Sunday, November 27, 2016

Importance and Uses of Polyester Fibers

Polyester :

Polyester is a category of polymers that contain the ester functional group in their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). polyesters include occurring chemicals, such as in the cutin of plant cuticles, as well as synthetics through step-growth polymerization such as polybutyrate.

The main raw materials:
  •  Purified terephthalic acid (PTA) or 1,4 benzenedicarboxylic acid,
  • Dimethylterephthalate (DMT) or1,4 benzenedicarboxylic acid dimethyl ester

  • Mono Ethylene Glycol (MEG) or 1,2 ethanediol

Production of Polyester: 

Synthesis of polyesters is generally achieved by a poly condensation reaction. The general equation for the reaction of a diol with a diacid is :

(n+1) R(OH)2 + n R´(COOH)2 → HO[ROOCR´COO]nROH + 2n H2O

Aliphatic polyesters can be assembled from lactones under very mild conditions, catalyzed anionically, cationically or metallorganically. A number of catalytic methods for the copolymerization of epoxides with cyclic anhydrides have also recently been shown to provide a wide array of functionalized polyesters, both saturated and unsaturated.

Importance of Polyester:

1.    The relatively easy accessible raw materials PTA or DMT and MEG
2.    The very well understood and described simple chemical process of polyester synthesis
3.  The low toxicity level of all raw materials and side products during polyester production and processing
4.    The possibility to produce PET in a closed loop at low emissions to the environment
5.    The outstanding mechanical and chemical properties of polyester
6.    The recyclability
7.    The wide variety of intermediate and final products made of polyester.

Uses of Polyester:

      1. Polyester fiber is used as cushioning and insulating material in pillows, comforters and upholstery padding.

    2. Polyesters are also used to make bottles, films, tarpaulin, canoes, liquid crystal displays, holograms, filters, dielectric film for capacitors, film insulation for wire and insulating tapes.

     3. Polyesters are widely used as a finish on high-quality wood products such as guitars, pianos and vehicle/yacht interiors.

To be continue........

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