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Nitrophenoxy groups containing polybenzimidazoles as polymer electrolytes for fuel cells: Synthesis and characterization
Author(s) -
Kulkarni Mahesh,
Potrekar Ravindra,
Kulkarni R.A.,
Vernekar S. P.
Publication year - 2010
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.30279
Subject(s) - phosphoric acid , polymer , thermal stability , polymer chemistry , materials science , electrolyte , membrane , thermal decomposition , ether , condensation polymer , chemistry , chemical engineering , organic chemistry , composite material , biochemistry , electrode , engineering
Abstract Polybenzimidazoles containing different contents of pendant nitrophenoxy groups were prepared by condensation of 3,3′‐diamino‐benzidine with a mixture of 3,5‐dicarboxyl‐4′‐nitro diphenyl ether and isophthalic acid (IPA) in different ratios in polyphosphoric acid. The polymers are soluble in polar aprotic solvents, they have inherent viscosities in the range of 0.75–1.10 dL g −1 and they form tough and transparent films on solution casting. They have good thermal stability with initial decomposition temperature ranging from 380 to 416°C in nitrogen, good tensile strength ranging from 56 to 65 MPa and reasonably good oxidative stability. Phosphoric acid uptake of these polymers is low compared with PBI and membranes doped with phosphoric acid exhibit good proton conductivity in the range of 6.6× 10 −3 to 1.9× 10 −2 S/cm at 25°C and 1.2× 10 −2 to 4.9× 10 −2 S/cm at 175°C, compared with 3.9× 10 −3 S/cm at 25°C and 3.2× 10 −2 S/cm at 175°C for PBI. These membranes are suitable for applications as polymer electrolyte for fuel cell and presumably for gas separation at high temperature. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010