Characterizing mechanical and microstructural properties of novel montmorillonite-rich polyethylene composites

Journal Article · Mon Oct 04 00:00:00 EDT 2021 · Journal of Materials Science

DOI:https://doi.org/10.1007/s10853-021-06562-1· OSTI ID:1827613

Hill, Ryan ^[1]; Peretti, Amanda S. ^[2]; Small, Leo J. ^[2]; Spoerke, Erik D. ^[2]; Cheng, Yang-Tse ^[1]

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1. Univ. of Kentucky, Lexington, KY (United States)
2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Montmorillonite (MMT) clays are important industrial materials used as catalysts, chemical sorbents and fillers in polymer–clay nanocomposites. The layered structure of these clays has motivated research into further applications of these low-cost materials, including use as ion exchange media and solid-state ionic conductors. In these applications, the mechanical properties of MMT are key when considering long-term, reliable performance. Previous studies have focused on the mechanical properties of nanocomposites with MMT as the minority component or pure MMT thin films. In this work, the microstructure and mechanical properties of pure MMT and majority MMT/polyethylene composites pressed into dense pellets are examined. Characterization methods such as X-ray diffraction, atomic force microscopy and scanning electron microscopy together with nanoindentation reveal important structure–property relationships in the clay-based materials. Here, utilizing these techniques, we have discovered that MMT processing impacts the layered microstructure, chemical stability and, critically, the elastic modulus and hardness of bulk MMT samples. Particularly, the density of the pellets and the ordering of the clay platelets within them strongly influence the elastic modulus and hardness of the pellets. By increasing pressing force or by incorporating secondary components, the density, and therefore mechanical properties, can be increased. If the layered structure of the clay is destroyed by exfoliation, the mechanical properties will be compromised. Understanding these relationships will help guide new studies to engineer mechanically stable MMT-based materials for industrial applications.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Electricity Delivery and Energy Reliability (OE)
• Grant/Contract Number: NA0003525
• OSTI ID: 1827613
• Report Number(s): SAND--2021-12484J; 700677
• Journal Information: Journal of Materials Science, Journal Name: Journal of Materials Science Vol. 57; ISSN 0022-2461
• Publisher: Springer
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ceramics
characterization
composites
ion-exchange
micromechanics