Anion Exchange Membrane Based on Sulfonated Poly (Styrene-Ethylene-Butylene-Styrene) Copolymers

Area of Science:

• Materials Science
• Polymer Chemistry
• Electrochemistry

Background:

• Anion exchange membranes (AEMs) are crucial for electrochemical devices.
• Developing AEMs with high ionic conductivity and stability remains a challenge.
• Sulfonated poly(styrene-ethylene-butylene-styrene) (S-SEBS) offers a promising base material.

Purpose of the Study:

• To synthesize and characterize a novel anion exchange membrane based on S-SEBS.
• To enhance the ionic conducting properties of S-SEBS through maleic anhydride (MA) grafting.
• To evaluate the electrochemical and mechanical performance of the modified membrane.

Main Methods:

• Anion exchange membranes were prepared using the casting method.
• S-SEBS was modified by introducing sulfonic acid groups and grafting with MA.
• Membrane characterization included FT-IR, DMA, and AFM.
• Electrochemical properties (water uptake, impedance spectroscopy, ionic conductivity, IEC) were measured.

Main Results:

• The modified S-SEBS-g-MA membranes exhibited well-defined ionic channels.
• The S-SEBS-g-MA anion exchange membrane achieved an ionic conductivity of 0.25 S/cm at 100% relative humidity.
• Water uptake capacity was measured at 72.5%.
• The modified membranes demonstrated excellent mechanical and chemical stability.

Conclusions:

• Grafting MA onto S-SEBS effectively enhances ionic conductivity and water uptake.
• The resulting S-SEBS-g-MA membrane is a robust material for anion exchange applications.
• The developed membrane shows potential for use in electrochemical devices requiring stable AEMs.