Nanoporous Flexible Polyurethane-Acrylate Aerogels
Aerogels are porous, low-density 3D assemblies of nanoparticles with large surface-to-volume ratios. Flexible aerogels are particularly attractive materials for thermal insulation. Herein, we report flexible aerogels synthesized via polyurethane-acrylate (PUAC) chemistry. A star-shaped monomer was prepared from tris(4-isocyanatophenyl)methane (TIPM) and 2-hydroxyethyl acrylate (HEA) in anhydrous acetone using dibutyltin dilaurate (DBTDL) as catalyst. Crosslinking was initiated with 2,2'-azobisisobutyronitrile (AIBN) in one pot. Wet-gels were dried with supercritical fluid CO2 to monolithic PUAC aerogels, which were characterized at the molecular (solids 13C NMR), nanoscopic (SEM, SAXS) and macroscopic level (compression and 3-point bending). Lower density PUAC aerogels (0.14 g cm-3) consist of large primary particles (88 nm in diameter) and are macroporous and flexible. Higher density samples (0.66 g cm-3) consist of smaller particles (18 nm in diameter), they are rigid and mechanically strong.
A. N. Bang et al., "Nanoporous Flexible Polyurethane-Acrylate Aerogels," Abstracts of Papers of the American Chemical Society, American Chemical Society (ACS), Apr 2013.
245th ACS National Meeting and Exposition (2013: Apr. 7-11, New Orleans, LA)
Article - Conference proceedings
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01 Apr 2013