Preparation of porous poly(trimethylene carbonate) structures for controlled release applications using high pressure CO2

Porous poly(trimethylene carbonate) structures can readily be prepared using high pressure CO2. Differences in CO2 solubility in the polymer matrix at the different processing temperatures and pressures lead to different pore morphologies upon depressurization. Furthermore, crystallization of the initially amorphous polymer leads to stable porous structures. This variation in pore structure can be used to tailor polymer matrix degradation rates and drug release profile

Intermolecular interactions between carbon dioxide and the carbonyl groups of polylactides and poly(ε-caprolactone)

Fourier transform infrared (FT-IR) spectroscopy was used to reveal weak intermolecular interactions between carbon dioxide (CO2) and the carbonyl groups of several polymers. This interaction affects the solubility of CO2. The polymers used in this study were poly(l-lactide) (PLLA), poly(d,l-lactide) (PDLLA) and poly (ε-caprolactone) (PCL). In the presence of CO2, the wavenumber of the carbonyl groups shifted to a higher value and in the bending mode region of CO2 a new absorption band appeared. For PCL, the effect of CO2 dissolution on the melting point depression could clearly be observed, even at low pressures