Comparative study on the preparation and properties of radiation‐grafted polymer electrolyte membranes based on fluoropolymer films

Abstract

In this study the fluoropolymers, poly(ethylene-co-tetrafluoroethylene) (ETFE) and poly(vinylidene fluoride) (PVDF) films, together with the radiation-induced crosslinked polytetrafluoroethylene (cPTFE) film were compared on the basis of their preparation and properties of radiation-grafted polymer electrolyte membranes. The polymer electrolyte membranes were prepared by radiation grafting of styrene into the base films and subsequent sulfonation. The proton conductivity and chemical stability of the three types of membranes with a similar ion exchange capacity (IEC) near 1.0 mmol/g were investigated and are discussed in detail. Although the ETFE-based polymer electrolyte membrane was relatively more stable, its proton conductivity was lower than those of the PVDF-and cPTFEbased membranes. On the other hand, the cPTFE-based membrane showed a significantly higher proton conductivity, but its chemical stability was shorter than that of the ETFE-based membrane. It is considered that the difference in the preparation and properties of the polymer electrolyte membranes was due to the difference in the degree of crystallinity as well as in the chemical structure of the fluoropolymer base films.

In situ polymerization: A novel route for thermally stable proton-conductive membranes

“…Pore filling/soaking/grafting method [5][6][7][8][9][10][11][12][13]: Using an available inert matrix by pore soaking, pore filling or pore grafting, polymerization of monomers is conducted. The base membrane is sulfonated by a strong acid.…”

“…Thus, there is a strong desire to find new ways of producing PCMs that combine a high level of performance with low cost. The common alternative is the development of nonperfluorosulfonated membranes [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] using versatile methods, as summarized below.…”

Variation in viscosity and ion conductivity of a polymer-salt complex exposed to gamma irradiation

“…A large number of reports on irradiation effects in polymers and particularly solid polymer electrolytes have appeared [3,[18][19][20][21]. Ferloni et al [19] have irradiated aqueous solutions of PEO 20 -LiClO 4 .…”

“…Both processes may occur simultaneously, but usually one dominates [1,2]. This is manifested in the different physical and electrical properties of solid polymer electrolytes (SPE) as well [3]. Since polymer electrolytes are extensively used in practical devices and appliances [4], it is helpful to study the effect of irradiation on them.…”

EFFECT OF PRE- Γ-Irradiation DOSE ON THE DURABILITY OF THE SULFONATED ETFE-G-POLYSTYRENE CONDUCTING MEMBRANES

“…On the other hand, the degree of grafting of about 30% can be prepared in a long grafting time when a low pre-irradiation dose was carried out. In the case of longer grafting time, the longer graft chains can be obtained [12][13][14] . In this work, we studied the effect of graft conditions, particularly radiation dose and grafting time on the durability of the sulfonated polystyrene-grafted ETFE polymer electrolyte membranes for fuel cells.…”