Evaluation of Weathering Performance of Rosin-Copper Based Treated Wood

This study aimed to evaluate the effect of natural weathering on some surface characteristics and mechanical properties of Styrax wood treated with mixtures of 1.0%,2.0%,or 4.0%rosin sizing agent and 3%copper sulfate.Wood samples after treatment were exposed to outdoor conditions for one year and changes in color,glossiness,weight loss,compression strength parallel to grain(CSPG),modulus of rupture(MOR),and modulus of elasticity(MOE)were investigated after 6 and 12-month of natural weathering.The results showed that rosin-copper treatment could improve color stability and gloss of samples after weathering.Mass losses of all rosin-copper treated samples after 12 months of exposure were negligible compared with the untreated control samples.In addition,rosin-copper treatment enhanced the CSPG compared to untreated controls,but slightly decreased the MOR and MOE of Styrax wood before weathering.Natural weathering factors induced a reduction for all strength properties,however,the decrease rate for strength properties of rosin-copper treated samples was negligible compared with the untreated control samples after 12-month natural weathering exposure.The FTIR and SEM-EDX confirmed that the use of the rosin-copper formulations to impregnate wood could decrease the hazard of the copper preservative leaching into the environment,while also enhancing more resistance against weathering factors and other biotic factors.