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Title: Reactive, anomalous compression in shocked polyurethane foams

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)
Authors:
;  [1] ; ;  [2] ;  [3]
  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)
Publication Date:
OSTI Identifier:
22273446
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 17; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; COMPRESSION; DECOMPOSITION; DENSITY; DIAMONDS; EQUATIONS OF STATE; FOAMS; FREE ENERGY; GRAPHITE; MATRIX MATERIALS; POLYURETHANES; POROSITY; POROUS MATERIALS