Polyurethane-silica hybrid foam by sol–gel approach: Chemical and functional properties

Robust and superhydrophobic thiourethane bridged polysilsesquioxane aerogels as potential thermal insulation materials

“…Figure 4c clearly shows that with the isolation of PSQ aerogel from the hot plate, there is an ice-water mixture (0 °C) in the left bottle even after heating for 5min at 180 °C. The thermal conductivities of these PSQ aerogels at room temperature are as low as 0.018 -0.021 W m -1 K -1 , which are similar to the lowest value for the reported silica aerogels (0.015 W m -1 K -1 ) 25 and lower than those those of reported thermal insulation aerogels, e.g., bridged silsesquioxane aerogels, [17] polyurethane aerogels, 39 inorganic oxide aerogels 40 and commercially available insulators such as polyurethane foams 41 (Table S2). …”

“…To improve the mechanical strength and facilely tailor the properties of the silica aerogels, the most popular method is to construct organic-inorganic composite, especially silica-polymer composites. 17,18 However, this approach presents challenges and shortcomings. For instance, the polymer reinforcement method, linking silica skeletons with polymer, usually led the silica aerogels lost the advantage of low density.…”

Dimensionally Stable Cellulose Aerogel Strengthened by Polyurethane Synthesized In Situ

“…Furthermore, majority of isocyanate groups of HMDI seem to be involved in the reaction with cellulose. This conclusion follows from the disappearance of vibrational mode at 2270 cm −1 which is associated with the stretching vibration of the functional group NCO in the initial monomer …”

Oligoetherols and polyurethane foams obtained from metasilicic acid

“…They can also be modified by hydroxyalkylation, epoxidation, amination, etc., to give modified silsesquioxanes able to react with isocyanate groups. Hybrid foams formed of polyurethane and polysiloxanes were demonstrated as better heat insulators than PUFs [17].…”