Thermally induced phase change type flow-equalizing wood fiber composite material as well as preparation method and application thereof

Abstract

The invention discloses a thermally induced phase change type flow equalizing wood fiber composite material and a preparation method and application thereof.The preparation method comprises the steps that S1, thermally induced phase change biomacromolecules and a tough biomass-based film-forming agent containing amino functional groups are dissolved under the acidic condition, then an epoxy group compound cross-linking agent is added, and uniform flow equalizing agent pre-polymerization liquid is formed; s2, mixing the pre-polymerized liquid of the flow equalizing agent with wood flour and cotton fibers; s3, kneading the obtained mixture to obtain a plastic kneaded material; and S4, the plastic kneaded material is subjected to hot-pressing curing, and the wood fiber-based composite material is obtained. Through the synergistic effect of thermally induced phase change and chemical crosslinking, the problems of flowing and interface bonding of wood fibers in integral forming are solved, and the prepared composite material is uniform in structure, excellent in performance and suitable for rapid manufacturing of furniture, decoration and building components.

Description

TECHNICAL FIELD

[0001] The present application relates to wood fiber composite materials, in particular, to a thermally induced phase change type flow uniform wood fiber composite material, a preparation method and application thereof. BACKGROUND

[0002] In recent years, with the increasing global environmental protection and the green consumption fashion, wood fiber-based composite materials have attracted more and more attention. At present, the demand for wood fibers in the international market continues to grow: the application scenarios of composite materials made of wood fibers as the main raw material continue to expand, and the sales of thermosetting / thermoplastic-based composites also promote the synchronous growth of reinforcing fillers and fiber reinforced products. Compared with industrial fibers such as glass fibers, wood fibers have wide sources, light weight, controllable cost, and can give the product a friendly touch and appearance, which makes them popular among producers and consumers worldwide. However, the surface of wood fibers is rich in polar hydroxyl groups, and there is a problem of insufficient polarity matching and interface compatibility between hydrophobic or semi-hydrophobic polymer matrix. In the processing process, there are often defects such as poor wetting, uneven dispersion, fiber aggregation, air entrapment and holes, insufficient interlayer adhesion, etc., which affect the uniformity of the organization, the stability of the interface bonding and the mechanical consistency of the product, and bring challenges to the one-piece molding of complex structures.

[0003] The existing modification methods often use surface chemical treatment, add coupling agents, or use urea-formaldehyde, isocyanate and other adhesive systems to improve the interface and forming flow, but there are often hidden dangers in environmental protection and occupational health (such as formaldehyde release, isocyanate toxicity, VOC emission), and the process is relatively complex, and the long-term stability and durability are also limited. Inert plasticization or emulsion type “flow modification” can reduce the mixing viscosity, but it is easy to migrate and age, and it is difficult to form a stable chemical bridge at the fiber interface, and it is also difficult to adapt to the forming route that needs multiple paving. SUMMARY

[0004] In view of the problems of poor wetting, uneven dispersion, air entrapment and holes, insufficient interlayer adhesion, and organic solvent and VOC hidden dangers of existing wood fiber-based composite materials in the one-piece molding process, the present application provides a thermally induced phase change type flow uniform wood fiber composite material, a preparation method and application thereof. Through the synergistic effect of thermally induced phase change and chemical crosslinking, the flow and interface bonding problems of wood fibers in one-piece molding are solved, and the prepared composite material has uniform organization and excellent performance.

[0005] Specifically, the preparation method comprises the following steps: S1, dissolving a thermally induced phase change biological macromolecule and a flexible biomass-based film-forming agent containing an amino functional group in an acidic condition, and then adding an epoxy group compound crosslinking agent to form a uniform flow agent prepolymer solution; S2, mixing the flow agent prepolymer solution with wood powder and cotton fibers; S3, kneading the obtained mixture to obtain a plastic kneadate; S4, hot-pressing and curing the plastic kneadate to obtain a wood fiber-based composite material.

