Electric Field Assisted Transport of the Crosslinking Byproducts in Low-Density Polyethylene

The intrinsic diffusion of the acetophenone in low density polyethylene (LDPE) is characterized with infrared mapping and it is found to be nearly Fickean with decaying diffusion coefficient over time. The impact of temperature on the diffusion coefficient is examined and an Arrhenius relationship is derived for the temperature dependence. To study the influence of electric field on the acetophenone diffusion, field-test cells were designed and constructed. The infrared mapping revealed presence of a gradient in the acetophenone concentration. Using the COMSOL simulation, we observed the higher acetophenone concentration near high electric field gradient regions. This is attributed to the dielectrophoresis phenomenon that occurs due to higher permittivity of the acetophenone molecules compared to the surrounding medium. The findings of this study help to understand where the byproducts migrate in high voltage power cables.