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CN-121991417-A - ZnCl-based material2Preparation method of modified wheat straw composite board

CN121991417ACN 121991417 ACN121991417 ACN 121991417ACN-121991417-A

Abstract

The invention discloses a preparation method of a ZnCl 2 -based modified wheat straw composite board, which belongs to the technical field of board manufacture and comprises the steps of S1, cutting up wheat straw, adding the cut wheat straw into 0.5mol/L hydrochloric acid for acid treatment, adjusting the pH value to be neutral by deionized water after treatment, and carrying out suction filtration treatment to obtain a neutral filter material, S2, mixing the neutral filter material with a mixed solution, adding NaClO powder, mixing the mixed solution with NaOH solution to adjust the pH value to 10, obtaining TEMPO oxidized pulp fiber, S3, dispersing the TEMPO oxidized pulp fiber into ZnCl 2 solution after ethanol water washing treatment, uniformly mixing the TEMPO oxidized pulp fiber with the ZnCl 2 solution, carrying out suction filtration treatment, obtaining a filter cake B, S4, the filter cake B, chitin and acetic acid, uniformly mixing the filter cake B with the mass ratio of 3:4:1, and carrying out suction filtration treatment, S3, placing the hot-pressed filter material into a hot-pressing die, and carrying out hot-pressing by a hot-pressing machine to obtain the composite board.

Inventors

  • ZHANG LIBO
  • Zeng can
  • CHENG LIHUA
  • WANG HUI
  • Fan Qinzhen
  • CHEN HONG
  • DENG YIQIANG
  • YANG CHONG
  • ZUO JIACHEN

Assignees

  • 广东石油化工学院

Dates

Publication Date
20260508
Application Date
20260209

Claims (10)

  1. 1. The preparation method of the ZnCl 2 -based modified wheat straw composite board is characterized by comprising the following steps of: S1, taking and cutting dry wheat straw to 3-5mm, adding the cut wheat straw into 0.5mol/L hydrochloric acid according to the amount of 100-150g/L, heating in a water bath at 85-95 ℃ for 4-5 hours to obtain a mixture, carrying out suction filtration on the mixture to obtain a filter cake A, stirring the filter cake A and deionized water in a mixer according to the volume ratio of 1:2 at the rotating speed of 80-90rpm for 3-5min, removing filtrate through suction filtration, and repeating the process until the pH value of the filtrate is neutral to obtain a neutral filter material; S2, mixing NaBr powder and TEMPO powder according to a mass ratio of 10:1 to obtain mixed powder, adding the mixed powder into deionized water according to a mass ratio of 1.1-1.5g/L to prepare a mixed solution, adding a neutral filter material and the mixed solution into a mixer according to a volume ratio of 1:1, mixing and stirring at 80-90rpm for 20-30min to obtain a mixed solution A, adding NaClO powder into the mixed solution A according to an addition amount of 11.2-12.5g/L, continuing stirring for 20-30min to obtain a mixed solution B, and regulating the pH value of the mixed solution to 10 through a NaOH solution while continuously stirring the mixed solution B to obtain TEMPO oxidized pulp fibers; S3, cleaning TEMPO oxidized pulp fibers in the step S2 by ethanol water to obtain a cleaned filter material, dispersing the cleaned filter material in a ZnCl 2 solution with the mass percent concentration of 40% according to the amount of 60-80g/L, continuously stirring at the stirring speed of 80-90rpm for 12-15h, standing for 24-48h to obtain a mixed solution C, and carrying out suction filtration on the mixed solution C to obtain a filter cake B; S4, mixing the filter cake B, chitin and acetic acid according to a mass ratio of 3:4:1, magnetically stirring for 20-30min at a stirring speed of 80-90rpm to obtain a mixed solution D, and carrying out suction filtration treatment on the mixed solution D to obtain a hot-pressed filter material; S5, placing the hot-pressed filter material into a hot-pressed die, and placing the hot-pressed die filled with the hot-pressed filter material into a hot press for hot pressing for 4-5 hours to obtain the composite board.
  2. 2. The preparation method of the ZnCl 2 -based modified wheat straw composite board is characterized in that in the step S3, ethanol water is cleaned, ethanol with the mass percent concentration of 95% and TEMPO oxidized pulp fiber are mixed and stirred for 20-30min according to the volume ratio of 1:9 under the condition of the stirring speed of 80-90rpm, and then suction filtration treatment is carried out, so as to separate filter materials.
  3. 3. The method for preparing the ZnCl 2 -based modified wheat straw composite board according to any one of claims 1-2, wherein the suction filtration treatment is performed by adopting a Buchner funnel under the conditions that the thickness of a filter layer is 10-15cm, the suction filtration pressure difference is 20-30kPa, the compaction density is 100kg/m 3 , and the aperture of the Buchner funnel is 1-1.5mm.
  4. 4. The preparation method of the ZnCl 2 -based modified wheat straw composite board as claimed in claim 1, wherein the concentration of NaOH solution in the S2 is 0.5-0.6mol/L.
  5. 5. The preparation method of the ZnCl 2 -based modified wheat straw composite board, which is characterized in that the hot pressing pressure in the step S5 is 14-16Mpa, and the hot pressing temperature is 75-85 ℃.
  6. 6. The preparation method of the ZnCl 2 -based modified wheat straw composite board, which is disclosed in claim 1, is characterized in that glass fiber is added into the mixed solution before the suction filtration treatment of the mixed solution D in the step S4, the fiber length of the glass fiber is 3-5cm, and the mass ratio of the added glass fiber to the filter cake B in the mixed solution is 1:3.
  7. 7. The preparation method of the ZnCl 2 -based modified wheat straw composite board as claimed in claim 1, which is characterized by further comprising the step S6 of airing the obtained composite board for 4-7d at 18-35 ℃ and performing film coating treatment on the composite board after airing.
  8. 8. The preparation method of the ZnCl 2 -based modified wheat straw composite board as claimed in claim 7, wherein the film coating treatment is to brush a layer of adhesive on the surface of the composite board, then bond waterproof aluminum foil on the surface of the composite board, and then bond a decorative layer on the surface of the waterproof aluminum foil to obtain the finished product composite board.
  9. 9. The preparation method of the ZnCl 2 -based modified wheat straw composite board, which is disclosed in claim 8, is characterized in that the adhesive consists of the following components, by mass, 95-100 parts of SIS1105, 50-60 parts of C5 petroleum resin, 40-50 parts of hydrogenated rosin glyceride, 15-20 parts of naphthenic oil, 0.5-1 part of antioxidant 1010 and 5-10 parts of nano silicon dioxide.
  10. 10. The preparation method of the ZnCl 2 -based modified wheat straw composite board as claimed in claim 7, wherein the film coating treatment is to brush a layer of adhesive on the surface of the composite board, and then bond waterproof aluminum foil on the surface of the composite board to obtain the finished product composite board.

