Fabrication of insulation spacers for ultra-high voltage gas-insulated switchgear using eco-friendly bio-based epoxy composite material characterisation evaluation

In the electric power equipment industry, various insulating materials and accessories are manufactured using petroleum-based epoxy resins. However, petrochemical resources are gradually becoming limited. In addition, the global surge in plastic usage has consistently raised concerns regarding greenhouse gas emissions, leading to worsening global warming. Therefore, to facilitate eco-friendly policies, industrialising epoxy systems applicable to high-pressure components using bio-based epoxy composites is essential. The results of the characterisation conducted in this research regarding bio-content were confirmed through thermogravimetric analysis and differential scanning calorimetry, which showed that as the bio-content increased, the thermal stability improved. Considering the operating temperature of 105°C for the insulation spacer, structurally, no issues would be encountered if the spacer was manufactured with a bio-content of 20% (bio 20%). Subsequent tensile and flexural strength measurements revealed mechanical properties equivalent to or better than those of their petroleum-based counterparts. The impact strength tended to decrease with increasing bio-content. Analysing the dielectric properties confirmed that the epoxy composite containing 20% biomaterial is suitable for manufacturing insulation spacers. Subsequently, a series of tests conducted after spacer fabrication confirmed the absence of internal metals and bubbles with no external discolouration or cracks observed.