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CN-122008369-A - Preparation method of light-permeable phase-change bamboo material

CN122008369ACN 122008369 ACN122008369 ACN 122008369ACN-122008369-A

Abstract

The invention discloses a preparation method of a light-permeable phase-change bamboo material, which relates to the technical field of bamboo material treatment, and adopts an acidic sodium chlorite system to remove lignin of alkali treated bamboo materials; the acid sodium chlorite method disclosed by the invention has the advantages that lignin is selectively removed while the complete structure of the bamboo fiber is maintained, the preparation method disclosed by the invention is concise in process steps, and the used acid sodium chlorite delignification system is combined with structural alkali treatment and vacuum impregnation, so that the high-efficiency delignification and high load of a phase change material are realized, meanwhile, the operability of the process and the final performance of the material are both realized, the prepared phase change bamboo material has light transmittance and high enthalpy value, and the phase change enthalpy is more than 80J/g, so that the phase change bamboo material can be used as a light-transmitting window with a heat storage function, an indoor partition, a decoration panel and a photo-thermal management furniture component.

Inventors

  • LIU YUXIN
  • ZHAO JIAAI
  • HUANG JIZHEN
  • LI KAI

Assignees

  • 昆明理工大学

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. The preparation method of the light-permeable phase-change bamboo material is characterized by comprising the following steps of: step 1, preprocessing bamboo wood; step 2, immersing the pretreated bamboo wood in a sodium hydroxide solution, stirring at 80 ℃ for 8-10 hours for alkali treatment, and washing residual reagent after the reaction is finished; Step 3, immersing the bamboo subjected to alkali treatment in a delignification solution, reacting for 3-8 hours at 80-90 ℃ to remove lignin, washing residual reagent after the reaction is finished, and immersing the bamboo subjected to lignin removal in absolute ethyl alcohol for later use; and 4, immersing the bamboo wood with lignin removed in the mixed solution, carrying out vacuum immersion treatment, and then taking out the bamboo chips, heating and solidifying to obtain the light-permeable phase-change bamboo wood.
  2. 2. The method for preparing light-permeable phase-change bamboo according to claim 1, wherein the pretreatment of the bamboo in step 1 is to cut the bamboo into pieces and polish the cut bamboo to be smooth.
  3. 3. The preparation method of the light-permeable phase-change bamboo material according to claim 1, wherein in the step 2, the mass fraction of the sodium hydroxide solution is 1% -2%, and the mass of the sodium hydroxide solution is 20% -40 times of that of the pretreated bamboo material.
  4. 4. The preparation method of the light-permeable phase-change bamboo wood is characterized in that the preparation method of the delignification solution in the step 3 comprises the steps of preparing sodium chlorite solution with the mass fraction of 3-5%, and then adding acetic acid to adjust the pH value of the solution to 4.6.
  5. 5. The method for preparing light-permeable phase-change bamboo according to claim 1, wherein the delignification solution in the step 3 is 20-30 times of the alkali-treated bamboo.
  6. 6. The preparation method of the light-permeable phase-change bamboo wood is characterized in that the preparation method of the mixed solution in the step 4 comprises the steps of mixing epoxy resin and polyethylene glycol according to the mass ratio of 8~6:2-4, heating to 60 ℃, stirring for 1 hour, adding a curing agent, and stirring for 20-30 minutes to obtain the mixed solution.
  7. 7. The method for preparing light-permeable phase-change bamboo according to claim 6, wherein the epoxy resin is E51.
  8. 8. The preparation method of the light-permeable phase-change bamboo wood is characterized in that the curing agent is obtained by mixing polyetheramine D-230 and N, N-dimethylacrylamide according to a mass ratio of 9:1, and the mass ratio of the curing agent to the epoxy resin is 3-4:7-6.
  9. 9. The method for preparing light-permeable phase-change bamboo according to claim 1, wherein the vacuum impregnation treatment is carried out in step 4, the impregnation is carried out for 1min at normal pressure every 10min, and the operation is repeated for 3-5 times.
  10. 10. The method for preparing the light-permeable phase-change bamboo material according to claim 1, wherein the heating curing in the step 4 is carried out at 60-70 ℃ for 24 hours.

