Ethylene glycol is also known as ethylene glycol, 1,2-ethylene glycol, abbreviated as EG, and its chemical formula is (CH2OH)2.
Ethylene glycol is mainly used to make polyester terylene, polyester resins, moisture absorbents, plasticizers, surfactants, synthetic fibers, cosmetics and explosives. It is also used as a solvent for dyes, inks, etc., an antifreeze for preparing engines, and a gas dehydrating agent. It can also be used as a wetting agent for cellophane, fiber, leather, and adhesives. It can produce synthetic resin PET, fiber-grade PET is polyester fiber, and bottle-grade PET is used to make mineral water bottles. It can also produce alkyd resins, glyoxal, etc., and 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 capacity. It is generally called a coolant. At the same time, it can also be used as a condenser like water.
Ethylene glycol methyl ether series products are high-level organic solvents with excellent properties. They are used as solvents and diluents for printing inks, industrial cleaning agents, coatings (nitrofiber paints, varnishes, enamels), copper clad laminates, printing and dyeing, etc.; they can be used as raw materials for the production of chemical products such as pesticide intermediates, pharmaceutical intermediates, and synthetic brake fluids; they are used as electrolytes for electrolytic capacitors, tanning chemical fiber dyes, etc. It is used as a raw material for textile auxiliaries, synthetic liquid dyes, and desulfurizers in chemical fertilizers and oil refining production.
When using ethylene glycol as a coolant, attention should be paid to:
1. Its 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. However, when the concentration exceeds 60%, as the concentration of ethylene glycol increases, its freezing point increases, and the viscosity increases with the increase of concentration. When the concentration reaches 99.9%, its freezing point rises to-13.2℃. This is an important reason why concentrated antifreeze (antifreeze mother liquor) cannot be used directly, and must attract the attention of users.
2. Ethylene glycol contains hydroxyl groups. When working at temperatures of 80 - 90 degrees Celsius for a long time, ethylene glycol will first be oxidized to glycolic acid, and then to oxalic acid, that is, oxalic acid (oxalic acid), which contains 2 carboxyl groups. Oxalic acid and its by-products affect the central nervous system first, then the heart, and then the kidneys. Ethylene glycol oxalic acid causes corrosion to equipment and causes it to leak. Therefore, preservatives must also be present in the formulated antifreeze to prevent corrosion of steel and aluminum and the formation of scale.
