| 초록 |
Grafting of styrene onto poly(vinylidene fluoride)(PVdF) membranes was carried out by impregnation and radical polymerization using supercritical carbon dioxide(scCO2). First, PVdF membranes were cast on a glass plate with various thickness. Styrene monomer, the initiator 2,2'-azoisobutyronitrile(AIBN) and the crosslinking agent divinylbenzene(DVB) were impregnated into PVdF membranes using scCO2 at 40℃ and 15 MPa for 4 hours. After releasing CO2, the polymerization was carried out at 80℃ and 10 MPa for 4 hours. PVdF-grafted-polystyrene(PVdF-g-ps) was sulfonated in concentrated sufuric acid(98%H2SO4) at 95℃. The sulfonated PVdF-g-ps membranes(PVdF-g-pssa) were characterized by measuring their permeability, ion conductivity, ion exchange capacity and performance. The results were compared with those of Nafion. EDS analysis shows that SO3- are uniformly distributed in cross-section area of PVdF-g-pssa membrane. |
