Sustainable nanocomposites of epoxy and silica xerogel synthesized from corn stalk ash: Enhanced thermal and acoustic insulation performance

The synthesis of silica xerogel from corn stalk ash in ambient pressure drying was carried out by sol-gel method. With the usage of silica xerogel (0.5, 1.0 and 1.5 wt%) in epoxy resin (ER), silica xerogel/epoxy nanocomposites were successfully prepared. The uniform dispersion of silica xerogel in neat ER was observed except nano composite including 1.5 wt% silica xerogel. The low density nanocomposites showed high thermal stability and low thermal conductivity. The char residue at 600 degrees C and thermal conductivity of nanocomposite including 1.5 wt% silica xerogel were specified as 20.30% and 0.220 W/mK, respectively. The acoustic velocity of the nanocomposites was decreased with increasing amount of silica xerogel. The water sorption of the nano composites was slightly higher than neat ER. The water contact angle of the nanocomposites were between 75 degrees and 70 degrees. The study provided a new thermal and acoustic insulation material instead of expensive and health risk traditional materials.