Monday, 21 September 2009

TRIETHYLENE GLYCOL/ TEG

TRIETHYLENE GLYCOL/ TEG

TEG is a colorless liquid with a slight, sweet odor. Its properties closely resemble those of diethylene glycol. In many instances, the applications for diethylene glycol and triethylene glycol overlap. Because TEG has a higher boiling point, it may be used in preferene to diethylene glycol when a less volatile compound is required.

Because it has two ether and two hydroxyl groups, TEG is a good solvent for nitrocellulose as well as for various gums and resins. It is miscible with water and many organic solvents. TEG is a solvent used in the formulation of steam-set printing inks.

TEG is an efficient hygroscopic agent. This property makes it useful as a liquid desiccant for removing water from natural gas, thus preventing the formation of hydrates in long distance transmission lines. TEG is also used as the desiccant in small packaged plants located at the gas well head in order to eliminate the need of line heaters in field gathering systems.

In air-conditioning systmes designed for dehumidifying air, TEG allows for the removal of water vapor without cooling the air. This offers advantages particularly in commercial installations where comfort cooling is not required. When vaporized under proper conditions in specially designed vaporizing devices for air sanitation, the air-treatment grade of TEG aids in the control of bacteria and virus content of air.

In the tobacco industry, it is standard practice to treat the tovacco with humectants such as triethylene of propylen glycols so that the tobacco reaches the consumer in proper condition. TEG is also used in the plasticization of composition cork and serves as a solvent for resin impregnants and other additives.

TEG gives increased pliability to various plastics, particularly celllulose derivatives. It aids in the retention of flexibility, even in dry atmospheres. Esther derivatives of TEG are important plasticizers for polyvinyl butyral resins, nitrocellulose lacquers, vinyl and polyvinyl chloride resins, and poly vinyl acetate. Other ester derivatives are plasticizers for synthetic rubber compounds or for cellulose esters.

TEG is used in the manufacture of alkyd type resins useful as laminating agents and in adhesives. Polyesters derived from TEG are useful in various applications-some as plasticizers and others as low pressure laminates for glasss fibers, asbestos, cloth or paper.

Besides being useful as plasticizers, the fatty acid derivatives of TEG are used as emulsifiers, demulsifiers and lubricants.

Mixtures of TEG and water exhibit selective solvent properties for the separation of aromatic hydrocarbons from mixtures containing paraffinic hydrocarbons. Like diglycol, TEG is used commercially to recover high purity aromatic fractions from mixtures of light oil fractions.

Special inhibited grades of TEG are available for use as heat transfer fluids, particularly in high temperature applications.

A special high purity grade of TEG is available for use in cellophane and paper that may come in contact with food.

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