This study evaluates the synthesis and electrical insulating capabilities a novel bio-based polyurethane. Epoxidized soybean oil and oleic acid react in the first step to form the polyol component (OLESO) of bio-based polyurethane. In order to produce congruent polyurethanes, OLESO is then reacted with hexamethylene diisocyanate (HMDI) and polymethylene diphenyl diisocyanate (PMDI). FTIR and H-1 NMR techniques were used to characterize the materials. The huntite mineral was then injected into these polyurethanes made of PMDI-OLESO and HMDI-OLESO. Samples that are up to 40% huntite loaded are prepared, and their electrical characteristics are also assessed. The samples' AC and DC properties were examined. Samples that have been prepared show excellent dielectric qualities. The electrical results and consequently the dielectric properties of PMDI and HMDI samples vary depending on the additive percentages used. It is possible to create insulation materials based on suggested materials for various power system switchgear because of their electrical characteristics, flame retardancy capabilities, and low densities.