Solubilities and diffusion coefficients of carbon dioxide in poly(vinyl acetate) and polystyrene

Solubilities of carbon dioxide in poly(vinyl acetate) (PVAc) were measured at temperatures from 313.15 to 373.15 K and pressures up to 17.5 MPa. Diffusion coefficients of carbon dioxide in PVAc were also measured at 313.15 K and pressures up to 7 MPa. Solubilities and diffusion coefficients of carbon dioxide in molten polystyrene (PS) were studied at temperatures from 373.15 to 473.15 K and pressures up to 20 MPa. An apparatus using a magnetic suspension balance (MSB) was constructed for the measurements. The solubilities in the PVAc and the PS were in good agreement with literature data. The solubility in both polymers were correlated with the Sanchez and Lacombe equation of state to within an average relative deviation of 3.6 and 1.6% for PVAc and PS systems, respectively. The diffusion coefficients in PS were correlated with free volume theory of Kulkarni and Stern to within 10% of relative average deviation. (C) 2001 Elsevier Science B.V. All rights reserved.