to heat enclosed spaces
- In fire extinguishing sprinkler systems
- To manufacture munitions
- To produce deicers for use on roadways and sidewalks
- As a component of heat transfer fluids in systems
On the basis of application, the DEG market is divided into
- Antifreeze and Coolant
- Solvents
- Humectants
- Polyester Resins and Plasticisers
- Emulsifiers and Lubricants
- Others
By end-use, the market is segmented into
- Agrochemical
- Automotive
- Cosmetic and Personal Care
- Paints and Coatings
- Oil and Gas
- Textiles
- Plastics Industry
- Others
The regional markets for the product include North America, Europe, the Asia Pacific,
Latin America, and the Middle East, and Africa.
Handling
– Wash thoroughly after handling.
– Use with adequate ventilation.
– Avoid breathing vapors from heated material.
– Avoid contact with eyes, skin, and clothing.
– Keep the container tightly closed.
– Avoid breathing spray or mist.
Storage
– Store in a cool, dry, well-ventilated area away from incompatible substances.
– Keep containers tightly closed.
– Store protected from moisture.
Hazards
– Eye: May cause mild eye irritation.
– Skin: May cause mild skin irritation.
– Ingestion: May cause liver and kidney damage.
– Inhalation: May cause respiratory tract irritation.
First Aid Measures
– Eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids.
– Skin: Get medical aid. Immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
– Ingestion: If the victim is conscious and alert, give 2-4 cupfuls of milk or water.
– Inhalation: Remove from exposure and move to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen.
Specification of Diethylene Glycol (DEG)
| Appearance | Colourless, transparent |
|---|---|
| Purity | 99.8 wt % min |
| MEG | 0.05 wt % max |
| TEG | 0.05 wt % max |
| Water | 0.05 wt % max |
| Color(Pt-Co) | 10 max |
| Specific Gravity , 20/20 C | 1.1175-1.1195 |
| Boiling range at 0.1013 Mpa | |
| 5% vol | Min 242 C |
| 95% vol | Max 250 C |
| Acidity(as acetic acid) | 50 mg/kg max |
| Ash | 50 mg/kg max |
PHYSICAL PROPERTIES OF DIETHYLENE GLYCOL
| Scientific Common | Autoignition Temperature 229°C 1013.25 hPa 444°F 760mm Hg |
|---|---|
| Critical Pressure 4,605 kPa 34,540.3 mm Hg | Critical Specific Volume 0.312 L/gmol 5.00 ft3/lbmol |
| Critical Temperature 406.85°C 764.33°F | Dielectric Constant 31.69 31.69 |
| Electrical Conductivity at 20°C 0.42 × 10-6 mhos/cm 0.0042 micromhos/cm | Evaporation Rate (Butyl Acetate = 1) <0.001 <0.001 |
| Flammable Limits in Air, Upper 12.3%(V) 12.3%(V) | Flammable Limits in Air, Lower 2.0%(V) 2.0%(V) |
| Flash Point, Closed Cup 138°C 1013.25 hPa 280°F 760 mm Hg | Heat of Combustion at 25°C -2,154.82 kJ/gmol -8,730.4 Btu/lb |
| Heat of Vaporization at 1 atm 57.9 kJ/gmol 234.4 Btu/lb | Molecular Weight 106.12 g/mol 106.12 g/mol |
| Normal Boiling Point 244.9°C 1013.25 hPa 473°F 760 mm Hg | Δ BP/Δ P (750 to 770 mm Hg) 0.052°C/mm Hg |
| Normal Freezing Point -6.5°C 20.3°F | Onset of Initial Decomposition 240°C 464°F |
| Refractive Index, nD , at 20°C 1.4472 1.4472 | Solubility in Water at 20°C 100.0 wt% 100.0 wt% |
| Solubility of Water in Diethylene Glycol at 20°C 100.0 wt% 100.0 wt% | Specific Gravity (20/20°C) 1.1182 1.1182 |
| C6.3 DEG | Δ Specific Gravity/Δ T (10 to 40°C) 0.00073/°C 0.00073/°C |
| Surface Tension at 25°C 44.8 mN/m 44.8 dynes/cm | Vapor Density (air = 1) 3.65 3.65 |
| Vapor Pressure at 25°C 0.008 hPa 0.006 mm Hg | Dynamic Viscosity at 20°C 35.7 mPa s 35.7 cP |
