Glycols
Glycols are liquid chemicals formulated from natural gas and crude oil. You will find glycols in many every day house hold items including engine coolants, plastic bottles and polyester fabric.
In a glycol molecule, two hydroxyl (-OH) groups are attached to different carbon atoms. The most common and simple types of glycol are ethylene glycol and propylene glycol.
Di Ethylene Glycol (DEG)
Di ethylene glycol has a variety of uses in industry. The tobacco industry makes use of its hygroscopic properties and uses it as humectant in tobacco production. This same property also makes it useful in the treatment of paper, cork, glue, and cellophane and it is utilised as a dehydrant in the natural gas industry where it removes the water from the gas pipelines.
Di ethylene glycol is also used as a chemical intermediate in the manufacture of unsaturated polyester resins, plasticisers, acrylate and methacrylate resins, and urethanes.
Mono Ethylene Glycol (MEG)
Mono Ethylene Glycol (also known as MEG) is a clear, colourless, virtually odourless, and slightly viscous liquid. It is miscible with water, alcohols, and many organic compounds, and has the formula C2H6O2. It is the most important of the commercially available ethylene glycols as it has many industrial applications.
There is strong global demand for Mono Ethylene Glycol as it is a vital ingredient in the production of polyester fibres, films, and resins, one of which is polyethylene terephthalate (PET).
The second largest market for MEG is in antifreeze applications where it is a component in the manufacture of antifreeze, coolants, aircraft anti-icer, and de-icers.
Monopropylene Glycol (MPG)
Monopropylene glycol (also known as propylene glycol, PG, propan1, 2diol and MPG) is a clear, colourless and viscous liquid with a characteristic odour and has the formula C3H8O2. This solvent is soluble in water and holds hygroscopic properties, meaning it can attract hard water molecules.
It is used across a wide range of industries as it has low toxicity, coupled with a freezing point which is depressed upon mixing with water.
The first grade is used in the food industry for food colourings and flavourings and is also a classified humectant food additive (E1520). There are also many applications in the cosmetics industry that use this solvent, specifically personal care products including shampoos, bubble baths, baby wipes and as a moisturiser in make-up.
The second is industrial grade MPG which has a variety of uses but the main application is as an antifreeze and aircraft wing and runway de-icer which is because its freezing point lowers upon mixing with water. It is also used in heat transfer liquids such as engine coolants.
Monopropylene Glycol is additionally used in the pharmaceutical industry, examples include as a chemical intermediate in the production of high-performance unsaturated polyester resins used in paints and varnishes and as an excellent solvent utilised in printing inks.
