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CN-121973303-A - Preparation method of high-flame-retardance high-strength modified wood

CN121973303ACN 121973303 ACN121973303 ACN 121973303ACN-121973303-A

Abstract

The invention belongs to the technical field of wood modification and flame retardance, and particularly relates to a preparation method of high-flame retardance and high-strength modified wood. According to the invention, the quaternized water-based epoxy resin and the condensed phase flame-retardant system are introduced to construct a flame-retardant-reinforced synergistic composite structure in the wood, so that the flame retardant property of the wood is remarkably improved while the mechanical property is maintained and improved. The preparation method of the invention fundamentally solves the industrial problem that the inflammability and mechanical property of wood are difficult to be compatible, the high-strength flame-retardant material of the wood fiber/epoxy resin is constructed through the regulation and control of the chemical components and microstructure of the wood fiber, the organic/inorganic hybridization and the in-situ heterogeneous combination, the flame-retardant performance and the mechanical property of the wood are improved, meanwhile, the whole process pays attention to the green chemistry principle, the low-toxicity halogen-free renewable flame-retardant components are preferentially used, the development of the green flame-retardant technology is promoted, and the national 'double carbon' strategic targets are met.

Inventors

  • CHEN GEGU
  • Jing Ruihan
  • LI ZEHUI
  • PENG FENG

Assignees

  • 北京林业大学

Dates

Publication Date
20260505
Application Date
20260302

Claims (10)

  1. 1. A method for preparing modified wood, comprising the steps of: S1, alkali treatment of wood, namely placing the wood in 5-10% sodium hydroxide aqueous solution for soaking treatment, washing the wood with deionized water until the pH value is 7.0 after the treatment is finished, and placing the wood in absolute ethyl alcohol for preservation; S2, preparing modified aqueous epoxy resin, namely dissolving bisphenol A epoxy resin in absolute ethyl alcohol to obtain epoxy groups, adding diethanolamine to the epoxy groups to react 2h, and sequentially adding polyether amine, glacial acetic acid and deionized water to form the modified aqueous epoxy resin containing quaternary ammonium groups; S3, preparing a condensed phase flame retardant, namely mixing montmorillonite with 4% boric acid solution, and performing ultrasonic centrifugation to obtain 5-10wt% of flame retardant; s4, placing the alkali-treated wood in a modified water-based epoxy resin and flame retardant mixed system, and carrying out vacuum impregnation and hot pressing to obtain the modified wood with high flame retardance and high mechanical property.
  2. 2. The method according to claim 1, wherein the soaking treatment in step S1 is performed under a condition of 60 to 80 ℃ for 6 to 12 h.
  3. 3. The preparation method according to claim 1, wherein the mass ratio of bisphenol A epoxy resin to absolute ethyl alcohol in the step S2 is 1:1, and the dissolution condition is stirring and dissolving at 65 ℃ and 300 r/min.
  4. 4. The preparation method according to claim 1, wherein the amount of the diethanolamine substance added in the step S2 is 30% of the amount of the E-44 epoxy group substance, and the polyetheramine is added in a ratio of bisphenol A type epoxy resin to polyetheramine of 4:1 by mole mass.
  5. 5. The preparation method of the epoxy resin composition according to claim 1, wherein the addition amount (amount of substances) of the glacial acetic acid in the step S2 is equal to the total amount of substances of amine groups in diethanolamine and polyetheramine (D230) so as to achieve complete neutralization, and the mass ratio of bisphenol A epoxy resin to deionized water is 1 (0.8-1.2).
  6. 6. The preparation method of the composite material according to claim 1, wherein the mixing mass ratio of boric acid to montmorillonite in the step S3 is 1 (1.0-4.0), and the ultrasonic centrifugation conditions are ultrasonic 30min and 9000 rpm for centrifugation 10min.
  7. 7. The preparation method according to claim 1, wherein the mixing mass ratio of the modified epoxy resin to the flame retardant in the step S4 is 1:3.
  8. 8. The preparation method of the vacuum impregnation agent according to claim 1, wherein the vacuum impregnation process in the step S4 is carried out for 3-6 times under the conditions of-0.1 to-0.6 MPa, and each time lasts for 3-50 minutes.
  9. 9. The preparation method of the wood material according to claim 1, wherein in the step S4, the wood material is horizontally placed under a hot press for hot press molding, the hot press temperature is 80-100 ℃, the pressure is 15-25 MPa, the hot press time is 8-12 hours, the compression ratio is controlled to be 65% -85%, and the density of the obtained wood material is 1.6-1.9 times of that of the original wood material.
  10. 10. Use of the preparation method according to any one of claims 1-9 for enhancing the flame retardancy and chemical strength of wood.

