Strain-induced density fluctuations in linear low-density polyethylene

In our previous study [Kishimoto <i>et al.</i> (2020). <i>Macromolecules</i>, <b>53</b>, 9097-9107], density fluctuations were induced on the submicrometre scale in polyethyl-ene (PE) during strain and led to the generation of voids. The strength of the induction was found to increase with the amplitude of the spatial inhomogeneity of the stress field. In this work, we investigated how comonomer species and content affect the behaviors of the strain-induced density fluctuations in linear low-density PE. We found that the strength of the induction decreased with an increase in the spatial homogeneity before stretching and the mechanical melting during strain and that the degree of spatial homogeneity and mechanical melting depend on the species and content of the comonomer.