本研究利用陰離子聚合法製備嵌段(苯乙烯-異戊二烯)共聚合物 (Poly(Styrene-b-Isoprene), SbI)，以正丁基鋰(n-Butyllithium, n-BuLi) 作為起始劑，合成三種不同苯乙烯/異戊二烯(SM/ IP)比例之共聚物，進而利用氯磺酸(chlorosulfonic acid)與1,4-二氧六環(p-dioxane)所製備之磺酸劑進行共聚物的磺酸化，將製備出之磺酸化共聚物以Casting方式製備出一系列之質子交換膜作為甲醇燃料電池中之電解質層，藉由討論由不同SM/ IP比例之質子交換膜，了解結構性質對薄膜特性及電池效能之影響。另外，為提升質子傳導度，增加磺酸劑反應量可有效提升磺酸根接枝量，進而達到增進質子傳導度的目的。本研究利用FT-IR與1H NMR鑑定磺酸化共聚物分子結構；由TEM觀察其磺酸化共聚物之微觀形態；由TGA顯示，sSbI共聚物之Td(重量損失5%時之溫度)約為220°C，具良好之熱穩定性質；以DSC測試薄膜內水之狀態以及質子交換膜之玻璃轉移溫度(Tg)；其中SM/IP=25/75 wt%/wt%之SbI共聚物進行磺酸化，可得到最高為2.11 mmol/g之離子交換當量(ion exchange capacity, IEC)，其質子傳導度為6.6×10-2 S/cm，優於商用品Nafion 117之質子傳導度為5.3×10-2 S/cm，可期待直接甲醇燃料電池上之應用。

Synthesis of Poly(Styrene-b-Isoprene)(SbI) via anionic polymerization with n-Butyllithium has been accomplished in this study. Sulfonation of the polyisoprene segment with different extents provided a series of copolymers that were casted into films to apply in proton exchange membranes for direct methanol fuel cell. These sulfonated copolymers were characterized with FT-IR and 1H NMR analysis to confirm the sulfonation for the exactly substitute. The microscopic characterization of membranes could be seen by TEM. The thermal stabilities of membranes were analyzed with TGA and revealed high thermal stability. DSC analyzed the states of water and glass transition temperature of membranes. The SbI polymers possess SM/IP= 25/75 wt%/wt%, shown were sulfonated to get the highest IEC of 2.11 mmol/g. The proton conductivity of sSbI achieved 6.6×10-2 S/cm, which was higher than that of Nafion 117. The methanol permeability of sSbI was lower than that of Nafion 117. The materials applied to the direct methanol fuel cells can be expected in the future.

[1] H. L. Hsieh and R. P. Quirk, Anionic Polymerization: Principles And Practical Applications, Marcel Dekker, New York, 1996.
[2] D. J. Cram, Fundamentals of Carbanion Chemistry, Academic Press, New York, 1965.
[3] A. Streitwieser, E. Juaristi, and L. L. Nebenzahl, In Comprehensive Carbanion Chemistry, Part A, E. Buncel and T. Durst, Eds., Elsevier, Chapt. 7, pp. 323, 1980.
[4] J. R. Jones, The Ionization of Carbon Acids, Academic Press, New York, 1973.
[5] O. A. Reutov, I. P. Beletskaya and K. P. Butin, CH-Acids, Pergamon, New York, 1978.
[6] F. G. Bordwell, Equilibrium acidities of carbon acids, Pure and Applied Chemistry, vol. 49, pp. 963-968, 1977.
[7] M. J. Pellerite and J. I. Brauman, In Comprehensive Carbanion Chemistry, Part A, E. Buncel and T. Durst, Eds., Elsevier, Chapt. 2, pp. 55, 1980.
[8] S. G. Lias, J. E. Bartmess, J. F. Liebman, J. L. Holmes, R. D. Levin, and W. G. Mallard, Gas-phase ion and neutral thermochemistry, J. Phys. Chem. Ref. Data, vol. 17, Suppl. 1, 1988.
[9] F. G. Bordwell, Equilibrium Acidities in Dimethyl Sulfoxide Solution, Acc. Chem. Res., vol. 21, pp. 456-463, 1988.
[10] R. R. Squires, Gas-phase Carbanion Chemistry, Acc. Chem. Res., vol. 25, pp. 461, 1992.
[11] F. E. Mathews and E. H. Strange, Anionic polymerizations of dienes, British Patent 24790, 1910.
[12] J. E. L. Roovers and S. Bywater, The polymerizarion od isoprene with sec-Butyllithium in hexane, Macromolecules, vol. 1, pp. 328-331, 1968.
[13] B. C. H. Steele, A. Heinzel, Materials for fuel-cell technologies, Nature, vol. 414, pp. 345-352, 2001.
[14] M. A. Hickner, H. Ghassemi, Y. S. Kim, B. R. Einsla, J. E. McGrath, Alternative Polymer Systems for Proton Exchange Membranes (PEMs), Chem. Reviews, vol. 104, pp. 10, 2004.
[15] O. Savadogo, Emerging membrane for electrochemical systems:(I) solid polymer electrolyte membranes for fuel cell systems, J. of New Materials for Electrochemical Systems, vol. 1, pp. 47-66, 1998.
