Test of the ``radical-like polymerization" scheme in molecular dynamics on the behavior of polymers under shock loading

The behavior of polymer melts under shock loading is a question attracting more and more attention because of applications such as polymer-bonded explosives, light-weight armor and civilian protective equipment, like sports and car equipment. Molecular dynamics (MD) simulations are a very good tool to characterize the microscopic response of the polymer to a shock wave. To do so, the initial configuration of the polymer melt needs to be realistic. The ``radical-like polymerization" scheme [Perez \textit{et al}, J. Chem. Phys. \textbf{128}, 234904 (2008), Wu \textit{et al}, Polymer \textbf{47}, 6004 (2006)] is a method to obtain near equilibrium configurations of a melt of long polymer chains. It consists in adding one neighboring monomer at a time to each growing chain. Between each polymerization step an MD run is performed to relax the new configuration. We test how details of our implementation of the ``radical-like polymerization" scheme can impact or not Hugoniot curves and changes of chain configuration under shock. We compare our results to other simulation and experimental results on reference polymers.