Effect of decabromodiphenylethane on the thermo-oxidative ageing property of epoxy resin

Epoxy resin (EP) with excellent insulation and mechanical properties is widely used as insulation material in power systems. Thermo-oxidative ageing of EP caused by high temperature can lead to serious accidents in systems. Therefore, it is necessary to study the thermo-oxidative ageing of EP. Decabromodiphenylethane (DBDPE) is a common flame retardant in EP. However, the effect of DBDPE on the thermo-oxidative ageing of EP is rarely studied. In this paper, neat EP and EP/DBDPE samples were prepared. The samples were aged for 32 days at 160 □. The color, chemical structure and dielectric properties of the two kinds of samples during thermo-oxidative ageing were investigated by Fourier transform infrared spectrometry (FTIR) and broadband dielectric spectroscopy (BDS). The results show that the effect of thermo-oxidative ageing on neat epoxy resin is relatively uniform, while the thermal oxygen aging of EP/DBDPE sample mainly occurs on the surface, which prevents the diffusion of oxygen and delays the internal aging of epoxy resin. With the increase of ageing time, the C-H bond of EP decreases while
$\mathrm{C}=\mathrm{C}$
bonds increase. The
$\mathrm{C}=\mathrm{O}$
bond of neat EP rises first and then decreases, while that of EP/DBDPE keeps rising. The real part of the complex permittivity of the EP decreases with the ageing time, and the imaginary part increases first and then decreases. The change of functional groups and dielectric properties of EP/DBDPE is more obvious before and after ageing. According to the results, the conclusion is drawn that DBDPE in EP can accelerate the thermos-oxidative ageing. This paper can provide theoretical guidance for engineering application of DBDPE filled EP.