OBTAINING MONO-SUBSTITUTED SORBITAN ESTERS

Polyol esters have recently been widely used in various fields: medicine, cosmetics, food industry, sanitation, science and technology. This is ensured by the specific physical and chemical properties of this group of substances. Polyols are polyhydric alcohols obtained by hydrogenation of monosaccharides. These compounds are found in natural sugars and are used in food and as dietary sweeteners. Esters of polyols with carboxylic acids are functionally divided into several groups. Thus, esters of saturated carboxylic acids С12-С18 - with a degree of substitution from 4:1 to 6:1 are mainly thick and hard artificial oils and, accordingly, are used in medicine, pharmacy and cosmetology. In engineering, polyol esters are mainly used in the machine tool, automotive and aviation industries as high temperature lubricating oils. Polyol esters containing C4-C12 carboxylic acids or unsaturated carboxylic acids are generally liquid or soft oils for use in ointments, cosmetic preparations, and the like. A variety of polyol esters with a degree of substitution from 1:1 to 3:1 are particularly widely used as emulsifiers, stabilizers, defoamers, dispersants and detergents. Our previous studies have focused on obtaining oil-like esters with the maximum degree of substitution. Using the examples of mannitol, sorbitol, xylitol, and erythritol, numerous samples of esters were obtained and the optimal conditions for esterification reactions, isolation, and analysis of the obtained products were worked out. In this work, we set a goal to study the patterns of obtaining monosubstituted esters of sorbitol and sorbitan, which are of interest as nonionic emulsifiers and detergents. In particular, the technical regulations of the Eurasian Economic Community allow the use of emulsifiers: E491 – sorbitan monostearate, E492 – sorbitan tristearate, E493 – sorbitan monolaurate, E494 sorbitan monooleate, E495 sorbitan monopalmite. Sorbitan monopalmitate or span 40 emulsifier is a flaky yellowish brown wax. It consists of a mixture of mono- and dianhydrides of sorbitan. Its liquid crystal structure is similar to the natural structure of the skin, easily absorbs water and effectively moisturizes the skin, transfers nutrients and medicinal substances deep into the skin.