[0006] The flow equalizer of the application is composed of the biological macromolecule, the film forming agent, the cross-linking agent and the acidic aqueous solution. The acidic condition is preferably achieved by an acetic acid solution, which provides a mild acidic environment, partially protonates the film forming agent containing amino functional groups (—NH3 + ), improves its swelling and dispersion capacity, and provides acid catalytic conditions for the subsequent epoxy ring-opening reaction. Under hot-pressing conditions, the epoxy groups at both ends of the multi-epoxy group compound undergo nucleophilic ring-opening reactions in the acidic medium: one reacts with the hydroxyl groups on the surface of the film forming agent / biological macromolecule with thermotropic phase change behavior and lignocellulose to form β-hydroxy ether bonds; the other reacts with the deprotonated amino groups to form β-hydroxy amine ether bonds, thereby constructing a chemical bridging network between the fiber-flow equalizer-matrix. At the same time, multi-point hydrogen bonding and electrostatic (ionic) association involving —OH / —NH3 + / ether oxygen sites exist in the system, forming a synergistic structure with coexisting chemical cross-linking and physical association, improving the interfacial adhesion stability and macroscopic density.

[0007] The biological macromolecule with thermotropic phase change behavior exhibits thermotropic phase change behavior in the forming temperature range of the system: it changes from uniform swelling state to shrinkage enrichment state as the temperature rises, and selectively enriches on the surface of wood powder and cotton fiber and its neighborhood, forming a thin interfacial lubricating layer. The lubrication induced by this phase change reduces the local interfacial tension and frictional resistance on one hand, promoting the flow leveling, fiber rearrangement and air entrapment, thereby realizing uniform flow and uniform spreading; on the other hand, it increases the local effective concentration and contact probability of the epoxy groups of the multi-epoxy group compound with the hydroxyl groups on the fiber surface and the amino groups of the film forming agent, accelerating the generation of the ring-opening bridging network. During the segmented laying and pressing process, the re-wetting and re-spreading caused by the thermotropic phase change exhibit self-fusion and self-densification between layers, which is beneficial to the interfacial closure and void elimination; in the subsequent heat preservation stage, the ring-opening reaction solidifies the lubricating enrichment layer formed by the phase change into a stable chemical connected interface, realizing the process conversion from physical lubrication to structural locking. In this way, the plastic flow in the kneading stage and the phase change guided flow and cross-linking densification in the pressing stage form a closed loop coupling in a single formula, and finally obtain an integrally formed wood fiber-based composite material with uniform organization and sufficient interfacial bonding (as shown in Figure 3 ).

[0008] Specifically, the bio-macromolecule with thermotropic phase transition behavior is a cellulose ether with thermotropic phase transition behavior, including but not limited to one of hydroxypropyl cellulose (HPC), methyl cellulose (MC), hydroxyethyl methyl cellulose (HEMC). Preferably, the HPC has a hydroxypropyl molar substitution degree of 0.6-1.2, which can ensure that its thermotropic phase transition behavior is optimally matched with the temperature window of the hot-pressing process. The tough biomass-based film-forming agent is a biomass polysaccharide containing amino functional groups, including but not limited to chitosan (CTS) and its derivatives. Preferably, the CTS has a degree of deacetylation of ≥85% to ensure its good solubility in weak acid aqueous solution and sufficient reactivity. The multi-epoxy group compound includes but is not limited to one of polyethylene glycol diglycidyl ether (PEGDGE) and glycerol polyglycidyl ether. Preferably, the PEGDGE has a number average molecular weight of 200-800, which achieves a better balance between the diffusion ability and crosslinking density of the crosslinking agent.

[0009] The pH of the flow agent pre-polymer solution is adjusted to 3-5, preferably 4, and the solid content is 15-35 wt%; the mass ratio of the tough biomass-based film-forming agent, the thermotropic phase transition bio-macromolecule, and the crosslinking agent is (5-15):(10-20):(0.7-1.5), preferably 15:10:1; and the total equivalent ratio of the multi-epoxy group compound (such as PEGDGE) to (—OH + —NH2) is 0.6-1.0.

[0010] Preferably, in step S2, the wood powder has a particle size of 60-200 mesh, and the cotton fiber has a length of 3-15 mm; both have a moisture content of 3%-10%. The wood powder is derived from redwood or fir, and the cotton fiber is natural cotton fiber.

[0011] Preferably, in step S3, the mixed mass fraction ratio of the flow agent pre-polymer solution, the wood powder, and the cotton fiber is (25-45):(55-60):(10-15), and further preferably 30:60:10, and the kneading time is 10-30 minutes to obtain a kneadate with good plasticity and inhibit subsequent forming defects.

