| 摘要 |
<p>The invention relates to novel esterification, transesterification and interesterification methods. Said novel methods can be used not only to reduce reaction times compared to standard methods but also to produce esters having remarkable physico-chemical properties. Moreover, said methods can be used to reduce considerably the acid value and the peroxide value of the mixture. According to the invention, the method consists in producing partially or fully esterified polyhydroxylated alcohols by means of dielectric heating (microwaves and high frequencies) from a mixture of vegetable or animal fats and oils, saturated or unsaturated fatty acids, saturated or unsaturated fatty acid esters, saturated or unsaturated hydrocarbons or derivatives of same and compounds comprising or generating hydroxyl functions, such as glycerol, polyglycerols, polyalkyleneglycols, polyvinyl alcohols, sugars, sterols. The heat treatment is performed by means of dielectric heating, preferably in an oxygen-depleted atmosphere. The electromagnetic wave frequencies vary between 30 Ghz and 3 Mhz approximately. The above-mentioned esters have multiple applications, e.g. polymer esters of polyhydric alcohols are used as surfactants in cosmetics and food products (margarine, chocolate, etc.).</p> |
