Crystal Structure Evolution of UHMWPE/HDPE Blend Fibers Prepared by Melt Spinning.

Fei Wang,Lichao Liu,Ping Xue,Mingyin Jia

doi:10.3390/polym9030096

Fei Wang, Lichao Liu + Show 2 more

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https://doi.org/10.3390/polym9030096

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Journal: Polymers	Publication Date: Mar 9, 2017
Citations: 20	License type: CC BY 4.0

Affiliation: Beijing University of Chemical Technology

Abstract

Ultra-high molecular weight polyethylene (UHMWPE) and high-density polyethylene (HDPE) blend fibers with the highest tensile strength of 1.13 GPa were prepared by a melt spinning process. The mechanical behavior and crystal structure of the as-spun filaments and fibers were studied by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD), sound velocity orientation testing, and tensile testing. The orientation degree, crystallinity, tensile strength, and initial modulus of the fibers increased with the increasing of the draw ratios. The grain size was shortened in the radial direction and elongated in the axial direction. The results suggested that the improvement of the tensile strength and initial modulus was a result of the compact crystal structure formed by slender grains composed of highly oriented molecular chains. Blending with HDPE could improve the formation of a slender and compact crystal structure, and the tensile strength and initial modulus of the blend fibers were higher.

Highlights

Ultra-high molecular weight polyethylene (UHMWPE) fibers were first developed by Smith et al
The tensile strength of UHMWPE fibers prepared by the gel spinning method can reach more than 4 GPa [3]
middle-molecular-weight polyethylene (MMWPE), as a fluidity modifier, can help UHMWPE molecular chains to slip and orient [27], and blending with high-density polyethylene (HDPE) can make the disentanglement of the UHMWPE molecular chains easier in the melt processing [28,29], so that the orientation degree of the U/H blend as-spun filaments is higher than that of the U as-spun filaments with the same initial draw ratios

Summary

Introduction

Ultra-high molecular weight polyethylene (UHMWPE) fibers were first developed by Smith et al. Using a gel spinning method in 1980, with a Young’s modulus >90 GPa, a tensile strength >3 GPa, and a strain at break of 6% [1]. These fibers have been widely used in medical, aerospace, sports, transportation, military, engineering, and other fields, replacing other fibers, such as Kevlar and carbon fiber [2]. The tensile strength of UHMWPE fibers prepared by the gel spinning method can reach more than 4 GPa [3]. The extremely long molecular chains of UHMWPE are entangled together, resulting in a high viscosity after melting

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