Abstract
Polymer porous medium is used as an ion exchange resin, a supported reagents etc.. Recently, it is also considered for use as a supporting structure for cell cultures. In order to use polymer porous medium for these purposes, the surface area and 3-dimensional form are important. The polymer porous medium is usually made by suspension polymerization. However, with this method, it is difficult to control the surface area and 3-dimensional form. It is also difficult to remove the water from the porous medium and expensive to treat the resulting waste water. We examined a method of producing the polymer porous medium using supercritical carbon dioxide as a solvent. The styrene and divinylbenzene (DVB) were cross-linked polymerized, and a porous medium was generated in the supercritical carbon dioxide. The polymerization rate and the properties of the form of the porous medium were investigated under varying conditions. As a result, it was found that the polymerization rate was fast under a low polymerization pressure and at a high DVB concentration, while the surface area of the porous medium was large at the high concentrations of the initiator and DVB. This large surface area was due to the fact that the primary particles in the porous medium were small under high pressure, and there was little coalescence of the primary particles at the high DVB concentration. In this study, it was shown that the 3-dimensional form of the porous medium can be quantitatively controlled by varying polymerization pressure, DVB concentration, and so on.
