The sorption of carbon dioxide in poly(lactic acid) (PLA) was studied by quartz crystal microbalance at high pressures. To address the effect of the D isomer present in the polymer on the gas sorption, measurements were performed in PLA with two different L:D contents, 80:20 and 98:2. New data for the solubility of carbon dioxide in PLA 80:20 and PLA 98:2 over a temperature range from 303.2 to 323.2 K and up to 5 MPa are presented. The results obtained were correlated with the dual-mode sorption model and the Flory-Huggins equation. (c) 2006 Wiley Periodicals, Inc.