Novel aromatic polyimide ionomers for proton exchange membranes: Enhancing the hydrolytic stability

Polymer ◽  
2011 ◽  
Vol 52 (13) ◽  
pp. 2735-2739 ◽  
Author(s):  
Haibing Wei ◽  
Xingzhong Fang
Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 652
Author(s):  
Chunmei Gao ◽  
Jiale Chen ◽  
Boping Zhang ◽  
Lei Wang

Hydrolytic stability and oxidative stability are the core properties of sulfonated polynaphthylimides (SPIs) as proton exchange membranes. The chemical structure of SPIs directly influences the performance. Herein, three different series of branched SPIs were designed and prepared using 1,3,5-tris (2-trifluoromethyl-4-aminophenoxy) benzene as a trifunctional monomer and three non-sulfonated diamine monomers, such as 4,4′-oxydianiline (ODA), 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (6FODA), and 4,4′-(9-fluorenylidene)dianiline (BFDA). The effect of the chemical structure and degree of branching on SPIs properties is discussed. The results showed that by controlling the chemical structure and degree of branching, the chemical stability of SPIs changed significantly. SPI-6FODA with two ether linkages and a hydrophobic CF3 group has higher hydrolytic stability than SPI-ODA with only one ether linkage. In addition, with the increase of the introduced B3 monomer, the oxidation stability of SPI-6FODA has been greatly improved. We successfully synthesized SPIs with a high hydrolytic stability and oxidative stability.


2014 ◽  
Vol 60 ◽  
pp. 235-246 ◽  
Author(s):  
Anaparthi Ganeshkumar ◽  
Debaditya Bera ◽  
Ershad Ali Mistri ◽  
Susanta Banerjee

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 475
Author(s):  
Luca Pasquini ◽  
Botagoz Zhakisheva ◽  
Emanuela Sgreccia ◽  
Riccardo Narducci ◽  
Maria Luisa Di Vona ◽  
...  

Proton-conducting ionomers are widespread materials for application in electrochemical energy storage devices. However, their properties depend strongly on operating conditions. In bio-fuel cells with a separator membrane, the swelling behavior as well as the conductivity need to be optimized with regard to the use of buffer solutions for the stability of the enzyme catalyst. This work presents a study of the hydrolytic stability, conductivity and mechanical behavior of different proton exchange membranes based on sulfonated poly(ether ether ketone) (SPEEK) and sulfonated poly(phenyl sulfone) (SPPSU) ionomers in phosphate buffer solution. The results show that the membrane stability can be adapted by changing the casting solvent (DMSO, water or ethanol) and procedures, including a crosslinking heat treatment, or by blending the two ionomers. A comparison with NafionTM shows the different behavior of this ionomer versus SPEEK membranes.


Polymer ◽  
2005 ◽  
Vol 46 (12) ◽  
pp. 4504-4509 ◽  
Author(s):  
L.C. Klein ◽  
Y. Daiko ◽  
M. Aparicio ◽  
F. Damay

2021 ◽  
Vol 29 (3) ◽  
pp. 199-210
Author(s):  
Zhihui Wu ◽  
Chunhui Shen ◽  
Shanjun Gao ◽  
Xi Zhu ◽  
Mingliang Zhang ◽  
...  

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 130
Author(s):  
Carlos Corona-García ◽  
Alejandro Onchi ◽  
Arlette A. Santiago ◽  
Araceli Martínez ◽  
Daniella Esperanza Pacheco-Catalán ◽  
...  

The future availability of synthetic polymers is compromised due to the continuous depletion of fossil reserves; thus, the quest for sustainable and eco-friendly specialty polymers is of the utmost importance to ensure our lifestyle. In this regard, this study reports on the use of oleic acid as a renewable source to develop new ionomers intended for proton exchange membranes. Firstly, the cross-metathesis of oleic acid was conducted to yield a renewable and unsaturated long-chain aliphatic dicarboxylic acid, which was further subjected to polycondensation reactions with two aromatic diamines, 4,4′-(hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline and 4,4′-diamino-2,2′-stilbenedisulfonic acid, as comonomers for the synthesis of a series of partially renewable aromatic-aliphatic polyamides with an increasing degree of sulfonation (DS). The polymer chemical structures were confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H, 13C, and 19F NMR) spectroscopy, which revealed that the DS was effectively tailored by adjusting the feed molar ratio of the diamines. Next, we performed a study involving the ion exchange capacity, the water uptake, and the proton conductivity in membranes prepared from these partially renewable long-chain polyamides, along with a thorough characterization of the thermomechanical and physical properties. The highest value of the proton conductivity determined by electrochemical impedance spectroscopy (EIS) was found to be 1.55 mS cm−1 at 30 °C after activation of the polymer membrane.


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