Abstract
A continuous RESS (rapid expansion of supercritical solution) process that combines an SEDS (solution enhanced dispersion by supercritical fluids) process and RESS process was developed to prepare the microparticles of polylactide–poly(ethylene glycol)–polylactide (PLA–PEG–PLA) triblock copolymer. The resulting microparticles exhibited a spherical shape and a narrow particle size distribution with a mean particle size of 2.2 μm. After supercritical processing, the results of Fourier transform infrared spectroscopy (FTIR) measurement indicated that the minor structural changes occurred on a molecular level; X-ray powder diffraction (XRPD) analysis revealed that the physical state of the copolymer shifted into an amorphous form; and the thermogravimetry-differential scanning calorimetry (TG-DSC) measurements demonstrated the increases in fusion temperature and decomposition temperature of the copolymer from 135.8 °C to 180.6 °C and 342.9 °C to 372.0 °C, respectively. The results indicate that the continuous RESS process could overcome the drawbacks of SEDS and RESS processes when processing the supercritical CO 2 partially soluble polymers and recrystallize such polymers continuously and constantly, which would widen the application of supercritical technologies in the treatment of polymers.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