[0012] Preferably, step S4 adopts a three-stage batch feeding integrated molding hot-pressing process: the total feeding mass of the kneadate is divided into 60% for the first stage, 20% for the second stage, and 20% for the third stage, which are sequentially fed into the mold cavity; the hot-pressing holding time of each stage is 3-6 minutes, the hot-pressing temperature is controlled at 130-140 ℃, preferably 135 ℃ for 4 minutes; after the hot-pressing is completed, the product is directly demolded and naturally cooled to room temperature in the air; and the hot-pressing pressure is 10-25 MPa.

[0013] The second aspect of the present application provides the thermally induced phase change type wood fiber composite material prepared by the preparation method. The composite material is composed of wood powder and cotton fiber as the reinforcing phase, and a chitosan / hydroxypropyl cellulose / polyethylene glycol diglycidyl ether crosslinking network as the matrix phase. The cross section is dense and uniform, the interface is fully bonded, and the composite material is suitable for one-piece forming of complex components.

[0014] The third aspect of the present application provides the application of the thermally induced phase change type wood fiber composite material in the preparation of furniture plates, indoor decoration parts, acoustic panels, boxes, covers or special-shaped components for buildings.

[0015] Through the above technical scheme, the present application has the following beneficial effects: The present application uses aqueous phase and acidic solution as the medium, uses biomacromolecules with thermally induced phase change behavior and film-forming agents containing amino functional groups to construct a multi-point hydrogen bond and electrostatic coupling network, and introduces a multi-epoxy group compound as a crosslinking agent to occur epoxy ring-opening reaction in the hot pressing stage, realizes in-situ reaction type flow and bridging of the fiber surface, thereby providing good wetting and flow in the kneading stage, and completing the interface lubrication driven by the structure densification induced by the thermally induced phase change in the heating and hot pressing stage, adapting to batch feeding and realizing one-piece forming of complex components (such as shown in the figure). Figure 1 Compared with the traditional scheme, the present application has the following advantages: 1. Interface bridging and defect suppression: the reactive flow agent builds a chemical bridging network through epoxy ring-opening in the hot pressing stage, and cooperates with multi-point hydrogen bond / ionic bonding, which significantly improves the interface bonding stability, reduces defects such as agglomeration, air entrainment and pores, and improves the organization uniformity and mechanical consistency of the product; 2. Flow and one-piece forming adaptation: the flow agent provides good wetting and dispersion in the mixing / kneading stage, so that the material is in a plastic kneading state; secondary infiltration and interlayer self-fusion can be realized during batch feeding, and the interlayer adhesion and fusion are more stable, which is suitable for integrated processing of complex molds and cavities; 3. Thermally induced phase change and interface lubrication: hydroxypropyl cellulose undergoes thermally induced phase change in the forming temperature zone and selectively enriches on the fiber interface to form a thin lubricating layer, which reduces the local interfacial tension and frictional resistance, promotes the flow of the material, the rearrangement of fibers and the elimination of voids, and at the same time, increases the local effective concentration of reaction sites, accelerates the generation of bridging network and shortens the densification time; 4. Green and environmentally friendly and equipment universal: the system is aqueous low acidity, low VOC, no formaldehyde and isocyanate curing agent, and the process is simple; the process parameters are compatible with existing kneading-hot pressing equipment, and have good industrialization promotion prospect; 5. Dimensional stability and durability improvement: the chemical bridging superimposes the multi-point hydrogen bond / ionic association to form a synergistic network, which significantly enhances the interface stability and dimensional stability in a humid heat environment, and reduces the risk of thickness expansion and warping; 6. Excellent comprehensive performance: the cross-phase crosslinking network provides a continuous load transmission path, and the thermal phase change of hydroxypropyl cellulose and the toughening effect of polyethylene glycol main chain are synergistic, so that the composite material has good interface bonding, strong and tough balance and stable appearance quality. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the component and forming mechanism schematic diagram of the wood fiber-based composite material described in the application; Figure 2 is a physical diagram of the preparation process of the wood fiber composite material; Figure 3 is a microelectroscope diagram of the wood fiber composite material; Figure 4 is a comparison diagram of the bending strength of wood fiber composite materials of different schemes. DETAILED DESCRIPTION

[0017] The specific embodiments of the application will be described in detail below in conjunction with the examples. It should be understood that the specific embodiments described herein are only for illustration and explanation of the application, and are not intended to limit the application.

