Structure and Dynamics of Drawn Gel‐Spun Ultrahigh‐Molecular‐Weight Polyethylene Fibers by ¹H, ¹³C and ¹²⁹Xe NMR

Abstract

Changes in morphology and chain dynamics of a series of drawn gel‐spun UHMWPE fibers were investigated by 1D and 2D 1H, 13C and 129Xe NMR spectroscopy. The dependence of the rms oscillation angle for the internuclear proton spin pairs around the chain axis can be evaluated from 13C/1H WISE and correlated with the Young modulus of UHMWPE fibers. Based on the novel 13C QUCPMAS method it was shown that the relative amount of orthorhombic, monoclinic and intermediate fractions increase with the Young modulus as opposed to the highly mobile amorphous phase. The chain dynamics of this last fraction becomes less hindered. 129Xe NMR spectroscopy shows that the volume‐average diameter of voids increases with the Young modulus and the production of nanovoids is accelerated in drawn UHMWPE fibers. magnified image

Design with Ultra Strong Polyethylene Fibers

“…Typical melting point is about 150˚C, it is slightly depending on specific crystal morphologies. Detailed discussions on morphology are presented by Demco et al [1]. Still 150˚C is low compared to other high performance fibers.…”

“…The crystallinity is high. Demco et al [1] analyzed various phases with NMR. Roughly summarized about 90% of the fiber material is crystalline.…”

Nanoscale interfibrillar adhesion in UHMWPE fibers

“…Ultra high molecular weight polyethylene (UHMWPE) fibers are commonly used in high performance applications due to their high specific strength and stiffness derived from the extended chain polymer chains . There exists a large body of literature examining the relationship between structure and fiber level mechanical properties from both an experimental and theoretical basis . For the vast majority of these works, molecular order, orientation and crystal morphology are the primary structural elements considered spanning length scales ranging from 0.1 nm to ∼10s of nm.…”

129Xenon NMR: Review of recent insights into porous materials

“…The symbols ◊,•,■ and ▲ are the observed δ, calculated δ and the δ D (dissolved) and δ H (adsorbed) components, respectively. From reference [176] with permission. Figure 25.…”

“…The solid lines represent the nonlinear least-square curve fit using the dual-mode sorption model. From reference [176] with permission Figure 26. The framework structures of (A) MOF-123, (B) MIL-246 and (C) MOF-47.…”