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Home > Polyester

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.

1 Applications

• Fibers (and microfibers) for fabric
• Bottles
• Foils
• Photographic film (after cellulose triacetate , polyester is the most important substrate)
• Liquid crystal displayFor other meanings of LCD, see LCD (disambiguation). polarize the light as it enters. Glass substrate with ITO electrodes. The shapes of these electrodes will determine the dark shapes that will appear when the LCD is turned on. Vertical ridges are etcheds
• Holograms

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.

2 Abbreviations

PEs polyesters (in general); PBT polybutylene terephthalatePolybutylene terephthalate (PBT) is a plastic that is used as an insulator in the electrical and electronics industries. It is a thermoplastic crystalline polymer, and a type of polyester. PBT is resistant to solvents, shrinks very little during forming,; PC polycarbonate; PET polyethylene terephthalate.

3 Synthesis

Synthesis of polyesters is generally achieved by a polycondensation reaction.

3.1 AzeotropeAn azeotrope is a liquid mixture of two or more components which has a unique constant boiling point. This azeotrope may boil at a higher, lower, or intermediate temperature, relative to the constituent liquids, and the liquid retains the same composition esterification

In this classical method an alcoholIn general usage, alcohol (from Arabic al-khwl , or al-ghawl ) refers almost always to ethanol, also known as grain alcohol and often to any beverage that contains ethanol (see alcoholic beverage . This sense underlies the term alcoholism ( addiction to a and a carboxylic acidIn chemistry, carboxylic acids (also called alkanoic acids are organic acids characterized by the presence of a carboxyl group. Carboxylic acids thus have the structure : where R is a hydrogen or an organic group. In chemical formulas, this is also writte react to form a carboxylic ester. To assemble a polymer, the water formed by the reaction must be continually removed by azeotrope distillation.

3.2 Alcoholic transesterification

3.3 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.

Silyl method

In this variant of the HCl method, the carboxylic acid chloride is converted with the trimethyl silyl ether of the alcohol component; trimethyl silyl chloride is produced.

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Topics: Polyester Polyesters Method Acid Silyl Chloride Pet Hcl...

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PolyesterSEM 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 ref