Alkylphenol
{{Short description|Family of organic compounds}}
Alkylphenols are a family of organic compounds obtained by the alkylation of phenols. The term is usually reserved for commercially important propylphenol, butylphenol, amylphenol, heptylphenol, octylphenol, nonylphenol, dodecylphenol and related "long chain alkylphenols" (LCAPs). Methylphenols and ethylphenols are also alkylphenols, but they are more commonly referred to by their specific names, cresols and xylenols.{{cite encyclopedia|author1=Helmut Fiege |author2=Heinz-Werner Voges |author3=Toshikazu Hamamoto |author4=Sumio Umemura |author5=Tadao Iwata |author6=Hisaya Miki |author7=Yasuhiro Fujita |author8=Hans-Josef Buysch |author9=Dorothea Garbe |author10=Wilfried Paulus |encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry|year=2002|publisher=Wiley-VCH|location=Weinheim|doi=10.1002/14356007.a19_313|isbn=978-3527306732 |chapter=Phenol Derivatives }} Some members of this group of compounds have proven controversial.Kovarova, J., Blahova, J., Divisova, L., & Svobodova, Z. (2013). Alkylphenol ethoxylates and alkylphenols – update information on occurrence, fate and toxicity in aquatic environment. Polish Journal of Veterinary Sciences, 16(4), 762–771. https://doi.org/10.2478/pjvs-2013-0111
Production and use
The long-chain alkylphenols are prepared by alkylation of phenol with alkenes:
:C6H5OH + RR'C=CH2 → RR'CH−CH2−C6H4OH
In this way, about 500M kg/y are produced. Alkylphenols ethoxylates are common surfactants. Long-chain alkylphenols are used extensively as precursors to detergents. By condensation with formaldehyde, some alkylphenols are components in phenolic resins. These compounds are also used as building-block chemicals in making fragrances, thermoplastic elastomers, antioxidants, oil field chemicals, and fire retardant materials. As plastizers and antioxidants, alkylphenols are also found in tires, adhesives, coatings, carbonless copy paper and high performance rubber products.
Environmental controversy over nonylphenols
Alkylphenols are xenoestrogens.{{Cite journal| last2 = Jeng| first1 = Y. | first2 = J.| last1 = Kochukov| title = Alkylphenol xenoestrogens with varying carbon chain lengths differentially and potently activate signaling and functional responses in GH3/B6/F10 somatomammotropes| last3 = Watson | first3 = S.| journal = Environmental Health Perspectives| volume = 117| issue = 5| pages = 723–730| date=May 2009 | issn = 0091-6765| pmid = 19479013| pmc = 2685833| doi = 10.1289/ehp.0800182}} Long chain Alkylphenols have the most potent estrogenic activity. The European Union has implemented sales and use restrictions on certain applications in which nonylphenols are used because of their "toxicity, persistence, and the liability to bioaccumulate" but the United States EPA has taken a slower approach.[http://pubs.acs.org/hotartcl/est/97/jul/euro.html European Bans on Surfactant Trigger Transatlantic Debate]{{Cite web |last=J. Kovarova, J. Blahova, L. Divisova, Z.Svobodova |title=Alkylphenol ethoxylates and alkylphenols– update information on occurrence,fate and toxicity in aquatic environment |pmid=24597317 |url=https://www.researchgate.net/publication/260561156}}