Vinyl‐addition type norbornene copolymers containing flexible spacers and sulfonated pendant groups for proton exchange membranes |
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| Authors: | Hongli Yao Xiaohui He Lu Chen Yiwang Chen Defu Chen |
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| Affiliation: | 1. Department of Chemistry, Institute of Polymers, Nanchang University, Nanchang 330031, China;2. School of Civil Engineering and Architecture, Nanchang University, Nanchang 330031, China |
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| Abstract: | Novel sulfonated poly(2‐butoxymethylenenorbornene‐co‐2‐(6‐phenoxy‐hexyloxymethylene)‐5‐norbornene [sP(BN/PhHN)] were prepared successfully through vinyl‐addition type polymerization and then sulfonated with concentrated sulfuric acid (98%) as sulfonating agent in a component solvent. The sP(BN/PhHN)‐40 with the maximal degree of sulfonation of 40% can be obtained by controlling the sulfonating reaction time from 8 to 20 h, and a proton conductivity of 3.35 × 10?3 S/cm was achieved at 70°C. The methanol permeabilities of these membranes were in the range from 0.26 to 6.58 × 10?7 cm2/s, which were remarkably lower than Nafion (2.36 × 10?6 cm2/s). TEM analysis revealed that these side‐chain type membranes have a microphase separated structure composed of hydrophilic side‐chain domains and hydrophobic polynorbornene main chain domains. Sulfonated polynorbornene containing soft spacers displayed better properties, such as lower water uptake, high thermal properties, mechanical properties, and low methanol permeability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 |
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| Keywords: | polyelectrolytes addition polymerization batteries and fuel cells functionalization of polymers membranes |
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