@article{cotugno_di maio_mensitieri_iannace_roberts_carbonell_hopfenberg_2005, title={Characterization of microcellular biodegradable polymeric foams produced from supercritical carbon dioxide solutions}, volume={44}, ISSN={["0888-5885"]}, DOI={10.1021/ie049445c}, abstractNote={The formation of foams of biodegradable poly(e-caprolactone) (PCL) from CO2 solutions in molten PCL was investigated. This study included characterization of the CO2 diffusion and equilibrium solubility in molten PCL in contact with supercritical CO2 (scCO2). Experiments were performed at 70, 80, and 90 °C at CO2 pressures up to 25 MPa. The effective mutual diffusivity of CO2 in molten PCL was measured as a function of the CO2 pressure. The data revealed a dramatic increase in apparent effective diffusivity at elevated pressure, likely related to the formation of fluid bubbles, phase-separated from the previously homogeneous, molten PCL solution of CO2. Microcellular PCL foams were produced by starting from an equilibrium CO2−PCL solution at 70 °C over a wide range of initial pressures (from 6.9 to 32 MPa) by quenching down to foaming temperatures (from 24 to 30 °C) followed by rapid depressurization to atmospheric pressure. Foam structures were characterized by scanning electron microscopy, and cell size...}, number={6}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Cotugno, S and Di Maio, E and Mensitieri, G and Iannace, S and Roberts, GW and Carbonell, RG and Hopfenberg, HB}, year={2005}, month={Mar}, pages={1795–1803} }