Hot spot and temperature analysis of shocked hydrocarbon polymer foams using molecular dynamics simulation

•MD captures quantitative Hugoniot shock response of polymers to twice ambient density.•MD allows for direct observation of void collapse and hot spot formation in foams.•Shock hot spots are localized at collapsing voids and thermalize on ps time scales.•Polymer dissociation follows hot spots and is seen at relatively low shock pressure.•Broad shock fronts result from vaporized material ahead of the compression wave Hydrocarbon polymers, foams and nanocomposites are increasingly being subjected to extreme environments. Molecular scale modeling of these materials offers insight into failure mechanisms and complex response. Prior classical molecular dynamics (MD) simulations of the principal shock Hugoniot for two hydrocarbon polymers, polyethylene (PE) and poly (4-methyl-1-pentene) (PMP) have shown good agreement with density functional theory (DFT) calculations and experiments conducted at Sandia National Laboratories. We extended these results to include low-density polymer foams using nonequilibrium MD techniques and found good quantitative agreement with experiment. Here, we have measured the local temperature during void collapse to investigate the formation of hot spots and their relationship to polymer dissociation in foams.