Mechanical and piezoresistive properties of GNP/UHMWPE composites and their cellular structures manufactured via selective laser sintering

Azam, M. U., Schiffer, A. and Kumar, S. (2023) Mechanical and piezoresistive properties of GNP/UHMWPE composites and their cellular structures manufactured via selective laser sintering. Journal of Materials Research and Technology, 28, pp. 1359-1369. (doi: 10.1016/j.jmrt.2023.12.089)

Abstract

In this study, we describe the development of composites comprising ultra-high molecular weight polyethylene (UHMWPE) reinforced with graphene nanoplatelets (GNP), specifically designed for additive manufacturing (AM) of self-sensing structures through selective laser sintering (SLS). We employed ball-milled GNP/UHMWPE powder feedstocks to fabricate standard test specimens and 2D cellular structures with varying GNP content. A comprehensive assessment of their mechanical and piezoresistive properties was carried out under uniaxial tensile loading. The incorporation of 1.5 wt% GNPs into UHMWPE demonstrated a notable increase in crystallinity by ∼28 % and a significant reduction in porosity by about 98 %. These enhancements contributed to a substantial improvement in both strength (∼21 %) and elastic modulus (∼40 %). Moreover, the introduction of 1.5 wt% GNPs resulted in the formation of electrically percolated composites characterized by prominent piezoresistive behavior. These composites exhibited gauge factors ranging from 9.6 to 18 under uniaxial tensile loading. During cyclic tensile loading, the GNP/UHMWPE composite displayed hysteresis in its piezoresistive response due to viscoelasticity, impeding an immediate return to its original state. Additionally, the gauge factors of the 2D cellular structures generally demonstrated lower values compared to those of the parent composite, scaling proportionally with the effective elastic modulus.

• Item Type: Articles
• Additional Information: The authors would like to express their appreciation to Khalifa University for the financial support they received in the form of the Competitive Internal Research Award (CIRA) [grant number CIRA-2018-128]. This work was supported in part by the EPSRC Centre, funded by the UK Engineering and Physical Sciences Research Council [grant number EP/R513222/1].
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Kumar, Professor Shanmugam
• Authors: Azam, M. U., Schiffer, A., and Kumar, S.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Journal of Materials Research and Technology
• Publisher: Elsevier
• ISSN: 2238-7854
• ISSN (Online): 2214-0697
• Published Online: 12 December 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Journal of Materials Research and Technology 28: 1359-1369
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
305200		DTP 2018-19 University of Glasgow	Mary Beth Kneafsey	Engineering and Physical Sciences Research Council (EPSRC)	EP/R513222/1	MVLS - Education Hub