What Is Ethylene Glycol Used For?

Ethylene glycol is also known as glycerol, 1,2-ethylene glycol, or EG. The chemical formula (CH2OH) 2 is the simplest binary alcohol. Ethylene glycol is a colorless, odorless, sweet liquid with low toxicity to animals. Ethylene glycol can interdissolve with water and acetone, but it has less solubility in ethers. Ethylene glycol can be used as a solvent, an antifreeze, and a raw material for synthetic polyester. Polyethylene glycol (PEG) is a phase transfer catalyst also used for cell fusion; its nitrate is an explosive.

Ethylene glycol is mainly used in making polyester, polyester resin, hygroscopic agent, plasticizer, surfactant, synthetic fiber, cosmetics, and explosives. It is also used as dyes, ink, and other solvents in the preparation of engine antifreeze, gas dewatering agent, and resin manufacturing. It can also be used in cellophane, fiber, leather, and adhesive wetting agents. It can produce synthetic resin PET, fiber grade PET, namely polyester fiber, bottle sheet grade PET, which is used for making mineral water bottles, etc. It can also produce alkyd resin, glyoxal, and so on, but is also used as antifreeze. In addition to being used as an antifreeze for automobiles, it is also used for the transportation of industrial cooling, generally known as the cooling agent. At the same time, it can also be used as water as a condensate.

Ethylene glycol methyl ether series products are advanced organic solvents with excellent performance, used as solvent and thinner for printing ink, industrial cleaning agent, paint (nitrofiber paint, varnish, porcelain paint), copper coating plate, printing, and dyeing; can be used as raw materials for chemical products such as pesticide intermediates, pharmaceutical intermediates, and synthetic brake fluid; as electrolyte of electrolytic capacitors, leather chemical fiber dye, etc. It is used as textile additives, synthetic liquid dyes, fertilizer, and desulfurizer in oil refining production.

Ethylene glycol should be noted when used as a load cooling agent:

1. The freezing point changes with the concentration of ethylene glycol in the aqueous solution. When the concentration is below 60%, the concentration of ethylene glycol in the aqueous solution increases and the freezing point decreases, but after the concentration exceeds 60%, with the increase in ethylene glycol concentration, the freezing point increases, and the viscosity will also increase with the increase in concentration. When the concentration reaches 99.9%, its freezing point rises to 13.2 °C, which is an important reason why the concentrated antifreeze (antifreeze mother liquor) cannot be directly used and must attract the attention of users.

2. Ethylene glycol contains a hydroxyl group. Working at 80°C–90°C for a long time, ethylene glycol is first oxidized to glycolic acid and then oxidized to oxalic acid, that is, acetic acid (oxalic acid), which contains two carboxyl groups. Oxalic acid and its side products first affect the central nervous system, then the heart, and then the kidneys. Ethylene glycol diacetic acid, causing corrosion to the equipment and leakage. Therefore, in the prepared antifreeze, there must also be preservatives to prevent the corrosion of steel and aluminum and scale generation.