抄録
Applying the electron beam-preirradiation method, glycidyl methacrylate (GMA) or its mixture with 2-hydroxyethyl methaclylate (HEMA) was grafted onto some inert polymer membranes such as polypropylene (PP), poly(vinylidene) fluoride (PVDF) and poly(tetrafluoroethylene)(PTFE). The epoxide rings of the graft chains were converted to chloride by reacting with HCl and then to -SH by reacting with NaSH. These membranes were analyzed by several methods and the metal ion sorption ability of the membranes was investigated. Consequently the following results were obtained; 1) PP and PVDF membranes could be easily grafted and the degree of grafting could be varied from a little % to approximately 1, 000% by changing the monomer concentration and the reaction time after EB-irradiation. In the case of PTFE membrane the degree of grafting was 40% even under the optimum condition. 2) The content of thiol group could be varied from 0.3 to 3.6mmol/g membrane. In spite of heterogeneous reaction the conversion efficiency of epoxide ring to -SH group was very high up to 66∼77% even under the mild condition such as at 323K. 3) The content of residual free-SH group in the NaSH-treated graft membranes was relatively low. It can be explained by the fact that the most of introduced -SH groups were combined to each other to form disulfide bonds by air oxidation. In contrast with these membranes, membranes grafted with a mixture of GMA/HEMA(45/55) possessed ca. 25mol% free -SH groups. 4) The -SH and -SS- introduced membranes showed selectively metal ion sorption ability, hence, extremely high sorption for Au ion.
