The influence of morphology on the dielectric and dynamic mechanical behavior of a linear low‐density polyethylene

The dielectric and viscoelastic relaxation behavior of linear low‐density polyethylene has been investigated. All three usual relaxation regions occur; however, the α process is more dominant than in conventional low‐density polyethylene made dielectrically active through the introduction of carbonyl groups. The observed behavior is very sensitive to orientation and morphology. There are significant differences between oriented samples (stretching or extrusion) and a single‐crystal texture specimen. Effects are caused by dipolar orientation and dipolar immobilization, the relative importance of each effect varying with specimen preparation. Active dipolar groups are not carbonyls, or any common organic species, but appear to be due to chain ends having residual dipoles caused by the catalyst used in synthesis.