纤维改性对柔性超薄木质复合材料性能影响研究

[Objective]Ultra-thin fiberboard,as a new product in the fiberboard industry,is mainly used to replace wood veneer as a veneer material for plywood,thus avoiding the problem of plywood surface cracking due to the anisotropy of wood veneer,which further expands the application fields of fiberboard.As a product of efficient use of low-quality materials,ultra-thin fiberboard to replace the traditional large-size wood veneer can not only provide better overall performance,but also save a lot of high-quality timber resources,reduce the logging of large diameter logs,with significant ecological benefits.Larger specifications of ultra-thin fiberboard with a certain degree of bending capacity,can also be used for micro-curved surfaces such as veneer,but even with its own weak flexibility for veneer will rebound,resulting in veneer layer cracking,for the curved surface curvature of the larger,irregularly shaped surfaces is even more inapplicable.[Method]In order to solve the problem of veneering large curved surfaces and irregular surfaces,it is necessary to soften and modify the ultra-thin fiberboard.Since wood fiber itself has a certain degree of rigidity,we start from the fiber perspective,through the sodium hydroxide(NaOH)and γ-aminopropyltriethoxysilane(KH550)on poplar fiber softening modification and polyurethane elastomers hot-pressed to make a flexible ultra-thin fiberboard.[Result]Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and scanning electron microscope(SEM)observations confirmed that some hemicellulose and lignin in the wood fibers were removed by NaOH modification,and the alkoxy structure was successfully grafted by KH550 modification,and the synergistic modification of NaOH&KH550 improved the interfacial compatibility of poplar wood fibers with polyurethane.NaOH&KH550 synergistic modification improved the interfacial compatibility between poplar fiber and polyurethane.The flexibility of the ultra-thin fiberboard was improved(113％reduction in fiber value),and flexible deformation such as bending,twisting and knotting could be achieved.In addition,thermal stability,tensile strength(105％improvement),elongation at break(125％improvement),and water resistance were improved.[Conclusion]This flexible ultra-thin fiberboard is expected to be applied to the veneer of curved materials and furniture with shaped structures,providing a theoretical basis for improving the added value of ultra-thin fiberboard products.