Polyester Guide, Meaning , Facts, Information and Description
picture of a bend in a high surface area polyester fiber with a seven-lobed cross section]]Polyester is a category of polymers which contain the ester functional group in their main chain. Although polyesters do exist in nature, polyester generally refers to the large family of synthetic polyesters (plastics) which includes polycarbonate and above all polyethylene terephthalate (PET). PET is one of the most important thermoplastic polyesters.
The first synthetic polyester, glycerine phthalate, was used in the First World War for waterproofing. Natural polyesters have been known since around 1830.
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This is an Article on Polyester. Page Contains Information, Facts Details or Explanation Guide About Polyester Applications
Liquid crystalline polyesters are among the first industrially used liquid crystalline polymers. In general they have extremely good mechanical properties and are extremely heat resistant. For that reason, they can be used as an abradable seal in jet engines.Abbreviations
PEs polyesters (in general); PBT polybutylene terephthalate; PC polycarbonate; PET polyethylene terephthalate.Synthesis
Synthesis of polyesters is generally achieved by a polycondensation reaction.Azeotrope esterification
In this classical method an alcohol and a carboxylic acid react to form a carboxylic ester.
To assemble a polymer, the water formed by the reaction must be continually removed by azeotrope distillation.Alcoholic transesterification
Acylation (HCl method)
The acid begins as an acid chloride, and thus the polycondensation proceeds with emission of hydrochloric acid (HCl) instead of water. This method can be carried out in solution or as an enamel.
Acetate method (esterification)
Ring-opening polymerization
Aliphatic polyesters can be assembled from lactones under very mild conditions, catalyzed anionically, cationically or metallorganically.