[0018] Example 1 As shown in the preparation process of the wood fiber-based composite material is as follows: Figure 2 S1, add glacial acetic acid to deionized water to adjust pH = 4, add hydroxypropyl cellulose and chitosan in turn, stir until dissolved uniformly, then add polyethylene glycol diglycidyl ether, continue stirring at room temperature until a uniform solution is formed. The solid mass ratio of CTS:HPC:PEGDGE is 10:15:1, stirring for 12 hours under a high-speed stirrer at a speed of 300 revolutions per minute, then standing for 6 hours to remove bubbles, finally obtaining a pre-polymer solution with a solid content of 26% (mass fraction) in a semi-gel state.

[0019] S2, dry the 80-mesh redwood powder and cotton fibers with a length of 3-15 mm in a 105℃ oven to a moisture content of 3%-10% for standby. Mix the pre-polymer solution prepared in S1 with the wood powder and cotton mixture, and knead with a kneading machine at room temperature for 25 minutes until the material is uniformly plastic kneaded (no dry powder, no obvious agglomeration, hand forming without sticking back), the mass ratio of pre-polymer solution, wood powder and cotton fiber is 3:6:1.

[0020] S3, the plastic kneading material is sequentially put into the mold cavity preheated to 135℃ at 60%, 20% and 20% of the total amount. Each section is hot pressed for 4 minutes, and the forming pressure is 15 Mpa. After the end, directly demold, and the workpiece is naturally cooled to room temperature in the air, to obtain a plate with a thickness of about 3 mm, then vacuum drying at 100℃ in an oven for 1 hour, finally obtaining the wood fiber composite material. ​

[0021] Example 2 S1, add glacial acetic acid to deionized water to adjust pH = 5, add methyl cellulose (MC) and chitosan in turn, stir until dissolved and uniform, then add poly 1,4-butanediol diglycidyl ether (BDDE), continue stirring at room temperature until a uniform solution is formed. The solid mass ratio of CTS:MC:BDDE is 15:15:1, stirring for 12 hours under a stirrer with a speed of 300 revolutions per minute, and standing for 3 hours to remove bubbles, to obtain a prepolymer solution with a solid content of 32%.

[0022] S2, dry 120 mesh redwood wood powder and cotton fibers with a length of 3-15 mm in an oven at 105°C to a moisture content of 3-10% for standby use. Mix the prepolymer solution prepared in S1 with the wood powder and cotton mixture in a proportion, and knead with a kneading machine at room temperature for 25 minutes until the material is in a uniform plastic kneading state (no dry powder, no obvious agglomeration, and no tackiness when hand molding), the mass ratio of prepolymer, wood powder, and cotton fiber being 25:60:15.

[0023] S3, the plastic kneading material is sequentially put into a mold cavity preheated to 130°C at 60%, 20%, and 20% of the total amount, and hot-pressed at 20 MPa for 5 minutes for each section. After completion, directly demold and naturally cool to room temperature to obtain a plate with a thickness of about 3 mm; then dry in a vacuum oven at 100°C for 1 hour to obtain a wood fiber composite material.

[0024] Example 3 S1, add glacial acetic acid to deionized water to adjust pH = 4, add hydroxyethyl methyl cellulose (HEMC) and chitosan in turn, stir until dissolved and uniform, then add polypropylene glycol diglycidyl ether (PPGDGE), continue stirring at room temperature until a uniform solution is formed. The solid mass ratio of CTS:HEMC:PPGDGE is 10:20:1.5, stirring for 12 hours under a high-speed stirrer with a speed of 300 revolutions per minute, and then standing for 6 hours to remove bubbles, finally obtaining a prepolymer solution with a solid content of 30% (mass fraction) in a semi-gel state.

[0025] S2, dry 80 mesh Chinese fir wood powder and cotton fibers with a length of 3-15 mm in an oven at 105°C to a moisture content of 3-10% for standby use. Mix the prepolymer solution prepared in S1 with the wood powder and cotton mixture, and knead with a kneading machine at room temperature for 10 minutes until the material is in a uniform plastic kneading state (no dry powder, no obvious agglomeration, and no tackiness when hand molding), the mass ratio of prepolymer, wood powder, and cotton fiber being 35:58:5.

