Electrical devices and dielectric fluids containing estolide base oils

An electrical transformer containing at least one dielectric fluid, said at least one dielectric fluid having an EN selected from an integer or fraction of an integer that is equal to or less than 1.5, wherein the EN is the average number of estolide linkages in compounds according to Formula I, and wherein the at least one dielectric fluid comprises at least one estolide compound of Formula I:

• wherein
• x is, independently for each occurrence, an integer selected from 0 to 20;
• y is, independently for each occurrence, an integer selected from 0 to 20;
• n is an integer equal to or greater than 0;
• R1 is an optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched;
• and
• R2 is selected from hydrogen and optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched;
• wherein each fatty acid chain residue of said at least one compound is independently optionally substituted.