Effect of Pressure on the Melting Point of Pluronics in Pressurized Carbon Dioxide

The melting points of Pluronic F-77, F-127, F-68, F-38, and F-108 were investigated in pressurized CO2 between a pressure range of 2.0–50.0 MPa. Unprocessed and CO2-processed Pluronic samples were analyzed by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). A melting point depression in the range of 18.1 (± 0.5 K) to 19.3 (± 0.3 K) was observed for all Pluronics studied in this work. The melting point of Pluronics in pressurized CO2 was found to be independent of their molecular weight and poly(propylene oxide) [PPO] content. Analysis by DSC and PXRD revealed that CO2 processing had no impact on the morphology of Pluronics