Shock-induced chemistry and high strain-rate viscoelastic behavior of a phenolic polymer

NW Moore and KA Jones and JL Wise and DG Talley and JMD Lane, JOURNAL OF APPLIED PHYSICS, 137, 055105 (2025).

DOI: 10.1063/5.0235804

We use impact experiments and a finite element model (up to 1.2 GPa), and molecular dynamics simulations (up to 60 GPa), to examine the behavior of a phenolic polymer under shock compression, spanning both nonreactive and reactive regimes. In the nonreactive regime, relaxation following compression at strain rates of similar to 10(5) s(-1) can be explained by viscoelasticity observed at ordinary laboratory rates (less than or similar to 1 s(-1)) by accounting for the temperature dependence of the phenolic beta-transition. Reasonable agreement is found between the measured shock Hugoniot up to 1.2 GPa and molecular dynamics simulation for cross-linked structures of comparable density. We also observed a first-order mechanical transition near 0.36 GPa shock stress and estimated a spall strength of 0.102 GPa and Hugoniot elastic limit of 1-2 GPa. The shock stress is found to vary up to 24% among phenolics made with different resin and/or cure processes. Finally, molecular dynamics simulations are used to identify a reactive regime at shock pressures greater than or similar to 20 GPa that is characterized by chemically driven, rate-dependent relaxation processes, including dehydrogenation and dehydration reactions that promote the formation of a dense, highly cross-linked carbonaceous solid and the release of light volatiles.

Return to Publications page