Fiber composite material, preparation method and application thereof, and composite sand-fixing barrier

Abstract

The invention belongs to the technical field of sand prevention and fixation, and particularly relates to a fiber composite material, a preparation method and application thereof and a composite sand fixation barrier. The fiber composite material provided by the invention comprises the following raw materials in percentage by mass: 55-80% of modified fibers, 10-20% of a flexibilizer, 5-10% of a fertilizer slow-release agent and 5-15% of an adhesive, the modified fibers comprise natural fibers and silane interface modifiers grafted on the surfaces of the natural fibers. The main raw materials adopted by the invention are natural materials such as wood fibers, bamboo fibers and jute fibers, and the fibers can be obtained through hot grinding of wood branches, waste materials and recycled materials, so that the obtaining threshold of the raw materials is greatly reduced; the composite material can be used for preparing a sand barrier, the sand barrier is decomposed into organic matters, carbon dioxide and water under the action of microorganisms in soil, meanwhile, the organic matters and the fertilizer slow-release agent are degraded, a good effect is achieved on protection of sand dunes and growth of plants, and pollution to the environment is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of sand prevention and fixation, and specifically relates to a fiber composite material, a preparation method and application thereof, and a composite sand fixation barrier. Background Art

[0002] The fixation of sand bodies is the most important part of the construction of sand prevention and control projects. At present, the main method of sand prevention and fixation is to set up sand barriers. Mechanical sand barriers refer to various forms of barriers set up on the sand surface using materials such as firewood, grass, branches, clay, pebbles, etc. The purpose is to control the direction, speed, and structure of wind and sand movement, change wind erosion conditions, prevent wind and sand, and change the effects of wind and micro-topography. Traditional sand barriers are mainly salix tamarisk sand barriers and wheat straw sand barriers. However, the raw materials of traditional salix tamarisk branches are in short supply in a short period of time, causing price increases, affecting the progress of project implementation and project costs; wheat straw sand barriers are made of materials such as rice straw, wheat straw or reed straw, which are easy to rot, resulting in a short service life of wheat straw sand barriers, and the sand fixation effect cannot be effectively guaranteed, and it cannot play a role in blocking the movement of wind and sand.

[0003] With the development of science and technology, some new materials for making sand barriers have emerged, such as nylon mesh sand barriers, high-density polyethylene (HDPE) board sand barriers, etc. However, due to the non-biodegradability of these materials, they also cause certain secondary pollution.

[0004] In addition, plant sand fixation is also a major technology for current sand prevention and control, and is often combined with sand barrier sand fixation. Plant sand fixation can not only fix the sand by using the plant growth process, but also reduce the wind speed in the sand. However, it is currently impossible to grow sand plants under many geological conditions. Even if plants are planted, they will lack sufficient nutrients and fertilizers, resulting in low plant groundbreaking rate and survival rate, making the two unable to be used together. Therefore, providing an environmentally friendly, degradable, low-cost, and large-scale industrial sand barrier material is a technical problem that urgently needs to be solved. Summary of the invention

[0005] In view of this, the present invention provides a fiber composite material, a preparation method and application thereof, and a composite sand-fixing barrier. The fiber composite material provided by the present invention uses natural fiber as raw material to improve the environmental protection and degradability of the material while reducing the production cost; at the same time, the fertilizer corrosion inhibitor is slowly released as the material degrades, which can effectively improve the survival rate of plants planted in the sand barrier.

[0006] In order to solve the above technical problems, the present invention provides a fiber composite material, comprising the following raw materials in percentage by weight: Modified fiber 55~80%; Flexibility agent 10~20%; Fertilizer slow-release agent 5~10%; Adhesive 5~15%; The modified fiber comprises natural fiber and a silane interfacial modifier grafted on the surface of the natural fiber.

[0007] Preferably, the natural fiber includes one or more of wood fiber, bamboo fiber, hemp fiber and seaweed fiber; the length of the natural fiber is less than or equal to 500 μm, and the diameter of the natural fiber is less than or equal to 250 μm; The silane interface modifier includes one or more of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, 1H,1H,2H,2Hperfluorodecyltrichlorosilane, 1H,1H,2H,2Hperfluorooctyltrichlorosilane and 1H,1H,2H,2Hperfluorodecyltriethoxysilane.

[0008] Preferably, the flexibilizer comprises polyurethane particles, polyurethane fibers, polypropylene fibers or polyester fibers.

