Poly(2,6-diphenylphenylene oxide)
Encyclopedia
Poly (PPPO) is a porous polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

 resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...

 based on oxidative polymerisation of 2,6-diphenylphenol. It is mostly known by its trademark Tenax.

Properties

Poly(2,6-diphenylphenylene oxide) is a low bleeding material with a low level of impurities, and has a high thermal stability (up to 350°C). Before use poly(2,6-diphenylphenylene oxide) should be thermally conditioned with a high purity gas at elevated temperatures to remove any residual components. During conditioning or thermal desorption the presence of oxygen should be avoided. Poly(2,6-diphenylphenylene oxide) reacts with oxidising agents such as chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...

, ozone
Ozone
Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope...

, nitrogen oxides and sulphur oxides forming acetophenone
Acetophenone
Acetophenone is the organic compound with the formula C6H5CCH3. It is the simplest aromatic ketone. This colourless, viscous liquid is a precursor to useful resins and fragrances.-Production:Acetophenone can be obtained by a variety of methods...

, benzaldehyde
Benzaldehyde
Benzaldehyde is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful. This colorless liquid has a characteristic pleasant almond-like odor...

 and phenol
Phenol
Phenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...

. Therefore control of blanks is essential and storage time of samples on poly(2,6-diphenylphenylene oxide) is less than a month. Pre-filters based on sodium thiosulphate or Teflon may be appropriate to use. The breakthrough volumes are low for very volatile substances. This problem is partly solved by graphitised poly(2,6-diphenylphenylene oxide). Although the polymer has a low affinity for water, high humidity in air may lower the breakthrough volumes of substances.

Use

Poly(2,6-diphenylphenylene oxide) is used for trapping of volatiles and semi-volatiles from air such as environmental air and human breath, and for personal exposure monitoring. It is also used for determining the emission of chemical substances from plants, soil and commercial products. Volatile substances in liquid or solid matrices can be made available by the purge and trap technique. The polymer is of particularly used for concentration of high boiling compounds such as alcohols, polyethylene glycols, diols, phenols
Phenols
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of a hydroxyl group bonded directly to an aromatic hydrocarbon group...

, monoamines and diamines, ethanolamines, amides, aldehydes, ketones and chlorinated aromatics.

Poly(2,6-diphenylphenylene oxide) is used as food simulant for testing the release of chemical substances from food contact materials
Food contact materials
Food contact materials are materials that are intended to be in contact with food. These can be things that are quite obvious like a glass, a can for soft drinks, but also machinery in a food factory or a coffee machine....

 into food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...

.

Trademarks

Tenax is a registered trademark of Buchem B.V.
  • Tenax® GC (replaced by Tenax® TA)
  • Tenax® TA (mesh 20-35, 35-60, 60-80, 80-100, 100-200)
  • Tenax® GR: 23% graphite (mesh 20-35, 35-60, 60-80, 80-100)

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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