Preparation and Properties of Cellulose/Silica Hybrid Composites

Cellulose/silica hybrid (CSH) composites were prepared from bleached Eucalyptus globulus kraft pulp or primary treatment sludge cellulose fibers by a sol-gel method, using solely tetraethoxysilane or with the addition of trimethoxyoctylsilane as the silica precursors and heteropoly acid (H3PW12O40) as the catalyst. Silica aging was accomplished during the hot pressing of preformed CSHs plates, and the properties of the resulting materials have been evaluated. The incorporation of a silica network in cellulosic materials increased their dimensional stability significantly during soaking in water, hydrophobicity, thermal stability, and bending strength. The thermal conductivity of these hybrid materials is comparable to commercially available insulation foams. POLYM. COMPOS., 30:1275-1282, 2009. (C) 2008 Society of Plastics Engineers