Bisphenol A polycarbonate:: Entanglement analysis from coarse-grained MD simulations

Simulation data are presented for a coarse-grained model of polycarbonate (BPA-PC), which allow for a detailed comparison of different ways to study the chain dynamics and predict the entanglement molecular weight. Most of the standard experimental quantities are determined for the very same set of systems and thus provide an opportunity for a detailed comparison of data far beyond typical experiments or simulations. By employing a suitably coarse-grained model, which still contains the essentials of the BPA-PC structure, simulation times compared to atomistic simulations could be extended by several orders of magnitude, reaching well into the characteristic experimental regime. We find that a recently developed topological entanglement analysis compares well with a direct determination of the modulus from simulations as with experiments on well-characterized samples. This confirms the extraordinarily small value of the entanglement molecular weight on M-e between 1200 and 1400 corresponding to N-e close to 5.