[0009] Preferably, the adhesive includes one or more of urea-formaldehyde resin adhesive, phenol-formaldehyde resin adhesive, melamine-modified urea-formaldehyde resin adhesive, epoxy resin adhesive and isocyanate adhesive.

[0010] Preferably, the fertilizer slow-release agent includes one or more of sulfur-coated urea, urea formaldehyde, isobutylene diurea, oxalamide fertilizer, nitrifying urease inhibitor fertilizer and resin-coated urea.

[0011] The present invention also provides a method for preparing the fiber composite material described in the above technical solution, comprising the following steps: The natural fiber and the silane interfacial modifier are first mixed and dehydrated to obtain modified fiber; The adhesive is atomized and sprayed onto the surface of the modified fiber, and then mixed with a flexibilizer and a fertilizer slow-release agent to obtain a mixed material; The mixed material is formed and then hot-pressed to obtain the fiber composite material.

[0012] Preferably, the temperature of the dehydration reaction is 50-150°C, and the time of the dehydration reaction is 30-150 minutes; The atomization pressure is 1-10 MPa; The thickness of the blank after forming is 3 to 50 cm; The temperature of the hot pressing is 100-180° C., and the holding time of the hot pressing is 0.5-5 min.

[0013] The present invention also provides the use of the fiber composite material described in the above technical solution or the fiber composite material prepared by the preparation method described in the above technical solution in the preparation of sand barriers.

[0014] The present invention also provides a composite sand-fixing barrier, comprising a sand barrier and sand-growing plants; The sand barrier material is the fiber composite material described in the above technical solution or the fiber composite material prepared by the preparation method described in the above technical solution.

[0015] Preferably, the desert plants include one or more of Haloxylon ammodendron, Nitraria tangutorum, Caragana microsporum, Cyperus rotundus, Calligonum mongolica and Artemisia ordosica; The sand barrier may be in the form of strip, grid or arc; When the sand barrier is in the form of strips, the sand-dwelling plants are planted in the intervals between adjacent strips; When the sand barrier is in a grid-type form, the sand-dwelling plants are planted in the middle area of ​​the grid-type sand barrier; When the sand barrier is in the shape of an arc, the sand-dwelling plants are planted in the interval areas between adjacent arc zones.

[0016] The present invention provides a fiber composite material, comprising the following raw materials in percentage by weight: 55-80% modified fiber, 10-20% flexibilizer, 5-10% fertilizer slow-release agent, 5-15% adhesive; the modified fiber comprises natural fiber and silane interface modifier grafted on the surface of the natural fiber. The main raw materials used in the present invention come from natural materials such as wood fiber, bamboo fiber, and hemp fiber. Such fibers can be obtained by hot grinding of wood branches, waste materials, and recycled materials, which greatly reduces the threshold for obtaining raw materials. The composite material can be used to prepare sand barriers. After use, the sand barriers are decomposed into organic matter, carbon dioxide, and water under the action of microorganisms in the soil, which has a good effect on the protection of sand dunes and the growth of plants, and will not pollute the environment.

[0017] The present invention adds a flexibilizer during the preparation process of the fiber composite material, giving the composite material flexibility to sway with the wind and sand, thereby reducing the wind speed and intercepting the sand. Compared with other traditional plate-type sand barriers (such as high-density polyethylene boards), the sand barrier of the present invention is well matched to the windy and sandy environment of the desert environment.

[0018] The invention adds a fertilizer slow-release agent to the fiber composite material, which can be slowly released during the subsequent degradation of the composite material, thereby promoting the growth of sand-dwelling plant seeds and sand-dwelling plants, further promoting the combination of mechanical sand fixation and plant sand fixation, and solving the bottleneck that the current mechanical sand fixation and plant sand fixation cannot be effectively used in coordination. The composite sand barrier can increase the roughness of the surface and slow down the flow speed of the airflow close to the surface to reduce the scale and degree of wind erosion. The wind-proof, sand-fixing, water-retaining and fertilizer-slow-release effects of the sand barrier can further promote the growth and development of seeds and further play a role in wind-proof and sand-fixing.

[0019] The fiber composite material provided by the present invention is significantly different from the tamarisk used for sand barriers. Although the tamarisk sand barriers degrade, rot and decay under the action of microorganisms as the service life increases, the degradation process is uncontrollable. The present invention uses adhesives to bond natural fibers, and the degradation and aging laws of the fiber composite material can be changed by adjusting the amount of adhesive used, so that it is suitable for areas with different wind and sand environments, expanding the scope of use of mechanical sand fixation materials.

