Study Of Sodium Silicate/2D Resin Impregnation Modified Poplar Wood Properties And Its Application In Furniture Gluing

For thousands of years,China has admired the unity of man and nature,and has a special feeling for wood.With the vigorous development of the furniture and construction industries,solid wood furniture,as the mainstream product of furniture,is increasingly favored by consumers.Although China has abundant natural forest resources,the per capita ownership is insufficient.The quantity of artificial forest is large but the material quality is defective,which can not be directly used in the production of solid wood furniture,so the raw material of solid wood furniture is scarce.Aiming at this problem,this paper takes fast-growing poplar as the research object,impregnates and modifates it to enhance its material properties and applies it to the production of solid wood furniture.Sodium silicate,as a commonly used modifier,has greatly improved the mechanical properties and flame retardancy of wood,but it has poor fixation and strong moisture absorption,making it difficult to maintain the dimensional stability of wood.Dihydroxymethyl dihydroxyethylene urea resin(DMDHEU,2D resin)has good wrinkle resistance,high permeability,and high reactivity to wood fibers.Therefore,2D resin was introduced as crosslinking curing agent and sodium silicate composite modified poplar.A kind of modified poplar wood with high quality and high strength,dimensional stability,flame retardancy,smoke suppression,and environmental protection and non-toxic was prepared by impregnation modification.The impregnation process,material properties and strengthening mechanism were studied,and its application in furniture gluing was emphatically analyzed.The research content and results of this paper are as follows:(1)Study on technology optimization of modified poplar impregnated with sodium silicate/2D resin.Single-factor experiment was used to determine the effect of various factors on modified poplar,and then response surface experiment was designed to further optimize the modification process.The results of single-factor experiment showed that the best wood properties were obtained when the resin concentration of 2D was 5%,the impregnation time was 100 min,the impregnation pressure was 0.5 MPa,and the curing temperature was 80℃.The results of response surface experiment showed that the lowest volume expansion rate of modified poplar could be predicted to be 2.88%when the resin concentration of 2D was 6%,the impregnation time was 107 min,the impregnation pressure was 0.3 MPa,and the curing temperature was 75℃.(2)Study on wood properties of modified poplar.The wood properties of poplar and modified wood were analyzed,and the strengthening mechanism of modified poplar was revealed by means of SEM,XPS,XRD,FT-IR.The results showed that the mechanical properties,dimensional stability,flame retardancy and smoke suppression of the modified poplar wood were improved by the addition of sodium silicate and 2D resin.C-O-C and Si-O-C structures were formed between the polyhydroxymethyl active group in 2D resin and sodium silicate and cellulose in cell wall.(3)Study on bonding properties and bonding mechanism of modified poplar.The square and mortise and tenon bonding of unmodified poplar wood,sodium silicate modified poplar and sodium silicate/2D resin modified poplar were discussed,and the bonding mechanism of three kinds of wood was characterized.The results showed that compared with the bonding strength of unmodified poplar square and mortise and tenon,the bonding strength of sodium silicate modified poplar decreased,and that of sodium silicate/2D resin modified polar increased.Sodium silicate 2D resin modified materials have the highest surface free energy and can be chemically crosslinked with polyvinyl acetate adhesives.(4)Explored the edge sealing and veneer bonding of unmodified poplar,sodium silicate modified poplar,and sodium silicate/2D resin modified poplar.The results showed that the edge sealing and veneer bonding properties of both modified poplar were lower than those of unmodified poplar,and the bonding strength of sodium silicate/2D resin modified poplar was higher than that of sodium silicate modified poplar.