Coarse-Grained Polymer-Modelle und die Wiedereinfuehrung der chemischen Details

For the computer simulation of polymers different time scale are necessary. One of the long standing challenges within the modeling of complex materials is to apply methods which allow to cover the range from microscopic to semi-macroscopic regimes. In this work we introduce a systematic procedure to coarse grain atomistic polymer models into a mesoscopic model, which then allows an effective and fast simulation of melts. The method, which provides information on both static and dynamic properties, is tested for three different modifications of polycarbonate. For instance, the diffusion constant D could be measured by monitoring the mean square displacement of the monomers of the chains or the center of gravity of the chains, respectively. The models also successfully describe the variation in the Vogel Fulcher temperature as well as the total chain extension. The effective speedup compared to the corresponding atomistic simulation is significantly above 10"3. After long simulation runs the chemical details are reintroduced into the coarse grained chains. The method is called inverse mapping. A computer simulation and minimization of a polymer melt with all details of the chemical structure of the monomers is included. The resulting microscopic structure is compared to neutron scattering results by measuring the coherent scattering function. The remapping procedure is tested for two different polycarbonate modifications. It can be shown that there is a good agreement between the experimental and simulation data67 refs.SIGLEAvailable from TIB Hannover: RA 831(3467) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman