| 摘要 |
A dielectric fluid composition for electrical apparatus comprises a functionalized methyl-12-carboxy methyl stearate having desirable properties including a pour point less than -30 °C and a fire point greater than 250 °C. It may be prepared by a process wherein methyl-12-hydroxy methyl stearate is transesterified by reaction with a C3-C20 alcohol to form the hydroxy methyl ester, followed by reaction with a linear or branched C4-C20 carboxylic acid selected from free acid chlorides, fatty acids, carboxylic acid anhydrides, and combinations thereof. The second step serves to end-cap the hydroxyl groups, thereby producing the functionalized methyl-12-carboxy methyl stearate compound that exhibits improved thermoxidative stability and low temperature flowability, as well as increased fire point. |
