Effect of crosslinkers on the preparation and properties of ETFE-based radiation-grafted polymer electrolyte membranes

This study concerns a comparative study of three crosslinkers, divinylbenzene (DVB), 1,2-bis(p,p-vinylphenyl)ethane (BVPE), and triallyl cyanurate (TAC) crosslinked poly(ethylene-co-tetrafluoroethylene) (ETFE)-based radiation-grafted membranes, which were prepared by radiation grafting of p-methylstyrene onto ETFE films and subsequent sulfonation. The effect of the different types and contents of the crosslinkers on the grafting and sulfonation, and the properties such as water uptake, proton conductivity, and thermal/chemical stability of the resulting polymer electrolyte membranes were investigated in detail. Introducing crosslink structure into the radiation-grafted membranes leads to a decrease in proton conductivity due to the decrease in water uptake. The thermal stability of the crosslinked radiation-grafted membranes is also somewhat lower than that of the noncrosslinked one. However, the crosslinked radiation-grafted membranes show significantly higher chemical stability characterized in the 3% H2O2 at 50°C. Among the three crosslinkers, the DVB shows a most pronounced efficiency on the crosslinking of the radiation-grafted membranes, while the TAC has no significant influence; the BVPE is a mild and effective crosslinker, showing the moderate influence between the DVB and TAC crosslinkers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4565–4574, 2006

[1]  T. Yamaki,et al.  Preparation of sulfonated crosslinked PTFE-graft-poly(alkyl vinyl ether) membranes for polymer electrolyte membrane fuel cells by radiation processing , 2005 .

[2]  K. Scott,et al.  Grafted polymer electrolyte membrane for direct methanol fuel cells , 2005 .

[3]  M. Washio,et al.  Pre-irradiation induced grafting of styrene into crosslinked and non-crosslinked polytetrafluoroethylene films for polymer electrolyte fuel cell applications. II: Characterization of the styrene grafted films , 2005 .

[4]  M. Nasef,et al.  Preparation and applications of ion exchange membranes by radiation-induced graft copolymerization of polar monomers onto non-polar films , 2004 .

[5]  Tim R. Dargaville,et al.  High energy radiation grafting of fluoropolymers , 2003 .

[6]  G. Sundholm,et al.  Membrane Durability in a PEM Fuel Cell Studied Using PVDF Based Radiation Grafted Membranes , 2003 .

[7]  R. Slade,et al.  The radiation-grafting of vinylbenzyl chloride onto poly(hexafluoropropylene-co-tetrafluoroethylene) films with subsequent conversion to alkaline anion-exchange membranes: optimisation of the experimental conditions and characterisation , 2003 .

[8]  W. M. Taama,et al.  Salt splitting with radiation grafted PVDF membranes , 2003 .

[9]  A. Tsukada,et al.  Radiation-grafted membrane/electrode assemblies with improved interface , 2002 .

[10]  K. V. Lovell,et al.  Comparison of fuel cell performance of selected fluoropolymer and hydrocarbon based grafted copolymers incorporating acrylic acid and styrene sulfonic acid , 2002 .

[11]  G. Inzelt,et al.  Electron and proton conducting polymers: Recent developments and prospects , 2000 .

[12]  G. Sundholm,et al.  Effect of crosslinking on the physicochemical properties of proton conducting PVDF-g-PSSA membranes , 1999 .

[13]  F. Sundholm,et al.  Synthesis and properties of sulfonated and crosslinked poly[(vinylidene fluoride)-graft-styrene] membranes , 1998 .

[14]  B. Gupta,et al.  Performance of Differently Cross‐Linked, Partially Fluorinated Proton Exchange Membranes in Polymer Electrolyte Fuel Cells , 1995 .

[15]  B. Gupta,et al.  Materials research aspects of organic solid proton conductors , 1993 .

[16]  R. Hollandsworth,et al.  Preparation of oxidatively stable cation-exchange membranes by the elimination of tertiary hydrogens , 1991 .

[17]  H. Bialy Toeprints and T7 Help Elucidate Translation , 1986, Bio/Technology.

[18]  J. L. Garnett,et al.  Polyfunctional monomers as additives for enhancing the radiation copolymerization of styrene with polyethylene, polypropylene, and PVC , 1982 .

[19]  T. Schmidt,et al.  Influence of Cross-Linking on Performance of Radiation-Grafted and Sulfonated FEP 25 Membranes in H 2 ­ O 2 PEFC , 2005 .

[20]  E. Roduner,et al.  EPR investigation of HO/ radical initiated degradation reactions of sulfonated aromatics as model compounds for fuel cell proton conducting membranes , 1999 .