Abstract:

Novel porous nanocomposites with uniquely interconnected silsesquioxane (SSQ)−organic networks were synthesized within high internal phase emulsions (HIPE). These nanocomposite polyHIPE, with densities of around 0.13 g/cm³, were synthesized from 2-ethylhexyl acrylate (EHA), divinylbenzene (DVB, organic cross-linker), and either methylsilsesquioxane (MSQ) or vinylsilsesquioxane (VSQ, SSQ cross-linker). The porous structure, thermal properties, and mechanical properties were investigated. The tan δ peak temperature and the room temperature modulus increased in a linear fashion with increasing DVB content, reflecting the increase in cross-link density and in backbone rigidity. These properties were significantly larger for polyHIPE with VSQ than for polyHIPE with MSQ. A comparison based on the cross-linking group content demonstrated that adding DVB produced more significant increases in thermal and mechanical stability than adding VSQ. The interconnected SSQ−organic networks, from combined VSQ and DVB cross-linking, produced the most thermally stable nanocomposite polyHIPE.