[16] T. D. Gierke, G. E. Munn and F. C. Wilson, The morphology in Nafion perfluorinated membrane products, as determined by wide-and small-angle X-ray studies, J. of Polymer Science: Polymer Physics Edition, vol. 19, pp. 1687-1704, 1981.
[17] D. E. Curtin, R. D. Lousenberg, T. J. Henry, P. C. Tangeman, M. E. Tisack, Advanced materials for improved PEMFC performance and life, J. Power Source, vol. 131, pp. 41-48, 2004.
[18] G. Alberti, M. Casciola, L. Massinelli, B. Bauer, Polymeric Proton Conducting Membranes for Medium temperatures fuel cells (110-160oC), J. Membrane Sci, vol. 185, pp.73-81, 2001.
[19] N. Caretta, V. Tricoli, F. Picchioni, Ionomeric membranes based on partially sulfonated poly(styrene): synthesis, proton conduction and methanol permeation, J. Membrane Sci, vol. 166, pp.189-197, 2000.
[20] Y. Z. Fu and A. Manthiram, Synthesis and Characterization of Sulfonated Polysulfone membranes for direct methanol fuel cells, J. Power Source, vol. 157, pp. 222-225, 2006.
[21] F. Wang, M. Hickner, Y. S. Kim, T. A. Zawodzinski, J. E. McGrath, Direct Polymerization of Sulfonated poly(arylene ether sulfone) random (statistical) copolymers: Candidates for new proton exchange membranes, J. Membrane Sci., vol. 197, pp. 231-242, 2002.
[22] K. Miyatake, E. Shouji, K. Yamamoto, E. Tsuchida, Synthesis and Proton Conductivity of Highly Sulfonated Poly(thiophenylene), Macromolecules, vol. 30, pp.2941-2946, 1997.
[23] J. Fang, X. Guo, S. Harada, T. Watari, K. Tanaka, H. Kita, K. Okamoto, Novel sulfonated polyimides as polyelectrolytes for fuel cell application, synthesis, proton conductivity, and water stability of polyimides from 4,4‘-diaminodiphenyl ether- 2,2-disulfonic acid, Macromolecules, vol. 35, pp.9022-9028, 2002.
[24] S. G. Ehrenberg, J. M. Serpico, G. E. Wnek, J. N. Rider, US Patent 5468574, 1995.
[25] X. Lu, W. P. Steckle, R. A. Weiss, Morphological studies of a triblock copolymer ionomer by small-angle x-ray scattering, Macromolecules, vol. 26, pp. 6525-6530, 1993.
[26] X. Lu, W. P. Steckle, B. Hsiao, R. A. Weiss, Thermally Induced Microstructure Transitions in a Block Copolymer Ionomer, Macromolecules, vol. 28, pp. 2831-2839, 1995.
[27] R. A. Weiss, A. Sen, C. L. Willis, L. A. Pottick, Block copolymer ionomers: 1.Synthesis physical properties of sulphonated and poly (styrene- ethylene/butylene-styrene), Polymer, vol. 32, pp.1867, 1991.
[28] R. A. Weiss, A. Sen, L. A. Pottick, C. L. Willis, Block copolymer ionomers: 2. Viscoelastic and mechanical properties of sulphonated poly(styrene- ethylene/butylene-styrene)Polymer, vol. 32, pp. 2785-2792, 1991.
[29] J. Kim, B. Kim, B. Jung, Proton conductivities and methanol permeabilities of membranes made from partially sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene copolymers, J. Membrane Sci, vol. 207, pp. 129-137, 2002.
[30] J. Kim, B. Kim, B. Jung, Y. S. Kang, H. Y. Ha, I. H. Oh,
K. Ihn, Effect of Casting Solvent on Morphology and Physical Properties of Partially Sulfonated Polystyrene- block- poly(ethylene-ran-butylene)- block- polystyrene Copolymers, Macromolecules Rapid Communication, vol. 23, pp. 753-756, 2002.
[31] W. J. Lee, H. R. Jung, M. S. Lee, J. H. Kim, K. S. Yang, Preparation and ionic conductivity of sulfonated-SEBS/SiO2/plasticizer composite polymer electrolyte for polymer battery, Solid State Ionics, vol. 164, pp. 65-72, 2003.
[32] K. A. Mauritz, R. I. Blackwell, F. L. Beyer, Viscoelastic properties and morphology of sulfonated poly(styrene-b-ethylene/butylene-b-styrene) block copolymers (sBCP), and sBCP/[silicate] nanostructured materials, Polymer, vol. 45, pp. 3001-3016, 2004.
[33] Y. A. Elabd, E. Napadensky, J. M. Sloan, D. M. Crawford, C. W. Walker, Triblock Copolymer Ionomer Membranes. Part I: Methanol and Proton Transport, J. Membrane Sci., vol. 217, pp. 227-242, 2003.
[34] Y. A. Elabd, C. W. Walker, F. L. Beyer, Triblock Copolymer Ionomer Membranes. Part II: Structure Characterization and its Effects on Transport Properties and Direct Methanol Fuel Cell Performance, J. Membrane Sci., vol. 231, pp. 181-188, 2004.