[0026] S3, the plastic kneadable material is sequentially put into the mold cavity preheated to 135°C at 60%, 20%, and 20% of the total amount. Each section is hot-pressed for 4 minutes, and the forming pressure is 15 Mpa. After the end, directly demold, the workpiece is naturally cooled to room temperature in the air, and a plate with a thickness of about 3 mm is obtained. Then, vacuum drying at 100°C in an oven for 1 hour, finally, wood fiber composite material is obtained.

[0027] Example 4 S1, add glacial acetic acid to deionized water to adjust pH = 4, and then add polylactic acid grafted hydroxypropyl cellulose (HPC-g-PLA) and chitosan. After stirring until dissolved and uniform, add polyethylene glycol diglycidyl ether, and continue stirring at room temperature until a uniform solution is formed. The solid mass ratio of CTS:HPC-g-PLA:PEGDGE is 5:15:0.7. Stir for 12 hours at a high-speed stirrer speed of 300 revolutions per minute, and then stand for 6 hours to remove bubbles. Finally, a pre-polymer solution with a solid content of 26% (mass fraction) in a semi-gel state is obtained.

[0028] S2, dry the 120-mesh fir wood powder and cotton fibers with a length of 3-15 mm in a 105°C oven to a moisture content of 3%-10% for standby use. Mix the pre-polymer solution prepared in S1 and the wood powder and cotton mixture in a ratio, and knead for 30 minutes at room temperature with a kneading machine until the material is in a uniform plastic kneadable state (no dry powder, no obvious agglomeration, and no tackiness when hand-molded), and the mass ratio of pre-polymer solution, wood powder, and cotton fiber is 25:55:7.

[0029] S3, the plastic kneadable material is sequentially put into the mold cavity preheated to 135°C at 60%, 20%, and 20% of the total amount. Each section is hot-pressed for 4 minutes, and the forming pressure is 15 Mpa. After the end, directly demold, the workpiece is naturally cooled to room temperature in the air, and a plate with a thickness of about 3 mm is obtained. Then, vacuum drying at 100°C in an oven for 1 hour, finally, wood fiber composite material is obtained.

[0030] Example 5 S1, add glacial acetic acid to deionized water to adjust pH = 6, and then add hydroxypropyl cellulose and chitosan grafted with polycaprolactone. After stirring until dissolved and uniform, add polyethylene glycol diglycidyl ether, and continue stirring at room temperature until a uniform solution is formed. The solid mass ratio of CTS-g-PCL:HPC:PEGDGE is 10:15:1. Stir for 12 hours at a high-speed stirrer speed of 300 revolutions per minute, and then stand for 6 hours to remove bubbles. Finally, a pre-polymer solution with a solid content of 26% (mass fraction) in a semi-gel state is obtained.

[0031] S2. Dry 60-mesh cedar wood powder and cotton fibers with a length of 3-15 mm in an oven at 105℃ until the moisture content is 3%-10% for later use. Mix the prepolymer liquid obtained in S1 with the wood powder and cotton mixture, and knead it in a kneading machine at room temperature for 25 minutes until the material is in a homogeneous and plastic kneaded state (no dry powder, no obvious agglomeration, and does not stick when hand-pressed). The mass ratio of prepolymer liquid, wood powder, and cotton fibers is 45:60:8.

[0032] S3. The plastic kneaded material is added sequentially in batches of 60%, 20%, and 20% to a mold cavity preheated to 140°C. Each batch is hot-pressed for 6 minutes at a forming pressure of 10 MPa. After hot pressing, the material is demolded directly and allowed to cool naturally to room temperature in air to obtain a board with a thickness of approximately 3 mm. Then, it is vacuum-dried in an oven at 100°C for 1 hour to finally obtain the wood fiber composite material.

[0033] Comparative Example 1 Other conditions are the same as in Example 1, except that in S1, glacial acetic acid is not added, and the prepolymer solution is prepared directly with deionized water.

[0034] Comparative Example 2 The other conditions are the same as in Example 1, except that polyethylene glycol diglycidyl ether is not added in S1.

[0035] Comparative Example 3 Other conditions are the same as in Example 1, except that only 80-mesh mahogany powder is used in S2.

[0036] Performance testing The flexural strength of the materials prepared in Examples 1-5 and Comparative Examples 1-3 was tested respectively.

