TY - JOUR
T1 - Novel sulfonated poly(ether ether ketone ketone)s for direct methanol fuel cells usage
T2 - Synthesis, water uptake, methanol diffusion coefficient and proton conductivity
AU - Zhang, Gang
AU - Fu, Tiezhu
AU - Shao, Ke
AU - Li, Xianfeng
AU - Zhao, Chengji
AU - Na, Hui
AU - Zhang, Hong
N1 - Funding Information:
The authors thank Dr. Lei Li from Changchun Institute of Applied Chemistry for the methanol permeability analysis and kindly discussions. We thank the China High-Tech Development 863 Program (Grant No. 2007AA03Z218) for financial support of this work.
PY - 2009/4/15
Y1 - 2009/4/15
N2 - A novel series of sulfonated poly(ether ether ketone ketone)s (SPEEKKs) with different degrees of sulfonation (Ds) were synthesized from 1,3-bis(3-sodium sulfonate-4-fluorobenzoyl)benzene (1,3-SFBB-Na), 1,3-bis(4-fluorobenzoyl)benzene (1,3-FBB) and 3,3′,5,5′-tetramethyl-4,4′-biphenol (TMBP) by aromatic nucleophilic polycondensation. The chemical structures of SPEEKKs were confirmed by FT-IR spectroscopy and the Ds values of the polymers were calculated by 1H NMR and titration methods, respectively. The thermal stabilities of the SPEEKKs in acid and sodium forms were characterized by thermogravimetric analysis (TGA), which showed that SPEEKKs had excellent thermal properties at high temperatures. All the SPEEKK polymers were easily solution cast into tough membranes. Water uptakes, proton conductivities and methanol diffusion coefficients of the SPEEKK membranes were measured. Water uptake increased with Ds and temperature. Compared to Nafion, the SPEEKK-60, -70 and -80 membranes showed higher proton conductivities at 80 °C, while the other SPEEKK membranes showed relatively lower proton conductivities. This may be due to the different distribution of ion-conducting domains in membrane. However, these membranes showed lower methanol diffusions in the range of 8.32 × 10-9 to 1.14 × 10-7 cm2 s-1 compared with that of Nafion (2 × 10-6 cm2 s-1) at the same temperature. The membranes also showed excellent mechanical properties (with a Young's modulus > 1 GPa and a tensile strength > 40 MPa). These results indicate that the SPEEKK membranes are promising materials for use in direct methanol fuel cell (DMFC) applications.
AB - A novel series of sulfonated poly(ether ether ketone ketone)s (SPEEKKs) with different degrees of sulfonation (Ds) were synthesized from 1,3-bis(3-sodium sulfonate-4-fluorobenzoyl)benzene (1,3-SFBB-Na), 1,3-bis(4-fluorobenzoyl)benzene (1,3-FBB) and 3,3′,5,5′-tetramethyl-4,4′-biphenol (TMBP) by aromatic nucleophilic polycondensation. The chemical structures of SPEEKKs were confirmed by FT-IR spectroscopy and the Ds values of the polymers were calculated by 1H NMR and titration methods, respectively. The thermal stabilities of the SPEEKKs in acid and sodium forms were characterized by thermogravimetric analysis (TGA), which showed that SPEEKKs had excellent thermal properties at high temperatures. All the SPEEKK polymers were easily solution cast into tough membranes. Water uptakes, proton conductivities and methanol diffusion coefficients of the SPEEKK membranes were measured. Water uptake increased with Ds and temperature. Compared to Nafion, the SPEEKK-60, -70 and -80 membranes showed higher proton conductivities at 80 °C, while the other SPEEKK membranes showed relatively lower proton conductivities. This may be due to the different distribution of ion-conducting domains in membrane. However, these membranes showed lower methanol diffusions in the range of 8.32 × 10-9 to 1.14 × 10-7 cm2 s-1 compared with that of Nafion (2 × 10-6 cm2 s-1) at the same temperature. The membranes also showed excellent mechanical properties (with a Young's modulus > 1 GPa and a tensile strength > 40 MPa). These results indicate that the SPEEKK membranes are promising materials for use in direct methanol fuel cell (DMFC) applications.
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U2 - 10.1016/j.jpowsour.2008.12.155
DO - 10.1016/j.jpowsour.2008.12.155
M3 - Article
AN - SCOPUS:62649146830
VL - 189
SP - 875
EP - 881
JO - Journal of Power Sources
JF - Journal of Power Sources
SN - 0378-7753
IS - 2
ER -