Dimensional stability and flame resistance of silicate-acetylated and -propionylated wood composites

Silicate-acetylated wood (SAW) and silicate-propionylated wood (SPW) composites were prepared, and the dimensional stability and flame resistance of these composites were evaluated. The silicate gels had insignificant effects on the rate of acetylation or propionylation of wood. In the presence of silicate gels, the SAW and SPW composites showed slightly lower anti-swelling efficiency (ASE) during water or moisture absorption and a lower moisture excluding efficiency (MEE) than the corresponding acetylated wood and propionylated wood, but the SAW and SPW composites still retained fairly good dimensional stability. The oxygen indices (OIs) of the SAW and SPW composites were higher than those of untreated wood specimens and increased with an increase in the weight percent gains (WPG(si)s) of silicate gel fixation. The silicate gel fixation endowed the composites with flame resistance.