1. Sulfonated Block Copolymers Containing Glassy Hydrophobic Blocks
Investigation of the Relationships Between the Morphology and Transport Properties of
Sulfonated Block Copolymers Containing Glassy Hydrophobic Blocks
Kevin Cavicchi, Department of Polymer Engineering, The University of Akron, Akron, OH
Polymer ion-exchange membranes are used in many applications including fuel cells, water purification and separations. Our strategy to fabricate membranes is to use neutral-ionic block copolymers that self-assemble into periodic morphologies with ionic-rich and ionic-poor domains. Different morphologies have a different balance of properties such as the conductive anisotropy, water uptake and solvent permeability. We are investigating how these bulk properties depend on both the volume fraction of the sulfonated blocks, which primarily determines the microphase separated morphology, and their degree of sulfonation, which controls the intrinsic conductivity and hydrophilicity of the ionic-rich domains. We have modified a commerically available sulfonated monomer through acid-base neutralization to produce a hydrophobic sulfonated monomer. This monomer can be copolymerized with other neutral hydrophobic monomers to independently vary both the volume fraction and degree of sulfonation of the sulfonated block in neutral-sulfonated block copolymers. Currently we are investigating the structure-property relationships between their chemical structure, morphology, and bulk properties of these polymers.