Influence of Molecular Weight and Entanglement Density on the Creep Response of the Uniaxially Drawn Tapes of dis -UHMWPE

作者：Ravindra P. Gote, Joris van der Eem, Jiayi Zhao, S.R. Lolage, A. Traidia, Yaping Zhang, Dario Romano, Sanjay Rastogi · 发表于：Macromolecules · 年份：2023 · DOI：10.1021/acs.macromol.3c01180 · 被引用次数：26 · 研究领域：Orthopaedic implants and arthroplasty、Polymer crystallization and properties、Polymer Nanocomposites and Properties

Polyethylene with a molecular weight greater than a million g/mol, is of increasing commercial interest because it provides a route to make fibers and films that have unprecedented mechanical properties. The unique properties are attributed to the chain alignment of the long molecules packed in the orthorhombic unit cell. The anisotropic orthorhombic unit cell, which has weak secondary interaction planes, is prone to slip under a constant load and increasing temperature, thereby restricting the life expectancy of a product. Recent advances in polymer synthesis have allowed us to tailor the molecular weight, molecular weight distribution, and the entangled state between crystalline regions of the semicrystalline polymer using a single-site catalytic system via homogeneous and heterogeneous routes. The decrease in the entanglement network in the polymer has opened the possibility of solid-state processing of the nascent powder, thus providing an economical and sustainable route to make films with oriented chains in the draw direction. In this paper, we aim to link the creep response of the solid-state processed tapes made from low-entangled ultrahigh molecular weight polyethylene (UHMWPE) with the entangled state and molecular weight. Our observations are that compared with the Ziegler–Natta-synthesized UHMWPE polymer, and all polymers synthesized using a single-site catalytic system show significantly low creep rate. The commercial tape prepared using entangled UHMWPE shows a ...