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CN-121989332-A - Biomass-based macromolecule inflation and interpenetrating network crosslinked cell wall strengthening and toughening and size stabilizing wood and preparation method thereof

CN121989332ACN 121989332 ACN121989332 ACN 121989332ACN-121989332-A

Abstract

The invention discloses biomass-based macromolecule inflation and interpenetrating network cross-linked cell wall strengthening and toughening and size stabilizing wood and a preparation method thereof. Adding biomass macromolecules and a silane coupling agent into an ethanol/water mixed solvent for reaction to obtain a modified biomass macromolecule solution, immersing wood into a pretreatment agent for selectively removing part of lignin, immersing the wood into a wood modifier for treatment to obtain modified pretreated wood, immersing the modified pretreated wood into the modified biomass macromolecule solution, and simultaneously or subsequently immersing the modified pretreated wood into a resin modification solution to obtain impregnated modified wood, and drying and solidifying the modified wood in an oven. On the basis of keeping the natural fiber reinforced skeleton structure of the wood, the invention obviously improves the mechanical strength, toughness and dimensional stability of the wood by a cell wall inflation and crosslinking modification strategy, and expands the application potential of the wood in the fields of wood structural materials and functional composite materials.

Inventors

  • LI YONGFENG
  • GAO XUDONG
  • DONG XIAOYING

Assignees

  • 山东农业大学

Dates

Publication Date
20260508
Application Date
20260312

Claims (10)

  1. 1. A biomass-based macromolecule inflation and interpenetrating network cross-linked cell wall strengthening and toughening and size stabilizing wood and a preparation method thereof are characterized in that the wood is prepared by the following steps: (1) Adding biomass macromolecules and a silane coupling agent into an ethanol/water mixed solvent for reaction to obtain a modified biomass macromolecule solution; (2) Immersing wood into a pretreatment reagent to selectively remove part of lignin, and then immersing the wood into a wood modifier to carry out treatment to obtain modified pretreated wood; (3) Immersing the modified pretreated wood in a modified biomass macromolecule solution, and simultaneously or subsequently immersing the modified pretreated wood in a resin modification solution to obtain impregnated modified wood, and drying and curing the modified wood in an oven.
  2. 2. The biomass-based macromolecule inflation and interpenetrating network cross-linked cell wall strengthening and toughening and size stabilizing wood and the preparation method thereof according to claim 1, wherein in the step (1), the biomass macromolecule is at least one selected from lignin, hemicellulose, cellulose and derivatives thereof, and the like, the lignin is ethanol lignin, the hemicellulose is xylan, the cellulose is microcrystalline cellulose, and the silane coupling agent is gamma-aminopropyl triethoxysilane or gamma- (2, 3-glycidoxy) propyl trimethoxysilane.
  3. 3. The biomass-based macromolecule inflation and interpenetrating network crosslinked cell wall strengthening and toughening and size stabilizing wood and the preparation method thereof are characterized in that in the step (1), the mass ratio of biomass macromolecules to silane coupling agents is 100:1-10, the reaction time is 6-10h, the temperature is 60-120 ℃, and the mass concentration of modified biomass macromolecules in the modified biomass macromolecule solution is 1-10%.
  4. 4. The biomass-based macromolecule inflation and interpenetrating network cross-linked cell wall strengthening and toughening and size stabilizing wood and the preparation method thereof according to claim 1 are characterized in that in the step (2), the wood is selected from poplar, eucalyptus, fir or pine, the pretreatment reagent is selected from an acid-base aqueous solution system, an oxidation pretreatment system or a eutectic solvent green solvent system, the acid-base aqueous solution system is a sodium hydroxide solution with the concentration of 2-10 wt% or a sodium sulfite aqueous solution with the concentration of 2-10 wt%, the oxidation pretreatment system is a chlorite solution with the pH of 3.5-5.0 prepared from sodium chlorite and acetic acid buffer, and the eutectic solvent green solvent system is a eutectic solvent formed by choline chloride and urea, lactic acid or glycerin.
  5. 5. The biomass-based macromolecule inflation and interpenetrating network cross-linked cell wall strengthening and toughening and size stabilizing wood and the preparation method thereof according to claim 1 are characterized in that in the step (2), the temperature of the selective removal of part of lignin is 70-120 ℃ and the time is 0.5-6h, the selective removal of part of lignin is that the lignin removal rate is controlled to be 5-20%, the wood is fully washed to be neutral and dried after lignin removal, the wood modifier is sodium periodate aqueous solution or glutaraldehyde, the concentration of the sodium periodate aqueous solution is 1-5 wt%, and the treatment is that aldehyde groups are specifically generated on the surface of a cellulose skeleton by treatment at a light-shielding temperature of 25-40 ℃ for 4-12 hours.
  6. 6. The biomass-based macromolecule inflation and interpenetrating network cross-linked cell wall strengthening and toughening and size stabilizing wood and the preparation method thereof according to claim 1, wherein in the step (2), the addition amount ratio of the pretreatment reagent to the wood is 5-20 mL/1 g, and the addition amount ratio of the wood modifier solution to the wood is 3-10 mL/1 g.
  7. 7. The biomass-based macromolecule inflation and interpenetrating network cross-linked cell wall strengthening and toughening and size stabilizing wood and the preparation method thereof according to claim 1 are characterized in that in the step (3), the resin modified solution is prepared from resin and solvent, the solvent is water or ethanol water solution, the volume ratio of ethanol to water in the ethanol water solution is 1:1-3, the resin is selected from phenolic resin, urea resin, melamine formaldehyde resin, alkaline/aqueous epoxy resin and unsaturated polyester resin, and the content of the resin in the resin modified solution is 0.1-30 wt%.
  8. 8. The biomass-based macromolecule inflation and interpenetrating network cross-linked cell wall toughening and dimension stabilization wood and the preparation method thereof are characterized in that in the step (3), the addition amount ratio of the modified biomass macromolecule solution to the modified pretreatment wood is 3-10 mL/1 g, the addition amount of the resin modification solution to the modified pretreatment wood is 5-15 mL/1 g, the condition that the modified pretreatment wood is immersed in the modified biomass macromolecule solution or the resin modification solution is that the vacuum degree is-0.01 MPa to 0.1MPa, the temperature is 25-80 ℃, the immersion time is 1-3 h, the curing temperature is 80-120 ℃, and the time is 2-6h.
  9. 9. Use of the biomass-based macromolecule inflation and interpenetrating network cross-linked cell wall strengthening and size stabilizing wood of any one of claims 1-8 in wood functionalization.
  10. 10. The use according to claim 9, wherein the functionalization comprises an increase in mechanical strength, structural stability, hydrophobicity, corrosion and mildew resistance, flame retardancy of the wood.

