Proton exchange membranes prepared by grafting of styrene/divinylbenzene into crosslinked PTFE membranes

Synthesis and characterization of PEFC membranes based on fluorinated-polymer-alloy using pre-soft-EB grafting method

“…The fabricated PEM based on crosslinked materials showed the high ion exchange capacity (IEC), reducing the crossover of fuels such as hydrogen gas and improved thermal properties, compared with conventional PFSA. However, the obtained PEMs showed the deterioration of mechanical properties and higher water uptake compared with conventional PFSA when those have the higher grafting yields [13][14][15][16][17].…”

“…It was suggested that the pre-irradiation grafting method should be powerful tools to fabricate low cost PEMs [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. For examples, in the Scherer's group at Paul Scherer Institute (PSI) [3,4,7,12] and Nasef's group at Malaysia University [5,8], their groups have studied PEMs based on non-crosslinked tetrafluoroethylene-co-hexafluoropropylene (FEP) for PEFC.…”

“…Our research group has studied the partially fluorinated PEMs applying soft electron beam (soft-EB) grafting onto crosslinked polytetrafluoroethylene (RX-PTFE), crosslinked fluorinated co-polymer films (FEP, PFA, ETFE), or crosslinked FEP/PTFE polymer-alloys with styrene monomers using pre-irradiation grafting method in gas and in liquid phase, respectively [6,[13][14][15][16][17]21]. The fabricated PEM based on crosslinked materials showed the high ion exchange capacity (IEC), reducing the crossover of fuels such as hydrogen gas and improved thermal properties, compared with conventional PFSA.…”

Performance of membrane electrode assemblies based on proton exchange membranes prepared by pre-irradiation induced grafting

“…Details of the preparation and characterization of the PEMs were reported in our previous papers [18,20].…”

“…Our research group is developing new PEMs based on RX-PTFE films with different crosslinking density by pre-irradiation induced graft polymerization of S and co-monomers and successive sulfonation [14][15][16][17][18][19][20][21]. In previous research we found that using the crosslinker co-monomer, DVB, in the grafting system, resulted in some difference in the properties of the PEMs: (i) the formation of the network structure in the poly(styrene-sulfonic acid) (PS-SA) graft chains effectively suppressed the water uptake of the PEMs due to the restrained PS-SA chains mobility [20], (ii) as observed by XPS analysis, the surfaces of the PEMs grafted by S were C-atom rich, while the surfaces of the PEMs grafted by S together with DVB were F-atom rich [17], (iii) the chemical resistance of the PEMs grafted by S/DVB to the oxidative radicals are much higher than those grafted by S. Also, the increasing in the crosslinking density of the RX-PTFE films has a positive effect on improving the chemical resistance of the PEMs [18,20].…”