Nano-ordered aromatic/alicyclic polybenzimidazole blend membranes

Kumar, B. Satheesh; Sana, Balakondareddy; Unnikrishnan, G.; Jana, Tushar; Kumar, Krishna

doi:10.1016/j.reactfunctpolym.2019.06.020

Cited by 2 publications

(2 citation statements)

References 67 publications

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“…T g values were determined from the temperature dependence of Tan δ ( Figure 4 b,c). As can be seen, all aliphatic PBIs have significantly lower T g in comparison to fully aromatic ones [ 5 , 31 , 42 , 45 ], which is attributed to the increased flexibility of the macromolecules containing aliphatic groups. Moreover, a general reduction in T g from C7-PBI to C14-PBI was observed, which could be due to the decrease in macromolecular rigidity with an increase in the number of methylene units.…”

Section: Resultsmentioning

confidence: 99%

Aliphatic Polybenzimidazoles: Synthesis, Characterization and High-Temperature Shape-Memory Performance

et al. 2023

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A series of aliphatic polybenzimidazoles (PBIs) with methylene groups of varying length were synthesized by the high-temperature polycondensation of 3,3′-diaminobenzidine (DAB) and the corresponding aliphatic dicarboxylic acid in Eaton’s reagent. The influence of the length of the methylene chain on PBIs’ properties was investigated by solution viscometry, thermogravimetric analysis, mechanical testing and dynamic mechanical analysis. All PBIs exhibited high mechanical strength (up to 129.3 ± 7.1 MPa), glass transition temperature (≥200 °C) and thermal decomposition temperature (≥460 °C). Moreover, all of the synthesized aliphatic PBIs possess a shape-memory effect, which is a result of the presence of soft aliphatic segments and rigid bis-benzimidazole groups in the macromolecules, as well as strong intermolecular hydrogen bonds that serve as non-covalent crosslinks. Among the studied polymers, the PBI based on DAB and dodecanedioic acid has high adequate mechanical and thermal properties and demonstrates the highest shape-fixity ratio and shape-recovery ratio of 99.6% and 95.6%, respectively. Because of these properties, aliphatic PBIs have great potential to be used as high-temperature materials for application in different high-tech fields, including the aerospace industry and structural component industries.

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Section: Resultsmentioning

confidence: 99%

Aliphatic Polybenzimidazoles: Synthesis, Characterization and High-Temperature Shape-Memory Performance

et al. 2023

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“…Mechanical degradation of the PA-doped PBI membranes is the primary reason for PEMFC performance degradation . There are many studies on this tradeoff, such as blending with other polymers, − modification of the backbone or the side chain, − crosslinking, − block modification, compositing with nanoparticles or organic–inorganic fillers, − and so on. Among them, block modification is an effective method to improve the PEM performance.…”

Section: Introductionmentioning

confidence: 99%

High-Performance Proton Exchange Membranes Based on Block Polybenzimidazole and Organic–Inorganic Fillers with a Low Acid Doping Level

Wang

et al. 2022

ACS Appl. Energy Mater.

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Herein, composite proton exchange membranes based on block polybenzimidazole (bPBI) and a phosphotungstic acid-ionic liquid (PWA-IL) organic−inorganic filler have been prepared. The bPBI was prepared by block copolymerization of poly[2,2′-(p-phenylene)-5,5′benzimidazole] and poly(4,4′-diphenylether-5,5′-bibenzimidazole) oligomers. bPBI combined the advantages of both rigid and flexible segments. The block structure of the segmented block copolymer helped build proton transmission channels and made the transmission of protons easier. The PWA-IL was evenly distributed in the membranes. The PWA-IL has good electrochemical properties and can also form hydrogen bonds with phosphoric acid (PA), which is beneficial to proton conduction. The membranes had excellent mechanical properties (11 MPa) owing to the low acid doping level (ADL). Moreover, the membranes exhibit 0.05 S cm −1 proton conductivity at 170 °C at a low ADL and exhibit over 60% PA retention.

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Nano-ordered aromatic/alicyclic polybenzimidazole blend membranes

Cited by 2 publications

References 67 publications

Aliphatic Polybenzimidazoles: Synthesis, Characterization and High-Temperature Shape-Memory Performance

Aliphatic Polybenzimidazoles: Synthesis, Characterization and High-Temperature Shape-Memory Performance

High-Performance Proton Exchange Membranes Based on Block Polybenzimidazole and Organic–Inorganic Fillers with a Low Acid Doping Level

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