Nonylphenol

The nonylphenol (NP ) are a mixture of chemical compounds consisting of an aromatic ring with a hydroxyl group and a Nonylseitenkette. The isomer with linear side chain is referred to as n- nonylphenol and is industrially only of secondary importance.

Production

The synthesis is carried out catalytically from phenol and nonene ( industrially from a mixture of Nonenisomeren that are trimerizes from propene ). The resulting mixture of isomers consisting of 22 isomers that have different branched alkyl chains. The commercial grade contains 85 % para- nonylphenol, 10% ortho -nonylphenol and other alkylphenols dialkylated.

Properties

The Nonylphenols are yellowish liquids with weak phenolartigem odor. Their melting point is at -8 ° C, the boiling range of 290-320 ° C.

Use

The nonyl phenols are mainly used for the production of nonylphenol ethoxylates ( NPEs ) are used, which are used as non-ionic surfactants, for example, in washing solutions. In addition, it is included in fungicides, drugs, and plasticizers for cellulose acetate. The production is declining in Europe and the United States. The nonyl phenols are among the priority substances of the European Union and are no longer authorized for industrial use since December 2003. According to a study by the Swedish Society for Nature Conservation SNF Nonylphenols reach but about imported textiles from countries such as China, India and Turkey to the EU countries.

Biological effect

Some Nonylphenols are as Xenoestrogen a hormonally active substance, they interact with the estrogen receptor. So this can trigger relevant to female fish vitellogenin synthesis, for example, in male juveniles.

In many organisms, the nonyl phenols are toxic - for example, many species of fish (eg pollock ) and freshwater mussel, water flea, green algae, crab or lobster. LD50 values ​​are of the order of 0.1-1 mg / l How Australian ecologists to Ashley Ward of the University of Sydney found out that nonylphenol affect the cohesive behavior of fish. Even small amounts of only 0.5 micrograms nonylphenol enough to mask the odor of the fish, which means that they comply with greater distance from each other.

Biodegradation

There are several reports on the tests carried out in or not taken degradation. In general it can be said that the linear nonylphenol is degraded rather quickly, while the branched compounds behave much more persistent. In addition to many unsuccessful experiments, but there are also some articles that report on the degradation of branched (branched ) nonylphenol in soil and water.

The synthesized from the NPEO nonyl phenols are not readily biodegradable. First, the ethoxylate chain is repeatedly reduced by units of two carbon atoms, to only one or two ethoxy groups are present. Depending on the environment (aerobic or anaerobic) as the corresponding carboxylic acids can be produced. The shorter the ethoxylate chain is, the more durable and also be hormonally active substances. In branched nonylphenol, nonylphenol ethoxylates ultimately achieve their hardly biodegradable end product, which is also hormonally active than the original substance or intermediates.