The solubility of CO2 in polylactide acid (PLA) and the pressure-volume-temperature (PVT) behavior of PLA were investigated using a magnetic suspension balance (MSB) and an in-house visualization device. Experiments were carried out at temperatures ranging from (453 to 473) K, and the pressure was varied from (6.89 to 20.68) MPa. The results indicated that as the temperature increased, the swelling and the solubility decreased, whereas increased pressure produced increases in swelling and solubility. The D-lactic acid content (D-content) did not have a pronounced effect on the solubility of CO2 or on the swollen volume of the PLA/CO2 mixture. We compared the theoretical and experimental swelling volume ratios and used the Simha Somcynsky (SS) equation of state (EOS) and the Sanchez Lacombe (SL) EOS to obtain the theoretical data. (C) 2013 Elsevier Ltd. All rights reserved.