Synthesis, pore structure and properties of polyurethane/silica hybrid aerogels dried at ambient pressure

Polyurethane/silica hybrid aerogels were synthesized at ambient pressure drying conditions with the specific surface area, pore volume and pore diameter in the range of 530-850 m(2)/g, 0.71-2.83 cm(3)/g, and 5-13 nm, respectively. TGA results showed that almost all polyurethane chains preserved as a part of gel network. The pore structure and properties of these hybrid aerogels showed an interesting dependence on the polyurethane content. The improved structure and properties compared to native silica aerogel was achieved with introducing 3 v/v% aqueous polyurethane dispersion into silica sol. High polyurethane content led to low porosity (61%) and small surface area (535 m(2)/g). (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.