Detergent range, fatty alcohols

The most widely used alkyl sulfate in shampoo preparation is lauryl sulfate. The alkyl component of this sulfate ranges from C-10 to C-18 with a predominance of the C-12 (lauryl) component. By distillation of the fatty alcohol, certain cuts can be obtained which offer the best effects in foaming, cleansing, and rinsing properties for the alkyl sulfate preparation. The range which appears to be most desirable is between C-12 and C-16. Lauryl sulfate detergents are available in various salt forms with the sodium, ammonium, and triethanolamine types being used most frequently in shampoos. 

Chlorosulfonic acid, particularly with batch operation, is best suited for production of a range of products on a relatively small scale. Chlorosulfonic acid is still used for the sulfonation of fatty alcohols, fatty alcohol/ethoxylates, and related detergent raw materials with OH groups available for the attachment of an S03H group. For example, the reaction of lauryl alcohol with chlorosulfonic acid illustrates for example the chemistry involved ... 

Transesterification of fat triglycerides is the predominant method for manufacture of mixed fatty acid methyl esters, and direct esterification of fatty acids (FA) is practiced if very selective cuts of product, in general as an intermediate detergent range alcohol, are desired. Methyl cocoate is a mobile, oily liquid above 25 °C with a yellow tint and a characteristic fatty pungent odor. FAME sulfonation to FAMES is technically possible but been rarely applied up to now (1990) (Table 13). 

Fatty alcohol can be fractionated to separate the C8-C10 fraction, known as plasticizer range alcohol, and the C12-C18, known as the detergent range alcohol. The plasticizer range alcohol is a liquid with good dissolving power. It can be used in a limited way as a solvent for printing inks and lacquers. Esterification with a polycarboxylic acid, such as phthalic anhydride, yields an excellent plasticizer especially for PVC. 

Higher alcohols in the range of C6 to C18 have many industrial applications. Commercial interest includes the whole group of primary and secondary, branched and unbranched, and even- and odd-numbered alcohols. Higher tertiary alcohols are not industrially significant [109]. The C6 to Cn alcohols are called plasticizer alcohols and the C,2 to Cj8 are called surface-active or detergent alcohols because of their respective major end use [109]. Alcohols > C8 are often called fatty alcohols because that was their first original primary source. The world production capacity is currently 3 million ton/yr, of which 88% are synthetic [108,109],... 

Only a few natural sources of fatty alcohols were known at this time. Production on a technical scale could be first realized by the reduction of methyl or butyl esters of fatty acids with metallic sodium after the Bouveault-Blanc process. Nearly simultaneously, the high-pressure hydrogenation of fatty acids to the resulting alcohols was developed by Schrauth. Hence, fatty alcohols were soon available on the market in a price range that made it possible to produce fatty alcohol sulfates for use in detergents. 

Membrane electrodes based on the TPB salts of barium-nonionic complexes have been used successfully to determine fatty alcohol-7EO condensates in detergent powders by direct potentiometry [7]. The electrodes were similar in construction to the first of the three types described in section 3.6.2. Two types of membrane were used, incorporating nonionics with EO chains ranging from four to 30 units. The most successful was prepared as follows. 

Antifoam incorporated in a molten matrix of a fatty acid or fatty alcohol, which is insoluble in water and of melting points ranging from 45°C to 80°C. The resulting emulsion is sprayed onto a fluidized bed of carrier particles (e.g., STP) for post-dosing into detergent powder... 

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