Effect of DMPA-Clay-POSS Content on Thermal and Mechanical Properties of Nanostructured Ionomeric Polyurethanes

Two series of ionomeric waterborne polyurethane (WBPU)/POSS-clay hybrid nanocomposites were synthesized using various amounts of a diol-functionalized polyhedral oligomeric silsesquioxane (POSS)/clay (Cloisite 15A) component with two different 2,2-dimethylol propionic acid (DMPA) contents (13.58 mole% and 23.89 mole%). The Tg of WBPU/POSS-clay hybrid nanocomposite was shifted towards higher temperatures in comparison to virgin WBPU and WBPU/clay nanocomposites. The thermal stability of the investigated WBPU/POSS-clay hybrid nanocomposites also dramatically improved compared to pristine WBPU and WBPU/clay nanocomposites. The higher Young's modulus of the WBPU/POSS-clay hybrid nanocomposites as a function of optimal POSS content suggests that the organic–inorganic hybrid networks are significantly reinforced by the inclusion of POSS.