Shock driven decomposition and reshock in PMMA

\justify Polymethyl methacrylate (PMMA) is a transparent thermoplastic often used as a Hugoniot standard or as a window material in shock compression experiments. We present new equations of state (EOS) for solid PMMA based on the \texttt{Sesame} framework, and for its shock-driven decomposition products based on thermochemical modeling. We compare our results to a wide variety of existing data, finding good agreement in all cases. Previous proceedings (AIP Conference Proceedings \textbf{845}, 131 (2006)) described plate impact experiments in which PMMA was reshocked to pressures of up to $\sim$130 GPa, well above that at which it decomposes on its principal Hugoniot. These results were reanalyzed in a later proceeding (\emph{ibid}. \textbf{1426}, 771 (2012)), motivated largely by a higher than anticipated Gruneisen coefficient ($\Gamma$) inferred originally. We revisit this discussion based on hydrodynamic simulations performed with our new EOS.