Journal of Supercritical Fluids, Vol.140, 279-289, 2018
The effects of molecular weight and supercritical CO2 on the phase morphology of organic solvent free porous scaffolds
Porous poly(epsilon-caprolactone) (PCL) scaffolds were prepared by extracting the poly(ethylene oxide) (PEO) phase from co-continuous PCL/PEO blends, which were annealed in supercritical carbon dioxide (scCO(2)). It was found that the coarsening temperature of PCL/PEO blend in scCO(2) is lower than that in atmosphere, which indicated that the scCO(2) could be used as an effective tool for morphology control. The effects of molecular weight of PEO, annealing time, temperature and pressure on the phase morphology of polymer blends have been systematically studied. The average pore size of PCL porous scaffold increases with the increase of annealing time, temperature and pressure. The coarsening effect of the PCL/PEO blends decreases with increasing molecular weight of PEO. The average pore size is in the range of 10-130 mu m with high interconnectivity. In addition, the preparation of scaffold is organic solvent free preparation for the reason that PEO and PEG are water-soluble polymers.