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Molecular dynamics simulation of structure, thermodynamic, and dynamic properties of poly(dimethylsilamethylene), poly(dimethylsilatrimethylene) and their alternating copolymer.

Makrodimitri ZA, Raptis VE, Economou IG

Molecular Thermodynamics and Modeling of Materials Laboratory, Institute of Physical Chemistry, National Center for Scientific Research "Demokritos", GR-153 10 Aghia Paraskevi Attikis, Greece.

Molecular dynamics is used for the simulation of silicon-containing polymers with promising membrane material properties. An atomistic force field is developed for the description of bond bending, torsional angle variation, and nonbonded intra- and intermolecular interactions. Detailed ab initio quantum mechanics calculations on corresponding monomers that appeared recently in the literature are used for the parametrization of the bonded and nonbonded local intramolecular force field. For the intermolecular and nonbonded nonlocal intramolecular interactions, parameters are obtained from accurate force fields proposed in the literature for similar compounds. The force field is used subsequently for the calculation of thermodynamic, structure, and dynamic properties of two homopolymers, namely, poly(dimethylsilamethylene) and poly(dimethylsilatrimethylene), and their alternating copolymer. A wide range of temperatures and pressures is examined. Polymer systems of different molecular weights are simulated. Experimental data available for these polymers are very limited. In all cases, simulation results are in good agreement with these data. Furthermore, simulation results agree very well with empirical macroscopic correlations used widely for rubbery polymers for the properties under consideration.

Published 10 August 2006 in J Phys Chem B Condens Matter Mater Surf Interfaces Biophys, 110(32): 16047-58.
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