Study On Preparation And Properties Of Dye-Reinforced Modified Pine Wood Based On Furniture Materials

Pine(Pinus sylvestris Linn),as the main cultivated tree species of plantation in China,has a wide range of forestry area and is an important wooden product material.However,pine has defects such as soft texture,low strength,numerous knots,and poor decorative properties,Which limit its widespread application in high-end solid wood furniture,flooring,and interior decoration.In response to this,this paper takes fast-growing pine as the research object,with the aim of simultaneously improving the mechanical and aesthetic qualities of pine.Uses glyoxal-urea resin(GU)and acid dye as the impregnation modifier,and the pine is dyed-reinforced composite modified through vacuum pressure impregnation treatment.Optimization the process conditions of the dyeing reinforcement modification,and the basic properties and modification mechanism of the modified pine are also studied,and analyzed the application performance of modified pine.The main research results of the paper are as follows:(1)Orthogonal experiments were used to optimize the dyeing reinforcement modification process of pine wood,examining the surface color and hardness of the modified material.The optimal process conditions for the dyeing reinforcement modification process of pine wood were obtained using a comprehensive evaluation method as follows:35%wt%GU resin,1wt%of acid red GR dye,1wt%of adjuvants.After dyeing-strengthening modification,the hardness of the chord and radial surfaces of pine increased by 61.24%and 85.04%,respectively,compared to unmodified pine.Its elastic modulus,static bending strength,and compressive strength along the grain increased to 8.97GPa,92.76MPa,and 45.11 MPa,respectively;The dye-reinforced modification treatment preserves the texture of the pine while giving it a vibrant and colorful color,greatly enriching the visual effect of the pine.(2)Characterization was conducted using scanning electron microscopy,Fourier transform infrared spectroscopy,and X-ray electron spectroscopy to explore the mechanism of dyeing reinforcement composite modification.SEM-EDS results showed that the modified agent compounded with GU resin and dye adhered to the inner wall of the tracheid after curing,with some pits covered and the tracheid cavities filled,providing a certain support for the tracheid wall and improving the hardness of pine;The spectrogram of FTIR show that the acid dye molecules were bonded with GU resin and pine without chemical bond,and the dye attached to the wood surface and interior only by van der Waals force to change the color of pine.Together with the photoelectron spectroscopy,they confirmed that the GU resin molecules in the modifier formed C=O and O-C-O chemical bonds with the hydroxyl groups in the wood,modifier changed the color of pine under the combined action of physics and chemistry,which was strengthened.(3)In view of the poor photochromism resistance of the surface color of dyed reinforced pine,the dyed reinforced pine was treated by color fixing impregnation with nano TiO2 sol as the main anti ultraviolet reagent.The response surface test was used to analyze the significance of the influence of various process factors on the color fastness to light:the mass fraction of nano TiO2 sol>the mass fraction of chitosan gel>the surface drying temperature.The best color fixing process was 23.50wt%of nano TiO2 sol,2.1wt%of Chitosan gel,drying temperature 120℃;Under the optimal fixation process conditions,the color difference value of light fastness is 8.75,with a decrease of 57.43.The antilight loss performance of the dye-reinforced modified material is significantly improved.(4)Modification treatment can improve the tenon joint performance and coating performance of pine,but it will reduce its bonding performance.The bonding strength of dye-reinforced pine after fixation treatment is weakened.When white latex and polyurethane are used as adhesives,the bonding shear strength is 4.86 MPa and 7.14 MPa,respectively,which is 10.91%and 2.86%lower than that of raw pine.The tensile strength and bending strength of the dye-reinforced pine loose tenon joint after fixation are 1518N and 636N respectively;Compared to untreated pine,it has increased by 32%and 107%respectively.After modification,the surface wettability of pine changes,specifically manifested as contact angle:fixed color treated dye-reinforced pine>pine>dyed pine>dye-reinforced pine,the adhesion of the paint film is improved;The color difference before and after coating is related to the adhesion of dyes to the surface of the substrate and the chemical properties of the substrate surface;The glossiness of the paint film is related to the glossiness of the substrate;Transparent coating has no effect on the texture contrast of the modified pine.After coating,treated dye-reinforced pine has a bright color and clear texture,is a highquality decorative material that combines color and texture.Its design products can be applied to fields such as crafts,solid wood furniture,and interior decoration.