Reactive, anomalous compression in shocked polyurethane foams

Journal Article · Wed May 07 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4875478· OSTI ID:22273446

Gustavsen, Richard L. ^[1]; Kiyanda, Charles B. ^[2]; Patterson, Brian M. ^[3]

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1. Shock and Detonation Physics, MS P952, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
3. Polymers and Coatings, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

We present the results of plate impact experiments performed on 30%–75% porous, polymeric methylene diphenyl diisocyanate polyurethane foams. The combination of new data with those previously obtained on full-density material was used to calibrate complete equations-of-state under both inert and chemically reactive frameworks. Description of unreacted polyurethane was based on a combination of Hayes and P-α models, whereas its decomposition products were predicted via free energy minimization under the assumption of chemical and thermodynamic equilibrium. Correspondence of experiment and theory suggests that polyurethane at all densities decomposes when shocked above some threshold pressure, and that this threshold falls dramatically as a function of initial porosity. The shock locus of foams at 50% or less of theoretical maximum density was found “anomalous” in the sense that final volumes increased with pressure. We attribute this anomaly to chemical decomposition of the initial matrix to a mixture of small-molecule fluids and bulk carbon (graphite or diamond, depending on the initial density)

• OSTI ID: 22273446
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 17 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPRESSION
DECOMPOSITION
DENSITY
DIAMONDS
EQUATIONS OF STATE
FOAMS
FREE ENERGY
GRAPHITE
MATRIX MATERIALS
POLYURETHANES
POROSITY
POROUS MATERIALS