In this study, crosslinked SPS/TMPETA membranes were fabricated by solution casting of various compositions of sulfonated polystyrene (SPS) prepared by sulfonation of polystyrene (PS) and trimethylolpropane ethoxylate triacrylate (TMPETA) crosslinker followed by an electron beam irradiation. We confirmed that SPS polymer was successfully prepared by the introduction of sulfonic acid group in PS from the results of FTIR analysis and measurement of sulfonation degree. The degree of crosslinking of the prepared membranes increased with an increase in absorption doses and crosslinker contents, which was obtained by measuring gel fraction. The effects of the crosslinker contents were estimated by measuring water uptake, chemical stability, and mechanical properties of the prepared membranes. It was confirmed that the introduction of crosslinked structures in SPS membranes improved the water uptake, chemical stability, and tensile strength. Also, the results of the electrochemical analysis showed that membrane area resistance increased with an increase in the degree of crosslinking.

본 연구에서는 polystyrene(PS) 술폰화 반응을 통하여 얻어진 sulfonated polystyrene(SPS)과 trimethylolpropane ethoxylate triacrylate(TMPETA) 가교제를 다양한 조성으로 혼합하여 캐스팅한 후, 전자선을 조사하여 가교 SPS/TMPETA 막을 제조하였다. FTIR 분석과 술폰화도 측정을 통하여 술폰산기가 PS 고분자에 도입되어 SPS 고분자가 성공적으로 제조되었음을 확인하였다. 제조된 SPS/TMPETA 막의 젤화율 측정을 통해 조사선량 및 가교제 함량이 증가할수록 가교도가 증가함을 확인하였다. 그리고 함수율, 화학적 안정성, 기계적 물성 측정을 통해 가교제 함량에 따른 영향을 평가하였고, 가교구조의 도입으로 인하여 제조된 막의 함수율, 화학적 안정성, 기계적 물성이 향상되었음을 확인하였다. 또한 전기화학적 분석을 통하여 막의 면적저항을 측정한 결과, 가교도의 증가로 인해 막 면적저항이 증가함을 확인하였다.

Keywords: ion exchange membrane; crosslinking; electron beam; sulfonated polystyrene