[0020] When wheat straw, rice straw, and salix psammophila are used as sand barrier materials, their sizes can only depend on the specifications of the original materials and cannot be adjusted according to actual needs. In addition, wheat straw and rice straw have the disadvantage that they cannot retain their long size after mechanical harvesting. The fiber composite material provided by the present invention is a material produced on an industrial scale, which has the characteristics of customizable size and adjustable specifications. When using it as a raw material to prepare sand barriers, the construction speed is fast, the construction labor intensity is low, and the engineering cost is low, which greatly improves the scope and efficiency of the fiber composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 for Figure 1 A physical picture of a splint (fixing device) used in the embodiment; Figure 2 This is a physical picture of the strip-type sand barrier (before planting plants) prepared in Example 1; Figure 3 This is a physical picture of the use of a clamping plate (fixing device) to fix the overlapping plates in Example 1; Figure 4 A physical picture of the composite sand-fixing barrier prepared in Example 1 (including planted plants); Figure 5 This is a physical picture of the grid-type sand barrier (before planting plants) prepared in Example 3; Figure 6 This is a physical picture of using a clamp (fixing device) to fix the checkered sand barrier in Example 3; Figure 7 A physical picture of the composite sand-fixing barrier prepared in Example 3 (including planted plants); Figure 8 This is a physical picture of the arc-shaped sand barrier of Example 5; Fig. 9 This is a physical picture of the grass grid sand barrier of Comparative Example 1; Fig.10 This is a photo of the composite sand barrier set in Example 1 after being used for half a year; Fig.11 This is a photo of the composite sand barrier set in Example 3 after being used for half a year; Fig.12 This is a photo of the grass grid sand barrier set up in Comparative Example 1 after being used for half a year. DETAILED DESCRIPTION

[0022] The present invention provides a fiber composite material, comprising the following raw materials in percentage by weight: Modified fiber 55~80%; Flexibility agent 10~20%; Fertilizer slow-release agent 5~10%; Adhesive 5~15%; The modified fiber comprises natural fiber and a silane interfacial modifier grafted on the surface of the natural fiber.

[0023] In terms of mass percentage, the raw materials for preparing the fiber composite material provided by the present invention include 55-80% modified fiber, which can be specifically 55%, 60%, 65%, 70%, 75% or 80%. In the present invention, the modified fiber includes natural fiber and a silane-based interfacial modifier grafted on the surface of the natural fiber. As a specific embodiment of the present invention, the natural fiber can include one or more of wood fiber, bamboo fiber, hemp fiber and seaweed fiber, which can be specifically wood fiber, bamboo fiber, hemp fiber or seaweed fiber; the tree species of the wood fiber can be one or more of balsa wood, paulownia, fir, poplar, ash and pine, which can be specifically balsa wood, paulownia, fir, poplar, ash or pine; the bamboo species of the bamboo fiber can be one or more of moso bamboo, ma bamboo, green bamboo and nan bamboo, which can be specifically moso bamboo, ma bamboo, green bamboo or nan bamboo. In the present invention, bamboo fiber has better flexibility than wood fiber. The composite material prepared by using bamboo fiber can improve the flexibility of the composite material (board), increase the ability to swing with the wind, increase the shaking amplitude of the board, and have a better wind-proof and sand-fixing effect.

[0024] As a specific embodiment of the present invention, the length of the natural fiber can be less than or equal to 500 μm, and can also be 50-300 μm, 200-400 μm, 200-500 μm or 300-500 μm; the diameter of the natural fiber can be less than or equal to 250 μm, and can also be 20-150 μm, 50-200 μm or 150-250 μm. The present invention uses natural fiber as the main raw material, which is conducive to the degradation of the fiber composite material, improves its environmental protection, and also provides its carbon fixation performance.

[0025] As a specific embodiment of the present invention, the silane interface modifier includes one or more of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, 1H,1H,2H,2H perfluorodecyltrichlorosilane, 1H,1H,2H,2H perfluorooctyltrichlorosilane and 1H,1H,2H,2H perfluorodecyltriethoxysilane, and can be specifically γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, 1H,1H,2H,2H perfluorodecyltrichlorosilane, 1H,1H,2H,2H perfluorooctyltrichlorosilane or 1H,1H,2H,2H perfluorodecyltriethoxysilane.

