A polymere

polymer (altgriech.: poly, much; meros, part) is a chemical compound, which consists of chain or branched molecules (macromolecules), which of same or homogeneous units (the so-called monomers) consist. The adjective polymere meant accordingly from many same parts developed.


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definition (in the sense of the chemical law)

inA material, whose molecules consist of concatenated monomer units, is polymere.

This material is considered then as polymer

  • if a simple weight majority of molecules with at least three monomer units contained is
  • which with a further monomer unit, or another reactant are linked
  • and by means of atomic bond (kovalente or connection of pair of electrons) a connection were received.

Likewise a material is considered as polymer, if deviating from it

  • less than a simple weight majority from molecules which is
  • contained in a certain molecular weight range lies
  • whereby the deviations in the molecular weight inSubstantial ones on the differences in the number of monomer units decrease/go back.

A monomer unit in the sense of this definition is the bound form of a monomer in a polymer.

organization

of polymers can be divided depending upon the number of basic monomers. Importantlyit is however that at least one substance the chain develops monomers.

  • In the simplest case this is exactly one monomer, examples of such Polymonomere is PE, PP, PVC and PA6.
  • Further there is Polydimere, to those z. B. Polyester, PU and alsosome PP (Pa 66) belong.
  • Natural polymers, like z. B. Proteins as basic modules of the life, are Poly polymers, since they are consisting of many amino acids developed.

polymer chemistry

the Kettenbildung, i.e. the connection of individual monomers, happens throughPolyreactions (like e.g.Polymerization, polycondensation or polyaddition). The monomers are connected to polymers.

One calls polymere one from differently built monomers hetero polymers or copolymers.

Most plastics are polymers, with those carbon for the molecular Kettenbildungensures.

One differentiates between ISO-tactical polymers, with which all substituents of a polymer chain have the same stereoelektronische Konformation, like e.g. ISO-tactical polystyrene with configuration R-R-R-r-r… or S-S-S-s-s… With ataktischen polymers the substituents are indiscriminately arranged (a kind Racemat). Syndiotaktisch callsone polymers, whose substituent consists alternating of R and S.


examples

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Ecological considerations

health risks practically never proceed from the polymer.

An example of it is PVC: Only with the burn develops the poisonous and strongly corroding gas hydrogen chloride, which separates in water under education from hydrochloric acid (hydrochloric acid).In addition dioxins develop with smoldering fires in larger quantities. One could observe the effects with the fire of the Düsseldorfer of airport, with which the side-effect proceeded predominantly from sheaths from PVC. The polymer PVC is food genuine and becomes due toits excellent gas density in the medicine for example for units of stored blood uses.

Further problems can result from additives, which are practically contained in each plastic article, like z. B. Softener. These are used predominantly with PVC.

polymer physics

aftertheir physical characteristics divides one the polymers into:

  1. The thermoplastics,
  2. the elastomers and
  3. the thermosetting polymers.

With the thermoplastics one still differentiates between (part) crystalline and the amorphous thermoplastics.

polymer electronics

here become leading (electrically active)Polymere one for the setting up of polytronischen applications uses. Differently than in the molecular electronics the information does not become in individual molecules, but processes in differently endowed volumes.

Such electronic applications are for example:

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