Dimer fatty acids

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Simplified structural formula of a dimer fatty acid. This can vary depending on the raw materials used. The cyclohexene ring formed by the Diels-Alder reaction is characteristic.

In dimer fatty acids is the oligomeric form of different unsaturated monomeric fatty acids . It is used in different areas, for example as a monomer for the production of polyamides , or as a plasticizing component in epoxy resins and polyester resins .

Manufacturing

Dimer fatty acids are produced from different fatty acids by means of boiling. A fatty acid with conjugated double bonds ( conjuenic acid ) and other unsaturated fatty acids are required . Examples of such fatty acids are conjugated linoleic acids . The reaction takes place by means of Diels-Alder addition, which forms a partially unsaturated C 6 ring. In addition to the dimer, trimers and monomers of the fatty acids can also be present in a mixture.

properties

The quality and consistency depends on the fluctuations in the properties of the natural raw materials. Dimer fatty acids are mixtures of substances.

It is typically a yellow liquid with a characteristic odor, the viscosity of which is 6700 mPa · s at 25 ° C. Dimer fatty acids are not classified as hazardous substances.

use

Dimer fatty acids are used in polyamides, polyesters and epoxy resins as plasticizing components. Reactions take place on the acid groups , the side chains in particular have a plasticizing effect. In addition to the properties in the solid film, dimer fatty acids also bring about some changes in behavior in the dissolved state. Polyamides, for example, are made compatible with solvents through higher proportions of dimer fatty acids. In addition, polyester resins and alkyd resins can be boiled with polyamides based on dimer fatty acids. This leads to a thixotropic effect of the binders obtained .

literature

Individual evidence

  1. ↑ a b c Bernd Strehmel, Peter Mischke, Michael Groteklaes, Thomas Brock: Textbook of lacquer technology . 4th revised edition. Vincentz Network, [p. l.], ISBN 3-86630-815-9 , pp. 101 .
  2. ↑ Ulrich Poth: Synthetic binders for coating systems . Vincentz Network, Hannover 2016, ISBN 978-3-86630-611-0 , p. 266 .
  3. ↑ Ulrich Poth: Synthetic binders for coating systems . Vincentz Network, Hannover 2016, ISBN 978-3-86630-611-0 , p. 60 .
  4. ↑ Walter Krauß: Binder for solvent-based and solvent-free systems . 2., ext. and rework. Edition. Hirzel, Stuttgart a. a. 1998, ISBN 3-7776-0886-6 , pp. 186 .
  5. ↑ a b Datasheet dimer fatty acid vegetable from Syskem, accessed on July 1, 2018.
  6. ↑ InfoCard for Fatty acids, C18-unsatd., Dimers from the European Chemicals Agency (ECHA), accessed on July 1, 2018.