Fatty acid esters, hydrophilic-lipophilic balanc

Sucrose reacts with fatty acids to produce esters with degrees of esterification (DE) from 1 to 8 and hydrophilic/lipophilic balances that provide them with numerous applications. Primary producers are Japan and the Nethedands, with total production at 6000 t/yr. Sucrose esters are nontoxic and biodegradable, and are approved for use in the EC, Japan, and the United States. 

Water-in-oil emulsions traditionally contain surfactants of natural origin such as cholesterol, wool fat, wool alcohols, lanolin, divalent salts of fatty acids soaps, calcium oleate and/or synthetic agents of low hydrophilic-lipophilic balance (HLB) (indicating high lipophilicity), such as Spans (fatty acid esters of sorbi-tan). An example of such a product is Oily Cream B.P. which consists of a 1 1 mixture of wool alcohols and water. 

EMSORB Ethoxylated Sorbltan Esters are the hydrophilic counterparts to the hydrophobic EMSORB Sorbltan Fatty Acid Esters. Varying moles of ethylene oxide are added to the Sorbltan Patty Acid Ester to produce these materials. The more ethylene oxide added the more hydrophilic the molecule becomes as seen by its increased Hydrophile-Lipophile balance Value (HLB). 

A tenside with a relatively strong lipophilic group and weak hydrophilic group is mainly soluble in oil and preferentially stabilizes a w/o emulsion, and vice versa. This fact led to the development of a standard with which the relative strength or activity of the hydrophilic and lipophilic groups of emulsifiers can be evaluated. It is called the HLB value (hydrophilic-lipophilic balance). It can be determined, e. g., from dielectric constants or from the chromatographic behavior of the surface-active substance. The HLB value of the fatty acid esters of polyhydroxy alcohols can also be calculated as follows (SV =... 

By selecting PEG grades with longer or shorter chains, preferably between PEG 200 and PEG 1000, it is possible to control the hydrophilic-lipophilic balance of the desired ester [ 16]. If the hydrophilic PEG chain of the ester predominates, that ester will tend to be used as emulsifiers in organic (predominant)-water systems, whereas esters with a short PEG chain and a longer fatty acid radical will tend to be used as emulsifiers in water (predominant)—water systems. 

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