Pore-filling electrolyte membranes based on microporous polyethylene matrices activated with plasma and sulfonated hydrogenated styrene butadiene block copolymer. Synthesis, microstructural and electrical characterization

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 46; no. 16; pp. 1684 - 1695
• Main Authors: Navarro, Amparo, del Río, Carmen, Acosta, José Luis
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15-08-2008; Wiley
• Subjects: Applied sciences; block copolymer; coatings; Exact sciences and technology; Exchange resins and membranes; Forms of application and semi-finished materials; fuel cells; polyethylene (PE); Polymer industry, paints, wood; pore-filling electrolyte membrane; Technology of polymers; Transport properties; Porous membrane; SEBS; In situ; Plasma assisted processing; polyethylene (PE); Polymer solid electrolyte; Water permeability; Styrenesulfonate copolymer; fuel cells; Sulfonation; Water absorption; Polyethylene; pore-filling electrolyte membrane; Butadiene derivative copolymer; Experimental study; Chemical coupling; Molecule scattering; Saturated copolymer; block copolymer; Triblock copolymer; Chemical modification; coatings; Morphology; Preparation; Cation exchange membrane; Membrane pore; Liquid permeability
• ISSN: 0887-6266; 1099-0488
• DOI: 10.1002/polb.21505

In this research a series of pore-filling electrolyte membranes were prepared, based on a sulfonated and hydrogenated styrene/butadiene block copolymer (SHSBS) and plasma-treated microporous polyethylene (PE) membranes. The pore-filling electrolyte membranes were characterized by means of scanning electronic microscopy (SEM), infrared spectroscopy (FTIR-ATR), and dynamic mechanical analysis (DMA). In addition, the water uptake and methanol/water uptake capacities of these membranes were determined using several methanol in water solutions, as well as the permeability coefficients, for both water and methanol, using a 2 M methanol in water solution and pure methanol. Finally, electrical behavior was recorded by means of electrochemical impedance spectroscopy (EIS) and the four probe technique (FPT). The SEM images recorded show good coating of the pore-filling electrolyte membranes on the plasma-treated PE matrices, and DMA shows the proper relaxations of the two components: PE and SHSBS. Furthermore, the methanol/water absorption capacity was observed to diminish with plasma treatment of the matrix. Methanol permeability of the pore-filling electrolyte membranes is notably lower than that of the Nafion® membrane, ion conductivity moving in the order of 10⁻² S cm⁻¹. Both of these characteristics qualify the experimental membranes as candidates to be applied as proton exchangers in fuel cells (FCs).