Thermodynamic Properties of Octamethylcyclotetrasiloxane
journal contributionposted on 10.06.2016, 14:20 by Monika Thol, Gábor Rutkai, Andreas Köster, Frithjof H. Dubberke, Thorsten Windmann, Roland Span, Jadran Vrabec
An equation of state for octamethylcyclotetrasiloxane is presented. The available experimental data from the literature are supplemented by new measurements on the speed of sound. Furthermore, a new force field is proposed, allowing the generation of a comprehensive thermodynamic data set by means of molecular simulation. Both the experimental and molecular simulation data are applied to develop a fundamental equation of state in terms of the Helmholtz energy. On the basis of the experimental data, the equation of state is valid from the triple-point temperature to T = 590 K for pressures up to p = 180 MPa and can be used to calculate any thermodynamic equilibrium state property. Its accuracy is assessed by a comprehensive analysis of the underlying experimental data. Finally, the range of validity was extended to Tmax = 1200 K and pmax = 520 MPa by means of molecular simulation data.