[0037] Bending strength: The three-point bending strength of the material was measured using a microcomputer mechanical testing machine. Based on the measurement results of the three-point bending test, the bending strength of the material was calculated. The specific method is as follows: the prepared material is placed between fixtures, and its three-point bending strength is measured using a microcomputer mechanical testing machine. Specific test results are as follows: Figure 4 As shown. From Figure 4 As can be seen, the flexural strengths of the wood fiber composites prepared in Examples 1-5 were 37.8±2.5 MPa, 29.2±2.8 MPa, 30.3±2.4 MPa, 36.7±2.8 MPa, and 35.1±2.3 MPa, respectively, with an average flexural strength of 33.6±2.1 MPa. In contrast, the flexural strengths of the materials prepared in Comparative Examples 1-3 were only 12.5±1.7 MPa, 19.6±1.8 MPa, and 17.6±1.5 MPa, respectively, with an average flexural strength of 16.7±1.6 MPa.

[0038] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details of the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0039] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0040] In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, and it should also be considered as disclosed by the present application.

Claims

1. A method for producing a thermally induced phase transition type flow- equalizing wood fiber composite material, characterized by, The preparation method comprises the following steps: S1, dissolving the thermally induced phase transition biological macromolecule and the tough biomass-based film-forming agent containing amino functional groups under acidic conditions, and then adding a compound crosslinking agent containing an epoxy group to form a uniform flow agent pre-polymer solution; S2, mixing the uniform flow agent pre-polymer solution with wood powder and cotton fibers; S3, kneading the obtained mixture to obtain a plastic kneadate; S4, hot-pressing and curing the plastic kneadate to obtain a wood fiber-based composite material.

2. The production method according to claim 1, characterized by, In step S1, the thermally induced phase transition biological macromolecule is a cellulose ether having a thermally induced phase transition behavior, selected from one of hydroxypropyl cellulose, methyl cellulose, and hydroxyethyl methyl cellulose, preferably, the hydroxypropyl cellulose has a hydroxypropyl molar substitution degree of 0.6-1.

2.

3. The preparation method according to claim 1, characterized in that, In step S1, the tough biomass-based film-forming agent is chitosan or a derivative thereof, preferably, the chitosan has a deacetylation degree of ≥85%.

4. The method of claim 1, wherein, In step S1, the compound crosslinking agent containing a plurality of epoxy groups is selected from one of polyethylene glycol diglycidyl ether and glycerol polyglycidyl ether, preferably, the polyethylene glycol diglycidyl ether has a number average molecular weight of 200-800.

5. The preparation method according to claim 1, characterized in that, In step S1, the acidic condition is provided by an acetic acid solution, and the pH is 3-5, preferably 4.

6. The method of claim 1, wherein, In step S1, the mass ratio of the tough biomass-based film-forming agent, the thermally induced phase transition biological macromolecule, and the crosslinking agent is (5-15):(10-20):(0.7-1.5), preferably 15:10:

1.

7. The preparation method according to claim 1, characterized in that, In step S2, the wood powder is derived from redwood or fir, and the cotton fiber is natural cotton fiber.

8. The production method according to claim 1, characterized by, In step S2, the wood powder has a particle size of 60-200 mesh, and the cotton fiber has a length of 3-15 mm; both have a moisture content of 3%-10%.

9. The method of claim 1, wherein, In step S2, the mass fraction ratio of the uniform flow agent pre-polymer solution, the wood powder, and the cotton fiber is (25-45):(55-60):(10-15), preferably 30:60:

10.

10. The method of claim 1, wherein, In step S3, the kneading time is 10-30 minutes.

11. The method of claim 1, wherein, In step S4, batch feeding is adopted for hot-pressing and curing.

12. The method of claim 11, wherein, The batch feeding is a three-stage feeding, and the feeding mass ratio is 60%, 20%, and 20% of the total kneadate mass.

13. The method of claim 1, wherein In step S4, the hot-pressing condition is 10-25 MPa, 130-140°C, and 3-6 minutes, preferably 135°C hot-pressing for 4 minutes.

14. A thermally induced phase transition type uniform flow wood fiber composite material prepared by the preparation method of any one of claims 1-13.

15. Use of the thermally induced phase transition type uniform flow wood fiber composite material of claim 14 in the preparation of furniture boards, indoor decoration parts, acoustic panels, boxes, covers, or building profiled members.

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