Effect of Bio-based Epoxy Resins on the Thermal, Mechanical Properties and their Applicability to Gas Insulated Switchgear Spacer Materials

Since the introduction of epoxy resin as an ultrahigh voltage insulating material, it has occupied a very important field in manufacturing applications in the high voltage electrical industry. In the case of an insulating material made of an epoxy resin, the performance of the manufactured insulating material will also be different because the characteristics vary depending on the process. In the insulating spacer manufacturing process, since the pressure applied during manufacturing is different depending on the mold, quantitative results on performance are required for practical use.Based on a liquid bisphenol-based epoxy resin and an acid anhydride-based curing agent, a core-shell rubber and micro-alumina were added to develop a liquid epoxy resin formulation with high heat resistance and excellent toughness for GIS(Gas-Insulated Switchgear) insulating spacers. It was confirmed that the heat resistance was improved through the optimal mixing ratio of the epoxy resin and the curing agent, and the toughness was improved with an appropriate content of the core-shell rubber. The crack resistance of the developed resin was evaluated by a crack index(KIC) using a single edge notched bending(SENB) specimen.In addition, the glass transition temperature, which is a measure of the heat resistance of the resin formulation, was confirmed through DSC, and the thermal decomposition activation energy, a characteristic of thermal decomposition, was confirmed through TGA.And the characteristics of the insulating spacer manufactured by using the APG(Air pressure gelation) method of the resin was confirmed through non-destructive tests such as insulation resistance, X-ray, and partial discharge, and a partition pressure test was performed as a mechanical destructive test. In addition, X-ray examination was performed to confirm the presence or absence of voids inside the spacer.