Description

Preparation method of light-permeable phase-change bamboo material Technical Field The invention relates to the technical field of bamboo processing, in particular to a preparation method of light-permeable phase-change bamboo. Background Along with the improvement of global energy structure transformation and building energy conservation requirements, the development of the green building material with photo-thermal regulation and control capability has important significance. The phase change material can reversibly absorb and release a large amount of latent heat through the phase change process, and the temperature regulation capacity and the energy efficiency of the building envelope are obviously improved. If the material is combined with traditional building materials, a new generation of intelligent energy-saving materials can be expected to be developed. Bamboo is used as a fast-growing renewable biomass resource, is highly similar to wood in structure and chemical composition, and is an ideal substrate for preparing functional composite materials. In recent years, transparent wood developed based on delignification technology has demonstrated a viable path for imparting light transmittance to biomass substrates. However, wood resources are increasingly scarce, driving research into bamboo. The difference between the horizontal and vertical dissolution of bamboo lignin and hemicellulose is obvious, and the sodium hydroxide and sodium sulfite solution method is used for preparing the light-transmitting wood, so the preparation time is longer, and the sodium chlorite solution method is selected. Meanwhile, the pure light-transmitting material can not meet the requirement of buildings on dynamic heat management. How to integrate the phase-change energy storage function into the transparent bamboo matrix efficiently and stably to form a composite material with dual characteristics of light transmission and heat regulation becomes the current research difficulty and key point. In the prior art, direct impregnation is difficult to realize high load and leakage prevention of the phase change material while maintaining the structural integrity of bamboo porous structures. Therefore, a high-efficiency and structure-friendly delignification method suitable for bamboo is developed, and a light-permeable phase-change bamboo with stable structure and light-heat property is constructed on the basis, so that the method has urgent practical significance for expanding the high-value application of the bamboo and promoting the development of the building energy-saving technology. Disclosure of Invention In order to achieve the aim, the invention provides a preparation method of light-permeable phase-change bamboo, which adopts a bamboo acidic sodium chlorite system to selectively remove lignin and then adopts a vacuum impregnation method to prepare the phase-change bamboo. The acidic sodium chlorite can maintain the complete structure of the bamboo fiber and simultaneously selectively remove lignin, and the method has the advantages of low cost and easy acquisition of raw materials and simple operation. The transparent bamboo material prepared by the invention has the characteristics of light transmittance and phase change energy storage, the melting enthalpy change is more than 80J/g at room temperature, the phase change enthalpy is 65% of polyethylene glycol 800, and the transparent bamboo material is light transmittance. In order to achieve the above purpose, the present invention provides the following technical solutions: A preparation method of a light-permeable phase-change bamboo material comprises the following steps: step 1, preprocessing bamboo wood; Step 2, immersing the pretreated bamboo wood in a sodium hydroxide solution, slowly stirring at 80 ℃ for 8-10 hours for alkali treatment, and washing residual reagent with hot water after the reaction is finished; Step 3, immersing the bamboo subjected to alkali treatment in a delignification solution, reacting for 3-8 hours at 80-90 ℃ to remove lignin, washing residual reagent with hot water after the reaction is finished, and immersing the bamboo subjected to lignin removal in absolute ethyl alcohol for later use; and 4, immersing the bamboo wood with lignin removed in the mixed solution, carrying out vacuum immersion treatment, and then taking out the bamboo chips, heating and solidifying to obtain the light-permeable phase-change bamboo wood. Further, the pretreatment mode in the step 1 is that bamboo is sliced into proper size and polished to be smooth. Further, in the step 2, the mass fraction of the sodium hydroxide solution is 1% -2%, and the mass of the sodium hydroxide solution is 20% -40 times of the mass of the pretreated bamboo wood. Further, the delignification solution in the step 3 is a mixed solution of sodium chlorite and acetic acid, and the preparation method comprises the steps of adding sodium chlorite into water to prepare a sodium chlo