Study On Hydrophobic Modification And Properties Of Poplar Wood

Wood,a fast growing and short planting rotation material,has won a high degree of attention around the world,and its products have been widely used in various daily applications such as interior decoration,pavement and so on.However,wood is sensitive to water,especially poplar,which greatly limit its use.Rosin is a kind of natural renewable resource,which contains three membered ring lipophilic groups.It could reduce the hydrophilic property of wood to a certain extent,and give the hydrophobic property of wood.In this paper,rosin and its derivatives are used as hydrophobic modification reagent to improve the hydrophobic property of wood.The rosin,dwasproportionated rosin,hydrogenated rosin,maleic rosin,rosin emulsion are adopted as modification reagents,which are hydrophobically modified by immersion method,hydrothermal method,microwave method respectively and analyzed and characterized wood properties by measuring the contact angle,scanning electron microscopy,thermogravimetric analyswas.The modification of wood rosin,rosin and hydrogenated rosin,resin filling effect is mainly in wood fiber,and the three kinds of rosin hydrophilic performance are poor,and the wood invasion and poor compatibility,hydrophobic performance is limited,and the contact angle is about 60°.In order to improve the compatibility of the modified reagents and wood,the wood rosin emulsion is selected for hydrophobic modification,and the contact angle can be increased to 117.5°,but due to stratification in emulsion soaking process,hydrophobic modification of uniformity is difficult to control.The soaking method with maleic rosin modified wood is not only a simple method,butmaleic anhydride can be reacted with the hydroxyl groups in the wood in the late drying process,which is better than other methods and other modification reagents.When maleic rosin concentration is 30%(w/w),the hydrophobic effect of wood is the best,and the contact angle can reach 1380,and the density of poplar has been optimized,increased from 0.378 g/cm3 to 0.433 g/cm3.In order to further improve the hydrophobic properties of wood,the bionic structure of lotus leaf is designed in the wood,that is,the introduction of lipophilic groups and the structure of micro nano convex concave structure to prepwere superhydrophobic wood.The hydrophobic surface of the wood substrate and the formation of TiO2 nano particle layer are introduced on the baswas of the stepwwase impregnation method of maleic rosin alcohol solution and four butyl titanate solution.When the concentration of maleic rosin is 30%(w/w),AICl3 concentration is 1%(w/w),the reaction temperature is 1800C,the concentration of TBOT is 10%(v/v),TBOT:ammonia=1:2(v/v),the prepwered superhydrophobic wood is better,the contact angle of the treated wood with superhydrophobic propertie can reach 154°.Scanning electron microscopy,energy dwaspersive spectroscopy and thermal gravimetric analyswas are employed to analyze the microstructure and chemical composition of superhydrophobic wood surfaces.The chemical bond between maleic rosin/titanium dioxide and wood is analyzed by Fu Liye transform infrwered spectroscopy,and the mechanwasm of the formation of superhydrophobic surface is analyzed in detail.The modified wood has good stability.The wood maintained super-hydrophobic property with the WCA larger than 150° after immersing in deionized water at room temperature for a week,irradiating under scorching sunlight for one week(λ=400～700 nm)and boiling at 100℃ for 10h.