Modification of the microstructure of polyethylene in ionic solution under electrical field

The influence of ageing on low density polyethylene (LDPE) in various ionic solutions and under electric field has been investigated by thermally stimulated creep (TSCr), which makes it possible to characterize the amorphous and paracrystalline phases. The TSCr spectrum of reference LDPE shows the existence of three mechanical retardation modes labeled α, β, and γ in the order of decreasing temperatures. The α mode has been associated with mechanisms involving the paracrystalline phase while the β and γ modes have been attributed to the amorphous phase. The experimental data deduced from the analysis of TSCr spectra have been plotted on a compensation diagram: they define the `structure´ of the disordered phases of reference LDPE. The comparative study of LDPE samples aged in various environmental conditions under electric field shows that the paracrystalline phase is destructured, and that a plasticization process takes place