Silica aerogels are lightweight, highly porous nanomaterial with extremely large internal surface area but fragile and brittleness. To enhance the applicability of aerogels, fiber reinforced silica aerogel insulation blocks are prepared by frothing method. Polyurethane emulsion acts as binder whereas polyethylene (PE) fiber and polyurethane (PU) fiber is used as reinforcing phase. The effect of polyethylene fiber and polyurethane fiber on the performance of composites were characterized by material's chemical microscopic morphology, compression performance, recovery performance, surface area, thermal conductivity and hydrophobicity. The research results show that the prepared PU fiber reinforced silica aerogel insulation block has excellent comprehensive performance. The water absorption rate of decreased from 19.35% (0 phr, PU fiber) to 6% (20 phr, PU fiber), and comprehensive rebound rate was increased by 97.83% at 20 phr PU fiber compared with pure insulation block (83.88%). Meanwhile, the dimensional stability of the composite aerogel block is above 96%. PU fiber reinforced silica aerogel insulation block has light weight, good hydrophobicity and good thermal and mechanical properties, so it has a wide range of application prospects in the field of insulation.
Preparation of Mullite Fiber Reinforced Mullite Composites
