Experimental study on the effect of thermal aging on epoxy composites used for UHV dry bushing

This paper studied the evolution of physical, chemical and dielectric properties of pure epoxy and epoxy/crepe paper composites under a thermal aging temperature that is close to the glass transition temperature. Firstly, the sample production platform and the vacuum pouring and curing system and a vacuum thermal aging experimental platform were introduced. Then the thermal aging temperature was set as 132 °C. At different aging periods (0 day, 30 days, 50 days, 70 days, 100 days), samples are taken out and a series of experiments are conducted. The infrared spectroscopy (short as FTIR) and differential scanning calorimetry experiment (short as DSC) are performed to see whether there are chemical or physical reactions going on during thermal aging. Scanning electron microscopy (short as SEM) is used to observe the change of micro-structures in epoxy resin and its composites. Furthermore, moisture absorption tests are carried out, so are the dielectric properties measurement, which is conducted on the IDAX platform.