[0026] As a specific embodiment of the present invention, the mass percentage of the silane interfacial modifier in the modified fiber may be less than or equal to 5%, and may be specifically 0.5%, 0.8%, 1.0%, 1.2%, 1.5%, 2.5%, 3.5% and 5%.

[0027] In terms of mass percentage, the raw materials for preparing the fiber composite material provided by the present invention include 10-20% of a flexibilizer, which may be specifically 10%, 13%, 15%, 18% or 20%. As a specific embodiment of the present invention, the flexibilizer may include polyurethane particles, polyurethane fibers, polypropylene fibers or polyester fibers, and the average particle size of the polyurethane particles may be 5-5000 μm, 5-300 μm or 300-5000 μm; the average particle size of the polyurethane particles may be specifically 50 μm, 100 μm or 500 μm; the length of the polyurethane fibers, polypropylene fibers and polyester fibers may be independently 1 mm to 10 cm, and the linear density may be independently 1.0-2.5 dtex.

[0028] In terms of mass percentage, the raw materials for preparing the fiber composite material provided by the present invention include 5-10% of a fertilizer slow-release agent, which may be specifically 5%, 6%, 8% or 10%. As a specific embodiment of the present invention, the fertilizer slow-release agent may include one or more of sulfur-coated urea, urea formaldehyde, isobutylene diurea, oxalamide fertilizer, nitrifying urease inhibitor fertilizer and resin-coated urea, which may be specifically sulfur-coated urea, urea formaldehyde, isobutylene diurea, oxalamide fertilizer, nitrifying urease inhibitor fertilizer or resin-coated urea.

[0029] In terms of mass percentage, the raw materials for preparing the fiber composite material provided by the present invention include 5-15% adhesive, which may be specifically 5%, 8%, 10%, 13% or 15%. As a specific embodiment of the present invention, the adhesive may include one or more of urea-formaldehyde resin adhesive, phenolic resin adhesive, melamine-modified urea-formaldehyde resin adhesive, epoxy resin adhesive and isocyanate adhesive, which may be specifically urea-formaldehyde resin adhesive, phenolic resin adhesive, melamine-modified urea-formaldehyde resin adhesive, epoxy resin adhesive or isocyanate adhesive.

[0030] As a specific implementation of the present invention, the thickness of the fiber composite material may be less than or equal to 20 mm, and may also be 2.5-15 mm.

[0031] The present invention also provides a method for preparing the fiber composite material described in the above technical solution, comprising the following steps: The natural fiber and the silane interfacial modifier are first mixed and dehydrated to obtain modified fiber; The adhesive is atomized and sprayed onto the surface of the modified fiber, and then mixed with a flexibilizer and a fertilizer slow-release agent to obtain a mixed material; The mixed material is formed and then hot-pressed to obtain the fiber composite material.

[0032] The present invention first mixes the natural fiber and the silane interface modifier for dehydration reaction to obtain the modified fiber. As a specific embodiment of the present invention, the total mass of the natural fiber and the silane interface modifier and the mass ratio of the silane interface modifier can be 100:0.5~5, and can be specifically 100:0.5, 100:1, 100:1.5, 100:2, 100:2.5, 100:3, 100:3.5, 100:4, 100:4.5 or 100:5; the first mixing method can be spraying the silane interface modifier onto the surface of the natural fiber. The present invention has no special requirements for the spraying method, and the conventional method in the art can be used. As a specific embodiment of the present invention, the temperature of the dehydration reaction can be 50~150°C, specifically 50°C, 80°C, 100°C, 120°C or 150°C; the time of the dehydration reaction can be 30~150min, specifically 30min, 50min, 80min, 100min, 120min, 130min or 150min.

[0033] In the present invention, Si-OH on the surface of the silane-based interfacial modifier and -OH on the surface of the natural fiber undergo a dehydration reaction at high temperature to generate Si-OC bonds. After modification, the surface of the natural fiber is linked to the hydrophobic functional groups of the silane-based interfacial modifier by chemical bonds, thereby improving the hydrophobic properties of the natural fiber and preventing it from becoming soft and breaking when exposed to rain in the desert.

