Recent Advances in Epoxy Resin Foaming Methods and Improvement of Epoxy Foam Thermal Insulation Performance

The thermal conductivity of epoxy resins is only 0.2–0.88 W m −1 K −1 , which can be used as thermal insulating materials to reduce energy loss. Adding thermal insulating fillers to epoxy resins makes it possible to synthesize composite materials with even better thermal insulating properties. Since the thermal conductivity of the gasses in the foam is nearly an order of magnitude lower than that of ordinary materials, epoxy foam is more suitable for use as thermal insulating materials. The factors affecting the thermal insulation performance of foams are mainly the cell density and diameter, and the blowing agents can change the size of the cell density and diameter, so the selection of suitable blowing agents is particularly important for improving the thermal insulation performance of epoxy foams. This paper summarizes the foaming methods of epoxy foam and the latest progress in improving the thermal insulation performance of epoxy foam and puts forward the outlook. Among them, there are two methods for foaming epoxy resin, namely traditional foaming and potential foaming. Furthermore, there are two ways to improve the thermal insulation performance of epoxy foam, namely increasing the amount of blowing agents and adding thermal insulating fillers within a certain range, while not affecting the performance of the foam itself.