Proton conductive reinforced poly(ethylene‐co‐styrene) membranes

Abstract

Polymers with ionic conductivity are useful materials for ion exchange membranes, separators, and electrolytes in electrochemical cells. New ionomers are currently being sought to replace the ionomers, which contain fluorine and are harmful to environment and expensive. A new and promising ionomer is a sulfonated ethylene/styrene copolymer. A nearby alternating copolymer with styrene content of 47 mol % was polymerized with metallocene/MAO catalyst. Membranes were prepared by hot-pressing copolymer films with a glassfiber tissue. Phenyl rings in the copolymers were sulfonated with chlorosulfonic acid as a sulfonating agent. As the alternating structure of the copolymer, sulfonic groups were evenly distributed along the membranes. The membranes were characterized by determining water uptake, ion exchange capacity, proton conductivity, and mechanical properties. The studies revealed that the sulfonated copolymers have promising properties for proton-conducting applications. All membranes had good ion exchange capacity, $ 3.5 meq/g, and proton conductivity, over 50 mS/ cm. Due to the high water uptake of the sulfonated copolymer, mechanical properties of the membranes were improved by using the glassfiber tissue as reinforcement.

Sodium ion dynamics in a sulfonate based ionomer system studied by 23Na solid-state nuclear magnetic resonance and impedance spectroscopy

“…Several sulfonate-based single-ion conducting ionomer systems have been developed including those based on poly(2-acrylamido-2-methyl-1-propane-sulfonate) (PAMPS) [22,25], copolymers of sulfonate polyesters [26,27], sulfonated ethylene and styrene systems [28] and styrene-ethylene and butylenestyrene systems [29,30]. Very recently, Noor et al studied a series of PAMPS-based systems containing both Na + and the methyltriethyl ammonium cation (N 1222 , where the subscript numbers indicate the number of carbon sites in each alkyl chain) [31,32].…”

Studies on Glass Fiber-Reinforced Poly(Ethylene-Grafted-Styrene)-Based Cation Exchange Membrane Composite

“…He confirmed that short polypropylene fibers rapidly increased the mechanical strength in machine direction. Annala et al reported that the storage modulus and loss modulus of sulfonated ethylene/styrene copolymer were improved moderately after adding GF [ 23 ]. The strengthening effect of GF on composite was confined without surface modification.…”

Ion conduction and phase morphology in sulfonate copolymer ionomers based on ionic liquid–sodium cation mixtures

“…Numerous singleion conductor ionomer systems have been developed over the years; for example those based on poly(2-acrylamido-2-methyl-1-propane-sulfonic acid) (PAMPS) 11,12 and copolymers of sulfonate polyester, sulfonated ethylene/styrene and styreneethylene/butylene-styrene. [13][14][15][16][17] In general, however, the anion on the polymer backbone is somewhat basic, from which the cation does not readily dissociate, resulting in low ionic conductivity. A number of methods have been employed in an attempt to increase the ionic conductivity; for example the AMPS monomer has been copolymerized with N,N 0 -dimethylacrylamide (DMAA) to separate the ionic moieties along the backbone and thereby avoid multiple anion association to the cation.…”