7569. Polyethylene Terephthalates

Nomenclature

PET.

Description and references

Fiber forming polyesters prepd from terephthalic acid, q.v. or its esters and ethylene glycol: Whinfield, Dickson, US 2465319 (1949 to du Pont). Review of structures, definition of trade names: R. W. Moncrieff, Man-Made Fibres (John Wiley & Sons, New York, 4th ed., 1963) pp 361-389, 707-723.

Chemical structure

Properties

R = OH, Dacron, Amilar, Fiber V. Solid, dec at approx 250°. Sp gr 1.38. Sol in hot m-cresol, trifluoroacetic acid, o-chlorophenol, a mixture of 7 parts of trichlorophenol and 10 parts (by wt) of phenol, a mixture of 2 parts of tetrachloroethane and 3 parts (by wt) of phenol. Fiber has good resistance to weak acids even at boiling temp, to strong acids in the cold, to weak alkalies, to bleaches, to most alcohols, ketones, soaps, detergents, and dry cleaning agents. Fabric has good resistance to creasing, abrasion, heat aging, and sunlight when behind glass. When “heat-set”, fabric will not shrink in either boiling water or boiling drycleaning solvent. Fabric burns, but local melting generally prevents spread of fire. Insects cannot thrive on the fiber, but some can cut through it. Molds, mildew, and fungi may grow on applied finishes, but do not attack fiber. R = OCH3, Terylene. For physical properties, see Dacron above. Other similar products: Diolen, Enkalene, Fortrel, Tergal, Terital, Terlenka, Trevira, Mylar.

Use

In fabric manufacture; as films; as base for magnetic coatings. Surgical aid (arterial grafts).