What is the meaning of fat in fatty alcohol?

Fatty alcohols are synthetic compounds containing saturated and unsaturated carbon chains.

Fatty alcohols can be divided into natural fatty alcohols and synthetic fatty alcohols.

Natural fatty alcohol takes natural animal and vegetable oils as raw materials, while synthetic fatty alcohol is obtained by refining, cracking and synthesizing petroleum. As the basic chemical raw materials for synthesizing wetting agents, dispersants, solubilizers, lubricants and other fine chemicals, fatty alcohols are widely used in cleaning, personal care products and industrial fields.

Fatty alcohols are fatty alcohols having a chain of 8 to 22 carbon atoms. Fatty alcohols usually have an even number of carbon atoms and a hydroxyl group at the end of the carbon chain. Some fatty alcohols are unsaturated alcohols, while others are branched alcohols. These alcohols are widely used in the chemical industry.

Fatty alcohols do not exist in large quantities in nature, but only in wax, fatty acid esters and fatty alcohols.

[1] fatty alcohol was not discovered until 1900. It is obtained by Buvo-Brown reduction reaction of sodium and wax ester. 19 in 1930s, catalytic hydrogenation began to enter the commercial field, in which fatty acid esters, that is, common animal fats, were hydrogenated to obtain fatty alcohols. In the 1940s and 1950s, petrochemical raw materials began to become important chemical raw materials, and Karl Ziegler discovered the polymerization of ethylene. These two important discoveries have opened the door to the synthesis of fatty alcohols.

The traditional and still effective method to obtain fatty alcohols from natural sources is through fatty carboxylic esters. Wax esters were previously obtained by catching whales and extracting whale oil from them. Another way is to plant jojoba. Fatty acid triglycerides, also known as triglycerides, can be obtained from animal and plant sources. These triglycerides can be transesterified to give methyl esters, and then hydrogenated to give alcohols. The typical animal oil is C 16-C 18, and the chain length of vegetable oil varies a lot. Longer fatty alcohol chains (C20-C22) can be obtained from rapeseed oil; The shorter fatty alcohol chain (C 12-C 14) can be obtained from coconut oil.

Fatty alcohols prepared from petrochemical raw materials can also be prepared from petrochemical raw materials. In the Ziegler process, ethylene is oligomerized under the condition of triethylaluminum and then oxidized by air. The method can obtain alcohol with uniform carbon chain:

Aluminum (C2H5)3+18 C2H4 → aluminum (C 14H29)3

al(c 14h 29)3+ 1.5 O2+ 1.5 H2O→3 hoc 14h 29+0.5 al2o 3

In addition, ethylene can be oligomerized to obtain olefin mixture, and then hydroformylation reaction can be carried out to obtain aldehydes with odd carbon chains, and then hydrogenation can be carried out to obtain alcohols with odd carbon chains. For example, an alcohol with C 1 1 is obtained by hydroformylation of decene:

c8 h 17CH = CH2+H2+CO→c8 h 17 ch 2ch2 CHO

c8 h 17 ch 2ch2 CHO+H2→c8 h 17 ch 2ch2 ch 2 oh

In Shell's high-carbon olefin process, Shell adjusted the carbon chain length distribution of the initial olefin oligomer to meet the market demand. This method is realized by the metathesis reaction of intermediates. [2] Fractionating the obtained mixture and hydroformylation or hydrogenation for the next production.

The application of fatty alcohol is mainly used to produce detergents and surfactants. They are ingredients in cosmetics, food and industrial solvents. Because of natural water-oil amphipathy, fatty alcohols can be used as nonionic surfactants, emulsifiers, lubricants and thickeners in cosmetics and food industries.

It is reported that very long chain fatty alcohol (VLCFA) obtained from plant wax and beeswax can reduce human plasma cholesterol. Very long-chain fatty alcohols exist in coarse grains, beeswax and many plant-derived foods. The report also suggests that each person should consume 5-20mg of mixed C24-C34 alcohol (including octacosanol and triacontanol) every day to reduce the intake of low-density lipoprotein (LDL) cholesterol by 265,438+0%-29%. The intake of high-density lipoprotein cholesterol increased by 8%–15%. Wax esters can be hydrolyzed by bile salts (dependent on carboxylesterase secreted by pancreas), releasing long-chain alcohols and fatty acids absorbed by gastrointestinal tract. The study of fatty alcohol metabolism in fibroblasts shows that in the fatty alcohol cycle, very long-chain fatty alcohols, fatty aldehydes and fatty acids can be reversibly transformed into each other. None of these compounds can be metabolized in patients with genetic diseases such as peroxisome disorder (including adrenal leukodystrophy and Siogren-Larsen syndrome).