Experimental Study on Improving the Properties of Rock Wool and Glass Wool by Silica Aerogel

Besides thermal insulation performance, waterproofness and mechanical strength are also important indexes for evaluating thermal insulation materials. In this paper, silica aerogel/rock wool (SA/RW) composite plates and silica aerogel/glass wool (SA/GW) composite plates were prepared by infiltration and atmospheric pressure drying method. The influence of silica aerogel mass fraction and infiltration time on thermal conductivity, short-term water absorption and compressive strength of composite plates were explored, and the modification effects of SA/RW and SA/GW composite plate under the optimum ratio were analyzed. The changes in microstructure before and after modification were obtained by SEM. The results showed that the addition of silica aerogel significantly changed the surface layer of inorganic fibers, which can form a relatively stable composite system. When the mass fraction of silica aerogel reached 8% and the infiltration time was 20 min, the thermal conductivity of SA/RW and SA/GW composite plate was 0.0330 W/(m.k) and 0.0263 W/(m.k), which were 26.7% and 20.3% lower than those before modification, and the apparent density reached 177.55 kg/m(3) and 53.61 kg/m(3), respectively. The short-term water absorption was 0.78 kg/m(3) and 0.65 kg/m(3), which was 35% and 36.2% lower than that before modification. The compressive strength was 42.6 kPa and 14 kPa, respectively, increased by 7% and 103% compared with that before modification. (C) 2021 Elsevier B.V. All rights reserved.