Molecular dynamics study of the shock response of polyurea
We leverage the phase segregated microstructure of polyurea to study its shock response using molecular dynamics (MD) simulation. The two phase segregated domains, the hard and the soft domains, are investigated separately. The shock response of the domains is studied using a multiscale shock-simulation approach that allows simulation of low pressure shocks. Both domains exhibit an unconventional behavior at low shock velocities that is typically associated with polymers. The shock response of the hard domain is marked by energy dissipation due to hydrogen bond breaking. Moreover, the radial distribution function suggests a severe distortion in the ring structure of aromatic moieties in the hard domain at high shock pressure. Finally, the shock Hugoniot of polyurea, obtained by combining the response of the two domains using a mixing rule, shows excellent match with experimental data.
© 2020 Elsevier Ltd. Received 7 August 2020, Revised 23 September 2020, Accepted 30 September 2020, Available online 9 October 2020. We gratefully acknowledge support from the US Office of Naval Research, Naval Materials S&T Division, Dr. R. G. Barsoum manager, through grant N000141512453. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.