Study on thermal aging characteristics of epoxy resin/inorganic filler composites for the fully casting bus bar

In this paper, the epoxy resin/ inorganic filler composites were fabricated. The thermal aging test to the epoxy resin/ inorganic filler composites at different temperatures was carried out, the variations regulation of the tensile strength, elongation at break and weight-loss ratio with the aging time and temperature were investigated. The results showed that the tensile strength of the composites after the thermal aging of 145°C, 160°C and 175°C was higher than that of un-aged one. At the same aging time, the higher the aging temperature was, the larger the tensile strength was, and the lower the elongation at break would be. However, as the aging time extending continuously, the tensile strength and the elongation at break kept descending. In the early stage of the thermal aging, the weight-loss ratio of those composites emerged exponential growth with aging time, and then tended to be stable in the later aging time. In the process of aging, further curing of composite materials, low molecular substances volatilization of epoxy resin and interface defects were the main factors that had large influence to the tensile strength and the weight-loss ratio of the composite materials.