Polyethylene Thermal pressure coefficient

At (ft—> 0 equation [7.2.37] gives a linear dependence of the relative vapor pressure, P°v(/Pvo on the solvent volume concentration with the angle coefficient exp(l+x). At 1 solution obeys the Raul s law. Note that the value of < )i in [7.2.37] is temperature-dependent due to difference in thermal expansion coefficients of components. The % value for a given solvent depends on the concentration and molar mass of a polymer as well as on temperature. However, to a first approximation, these features may be ignored. Usually % varies within the range 0.2 - 0.5. For example, for solutions of polyethylene, natural rubber, and polystyrene in toluene % = 0.28,0.393 and 0.456, correspondingly. 

Table 7.2 shows the viscosity, mutual diffusion coefficient, and thermodynamic factor for aqueous solutions of ethylene glycol and polyethylene glycol (PEG) at 25°C the diffusivity decreases considerably with increasing molecular weight, while the viscosity increases. Table 7.2 shows the thermal diffusion ratios for liquids and gases at low density and pressure the thermal diffusion ratios are relatively larger in liquids. 

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