pρT measurements of polyethylene glycol dimethylethers between 278.15 and 328.15 K at pressures to 12 MPa

In this paper we present a new experimental apparatus designed to measure pressure-density-temperature (p rho T) properties with a high-pressure vibrating tube densimeter. Data reliability has been verified by comparing our experimental results for methanol, n-heptane, toluene, and HFC-134a with literature data. In this work we also report new experimental densities from 278.15 to 328.15 K, and up to 12 MPa, of triethylene glycol dimethylether (TrEGDME) and tetraethylene glycol dimethylether (TEGDME). The isobaric thermal expansion coefficients, isothermal compressibility, and internal pressure have been calculated. The dependence of these properties on the length of polyethylene glycol dimethylether. CH sub(3)O-((CH sub(2)) sub(2)O) sub(n)-CH sub(3), is analyzed.