Description

Biomass-based macromolecule inflation and interpenetrating network crosslinked cell wall strengthening and toughening and size stabilizing wood and preparation method thereof Technical Field The invention relates to the technical field of wood modification treatment, in particular to biomass-based macromolecule inflation and interpenetrating network cross-linked cell wall strengthening and toughening and size stabilizing wood and a preparation method thereof. Background Reinforced concrete is used as a traditional building structure material, and has high energy consumption and large carbon emission in the production and use processes, which is contrary to the development trend of green buildings. In contrast, the wood is carbon-fixed in the growth process, has natural 'negative carbon' attribute, has the advantages of light weight, high strength, heat preservation, energy conservation, reproducibility and the like, and is an ideal green structural material. However, fast-growing wood (such as poplar, fir, etc.) which can be supplied in large scale currently has the common problems of loose material, low strength, poor toughness, poor dimensional stability when meeting water, and the like, and is difficult to be directly used as a structural material with strict requirements on performance. Aiming at the high-performance modification of fast-growing wood, the prior study mainly follows the technical route of combining partial delignification and cell densification, and synchronously improves the strength and toughness of the wood by improving the density and dynamic hydrogen bonds. However, in general, the technical strategy is to solve the problems of synchronous reinforcement and toughening of the wood, but the dimensional stability of the wood is reduced negatively due to the single change of the pore structure, and even if metal ion crosslinking is introduced, the problem of synchronous improvement of the toughness and the dimensional stability of the wood is not solved effectively. There have also been some studies to further introduce inorganic materials into the above delignified wood skeleton and then to carry out densification treatment. The multi-component modification method often faces the problems that different modification components permeate unevenly and compete mutually in wood multi-stage pores, and are difficult to form strong and stable interface chemical combination with a wood matrix, so that the built composite structure is poor in uniformity and insufficient in long-term stability. The application number CN 116061279A discloses a modification treatment agent for in-situ reinforcing and toughening of wood and a modification method thereof, and micro-nano pores in the cell wall of the wood can be filled in-situ hybridization through the modification treatment agent and the treatment method, so that the synchronous improvement of the strength and toughness of the wood is realized. The expansion strategy can successfully add new functions of flame retardance, corrosion resistance and the like to the wood while improving the strength and the toughness. Unfortunately, this approach still fails to fundamentally overcome the core defect of poor dimensional stability, i.e., the difficulty in balancing toughness with dimensional stability, due to its inability to solve the problem of efficient synergy and robust compounding of multiple components. Therefore, how to develop a new modification method capable of effectively coordinating multicomponent penetration and crosslinking so as to synchronously realize high toughness and high dimensional stability of wood and even multifunctionality has become a key technical bottleneck to be broken through in the field. Disclosure of Invention Aiming at the problems that the wood modification in the prior art is difficult to synchronously realize high strength, high toughness and high dimensional stability, and different reagents are difficult to cooperatively permeate and construct a stable composite network due to competing reaction or pore blocking in the multi-component modification process, the invention aims to provide the biomass-based macromolecule inflation and interpenetrating network crosslinked cell wall strengthening and toughening and dimensional stabilizing wood and the preparation method thereof. The preparation method comprises the steps of pretreating wood, selectively removing part of lignin, retaining a cellulose rigid skeleton, carrying out surface functional activation on the cellulose skeleton to obtain pretreated wood with active groups, and then introducing a biomass-based macromolecule modified by a silane coupling agent, so that cell walls can be effectively filled and swelled, and further, the active functional groups carried by the macromolecule can be subjected to chemical reaction with active groups on the surface of the wood to form firm covalent bond interface combination. Then, introducing solidified resin to enable the