(128e) Sulfonated Block Copolymer Membranes

Numerous researchers have studied sulfonated styrenic block copolymers as semi-permeable membranes for various applications. Traditionally, the styrenic endblocks of triblock copolymers have been sulfonated, as was first practiced by Kraton Polymers as far back as the late 1960's. Under this process, once the polymer is hydrated, water plasticizes the endblocks which results in a significant degradation in the mechanical properties. Recently designed sulfonated block copolymer structures have been obtained that have continuous ionic domains and retain strength when fully hydrated. Utilizing 40+ years of experience in block copolymer structure and morphology, Kraton Polymers is now able to tailor the properties of the sulfonated polymer membranes via numerous methodologies including polymer structure, placement of sulfonic acid functionality, and membrane formation. The ability to tailor membrane properties provides the ability to manage the morphology of the membrane and decouple the degree of sulfonation and water swelling, as well as water swelling and transport properties. The initial characterization and the ability to manipulate the mechanical and transport properties of these polymers will be discussed.