Properties of Colloidal Silica‐Fixed and Propionylated Wood Composite (II): Flame Resistance and Other Properties of the Composites

Abstract

The flame resistance, color change, strength, and decay resistance of colloidal silica‐fixed (CSW), propionylated only, and propionylated dual‐treated wood (CSPW) composites were evaluated. The oxygen indexes of the CSPW composites were similar to the CSW composites but much higher than those of untreated woods and the propionylated woods. The oxygen indexes increased with an increase in the weight percent gain of the colloidal silica (WPGcsi) in the composites, showing an effective reduction in the flammability by the fixation of colloidal silica. The CSPW composites showed little or no difference in the modulus of elasticity and modulus of rupture compared with the untreated woods, indicating little or no significant reduction in strength properties of the wood specimens. The color difference of the wood specimens before and after treatment changed slightly. Minimal weight losses of the CSPW composites occurred upon fungal attack by T. versicolor and F. palustris, showing good decay resistance by propionylation of the composites.