Synthesis and characterization of poly(ethylene oxide‐co‐ethylene carbonate) macromonomers and their use in the preparation of crosslinked polymer electrolytes

Abstract

Methacrylate‐functionalized poly(ethylene oxide‐co‐ethylene carbonate) macromonomers were prepared in two steps by the anionic ring‐opening polymerization of ethylene carbonate at 180 °C, with potassium methoxide as the initiator, followed by the reaction of the terminal hydroxyl groups of the polymers with methacryloyl chloride. The molecular weight of the polymer went through a maximum after approximately 45 min of polymerization, and the content of ethylene carbonate units in the polymer decreased with the reaction time. A polymer having a number‐average molecular weight of 2650 g mol−1 and an ethylene carbonate content of 28 mol % was selected and used to prepare a macromonomer, which was subsequently polymerized by UV irradiation in the presence of different concentrations of lithium bis(trifluoromethanesulfonyl)imide salt. The resulting self‐supportive crosslinked polymer electrolyte membranes reached ionic conductivities of 6.3 × 10−6 S cm−1 at 20 °C. The coordination of the lithium ions by both the ether and carbonate oxygens in the polymer structure was indicated by Fourier transform infrared spectroscopy. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2195–2205, 2006

Characterization of crosslinked poly(vinyl alcohol)‐based membranes with different hydrolysis degrees for their use as electrolytes in direct methanol fuel cells

“…Finally, a weaker process is observed in the 400–500°C region which is attributed to the degradation of the polymeric backbone (Process 3). The results are in agreement with those reported in the literature 6, 24, 25…”

“…In response to this challenge, intense research has focused on the design of new materials having improved transport properties compared to the commercial membranes presently used as electrolytes in fuel cells, such as Nafion 5. The aim of this work is to prepare materials with structures that combine high water contents to facilitate and promote proton conductivity with low methanol permeability to avoid fuel crossover 6. To achieve this goal in a rational manner, we must both understand the morphology of the membrane, and learn how to control several parameters such as the interactions between functional groups, the organization of absorbed water, the extent of hydrogen bonding, and the chemical environment of the proton conducting groups.…”

Synthesis of Poly[(ethylene carbonate)‐co‐(ethylene oxide)] Copolymer by Phosphazene‐Catalyzed ROP

“…It clearly shows that the proton d (at δ = 4.27) is related -20 and + 20 ° C was observed. [ 30 ] This is understandable because either EC or EO segments are so short that they can not fold or pack in ordered crystalline domains. DSC results also show that the copolymer has only one glass transition temperature ( T g ) around -42 ° C, further indicating that the copolymer chain is amorphous.…”

Synthesis and properties of random copolymers of 2,2‐dimethyltrimethylene carbonate and ethylene carbonate catalyzed by lanthanide tris(2,6‐di‐tert‐butyl‐4‐methylphenolate)

“…[28][29][30][31] Usually, the polymerization of EC is accompanied by decarboxylation, which most likely involves metal carbonate species formation due to ring opening via CAO bond cleavage. 1,21,32 The absence of a signal between 3.10 and 3.30 ppm indicates that the polymers obtained with Ln(DBMP) 3 are free of ether units developed from carbon dioxide elimination of EC or DTC, and this indicates that these lanthanide complexes are efficient catalysts for the synthesis of aliphatic polycarbonates at reasonably low temperatures. 28,29 The SEC measurements showed that poly(DTC-co-EC)s with high molecular weights as well as reasonably narrow molecular weight distributions were successfully prepared with La(DBMP) 3 .…”