Synthesis of polybenzimidazoles having improved processability by introducing two and three ether groups in a repeating unit

Kim, Eun-Ki; Jung, Ji‐Won; Cho, Kyunghwa; Yun, Gun Jin; Lee, Jong-Chan

doi:10.1016/j.eurpolymj.2021.110900

Cited by 7 publications

(3 citation statements)

References 44 publications

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“…The glass transition temperature (T g ) of the PBI is found at 367 °C, in good accordance with the literature. [53] The T g of the PVIm measured at 135 °C was slightly lower than the literature value [52] at 148 °C, possibly attributed to the impurities, i.e., water and NMP in PVIm polymer. Remarkably, a single T g was observed for composite membranes PBI-VED-25%, 40%, and 50%, indicating favorable miscibility and effective chain entanglement between the PVIm and the PBI, thus the formation of sIPN structure.…”

Section: Formation Of Sipn Membranes Thermal Structural Propertiesmentioning

confidence: 61%

Achieving 1060 mW cm⁻² with 0.6 mg cm⁻² Pt Loading Based on Imidazole‐Riched Semi‐Interpenetrating Proton Exchange Membrane at High‐Temperature Fuel Cells

Lin,

Wang,

Bin

et al. 2024

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Enhancing phosphoric acid (PA) doping in polybenzimidazole (PBI) membranes is crucial for improving the performance of high‐temperature proton exchange membrane fuel cells (HT‐PEMFCs). However, excessive PA uptake often leads to drawbacks such as PA loss and compromised mechanical properties when surpassing PA capacity of PBI basic functionality. Herein, a new strategy that integrates high PA uptake, mechanical strength, and acid retention is proposed by embedding linear PBI chains into a crosslinked poly(N‐vinylimidazole) (PVIm) backbone via in‐situ polymerization. The imidazole (Im)‐riched semi‐interpenetrating polymer network (sIPN) membrane with high‐density nitrogen moieties, significantly enhancing the PA doping degree to 380% shows an excellent conductivity (0.108 S cm−1). Meanwhile, the crosslinking structure in the sIPN membrane ensures adequate mechanical properties, low hydrogen permeability, and a relatively low swelling ratio. As a result, the single cell based on the membrane achieves the highest power density of 1060 mW cm−2 with a low Pt loading (0.6 mg cm−2) up to now and exhibits excellent fuel cell stability.

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Section: Formation Of Sipn Membranes Thermal Structural Propertiesmentioning

confidence: 61%

Achieving 1060 mW cm⁻² with 0.6 mg cm⁻² Pt Loading Based on Imidazole‐Riched Semi‐Interpenetrating Proton Exchange Membrane at High‐Temperature Fuel Cells

Lin,

Wang,

Bin

et al. 2024

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“…p-OPBI-X与OPBI和p-PBI的性质比较 [23] Table 1 Comparison of properties between p-OPBI-X,OPBI and p-PBI [23] 聚合物溶解(DMAc中)/mg 图 4 DOPBI和TOPBI的合成 [24] Figure 4 Synthesis of DOPBI and TOPBI [24] S 图 5 在伊顿试剂中合成聚苯并咪唑 [27] Figure 5 Synthesis of polybenzimidazole using Eaton's reagent as a solvent [27] (亚苯基)-5，5′二苯并咪唑](p-PBI)的共聚物(Co-…”

Section: 下，后者的工作温度为 100~200℃。相较于lt-unclassified

Progress in High Temperature Proton Exchange Membranes for Fuel Cell

Li,

Ji,

et al. 2023

JES

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Owing to their facile hydrothermal management and high carbon monoxide tolerance, high temperature proton exchange membrane fuel cells (HT-PEMFCs) exhibit promising potential for various applications. In particular, high temperature proton exchange membranes (HTPEMs), as the core components of HT-PEMFCs, determine the performance of HT-PEMFCs. This paper primarily focuses on methods for improving the solubility and proton conductivity of HTPEMs. To address the current challenges encountered by HT-PEMFCs, various methods, including main chain structure design, co-blending, grafting, cross-linking, composite doping, and modifications of membrane morphology, are summarized.

