Proton conducting blends based on polysulfones and elastomers

Abstract

ABSTRACT:With the aim of improving the performance of conventional proton conducting membranes, systems based on two poly(arylene ether sulfone)s and two elastomers were obtained by heterogeneous sulfonation with chlorosulfonic acid. Subsequently, they were characterized, morphologically and electrically, by techniques such as infrared spectroscopy (FTIR), differential scanning calorimetry, dynamic-mechanical analysis, and complex impedance spectroscopy. From the results, it was verified that the reaction of sulfonation had taken place, as well as that these materials formed incompatible and good proton conducting blends. In addition, the storage modulus and the conductivity were subjected to a statistical design to predict the optimum composition, presenting the best mechanical and conducting proton values and as a consequence the most suitable membrane from the point of view of its application in the field of the fuel cells. Very promising results have been found especially with membranes based on binary blends constituted by thermoplastic/elastomer polymers.

New route to functional polyolefins: sulfonation of poly[ethylene‐co‐(5,7‐dimethylocta‐1,6‐diene)] and evaluation of properties

“…This is explained by the disruptive effect of the introduction of sulfonate groups that limit the maximum size of the crystallites and therefore results in lower T m and f c values. These observations are also in agreement with those for other sulfonated copolymers reported in the literature . Nevertheless, the decrease in T m and f c values is not very substantial, showing that this procedure does not alter markedly the physical properties of the polymer.…”

“…The copolymer was sulfonated using the procedure developed by Linares et al . Briefly, the copolymer was sulfonated as films which were obtained by placing polymer samples ( ca 10 mg) between stainless steel plates at the same temperature and pressure and held there for about 1 min.…”

Mechanical and Dynamic Mechanical Analysis of Proton‐Conducting Polymers

“…On the other hand, wholly aromatic polymers are thought to be one of the most promising routes to high-performance PEMs. Polymers such as poly(arylether ketones) and derivatives [32], polyimides [33], polyphenylene oxide [34], polybenzimidazoles [35], polysulfones [36,37], and perfluoroalkyl sulfonic acid modified derivatives [38,39] and polystyrene derivatives [40] are then largely studied, and an effective approach is the functionalization of such materials (see Chapter 9).…”

“…In an early study, Linares prepared incompatible proton-conducting blends based on polysulfones and elastomers [36].…”

Proton Conducting Hybrid Membranes Based on Aromatic Polymers Blends for Direct Methanol Fuel Cell Applications

“…In our group, attention has been focused on aromatic main chain polymers such as polyetheretherketone (PEEK) and polyphenylsulphone (PPSU). These polymers show excellent chemical resistance, high thermo-oxidative stability, good mechanical properties, ease of direct functionalisation, low cost, and, when adequately sulphonated, good conductivity [7,8]. Several approaches have been followed to modulate the ratio between hydrophilic and hydrophobic domains: such ratio, in fact, determines hydrolytic stability and conductivity, whose balance will eventually be responsible for the electrolyte performance under FC operating conditions [9].…”