cm020797o_si_001.pdf (23.67 kB)
A Polyimide Nanocomposite from Octa(aminophenyl)silsesquioxane
journal contribution
posted on 2003-01-17, 00:00 authored by Ryo Tamaki, Jiwon Choi, Richard M. LaineOctaaminophenylsilsesquioxane (OAPS) can serve as a nanosized building block for the
construction of materials with nanometer control of the periodicity of the organic and
inorganic components and bonding between components. We describe here the synthesis of
a prototypical three-dimensional polyimide by reaction of OAPS with pyromellitic dianhydride
(PMDA). Model studies with phthalic anhydride provided useful cure conditions. Thus,
stoichiometrically correct OAPS/PMDA nanocomposites were obtained following curing of
NMP and DMF reaction solutions at lower temperatures and then to >350 °C/N2 under
vacuum. The resulting materials offer thermal stabilities in air and N2 of >500 °C (5% mass
loss temperature) and char yields >75%/N2. X-ray powder patterns indicate that the resulting
materials are completely amorphous, as might be expected from the extreme rigidity of the
organic tethers linking cube vertexes that will prevent long-range ordering from occurring
during curing. These materials hold promise for high compressive strength applications.