Mechanical and Thermal Properties of Epoxy Containing Aluminum Isopropoxide Precursors Compared to Aluminum Oxide

Epoxy resins are often used as dielectric encapsulants for transformer windings. While their dielectric properties are outstanding, they lack thermal conductivity and suffer under substantial shrinking and large coefficient of thermal expansion. A common solution is to mix micro-sized aluminum oxide particles into the epoxy, which improves the thermal performance. We compare this to an alternative approach: adding aluminum isopropoxide precursors, which could chemically react and bond to the epoxy chains at the molecular level. We compare both solutions experimentally and test the tensile strength, specific heat capacity, and thermal conductivity. An innovative method for mixing the aluminum isopropoxide with epoxy resin has also been proposed.