Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 26, 2022 - September 28, 2022
We proposed a novel deformation process in the tensile stress-strain behavior of semicrystalline polymer solids. At the yield point, the stacked lamellar clusters are fragmented into cubic cluster blocks of single chain size; the rearrangement of these blocks under uniaxial tension produces the texture of necking. The initiation of necking is explained by a first-order catastrophic phase transition analogous to the model of a van der Waals gas. Thus, the catastrophic arrangement of the cluster blocks results in a sudden emergence of a locally close-packed layer structure. The negative molecular dependence of the natural draw ratio at the necked portion can be explained by the catastrophic rearrangement of the cluster blocks, the size of which is proportional to the square root of the molecular weight.
