Research On The Properties And Mechanisms Of Chemical Modified Wood By DMDHEU

In this paper, by using the method of vacuum pressure impregnation, the fast-growing poplar was modified by composite modifier contained DMDHEU and acrylate. Assess the effects of modification from the test of physical and mechanical performance with natural and modified wood. And study the mechanism of chemical modification of woodThe microstructure, physical and mechanical strength and dimensional stability of modified wood were improved vastly. Found by SEM observation, modifier has been dipping into the wood catheter and intercellular space, filled the space inside the wood effectively. On the physical and mechanical properties test of modified wood, the bending strength, flexural elastic modulus and compressive strength increased by 46.3%,68.9% and 46.3% respectively. The bibulous rate of modified wood was reduced from 113.5% to 63.4%. On the test of bulking factor, the increasing rate of modified wood reduced to 3.6% from 8.9%.As a contrast test, the fast-growing poplar was also modified by composite modifier contained acrylate. After modification, the modifier permeated into the wood structure uniformly. The bending strength, flexural elastic modulus and compressive strength of modified wood were increased by 54.6%,77.5% and 55.1% respectively. The bibulous rate of modified wood was reduced from 113.5% to 78.6%. On the test of bulking factor, the increasing rate of modified wood reduced to 4.4% from 8.9%.The modified wood was characterized by XRD, TG, FTIR,13C-NMR, XPS, and the results showed that the modifier reacted with the chemical composition in the wood. The main reaction position was terminal hydroxyl of cellulose, hemicellulose and lignin, the reaction form was esterification and etherification reaction. And try to explain the mechanism of chemical modification of wood in this study by the comprehensive analysis of the above characterization results.