| 초록 |
Supercritical CO2 is a poor quality solvent for PLGA copolymers. As the glycolide content in the backbone increases, the pressures needed to obtain a single phase also increase substantially and it is not possible to dissolve PLGA50 to pressures of 2,600 bar. The CHClF2 data strongly suggest that a polar cosolvent capable of hydrogen bonding to the ester linkage in PLGA is needed if low pressure, single-phase processing of this copolymer is desired. However, PLGA copolymers can be intimately mixed with a variety of insoluble materials at low pressures in pure CO2 since the glass transition temperature of the PLGA is significantly lowered by the plasticization effect of supercritical CO2. |
