Branched triglyceride-based fluids useful for dielectric and/or heat transfer applications

1. An electrical device comprising:

a transformer comprising a dielectric fluid composition comprising the triglycerides of iso-stearic N triglyceride having the structure (I);

or an unsaturated C 14 -triglyceride having the structure (II);

having at least one alpha-branched fatty acid residue, wherein each alpha-branched fatty acid residue comprises at least one alkyl chain having a total number of carbon atoms ranging from 12 to 20, and is saturated or mono-unsaturated, and wherein the triglycerides have at least one of

(a) a flash point of at least 185° C.,

(b) a fire point of at least 230° C.,

(c) a pour point of −25° C. or lower, or

(d) a combination thereof.

2. The electrical device of claim 1 wherein the carboxyl group of the alpha-branched fatty acid residue is located between C6 and C10 on the alkyl chain.

3. The electrical device of claim 1 wherein the alkyl chain contains at least one pendant methyl moiety.

4. The electrical device of claim 1 wherein the alkyl chain contains one or two pendant methyl moieties.

5. The electrical device of claim 1 wherein the triglycerides have at least one of

(a) a flash point of at least 275° C.;

(b) a fire point of at least 265° C.;

(c) a pour point of −35° C. or lower; or

(d) a combination thereof.

6. The electrical device of claim 1 wherein the triglycerides have at least one of

(a) a fire point of at least 300° C.;

(b) a pour point of −45° C. or lower; or

(c) a combination thereof.

7. The electrical device of claim 1 wherein the total number of carbon atoms in the alkyl chain ranges from 14 to 18.

8. The electrical device of claim 1 further having a dynamic viscosity at 40° C. of 0.09 Pascal*second or lower.

9. The electrical device of claim 1 , wherein the dielectric fluid composition is an insulating oil.