Popis: |
Cationic surfactants refer to molecules with at least one hydrophobic hydrocarbon tail attached to a hydrophilic head-group carrying a positive charge. Of the cationic surfactants especially quaternary ammonium salts are of commercial significance. These compounds consist of one or more hydrophobic alkyl chain(s), benzyl, hydroxyethyl, polyethylene glycol and/or methyl groups linked to a positively charged nitrogen atom (Figure 6.1). Primary, secondary and tertiary long-chain amine salts may be positively charged and can therefore be regarded as cationic surfactants. Most cationic surfactants have straight alkyl chain(s) with lengths between 8 and 24 carbon atoms. These compounds are primarily produced on the basis of natural fats and oils such as tallow fat, coconut oil and palm oil, resulting in mixed alkyl chain lengths in most of the products. |