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Comparatively Speaking: Fatty Alcohols vs. Fatty Acids vs. Esters

Figures

  • Figure 1. Esterification

    Figure 1. Esterification

    Esterification is a condensation reaction where an acid molecule reacts with an alcohol molecule to produce an ester and water.

    Esterification

Tables

  • Table 1. Alcohols

    Table 1. Alcohols

    Alcohols from Natural Fats/Oils No. of Carbons   Alcohols from Synthetic Origin
    Capryl alcohol(1-octanol) 8 2-ethyl hexanol (oxo, branched)
    Pelargonyl alcohol(1-nonanol) 9 Isononanol (iso, branched)
    Capric alcohol (1-decanol) 10 Isodecyl alcohol (branched)
    Lauryl alcohol( 1-dodecanol) 12 Dodecyl/tridecyl alcohol(mixed branched)
      13 Tridecyl alcohol (iso, branched)
    Myristyl alcohol (1-tetradecanol) 14  
    Cetyl alcohol(1-hexadecanol) 16 Isocetyl alcohol (branched)
    Stearyl alcohol(1-octadecanol) 18  Isostearyl alcohol (branched)
    Oleyl alcohol (1-octadecenol) 18-1  
    Arachidyl alcohol ( 1-eicosanol) 20  
    Behenyl alcohol ( 1-docosanol) 22  

     

                    

  • Table 2. Fatty acids

    Table 2. Fatty acids

    Common Name IUPAC Name Chemical Structure Abbreviated Acid
    Butyric Butanoic acid CH3(CH2)2COOH C4:0
    Caproic Hexanoic acid CH3(CH2)4COOH C6:0
    Caprylic Octanoic acid CH3(CH2)6COOH C8:0
    Capric Decanoic acid CH3(CH2)8COOH C10:0
    Lauric Dodecanoic acid CH3(CH2)10COOH C12:0
    Myristic Tetradecanoic acid CH3(CH2)12COOH C14:0
    Palmitic Hexdecanoic acid CH3(CH2)14COOH C16:0
    Stearic Octadecanoic acid CH3(CH2)16COOH C18:0
    Arachidic Eicosanoic acid CH3(CH2)18COOH C20:0
    Behenic acid Docosanoic acid CH3(CH2)20COOH C22:0

     

           

By: Anthony J. O'Lenick Jr., Siltech LLC
Posted: July 6, 2010

In the present discussion, Tony O’Lenick recruits Ismail Walele of Phoenix Chemical to explain the differences between fatty alcohols, fatty acids and esters.

Alcohols
Alcohols are alkanes with a hydroxyl group on the terminal carbon, which makes them primary alcohols. These are also called 1-alcohols, an example being 1-butanol or n-butanol. Some alcohols have their hydroxyl group on the c-chain, excluding the terminal primary carbon and making them secondary alcohols. Butanol has three isomers: n-butanol (1-butanol), 2-butanol (secondary butanol) and t-butanol, meaning tert-butanol with hindered hydroxyl on the same carbon with three methyl groups.

Fatty alcohols are aliphatic alcohols derived from natural fats and oils originating in plants and animals. Fatty alcohols are derived from fatty acids and have an even number of carbon atoms. The production of fatty alcohols from fatty acids yields normal-chain alcohols wherein the –OH group attaches to the terminal carbon. Fatty alcohols, due to their amphipatic nature, act as non-ionic surfactants/co-surfactants. Fatty alcohols can be used in cosmetic formulations as emulsifiers, emollients and thickeners.

Generally, alcohols are normal alcohols from natural fats and oils, meaning that they all have an even number of carbons. They can be saturated or unsaturated alcohols. Another type of alcohol is a branched chain alcohol, which is termed a synthetic higher alcohol or an oxo alcohol. Branched alcohols can be mono-methyl branched or multi-carbon chained on the side at any or specific interior carbon of the main carbon chain. Table 1 provides the common names, carbon numbers and the synthetic branched counterparts of alcohols.

Named after inventor M. Guerbet, Guerbet alcohols are alkaline condensation reaction products of primary alcohols. They are primary, alpha branched dimeric alcohols and are 100% defined branched at the second carbon position.