Heat insulating, fire retardant and flexible inorganic nanocomposite paper

Organic heat insulating materials with low density and low thermal conductivity have been widely used in building and domestic appliances. However, their highly flammable and poorly flexible characteristics hamper the application under certain circumstances. In this work, novel nanocomposite paper with low thermal conductivity, flame retardancy and good mechanical property was prepared by employing ultralong hydroxyapatite (HAP) nanowires as scaffolds for silica aerogels. The conductivity of the HAP/silica aerogel nanocomposite paper at room temperature decreased from 0.056 to 0.045 Wm(-1) K-1 as the amounts of silica aerogels increased from 0 to 50 wt%, indicating the excellent heat insulating performance. Meanwhile, the prepared paper showed remarkable flame retardancy with the peak heat release rate (HRR) of only 33.1 W/g when silica aerogel content was 50 wt%. Thermal stability analysis showed that the weight losses of all the nanocomposite papers with different contents of silica aerogels were <10wt% even at 800 degrees C, which showed that the nanocomposite paper possessed prominent thermal stability. Besides, the nanocomposite paper exhibited good mechanical property. Therefore, the as-prepared HAP/silica aerogel nanocomposite paper is promising for applications in the protection layer of insulation materials, fire-retardant wallpaper, specialty fire clothing, and so on. (C) 2018 Elsevier Ltd. All rights reserved.