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. Diffu sion coefficients of carbon dioxide in PVAc were also measured at 313.15 K and pressures up to 7 MPa. Solubilities and diffusion coefficients of carbo n 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 su spension balance (MSB) was constructed for the measurements. The solubiliti es 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 eq uation 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 c orrelated with free volume theory of Kulkarni and Stern to within 10% of re lative average deviation. (C) 2001 Elsevier Science B.V. All rights reserve d.