[0034] After obtaining the modified fiber, the present invention sprays the adhesive onto the surface of the modified fiber after atomization, and then mixes it with a flexibilizer and a fertilizer slow-release agent for a second time to obtain a mixed material. As a specific embodiment of the present invention, the atomization pressure can be 1-10MPa, and can be specifically 1MPa, 3MPa, 5MPa, 8MPa or 10MPa. The present invention sprays the adhesive onto the surface of the modified fiber by atomization, which can improve the uniformity of the adhesive dispersion, so that the adhesive is evenly sprayed on the fiber surface, which is beneficial to improving the interface bonding performance and reducing the amount of adhesive used.

[0035] The present invention has no special requirements for the second mixing method, as long as it can be mixed evenly.

[0036] After obtaining the mixed material, the present invention forms the mixed material and then hot presses it to obtain the fiber composite material. As a specific embodiment of the present invention, the forming can be to pave the mixed material using a fiber pavement machine to obtain a blank; the thickness of the blank can be 3 to 50 cm, can also be 5 to 40 cm, and can further be 10 to 30 cm.

[0037] As a specific embodiment of the present invention, the temperature of the hot pressing can be 100-180°C, and can be specifically 100°C, 120°C, 140°C, 150°C, 160°C or 180°C; the holding time of the hot pressing can be 0.5-5min, and can be specifically 0.5min, 1min, 2min, 3min, 4min or 5min.

[0038] The present invention also provides the use of the fiber composite material described in the above technical solution or the fiber composite material prepared by the preparation method described in the above technical solution in the preparation of sand barriers.

[0039] The present invention also provides a composite sand-fixing barrier, comprising a sand barrier and sand-growing plants; The sand barrier material is the fiber composite material described in the above technical solution or the fiber composite material prepared by the preparation method described in the above technical solution.

[0040] As a specific embodiment of the present invention, the desert plants may include one or more of Haloxylon ammodendron, Nitraria tangutorum, Caragana korshinskii, Cyperus rotundus, Calligonum mongolica and Artemisia ordosica, and may specifically be Haloxylon ammodendron, Nitraria tangutorum, Caragana korshinskii, Cyperus rotundus, Calligonum mongolica or Artemisia ordosica; the desert plants can be grown into desert plants by sowing desert plant seeds.

[0041] As a specific embodiment of the present invention, the sand barrier may be in the form of a strip, a grid or an arc; when the sand barrier is in the form of a strip, the sand-dwelling plants are planted in the interval areas between adjacent strips, or the sand-dwelling plant seeds are sown along the plate barrier body; when the sand barrier is in the form of a grid, the sand-dwelling plants are planted in the middle area of ​​the grid-type sand barrier, or the sand-dwelling plant seeds are sown along the plate barrier body; when the sand barrier is in the form of an arc, the sand-dwelling plants are planted in the interval areas between adjacent arc belts.

[0042] As a specific embodiment of the present invention, when the sand barrier is a strip-type sand barrier, the method for preparing the sand barrier may include the following steps: Performing a first cutting on the fiber composite material to obtain a first board; The first panels are overlapped for the first time and buried in the sand to form strips; The first overlapping portion is first fixed by using a first clamping plate with a gap.

[0043] As a specific embodiment of the present invention, the height of the first board can be 20~40cm, the length of the first board can be 1~3m, and the depth of the first board buried in the sand can be 5~15cm; the height of the first board buried in the sand above the sand can be 15~25cm, which can be specifically 20cm; the row spacing of adjacent strips can be 1~5m; the overlap length of the first overlap can be 2~5cm. As a specific embodiment of the present invention, the material of the first plywood can be particleboard; the present invention has no special limitation on the size of the gap in the first plywood, and it can be designed according to the thickness of the first board; the first fixation can be to insert the overlap portion formed by the first overlap into the gap, the first plywood and the first board are perpendicular to each other, and the first plywood can be buried in the sand to further improve the fixation of the strip.

[0044] As a specific embodiment of the present invention, when the sand barrier is a grid-type sand barrier, the method for preparing the sand barrier may include the following steps: Performing a second cutting on the fiber composite material to obtain a second board; The second panels are overlapped for a second time and buried in the sand to form a grid; The second overlapping portion is fixed for a second time using a second clamping plate with a gap.