[35] R. F. Storey, B. J. Chisholm, M. A. Masse, Morphology and physical properties of poly(styrene-b-isobutylene-b-styrene) block copolymers, Polymer, vol. 37, pp. 2925-2938, 1996.
[36] K. A. Mauritz, R. F. Storey, D. A. Reuschle, N. B. Tan, Poly(styrene-b-isobutylene-b-styrene)block copolymer ionomers (BCPI) and BCPI/silicate nanocomposites. 2. Na+BCPI sol-gel polymerization templates, Polymer, vol. 43, pp. 5949-5958, 2002.
[37] K. A. Mauritz, R. F. Storey, D. A. Mountz, D. A. Reuschle, Poly(styrene-b-isobutylene-b-styrene) block copolymer ionomers (BCPI), and BCPI/silicate nanocomposites. 1. Organic counterion: BCPI sol-gel reaction template, Polymer, vol. 43, pp. 4315-4323, 2002.
[38] A. Mokrini, J. L. Acosta, Studies of sulfonated block copolymer and its blends, Polymer, vol. 42, pp. 9-15, 2001.
[39] A. Mokrini, C. D. Rio, J. L. Acosta, Synthesis and characterization of new ion conductors based on butadiene styrene copolymers, Solid State Ionics, vol. 166, pp. 375-381, 2004.
[40] S. Mani, R. A. Weiss, C. E. Williams, S. F. Hahn, Microstructure of Ionomers Based on Sulfonated Block Copolymers of Polystyrene and Poly(ethylene-alt-propylene), Macromolecules, vol. 32, pp. 3663-3670, 1999.
[41] G. Zhang, L. Liu, H. Wang, M. Jiang, Preparation and association behavior of diblock copolymer ionomers based on poly(styrene-b-ethylene-co-propylene), Eur. Polym. J., vol. 36, pp. 61-68, 2000.
[42] V. A. Paganin, E. A. Ticianelli and E. R. Gonzalez, Development and electrochemical studies of gas diffusion electrodes for polymer electrolyte fuel cells, J. of Applied Electrochemistry, vol. 26, pp. 297-304, 1996.
[43] D. Chu and R. Jiang, Performance of polymer electrolyte membrane fuel cell (PEMFC) stacks: Part I. Evaluation and simulation of an air-breathing PEMFC stack, J. of Power Sources, vol. 83, pp. 128-133, 1999.
[44] Y. G. Chun, C. S. Kim, D. H. Peck and D. R. Shin, Performance of a polymer electrolyte membrane fuel cell with thin film catalyst electrodes, Journal of Power Sources, vol. 71, pp. 174-178, 1998.
[45] S. Cha and W. Lee, Performance of proton exchange membrane fuel cell electrodes prepared by direct deposition of ultrathin platinum on the membrane surface, J. of the Electrochemical Society, vol. 146, pp. 4055, 1999.
[46] 曾育貞, Investigation of the Modified Poly(Vinyl Alcohol) Polymer Electrolyte Membrane for DMFCs, 化學工程系, 台灣科技大學, 2006.
[47] X. Qian, N. Gu, Z. Cheng, X. Yang, E. Wang E, S. Dong, Plasticizer effect on the ionic conductivity of PEO-based polymer electrolyte, Materials Chemistry and Physics, vol. 74, pp. 98-103, 2002.
[48] F. Gray, Solid polymer electrolytes: fundamentals and technological applications, VCH New York, 1991.
[49] R. Linford, Electrochemical science and technology of polymers, Kluwer Academic Pub., 1990.
[50] X. Yuan, H. Wang, J. C. Sun, J. Zhang, AC impedance technique in PEM fuel cell diagnosis—A review, International J. of Hydrogen Energy, vol. 32, pp. 4365–4380, 2007.
[51] T. Y. Kim, J. E. Kim, Y. S. Kim, T. H. Lee, W. J. Kim, K. S. Suh, Preparation and characterization of poly(3,4-ethylenedioxythiophene) (PEDOT) using partially sulfonated poly(styrene-butadiene-styrene) triblock copolymer as a polyelectrolyte, Current Applied Physics, vol. 9, pp. 120–125, 2009.
[52] Z. Shi and S. Holdcroft, Synthesis and Proton Conductivity of Partially Sulfonated Poly([vinylidene difluoride-co-hexafluoropropylene]-b-styrene) Block Copolymers, Macromolecules vol. 38, pp. 4193-4201, 2005.
[53] J. Samuel, T. Xavier and T. Kurian, High Styrene–Rubber Ionomers, an Alternative to Thermoplastic Elastomers, J. of Applied Polymer Science, vol. 85, pp. 2294–2300, 2002.
[54] B. S. Pivovar, Y. Wang, E. L. Cussler, Pervaporation membranes in direct methanol fuel cells, J. of Membrane Science, vol. 154, pp. 155-162, 1999.
[55] K. D. Kreuer, Proton Conductivity: Materials and Applications, Chem. Mater. , vol. 8, pp. 610-641, 1996.