Title: In Situ X-ray Diffraction of High Density Polyethylene During Dynamic Compression: Polymer Chain Compression and Phase Transformations

Abstract

Polymers are widely implemented materials often used for safety and security in our daily lives. However, we do not have a thorough understanding of the phase transformations of these materials when exposed to extreme condition, high strain rate events. To study polymers in these severe environments, we performed plate impact experiments that impart a one-dimensional shockwave, at high pressures and temperatures, to observe the materials response. Generally, velocimetry is the experimental diagnostic used to capture the movement of high velocity interfaces to then calculate the mechanical variables associated with shock compression. However, when a material undergoes a phase transition, such as between two crystalline phases or melting to decomposition during shock compression, velocimetry does not explicitly indicate what structural change occurred. At the Dynamic Compression Sector at the Advanced Photon Source, gas gun driven compression has been paired with x-ray diffraction, providing the ability to study both the shock parameters and structural changes concurrently. We explored high density polyethylene (HDPE) both on its reactants Hugoniot (<10.12 GPa) and within its transition region (24.3  GPa) where HDPE is hypothesized to decompose from reactants to products. With x-ray diffraction, we observed both polymer chain compression and crystal structure reorientation from orthorhombic to monoclinicmore » above 6  GPa as well as either a possible phase change or chemical decomposition at 24.3 GPa. With these experiments, we were able to determine the crystalline and amorphous Hugoniot loci at pressures below the polymer transition region.« less

Authors:

Huber, Rachel Colleen  ^[1];

• Search DOE PAGES for author "Huber, Rachel Colleen"
• Search DOE PAGES for ORCID "0000-0001-5875-0208"

Watkins, Erik Benjamin  ^[1];

• Search DOE PAGES for author "Watkins, Erik Benjamin"
• Search DOE PAGES for ORCID "0000-0001-8573-9629"

Dattelbaum, Dana Mcgraw  ^[1];

• Search DOE PAGES for author "Dattelbaum, Dana Mcgraw"
• Search DOE PAGES for ORCID "0000-0002-9412-5917"

Bartram, Brian Douglas ^[1]; Gibson, Lloyd Lee ^[1]; Gustavsen, Richard L.  ^[1]

• Search DOE PAGES for author "Gustavsen, Richard L."
• Search DOE PAGES for ORCID "0000-0002-2281-2742"

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+ Show Author Affiliations

1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Publication Date:

Sun Nov 07 00:00:00 EDT 2021

Research Org.:

Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1866955

Alternate Identifier(s):

OSTI ID: 1829005

Report Number(s):

LA-UR-21-24261
Journal ID: ISSN 0021-8979; TRN: US2306115

Grant/Contract Number:  

89233218CNA000001; AC52-06NA25396

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Applied Physics

Additional Journal Information:

Journal Volume: 130; Journal Issue: 17; Journal ID: ISSN 0021-8979

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 74 ATOMIC AND MOLECULAR PHYSICS; Carbon based materials; Crystalline solids; Shock compression; Polymers; Crystal structure; X-ray diffraction; Shock waves; Velocimetry; Phase transitions