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“…Since Vogel and Marvel reported the first PBI synthesis via high-temperature melt condensation in the early 1960s [17], other synthetic methods have been developed to obtain better processable PBIs under milder conditions [3,[18][19][20][21][22][23][24][25]. Mostly, for laboratory scale production, PBIs are synthesized by direct polycondensation between an aromatic dicarboxylic acid and tetraamine in an acidic media using a polyphosphoric acid (PPA) or Eaton's reagent (ER) at high temperatures (200 • C or more in PPA and 140 • C in ER).…”

Section: Introductionmentioning

confidence: 99%

Effect of the Acid Medium on the Synthesis of Polybenzimidazoles Using Eaton’s Reagent

et al. 2023

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The influence of trifluoromethanesulfonic (TFSA) superacid on conditions of the synthesis of polybenzimidazoles, such as OPBI and CF3PBI, was studied. It was shown that the polycondensations proceeded smoother and at lower temperatures in the presence of the TFSA in Eaton’s Reagent and that polymers of high molecular weights, and readily soluble in organic solvents, were obtained. The effect was more pronounced for CF3PBI, where the low reactivity monomer, 4,4′ (hexafluoroisoproylidene)bis (benzoic acid), was used. CF3PBI was obtained at a moderate temperature of 140 °C with no gel fraction and exhibited an inherent viscosity twice higher than the one obtained by the traditional method. In fact, the addition of TFSA allows for the obtention of soluble N-phenyl substituted CF3PBI by direct synthesis, which had not been obtained otherwise. Thus, the use of TFSA is a good media for the synthesis of N-substituted PBIs under relatively mild conditions.

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Synthesis of polybenzimidazoles having improved processability by introducing two and three ether groups in a repeating unit

Cited by 7 publications

References 44 publications

Achieving 1060 mW cm⁻² with 0.6 mg cm⁻² Pt Loading Based on Imidazole‐Riched Semi‐Interpenetrating Proton Exchange Membrane at High‐Temperature Fuel Cells

Achieving 1060 mW cm⁻² with 0.6 mg cm⁻² Pt Loading Based on Imidazole‐Riched Semi‐Interpenetrating Proton Exchange Membrane at High‐Temperature Fuel Cells

Progress in High Temperature Proton Exchange Membranes for Fuel Cell

Effect of the Acid Medium on the Synthesis of Polybenzimidazoles Using Eaton’s Reagent

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Synthesis of polybenzimidazoles having improved processability by introducing two and three ether groups in a repeating unit

Cited by 7 publications

References 44 publications

Achieving 1060 mW cm−2 with 0.6 mg cm−2 Pt Loading Based on Imidazole‐Riched Semi‐Interpenetrating Proton Exchange Membrane at High‐Temperature Fuel Cells

Achieving 1060 mW cm−2 with 0.6 mg cm−2 Pt Loading Based on Imidazole‐Riched Semi‐Interpenetrating Proton Exchange Membrane at High‐Temperature Fuel Cells

Progress in High Temperature Proton Exchange Membranes for Fuel Cell

Effect of the Acid Medium on the Synthesis of Polybenzimidazoles Using Eaton’s Reagent

Contact Info

Product

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Achieving 1060 mW cm⁻² with 0.6 mg cm⁻² Pt Loading Based on Imidazole‐Riched Semi‐Interpenetrating Proton Exchange Membrane at High‐Temperature Fuel Cells

Achieving 1060 mW cm⁻² with 0.6 mg cm⁻² Pt Loading Based on Imidazole‐Riched Semi‐Interpenetrating Proton Exchange Membrane at High‐Temperature Fuel Cells