[0045] As a specific embodiment of the present invention, the height of the second plate can be 10~30cm, the length of the second plate can be 1~3m, the depth of the second plate buried in the sand can be less than or equal to 10cm; the height of the second plate buried in the sand above the sand can be 5~20cm, which can be specifically 5cm, 10cm, 15cm or 20cm; the size of the square can be 1×1m~3×3m; the overlap length of the second overlap can be 2~5cm. As a specific embodiment of the present invention, the material of the second plywood can be particleboard; the second plywood can be buried in the sand to further improve the fixation of the square, the second fixation can be to fix the second plywood and the second plate with screws, drilling is required before fixing the screws, the holes formed by the drilling can be circular or square, the diameter of the circle can be 3~15mm, and the side length of the square can be 5~15mm.

[0046] As a specific embodiment of the present invention, when the sand barrier is an arc-shaped sand barrier, the method for preparing the sand barrier may include the following steps: Cutting the fiber composite material for the third time to obtain a third board; Finishing the third plate and performing a third overlap to form an arc monomer; The arc monomer is buried in the sand and fixed to form an arc-shaped sand barrier.

[0047] As a specific embodiment of the present invention, the height of the third plate can be 20~40cm, the length of the third plate can be 1~3m, and the overlap length of the third overlap can be 2~5cm. As a specific embodiment of the present invention, the material of the third plywood used for the third overlap can be particle board; the present invention has no special limitation on the size of the gap in the third plywood, and it can be designed according to the thickness of the third plate. As a specific embodiment of the present invention, the depth of the arc monomer buried in the sand can be 5~15cm; the height of the first plate buried in the sand above the sand can be 15~25cm, specifically 20cm; the outer wall spacing of adjacent arc monomers can be 1.0~3.0m.

[0048] Figure 1 It is a physical picture of the first splint, the second splint or the third splint used in the embodiment.

[0049] The present invention uses natural fiber as raw material, performs interface modification on silane-based interfacial modifier and natural fiber, and then mixes them evenly with adhesive, flexibilizer and fertilizer slow-release agent, and forms a plate-type composite material based on natural fiber through high temperature hot pressing; the plate-type composite material is penetrated and punched by a drilling machine, and the perforated plate-type composite material is sawed into small plates of customized size, and then the plates of customized size are paved on the desert to form strip-type, grid-type or arc-shaped sand barriers, and finally sand-dwelling plants are planted in the strip-type, arc-shaped sand barrier interval area or in the grid-type sand barrier grid, and the plate-type sand barrier structure and plants are used to form a composite sand barrier structure. The present invention adopts a combination of mechanical sand barriers and sand-dwelling plants to prevent wind and sand fixation, which not only overcomes the problem of secondary pollution caused by the inability to degrade plastic plate-type sand barriers, but also reduces costs. The grid-type configuration method, strip-type or arc-shaped configuration method adopted by the sand barrier of the present invention realizes effective protection of sand and soil, prevents sand and soil loss, has a simple method, and has obvious effects, and the fertilizer slow-release agent is slowly released during the daily degradation process of the sand barrier to promote plant growth. The composite sand-fixing barrier provided by the invention shortens the effective time of plant sand-fixing and improves the survival rate of plants and the sand-fixing effect.

[0050] The existing afforestation and sand control methods take a long time to form shelterbelts, and the sand in the mobile sand dune zone is always in a mobile state, which can easily blow down or bury the planted shrubs and tree seedlings, resulting in a low survival rate of shrubs and trees. The mechanical sand fixation technology adopted by the present invention is combined with plant afforestation and sand control, and the mechanical sand barrier is used to fix the quicksand, thereby avoiding the low survival rate of plants caused by the action of wind and sand, and can absorb and retain rainwater, slow down the evaporation rate of water in the sand, and reduce the degree of surface soil loss.

[0051] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0052] The embodiments all use Dengkou County in the Ulan Buh Desert in Inner Mongolia as a test site for laying sand barriers.

