Session D40 - Poster Session I.
POSTER session, Monday afternoon, March 12
Exhibit Hall, Washington State Convention Center
Previous studies of ionomers using scanning transmission electron microscopy (STEM) indicate a difference in the shape, size and spatial distribution of ionic aggregates depending on the chemistry and processing. For example, melt neutralized ethylene-methacrylic acid ionomers neutralized with Zn exhibit randomly dispersed solid spherical aggregates ~ 2 nm in diameter. However, solution neutralized styrene-methacrylic acid ionomers neutralized with Cs and sulfonated polystyrene neutralized with Zn show randomly dispersed vesicular aggregates greater than 10 nm in diameter with shell wall thicknesses of ~ 3-4 nm. The current study seeks to resolve the nature of some of these differences, specifically with respect to neutralization method and neutralizing cation. Styrenic ionomers will be neutralized using both melt and solution methods as well as different neutralizing agents. Characterization of the microstructures with STEM, small-angle x-ray scattering (SAXS) and infrared (FTIR) spectroscopy will be conducted to determine the morphology of these materials.