Membrane Journal (멤브레인)

The Membrane Society of Korea (한국막학회)
권호 표지
DOI QR코드

DOI QR Code

Polymer Electrolyte Membranes of Poly(Styrene-Butadiene-Styrene) Star Triblock Copolymer for Fuel Cell

연료전지용 Poly(Styrene-Butadiene-Styrene) Star Triblock Copolymer의 고분자 전해질 분리막

  • Garcia, Edwin D. (Department of Environmental Engineering and Energy, Myongji University) ;
  • Jung, Bumsuk (Department of Environmental Engineering and Energy, Myongji University)
  • Received : 2019.09.11
  • Accepted : 2019.10.27
  • Published : 2019.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

A sulfonated star branched poly(styrene-b-butadiene-b-styrene) triblock copolymer (SSBS) was synthesized with varying degrees of sulfonation. The effective sulfonation on the butadiene block was confirmed by FT-IR spectroscopy. Ion exchange capacity by titration was used to determine the degree of sulfonation. The synthesized polymer observed enhanced water uptake and proton conductivity. At room temperature, the SSBS with 25 mol% degree of sulfonation showed an outstanding proton conductivity of 0.114 S/cm, similar to that of commercial membrane, Nafion. The effect of temperature at constant relative humidity on conductivity resulted to a remarkable increase in proton conductivity. Methanol permeability studies showed a value lower than Nafion for all the sulfonated membranes. Structural nature observed using AFM showed that the membranes observed microphase separated nanostructures and the connectivity of the interionic channels.

서로 다른 술폰화 정도에 따라 sulfonated star branched poly(styrene-b-butadiene-b-styrene) triblock copolymer (SSBS)가 합성되었다. 술폰화된 butadiene block은 FT-IR spectroscopy로 확인할 수 있다. 술폰화 정도를 측정 비교하기 위해서 산-염기 적정을 통하여, ion exchange capacity (IEC)를 계산하였다. 술폰화된 SSEB 전해질막은 높은 water uptake와 proton conductivity를 보였다. 실온에서 25 mol% 술폰화된 SSBS는 0.114 S/cm라는 높은 값을 나타냈으며, 이는 Nafion과 비슷한 수치였다. 일정한 상대 습도에서 온도의 증가는 현저하게 높은 수소이온전도도를 나타냄을 알 수 있었다. 모든 술폰화된 막은 Nafion과 비교했을 때 낮은 methanol 투과도를 보여주었다. AFM을 이용하여 술폰화된 전해질막의 구조는 이른바 분리된 나노구조의 미세상과 ionic channel의 접속으로 이루어졌음을 확인할 수 있었다.

