Properties of fused polysulphides—II. The density, surface tension and viscosity of fused sodium polysulphides

The density, surface tension and viscosity of fused sodium polysulphides have been measured, over the composition range Na2S3-Na2S5 and the temperature range 280–400° C. Na2S5 has a higher density than liquid sulphur, so forms the lower layer in two-phase mixtures. Arrhenius plots for the viscosity were non-linear, but good fit was obtained to the Vogel-Tammann-Fulcher equation The values of T0 giving best fit were in reasonable agreement with those previously obtained from conductivity measurements and from differential thermal analysis.