Thermal Insulation and Flame Retardancy Properties of Polysaccharide‐Based Composite Aerogels

Abstract

ABSTRACT In this study, polysaccharide‐based composite aerogels with excellent thermal insulation and flame‐retardant properties were prepared by combining silica microspheres with konjac glucomannan (KGM) and starch (S) as raw materials. It was shown that the interaction of KGM and S formed a network skeleton structure in the aerogel, and the incorporation of S can regulate the pore structure of the aerogel and inhibit its gas‐phase thermal conductivity. At the same time, silica microspheres can reduce the thermal conductivity of the aerogel by thickening the pore walls and reducing the pore diameter. Silicon dioxide synergized with the carbon layer formed when S is burned, preventing the ingress of oxygen and providing a flame‐retardant effect. Compared with the traditional petroleum‐based materials polyurethane (PU) and expanded polystyrene (EPS), the thermal conductivity was reduced by 20.8% and 26.5%, and the limiting oxygen index was increased by 32.6% and 60%, respectively. The bio‐based composite aerogels prepared in this study exhibit excellent building thermal insulation and flame‐retardant properties and have the potential to replace petroleum‐based materials, and their natural polysaccharide‐based eco‐friendly design provides an innovative way for the development of new thermal insulation and flame‐retardant materials.