[0053] Example 1 Poplar fibers with a length of 50-300 μm and a diameter of 20-150 μm were used as the main raw material. γ-aminopropyltriethoxysilane (silane-based interfacial modifier) ​​was sprayed onto the surface of the poplar fibers and then placed in an oven for dehydration reaction at 100°C for 30 minutes to obtain modified wood fibers. The mass ratio of the poplar fibers to γ-aminopropyltriethoxysilane was 99:1. The urea-formaldehyde resin adhesive is atomized at a pressure of 5 MPa and then sprayed onto the surface of the modified wood fiber, and then uniformly mixed with polyurethane particles with an average particle size of 50 μm and sulfur-coated urea to obtain a mixed material; The mixed material was laid into a 5 cm thick fiber fluffy mat (blank) by a fiber laying machine, and the blank was placed in a high temperature hot press and hot pressed at 150°C for 5 minutes to obtain a wood fiber composite material with a thickness of 2.5 mm; in terms of mass percentage, the raw materials included 70% modified poplar fiber, 15% urea-formaldehyde resin adhesive, 10% polyurethane particles, and 5% sulfur-coated urea; The wood fiber composite material was sawn into boards with a height of 30 cm and a length of 1 m. Two boards were buried in the sand in an overlapping manner for 10 cm, with an overlapping area of ​​3 cm. A piece of oriented strand board with a gap was used as a fixing device, and the overlapping part was inserted into the gap. The fixing device and the wood fiber composite material board were perpendicular to each other. According to this method, boards were continuously laid at both ends of the board to form a strip-shaped sand barrier with a length of 50 m. In the area 1.5 m away from this strip-shaped sand barrier (the spacing between adjacent strips), multiple sand barriers were laid again according to the same method to form a strip-shaped sand barrier; The fixing device is inserted into the sand to fix the wood fiber composite material board in the sand, and the sand-dwelling plant Haloxylon ammodendron is planted in the interval area of ​​the strip-type sand barrier. The strip-type sand barrier structure and the sand-dwelling plants are used to form a composite sand-fixing barrier.

[0054] Example 2 A bamboo fiber composite material is prepared according to the method of Example 1, except that bamboo fiber (derived from moso bamboo) with a length of 200-400 μm and a diameter of 50-200 μm is used as the main raw material; γ-glycidyloxypropyltrimethoxysilane is used as the silane interface modifier; isocyanate adhesive is used as the adhesive; and the raw materials for preparation include 60% modified bamboo fiber, 10% isocyanate adhesive, 20% polyurethane particles, and 10% sulfur-coated urea in terms of mass percentage; A composite sand-fixing barrier was prepared according to the method of Example 1, except that the spacing between adjacent strips was 2 m.

[0055] Example 3 Using eucalyptus fiber with a length of 200-500 μm and a diameter of 150-250 μm as the main raw material, γ-glycidyloxypropyltrimethoxysilane (silane-based interface modifier) ​​was sprayed onto the surface of the wood fiber and then placed in an oven for dehydration reaction at 100°C for 30 minutes to obtain modified wood fiber; wherein the mass ratio of eucalyptus fiber to γ-glycidyloxypropyltrimethoxysilane was 98.5:1.5; The phenolic resin adhesive is atomized at a pressure of 5 MPa and then sprayed onto the surface of the modified wood fiber, and then uniformly mixed with polyurethane particles with an average particle size of 100 μm and sulfur-coated urea to obtain a mixed material; The mixed material was laid into a 5 cm thick fiber fluffy mat (blank) by using a fiber laying machine, and the blank was placed in a high temperature hot press and hot pressed at 150°C for 5 minutes to obtain a wood fiber composite material with a thickness of 2.5 mm; in terms of mass percentage, the raw materials included 70% modified wood fiber, 15% phenolic resin adhesive, 10% polyurethane particles, and 5% sulfur-coated urea; The wood fiber composite material was sawed into boards with a height of 20 cm and a length of 102 cm. Two boards were buried in the sand in an overlapping manner with an overlap of 10 cm and an overlap area of ​​2 cm. A piece of oriented structural particle board with a gap was used as a fixing device, and the overlapping part was inserted into the gap. The fixing device and the wood fiber composite material board were perpendicular to each other. According to this method, boards were continuously laid at both ends of the board to form a strip-type sand barrier with a length of 50 m. The distance between the fixing devices was 100 cm. Further, multiple sand barriers were laid again in the area 1 m away from this strip-type sand barrier according to the same method, thereby forming multiple strip-type sand barriers with an interval of 1 m.

[0056] A 1m long wood fiber composite board is laid in the interval area of ​​the strip-type sand barrier at a position perpendicular to the strip-type sand barrier, and overlapped with the fixing device of the strip-type sand barrier. Finally, screws (drilled into circular holes with a diameter of 5mm) are used to fix the fixing device and the vertically laid board at the overlapping position, so that the natural fiber composite board is fixed in the sand in a grid shape, and the grid size is 1m×1m. The sand-dwelling plant Haloxylon ammodendron is planted in the middle area of ​​the grid-type sand barrier, and a composite sand-fixing barrier is formed using the grid-type sand barrier structure and sand-dwelling plants.

