Synthesis and Characterization of Sulfonated Polybenzoxazole for High Temperature Proton Exchange Membranes

2013 ◽  
Vol 821-822 ◽  
pp. 1261-1265 ◽  
Author(s):  
Wen Feng Wang ◽  
Rong Rong Hao ◽  
Sheng Lin Yang ◽  
Jun Hong Jin ◽  
Guang Li
Keyword(s):  
High Temperature ◽  
Proton Conductivity ◽  
Polyphosphoric Acid ◽  
Theoretical Calculations ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Sulfonation Degree ◽  
Monosodium Salt ◽  
Thermal Stable

Sulfonated Polybenzoxazoles (sPBO) with sulfonation degree ranging from 10% to 30% were synthesized from 4,6-diaminoresorcinol dihydrochloride (DAR), terephthalic acid (TPA), 5-sulfoisophthalic acid monosodium salt (SIPA) by direct polycondensation in polyphosphoric acid (PPA). The structures of sPBOs were verified by FTIR and elemental analysis. The values of inherent viscosity ranged from 2.56 to 1.12 dL/g and decreased with the increasing of sulfonation degree. TGA analysis showed sPBOs were thermal stable up to nearly 250°C. sPBO/PPA polymerization solution were hot pressed directly to form PPA doped sPBO membranes since sPBO was insouble in common solvents. The PPA doping level was about 340%(wt) per gram of sPBOs by theoretical calculations. The tensile strength of PPA doped sPBOs membrances ranged from 9.1 to 3.2 Mpa. At high temperature, sPBO membranes showed excellent proton conductivity. For instance, sPBO membrane with a sulfonation degree of 10% exhibited a proton conductivity of 0.123 S/cm at 170°C.The experimental results indicated sPBO are promising for proton exchange membranes for high temperature proton exchange membranes.

scholarly journals Synthesis and Characterization of Partially Renewable Oleic Acid-Based Ionomers for Proton Exchange Membranes

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 130
Author(s):  
Carlos Corona-García ◽  
Alejandro Onchi ◽  
Arlette A. Santiago ◽  
Araceli Martínez ◽  
Daniella Esperanza Pacheco-Catalán ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Proton Conductivity ◽  
Electrochemical Impedance ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Molar Ratio ◽  
Aromatic Diamines ◽  
Chemical Structures ◽  
Long Chain

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.

scholarly journals Effect of metallacarborane salt H[COSANE] doping on the performance properties of polybenzimidazole membranes for high temperature PEMFCs

Soft Matter ◽  
2020 ◽  
Vol 16 (32) ◽  
pp. 7624-7635 ◽  
Author(s):  
Jessica Olvera-Mancilla ◽  
Jorge Escorihuela ◽  
Larissa Alexandrova ◽  
Andreu Andrio ◽  
Abel García-Bernabé ◽  
...  
Keyword(s):  
High Temperature ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Performance Properties

The preparation and characterization of composite proton exchange membranes containing protonated cobaltacarborane H[Co(C2B9H11)2] names as H[COSANE] and different polybenzimidazole (PBI) for a high temperature PEMFC applications is reported.

scholarly journals Synthesis and Properties of Phosphoric-Acid-Doped Polybenzimidazole with Hyperbranched Cross-Linkers Decorated with Imidazolium Groups as High-Temperature Proton Exchange Membranes

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 515 ◽  
Author(s):  
Chunmei Gao ◽  
Meishao Hu ◽  
Li Wang ◽  
Lei Wang
Keyword(s):  
High Temperature ◽  
Phosphoric Acid ◽  
Proton Conductivity ◽  
Proton Exchange Membrane ◽  
Mechanical Performance ◽  
Weak Interactions ◽  
Weight Ratio ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Hydrogen Bond Formation

Highly phosphoric-acid (PA)-doped polybenzimidazole (PBI) membranes exhibit good proton conductivity at high temperatures; however, they suffer from reduced mechanical properties and loss of PA molecules due to the plasticity of PA and the weak interactions between PA and benzimidazoles, especially with the absorption of water. In this work, a series of PBIs with hyperbranched cross-linkers decorated with imidazolium groups (ImOPBI-x, where x is the weight ratio of the hyperbranched cross-linker) as high-temperature proton exchange membranes are designed and synthesized for the first time. We observe how the hyperbranched cross-linkers can endow the membranes with improved oxidative stability and acceptable mechanical performance, and imidazolium groups with strong basicity can stabilize the PA molecules by delocalization and hydrogen bond formation to endow the membranes with an enhanced proton conductivity and a decreased loss of PA molecules. We measured a high proton conductivity of the ImOPBI-x membranes, ranging from 0.058 to 0.089 S cm−1 at 160 °C. In addition, all the ImOPBI-x membranes displayed good mechanical and oxidative properties. At 160 °C, a fuel cell based on the ImOPBI-5 membrane showed a power density of 638 mW cm−2 and good durability under a hydrogen/oxygen atmosphere, indicating its promising use in anhydrous proton exchange membrane applications.

Novel PA-doped polybenzimidazole membranes with high doping level, high proton conductivity and high stability for HT-PEMFCs

RSC Advances ◽  
2015 ◽  
Vol 5 (66) ◽  
pp. 53870-53873 ◽  
Author(s):  
Xiaobai Li ◽  
Hongwei Ma ◽  
Hailong Wang ◽  
Shitong Zhang ◽  
Zhenhua Jiang ◽  
...  
Keyword(s):  
High Temperature ◽  
Phosphoric Acid ◽  
Proton Conductivity ◽  
Doping Level ◽  
High Stability ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
High Proton Conductivity ◽  
High Doping Level ◽  
High Proton

This work outlines polybenzimidazole-based high temperature proton exchange membranes with a high phosphoric acid-doping level, high proton conductivity and high stability.

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