Synergistic effect of electric field and temperature on the ageing of LPDE in contact with electrolyte solution

The synergistic effect of electric field and temperature on the ageing of low-density polyethylene (LDPE) was studied by thermally stimulated creep spectroscopy and Fourier-transform infrared spectroscopy, using deionized H₂O and NaBr as electrolytes. Insulating polymeric materials generally consist of a mixture of ordered crystals and amorphous regions, resulting in interphase paracrystalline domains and/or rigid amorphous domains stressed by crystallites. Stresses such as electrical and environmental conditions influence the molecular mobility of the disordered phases, ultimately allowing the ageing process to be quantified. Ageing was carried out for 1000 h under 10-kV, 50-Hz voltage at 75°C and 50°C for NaBr. The effects on the compensation lines, the enthalpy, and the behavior of the rigid amorphous phase were studied. The synergistic effect is shown by comparing the results with the zero phase behavior