Description

Preparation method of high-flame-retardance high-strength modified wood Technical Field The invention belongs to the technical field of wood modification and flame retardance, and particularly relates to a preparation method of high-flame retardance and high-strength modified wood. Background Fire disaster is one of the most damaging disasters facing human society, and the fire disaster happens more than 60 tens of thousands of people in China in recent five years, so that thousands of people die and thousands of people are injured, and the direct property loss exceeds one hundred billion yuan. Among them, flammability of the decorative material is a key cause. Along with the improvement of space aesthetic requirements, the wood decorative material becomes the first choice of scenes such as buildings, high-speed rail carriages, ship cabins and the like due to natural textures and warm texture. However, the traditional wood decorative materials have hidden major potential safety hazards, namely, the ignition point is only about 260 ℃, the wood decorative materials are extremely easy to burn when exposed to open fire or high temperature, the combustion speed is high, the heat release amount is large, and a large area of fire can be formed in a short period of time. Therefore, the development of a novel wood composite material with high-efficiency flame retardance, excellent mechanical property and environmental-friendly property has become an urgent research direction in the fields of material science and forestry engineering. Disclosure of Invention The invention aims to provide a preparation method of high-flame-retardance high-strength modified wood, which fundamentally solves the industrial problem that the flammability and mechanical properties of the wood are difficult to consider, and the whole preparation process pays attention to the green chemistry principle while improving the flame retardance and mechanical properties of the wood, preferentially uses low-toxicity, halogen-free and renewable flame retardant components, promotes the development of the 'green flame retardance' technology and meets the national 'double carbon' strategic goal. In order to achieve the above object, the present invention provides the following technical solutions: the invention provides a preparation method of modified wood, which comprises the following steps: S1, alkali treatment of wood, namely placing the wood in 5-10% sodium hydroxide aqueous solution for soaking treatment, washing the wood with deionized water until the pH value is 7.0 after the treatment is finished, and placing the wood in absolute ethyl alcohol for preservation; S2, preparing modified aqueous epoxy resin, namely dissolving bisphenol A epoxy resin in absolute ethyl alcohol to obtain epoxy groups, adding diethanolamine to the epoxy groups to react 2h, and sequentially adding polyether amine, glacial acetic acid and deionized water to form the modified aqueous epoxy resin containing quaternary ammonium groups; S3, preparing a condensed phase flame retardant, namely mixing montmorillonite with 4% boric acid solution, and performing ultrasonic centrifugation to obtain 5-10wt% of flame retardant; s4, placing the alkali-treated wood in a modified water-based epoxy resin and flame retardant mixed system, and carrying out vacuum impregnation and hot pressing to obtain the modified wood with high flame retardance and high mechanical property. Preferably, the condition of the soaking treatment in the step S1 is that the soaking treatment is 6-12 h under the temperature of 60-80 ℃. Preferably, the mass ratio of the bisphenol A epoxy resin to the absolute ethyl alcohol in the step S2 is 1:1, and the dissolution condition is that the bisphenol A epoxy resin and the absolute ethyl alcohol are stirred and dissolved at 65 ℃ and 300 r/min. Preferably, the amount of the diethanolamine substance added in the step S2 is 30% of the amount of the E-44 epoxy group substance, and polyetheramine is added according to the ratio of bisphenol A type epoxy resin to polyetheramine of 4:1; Preferably, the addition amount (the amount of substances) of the glacial acetic acid in the step S2 is equal to the total amount of substances of amine groups in diethanolamine and polyetheramine (D230), and the mass ratio of bisphenol A epoxy resin to deionized water is 1 (0.8-1.2). Preferably, in the step S3, the mixing mass ratio of the boric acid to the montmorillonite is 1 (1.0-4.0), and the ultrasonic centrifugation conditions are ultrasonic 30 min and 9000 rpm and centrifugal 10min. Preferably, the vacuum impregnation process in the step S4 is carried out for 3-6 times under the conditions of-0.1 to-0.6 MPa, and each time lasts for 3-50 minutes. Preferably, in the step S4, the timber is horizontally placed under a hot press for hot press forming, the hot press temperature is 80-100 ℃, the pressure is 15-25 MPa, the hot press time is 8-12 hours, the compression ratio is controlled to