Description

Preparation method of ZnCl 2 -based modified wheat straw composite board Technical Field The invention relates to the technical field of plate manufacturing, in particular to a preparation method of a ZnCl 2 -based modified wheat straw composite plate. Background In the field of manufacturing of modern furniture boards, key scientific problems to be solved are mainly focused on two aspects, and development of environment-friendly adhesives replaces traditional synthetic resins, and low-quality wood raw materials (such as agricultural solid waste straws) are developed and utilized. From the analysis of the current state of industry, plywood is taken as a market leading product, and the preparation process of the plywood is generally formed by taking wood fiber as a base material and compounding the wood fiber through hot pressing of a synthetic resin adhesive. But this production process has significant raw material loss problems. According to life cycle evaluation data, the log consumption amount is up to 1.5-2 cubic meters (based on dry basis) per 1 cubic meter of plywood product produced, and the comprehensive utilization rate of raw materials is less than 60%. At present, the adhesives such as Urea Formaldehyde (UF) and Phenol Formaldehyde (PF) widely used in the industry all use nonrenewable petroleum as raw materials, and the dosage of the adhesives accounts for 13-15% of the total mass of the board, and pollutants such as formaldehyde are used in the synthesis process, so that the adhesives have certain significance for development of raw materials for manufacturing furniture boards and development of glue-free preparation processes, technical innovation of the industry, green equipment and the like. Current glue-free board production typically involves a highly destructive pretreatment of the composition of the lignocellulosic feedstock. For example, acid treatment removes hemicellulose from the raw material, and alkali treatment removes lignin from the raw material. These pretreatment modes, while fully exposing the functional groups on the surface of the lignocellulosic feedstock, greatly deplete the feedstock, which obviously reduces the utilization of the lignocellulosic feedstock. At present, the technology for preparing the glue-free composite board from the agricultural solid waste has obvious defects that the conventional pretreatment method can damage raw material components, so that effective components such as hemicellulose, lignin and the like are lost, the comprehensive utilization rate of raw materials is low, meanwhile, the prior art is difficult to fully swell fibers and release internal hydrogen bonds, accessibility of active functional groups is limited, subsequent biomass self-gluing efficiency is low, interface bonding is weak, an external adhesive is always needed, in addition, the board prepared by the conventional method is difficult to balance among mechanical property, water resistance (high water absorption) and flame retardance, and links such as strong acid treatment, high energy consumption hot pressing and the like in the process have great negative environmental influences, so that green sustainable application of the board is restricted. Disclosure of Invention In order to solve the technical problems, the invention provides a preparation method of a ZnCl 2 -based modified wheat straw composite board. The technical scheme of the invention is that the preparation method of the ZnCl 2 -based modified wheat straw composite board comprises the following steps: S1, taking and cutting dry wheat straw to 3-5mm, adding the cut wheat straw into 0.5mol/L hydrochloric acid according to the amount of 100-150g/L, heating in a water bath at 85-95 ℃ for 4-5 hours to obtain a mixture, carrying out suction filtration on the mixture to obtain a filter cake A, stirring the filter cake A and deionized water in a mixer according to the volume ratio of 1:2 at the rotating speed of 80-90rpm for 3-5min, removing filtrate through suction filtration, and repeating the process until the pH value of the filtrate is neutral to obtain a neutral filter material; S2, mixing NaBr powder and TEMPO powder according to a mass ratio of 10:1 to obtain mixed powder, adding the mixed powder into deionized water according to a mass ratio of 1.1-1.5g/L to prepare a mixed solution, adding a neutral filter material and the mixed solution into a mixer according to a volume ratio of 1:1, mixing and stirring at 80-90rpm for 20-30min to obtain a mixed solution A, adding NaClO powder into the mixed solution A according to an addition amount of 11.2-12.5g/L, continuing stirring for 20-30min to obtain a mixed solution B, and regulating the pH value of the mixed solution to 10 through a NaOH solution while continuously stirring the mixed solution B to obtain TEMPO oxidized pulp fibers; S3, cleaning TEMPO oxidized pulp fibers in the step S2 by ethanol water to obtain a cleaned filter material, dispersing the cleaned filt