New monitoring by thermogravimetry for radiation degradation of EVA

The radiation ageing of ethylene vinyl-acetate copolymer (EVA) as the jacket of cable applied in nuclear power plant was carried out by gamma rays irradiation, and the degradation was monitored by a thermo-gravimetric analysis (TGA). The EVA decomposition rate in air by the isothermal at 400°C decreased with increase of dose and also with decrease of the dose rate. The behavior of EVA jacket of cable indicated that the decomposition rate at 400°C was reduced with increase of oxidation. The elongation at break by tensile test for the radiation aged EVA was closely related to the decomposition rate at 400°C; therefore, the TGA might be applied for a diagnostic technique of the cable degradation. •Radiation degradation of EVA cable jacket was tested by dynamic and isothermal TGA.•Thermal stability of degraded EVA cable measured by TGA depends on access of oxygen.•The larger the dose absorbed, the higher the thermal stability of EVA jacket observed.