Crosslinked poly(ether ether ketone): cost-effective proton exchange membranes for fuel cell application

Abstract

Sulphonated poly(ether ether ketone) copolymers bearing pendant carboxylic acid (SPEEK-C) have been synthesized via nucleophilic condensation reaction of 4,4-difluorobenzophenone, sulphonated 4,4-difluorobenzophenone and 3,5-dihydroxy benzoic acid. The structure of the sulphonated copolymer was identified from FT-IR and 1 H-NMR spectrum. The pendant carboxylic groups of SPEEK-C were further crosslinked with poly(vinyl alcohol) (PVA) to fabricate the crosslinked (SPEEK/PVA) membranes. The performance of the membranes was evaluated in terms of water uptake, proton conductivity and oxidative stability. The thermal stabilities of the membranes were determined by thermogravimetric analysis and differential scanning calorimetry techniques, whereas the morphological analysis was performed by atomic force microscopy.

Functionalized carbon nanotube and carbon nanodot modified multiblock poly(arylene ether ketone sulfone) copolymer as proton exchange composite membranes for fuel cell applications

“…Table S2 also summarizes the LOI values of all prepared membranes. Awasthi et al 49 . reported that polymer membranes with LOI values greater than 26 are considered to have self‐extinguishing behavior.…”

“…Table S2 also summarizes the LOI values of all prepared membranes. Awasthi et al 49 reported that polymer membranes with LOI values greater than 26 are considered to have selfextinguishing behavior. The f-CNTs/f-CNDs based composite membranes do exhibit LOI values greater than 26 which proves their flame retardant nature.…”

“…Proton conductivity and ion exchange capacity IEC and proton conductivity are the two major parameters related to the PEM fuel cell 49 and were determined by the acid-base titration method and the four-point probe technique at room temperature, respectively. Table S3 elucidates the proton conductivity and IEC values of the pristine, EFN crosslinked and EFN with f-CNT based composite membranes of N 1 , N 2 and N 3 multiblock copolymers, respectively.…”

Precise modification of poly(aryl ether ketone sulfone) proton exchange membranes with positively charged bismuth oxide clusters for high proton conduction performance

“…The monomer was synthesized according to the method reported by Chen and Awasthi; some modifications had been added. 36,37 4,4′-dichlorodiphenylsulfone (14.358 g, 50 mmol) and 30 ml fuming sulfuric acid (20% SO 3 ) were placed in a round bottom flask and the solution was stirred at 40 • C to dissolve; an amber homogeneous transparent solution was obtained. The mixture was slowly heated to 110 • C and held at this temperature for 10 h. After heating, the mixture was cooled down to room temperature and 370 ml ice water was added.…”

Carbon Nanotubes Doped Poly (arylene) Ether Copolymerised Multiblock Based Proton Exchange Composite Membranes for Fuel Cell Application

“…Also, due to the structural and morphological differences, the random copolymers shows the difference in exchange capacities (IEC) which influence the stability and conductivity of membranes. [15][16][17][18] Therefore, the present study aimed to develop multiblock copolymer membranes, which could exhibit well-defined nanophase morphologies, display better hydrolytic stability and facilitate high proton conductivity with a well-connected hydrophobic segment that could also provide dimensional stability and durability. The possibility of randomization of hydrophilic-hydrophobic arrangement at high reaction temperatures as reported by James E. McGrath et al, 2008, was addressed by end-capping the phenoxide telechelic functionality bearing hydrophobic oligomer by highly reactive perfluorinated end group, decafluorobiphenyl (DFBP) monomer.…”