Varnish compositions for electrical insulation and method of using the same

A method for electrically insulating a motor using a varnish composition comprising:

• applying a varnish composition to a motor component;
• wherein the varnish composition comprises
• about 10 to about 45 weight percent of a functionalized poly(phenylene ether) having at least one aliphatic unsaturated group and exhibiting an intrinsic viscosity of about 0.06 deciliter per gram to about 0.25 deciliter per gram, measured in chloroform at 25° C.;
• an unsaturated polyester resin or vinyl ester resin;
• about 20 to about 70 weight percent of a reactive liquid monomer;
• and
• about 2 to about 20 weight percent of a compatibilizing agent;
• wherein the compatibilizing agent is a block copolymer comprising a block derived from an aromatic monomer that is miscible with the functionalized poly(phenylene ether) and a block derived from a monomer that is miscible with the unsaturated polyester resin or vinyl ester resin;
• wherein the ratio of the total amount of functionalized poly(phenylene ether) and unsaturated polyester resin or vinyl ester resin to the reactive liquid monomer is about 2:1 to about 1:5 by weight;
• and
• curing the varnish composition to form an electrically insulative thermoset coating over the motor component.