A Force Field for Poly(oxymethylene) Dimethyl Ethers (OMEn)

A united atom force field for the homologous series of the poly(oxymethylene) dimethyl ethers (OME n ), H 3 C-O-(CH 2 O) n -CH 3 , is presented. OME n are oxygenates and promising new synthetic fuels and solvents. The molecular geometry of the OME n , the internal degrees of freedom, and their electrostatic properties were obtained from quantum mechanical calculations. To model repulsion and dispersion, Lennard-Jones parameters were fitted to the experimental liquid densities and vapor pressures of pure OME n ( n = 1-4). The critical properties of OME n ( n = 1-4) were determined from the simulation data. Additionally, the shear viscosity of pure liquid OME n is evaluated and compared with literature data. Finally, the solubility of CO 2 in OME2, OME3, and OME4 is predicted using a literature model for CO 2 and the Lorentz-Berthelot combining rules. The results agree well with experimental data from the literature.