Polyethylene terephtalateWikipedia open wikipedia design.
|Young modulus(E)||2800–3100 MPa|
|Tensile strength(σt)||55–75 MPa|
|Elongation @ break||50–150%|
|notch test||3.6 kJ/m2|
|Glass temperature||75 °C|
|melting point||260 °C|
|Vicat B||170 °C|
|Thermal conductivity||0.24 W/m.K|
|linear expansion coefficient (α)||7×10−5/K|
|Specific heat (c)||1.0 kJ/kg.K|
|Water absorption (ASTM)||0.16|
|source: A.K. van der Vegt & L.E. Govaert, Polymeren, van keten tot kunstof, ISBN 90-407-2388-5|
Polyethylene terephthalate (aka PET, PETE or the obsolete PETP or PET-P) is a thermoplastic polymer resin of the polyester family. The chemical industry makes it. It is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination with glass fiber. It is one of the most important raw materials used in man-made fibers. It is also used as the dielectric in multi-purpose capacitors (K73-16 series).
Depending on its processing and thermal history, it may exist both as an amorphous (transparent) and as a semi-crystalline (opaque and white) material. Its monomer can be synthesized by the esterification reaction between terephthalic acid and ethylene glycol with water as a byproduct or the transesterification reaction between ethylene glycol and dimethyl terephthalate with methanol as a byproduct. Polymerization is through a polycondensation reaction of the monomers (done immediately after esterification/transesterification) with ethylene glycol as the byproduct (the ethylene glycol is recycled in production).
The majority of the world's PET production is for man-made fibers (in excess of 60%) with bottle-making accounting for around 30% of global demand. In discussing cloth uses, PET is generally referred to as simply "polyester" while "PET" is used most often to refer to packaging applications.
sails are often made of PET-fibers.