Keywords

References

  1. K. Kordesch and G. Simander, "Fuel cells and their applications", Wiley-VCH, Weinheim (1996).
  2. Y. F. Zhang, J. Li, L. Ma, W. W. Cai, and H. S. Cheng, "Recent developments on alternative proton exchange membranes: strategies for systematic performance improvement", Energy Technol., 3, 675 (2015). https://doi.org/10.1002/ente.201500028
  3. Z. Zhuang, D. Qi, C. Zhao, and H. Na, "A novel highly sensitive humidity sensor derived from sulfonated poly(ether ether ketone) with metal salts-ion substitution", Sensors and Actuators B: Chemical, 236, 701 (2016). https://doi.org/10.1016/j.snb.2016.06.063
  4. "Ionomers: Characterization, theory, and applications", Schlick, S., Ed., CRC, Boca Raton, FL (1996).
  5. T. R. Earnest jr, and W. J. MacKnight, "Infrared studies of hydrogen bonding in ethylene-methacrylic acid copolymers and ionomers", Macromolecules, 13, 844 (1980). https://doi.org/10.1021/ma60076a014
  6. N. A. Agudelo, J. Palacio, and B. L. Lopez, "Effect of the preparation method on the morphology and proton conductivity of membranes based on sulfonated ABA triblock copolymers", J. Mater. Sci., 54, 4135 (2019). https://doi.org/10.1007/s10853-018-3115-5
  7. Y. A. Elabd and E. Napadensky, "Sulfonation and characterization of poly(styrene-isobutylene-styrene) triblock copolymers at high ion-exchange capacities", Polymer, 45, 3037 (2004). https://doi.org/10.1016/j.polymer.2004.02.061
  8. Y. A. Elabd and M. A. Hickner, "Block copolymers for fuel cells", Macromolecules, 44, 1 (2011). https://doi.org/10.1021/ma101247c
  9. J. Li, G. Xu, X. Luo, J. Xiong, Z. Liu, and W. Cai, "Effect of nano-size of functionalized silica on overall performance of swelling-filling modified Nafion membrane for direct methanol fuel cell application", Appl. Energy, 213, 408 (2018). https://doi.org/10.1016/j.apenergy.2018.01.052
  10. B. Kim and B. Jung, "Partially sulfonated polystyrene and poly(2,6-dimethyl-1,4-phenylene oxide) blend membranes for fuel cells", Macromol. Rapid Comm., 25, 1263 (2004). https://doi.org/10.1002/marc.200400119
  11. J. A. Kerres, "Blended and cross-linked ionomer membranes for application in membrane fuel cells", Fuel Cells, 5, 230 (2005). https://doi.org/10.1002/fuce.200400079
  12. L. Gubler, S. A. Gürsel, and G. G. Scherer, "Radiation grafted membranes for polymer electrolyte fuel cells", Fuel cells, 5, 317 (2005). https://doi.org/10.1002/fuce.200400078
  13. J. Kim, B. Kim, B. Jung, Y. S. Kang, H. Y. Ha, I. H. Oh, and K. J. Ihn, "Effects of casting solvent on morphology and physical properties of partially sulfonated polystyrene-block-poly(ethylene-ran-butylene)- block-polystyrene copolymers", Macromol. Rapid Comm., 23, 753 (2002). https://doi.org/10.1002/1521-3927(20020901)23:13<753::AID-MARC753>3.0.CO;2-G
  14. B. Kim, J. Kim, B. J. Cha, and B. Jung, "Effect of selective swelling on protons and methanol transport properties through partially sulfonated block copolymer membranes", J. Membr. Sci., 280, 270 (2006). https://doi.org/10.1016/j.memsci.2006.01.042
  15. M. A. Hickner and B. S. Pivovar, "The chemical and structural nature of proton exchange membrane fuel cell properties", Fuel cell, 5, 213 (2005). https://doi.org/10.1002/fuce.200400064
  16. G. N. B. Barona, B. J. Cha, and B. Jung, "Negatively charged poly(vinylidene fluoride) microfiltration membranes by sulfonation", J. Membr. Sci., 290, 46 (2007). https://doi.org/10.1016/j.memsci.2006.12.013
  17. F. Trotta, E. Drioli, G. Moraglio, and E. B. Poma, "Sulfonation of polyetheretherketone by chlorosulfuric acid", J. Appl. Polym. Sci., 70, 470 (1998).
  18. W. Schnabel, G. F. Levchik, C. A. Wilkie, D. D. Jiang, and S. V. Levchik, "Thermal degradation of polystyrene, poly(1,4-butadiene) and copolymers of styrene and 1,4-butadiene irradiated under air or argon with $^{60}Co-rays$", Polym. Degrad. Stabil., 63, 365 (1999). https://doi.org/10.1016/S0141-3910(98)00114-1
  19. D. Suleiman, Y. A. Elabd, E. Napadensky, J. M. Sloan, and D. M. Crawford, "Thermogravimetric characterization of sulfonated poly(styrene-isobutylene-styrene) block copolymers: Effects of processing conditions", Thermochimica Acta, 430, 149 (2005). https://doi.org/10.1016/j.tca.2005.01.030
  20. Y. Woo, S. Y. Oh, Y. S. Kang, and B. Jung, "Synthesis and characterization of sulfonated polyimide membranes for direct methanol fuel cell", J. Membr. Sci., 220, 31 (2003). https://doi.org/10.1016/S0376-7388(03)00185-6
  21. X. Zhang, S. Liu, and J. Yin, "Synthesis and characterization of a new block copolymer for proton exchange membrane", J. Membr. Sci., 258, 78 (2005). https://doi.org/10.1016/j.memsci.2005.02.028
  22. J. J. Sumner, S. E. Creager, J. J. Ma, and D. D. DesMarteau, "Proton conductivity in Nafion$^{(R)}$ 117 and in a novel Bis[(perfluoroalkyl)sulfonyl]imide ionomer membrane", J. Electrochem. Soc., 145, 107 (1998). https://doi.org/10.1149/1.1838220
  23. J. Li and H. Yu, "Synthesis and characterization of sulfonated poly(benzoxazole ether ketone)s by direct copolymerization as novel polymers for proton-exchange membranes", J. Polym. Sci. A, Polym. Chem., 45, 273 (2007).
  24. C. H. Lee, H. B. Park, Y. M. Lee, and R. D. Lee, "Importance of proton conductivity measurement in polymer electrolyte membrane for fuel cell application", Ind. Eng. Chem. Res., 44, 7617 (2005). https://doi.org/10.1021/ie0501172