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Measurement and prediction of diffusion coefficients of supercritical CO 2 in molten polymers
Author(s) -
Areerat Surat,
Funami Eita,
Hayata Yusuke,
Nakagawa Dai,
Ohshima Masahiro
Publication year - 2004
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.20194
Subject(s) - high density polyethylene , materials science , supercritical fluid , solubility , polymer , low density polyethylene , thermodynamics , polyethylene , diffusion , polypropylene , gravimetric analysis , volume (thermodynamics) , polystyrene , polymer chemistry , thermal diffusivity , gaseous diffusion , sorption , chemistry , organic chemistry , composite material , adsorption , physics , electrode
The solubility and diffusivity of supercritical carbon dioxide (sc‐CO 2 ) in low‐density polyethylene (LDPE), high‐density polyethylene (HDPE), polypropylene (PP), ethylene‐ethylacrylate copolymer (EEA) and polystyrene (PS) were measured at temperatures from 150°C to 200°C and pressures up to 12 MPa by using the Magnetic Suspension Balance (MSB), a gravimetric technique for gas sorption measurements. The solubility of CO 2 in each polymer was expressed by Henry's constant. The interaction parameter between CO 2 and polymer could be obtained from the solubility data, and it was used to estimate the Pressure‐Volume‐Temperature relationship and the specific free volume of polymer/CO 2 mixtures. The diffusion coefficients were also measured by the MSB for each polymer. The resulting diffusion coefficients were correlated with the estimated free volume of polymer/CO 2 mixture. Combining Fujita's and Maeda and Paul's diffusion models, a model was newly developed in order to predict diffusion coefficients for the polymers studied. Polym. Eng. Sci. 44:1915–1924, 2004. © 2004 Society of Plastics Engineers.