Investigation of sorption and diffusion of supercritical carbon dioxide into poly(vinyl chloride)

Citation
O. Muth et al., Investigation of sorption and diffusion of supercritical carbon dioxide into poly(vinyl chloride), J SUPERCR F, 19(3), 2001, pp. 299-306
Citations number
16
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics","Chemical Engineering
Journal title
JOURNAL OF SUPERCRITICAL FLUIDS
ISSN journal
0896-8446 → ACNP
Volume
19
Issue
3
Year of publication
2001
Pages
299 - 306
Database
ISI
SICI code
0896-8446(200104)19:3<299:IOSADO>2.0.ZU;2-Z
Abstract
The interaction of supercritical carbon dioxide (scCO(2)) with poly(vinyl c hloride) (PVC) was systematically investigated. PVC films of 0.5 mm thickne ss were treated with CO2 at pressures between 5 and 40 MPa, at temperatures between 40 and 70 degreesC and soaking times between 0.5 and 7 h. The grav imetric desorption data were kinetically and thermodynamically evaluated as suming Fickian diffusion and the morphology changes due to the CO2 treatmen t investigated by microscopic methods. The sorbed amount of CO2, q (q = g(C O2)/g(polymer)) ranged between 0.03 (5 MPa, 70 degreesC) and 0.13 (15 MPa, 40 degreesC). The desorption diffusivities, D-d, were in the order of 0.1 x 10(-11) m(2)/s and decreased with decreasing amounts of CO2. In contrast, the sorption diffusivities, D-d, were markedly higher and varied between 0. 7 x 10(-11) and 2.5 x 10(-11) m(2)/s (20 MPa, 40-70 degreesC). The CO2 trea tment changed the polymer chain structure. macroscopically visualized by th e film opaqueness and by the density decrease to 1.05 g/cm(3). Microcellula r structures were not detected. (C) 2001 Elsevier Science B.V. All rights r eserved.