## Abstract Synthesis and characterization of the novel sulfonated BAPPO monomer and its use in the synthesis of a new phosphine oxide‐based sulfonated polyimide are described. BTDA, 6FDA, and DDS were used as monomers in the polyimide synthesis. Sulfonated polyimide membranes were obtained by a so
Synthesis and Characterization of Sulfonated Polyimides Containing Trifluoromethyl Groups as Proton Exchange Membranes
✍ Scribed by Qingshuang Zhang; Qiaoling Li
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 129 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0256-7660
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✦ Synopsis
A novel sulfonated diamine, 4,4'-bis(4-amino-3-trifluoromethylphenoxy) biphenyl 3,3'-disulfonic acid (F-BAPBDS), was successfully synthesized by nucleophilic aromatic substitution of 4,4'-dihydroxybiphenyl with 2-chloro-5-nitrobenzotrifluoride, followed by reduction and sulfonation. A series of sulfonated polyimides of high molecular weight (SPI-x, x represents the molar percentage of the sulfonated monomer) were prepared by copolymerization of 1,4,5,8-naphathlenetetracarboxylic dianhydride (NTDA) with F-BAPBDS and nonsulfonated diamine. Flexible and tough membranes of high mechanical strength were obtained by solution casting and the electrolyte properties of the polymers were intensively investigated. The copolymer membranes exhibited excellent oxidative stability due to the introducing of the CF 3 groups. The SPI membranes displayed desirable proton conductivity (0.52×10 -1 -0.97×10
-1 S•cm -1 ) and low methanol permeability (less than 2.8×10 -7 cm 2 •s -1 ). The highest proton conductivity (1.89×10 -1 S•cm -1 ) was obtained for the SPI-90 membrane at 80 ℃, with an IEC of 2.12 mequiv/g. This value is higher than that of Nafion 117 (1.7×10 -1 S•cm -1 ). Furthermore, the hydrolytic stability of the obtained SPIs is better than the BDSA and ODADS based SPIs due to the hydrophobic CF 3 groups which protect the imide ring from being attacked by water molecules, in spite of its strong electron-withdrawing behaviors.
📜 SIMILAR VOLUMES
## Abstract A series of sulfonated poly(ether sulfone ether ketone ketone) (SPESEKK) with different degree of sulfonation (DS) are prepared by the postsulfonation of PESEKK using chlorosulfonic acid as sulfonating agent and concentrated sulfuric acid as solvent. The chemical structures of the polym
## Abstract A series of random sulfonated copolyimides containing aliphatic linkages (co‐SPIAs) with controlled degrees of sulfonic acid groups were synthesized via a conventional two‐step polyimidization method. 2,4‐Diaminobenzene sulfonic acid (2,4‐DABS) and 1,6‐diaminohexane (DAH) were used as s
## Abstract We focus our attention here on semisquaric acid, which is known to show high acidity, as a new proton dissociating group for proton exchange membranes (PEMs). The introduction of a squaric acid group into aromatic polymers was conducted by the reaction of lithiated aromatic polymers and