Plasticization of Polymers with Supercritical Carbon Dioxide: Experimental Determination of Glass Transition Temperatures

High-pressure partition chromatography, a modification of the inverse gas chromatography technique, is presented as suitable technique for the study of the plasticization effect of carbon dioxide on the following polymers: poly(methyl methacrylate), polystyrene, and bisphenol A\u2013polycarbonate. Polymers in the presence of a compressed gas or a supercritical fluid become plasticized; this means that their glass-transition temperatures (Tg\u2019s) can be lowered by 10s of degrees, which causes changes in their mechanical and physical properties. CO2-induced plasticization has an important impact on many polymer processing operations in which the Tg depressions of the polymers can be evaluated. The experimental results are discussed and compared with data available from literature for each polymer we considered