[0057] Example 4 A bamboo fiber composite material was prepared according to the method of Example 2, except that the raw materials included 60% modified bamboo fiber, 15% urea-formaldehyde resin adhesive, 20% polyurethane particles, and 5% sulfur-coated urea; A composite sand-fixing barrier is prepared according to the method of Example 3, except that the bamboo fiber composite material is sawed into boards with a height of 20 cm and a length of 202 cm, and two boards are buried in the sand in an overlapping manner for 10 cm, with an overlapping area of ​​2 cm. An oriented structural particle board with a gap is used as a fixing device, and the overlapping part is inserted into the gap. The fixing device and the bamboo fiber composite material board are perpendicular to each other. According to this method, boards are continuously laid at both ends of the board to form a strip-type sand barrier with a length of 50 m. The distance between the fixing devices is 200 cm, and further, multiple sand barriers are laid again in an area 2 m away from the strip-type sand barrier according to the same method, thereby forming multiple strip-type sand barriers with an interval of 2 meters.

[0058] A bamboo fiber composite material sheet with a length of 2m is laid in the interval area of ​​the strip-type sand barrier at a position perpendicular to the strip-type sand barrier, and overlapped with the fixing device of the strip-type sand barrier. Finally, screws (drilled holes are circular holes with a diameter of 5mm) are used to fix the fixing device and the vertically laid bamboo fiber composite material sheet at the overlapping position, so that the natural fiber composite material sheet is fixed in the sand in a grid shape, and the grid size is 2m×2m; The sand-dwelling plant Haloxylon ammodendron is planted in the middle area of ​​the grid-type sand barrier, and a composite sand-fixing barrier is formed using the grid-type sand barrier structure and sand-dwelling plants.

[0059] Example 5 A wood fiber composite material is prepared according to the method of Example 1, except that fir fibers with a length of 300-500 μm and a diameter of 150-250 μm are used as the main raw material; The wood fiber composite material was sawn into boards with a height of 20 cm and a length of 300 cm. The boards were fixed by overlapping the ends. A piece of oriented structural particle board with a gap was used as a fixing device to fix the overlapping part. The overlapping area was 2 cm to form an arc-shaped sand barrier. The bottom of the arc-shaped sand barrier was buried 10 cm in the sand. According to this method, the boards were fixed to form an arc-shaped sand barrier, which was laid in parallel in the desert. Further, multiple arc-shaped sand barriers were laid again in the same way in an area 2 m away from the outer wall of the arc-shaped sand barrier, thereby forming multiple arc-shaped sand barriers, and the outer walls of two adjacent arc-shaped sand barriers were 2 m apart.

[0060] Comparative Example 1 In early March 2024, a multifunctional three-dimensional sand-fixing vehicle developed by Beijing Forestry University was used to lay a straw grid sand barrier (made of wheat straw). The side length of the straw grid sand barrier was 1m, and the scattered grass was inserted into the sand layer about 15cm, with a height of 25cm above the ground. The direction of the straw sand barrier was perpendicular to the main wind direction of the planting site.

[0061] Comparative Example 2 Taking bare sand as a comparison, no sand barriers are set up on the sand.

[0062] Figure 2 This is a photo of the 1.5-meter-spaced strip-type sand barrier (before planting plants) prepared in Example 1. The plants in the photo are the original plants on the sand. Figure 3 A physical picture of the clamping plate (fixing device) used to fix the overlapping plates; Figure 4 A physical picture of the composite sand-fixing barrier prepared in Example 1 (including plants, taken in July); Figure 5 This is a physical picture of the grid-type sand barrier (before planting plants) prepared in Example 3; Figure 6 This is a physical picture of the clamping plate (fixing device) used to fix the checkered sand barrier in Example 3; Figure 7This is a physical picture of the composite sand-fixing barrier prepared in Example 3 (including plants, taken in July). Figure 8 This is a physical picture of the circular arc sand-fixing barrier prepared in Example 5; Fig. 9 This is a physical picture of the grass grid sand barrier of comparative example 1.

[0063] The sand fixation and sand prevention performance of Examples 1 to 5 and Comparative Examples 1 to 2 were tested by on-site measurements using a sand collector and a wind speed profile collector as well as wind tunnel simulation experiments. The results are listed in Table 1.

[0064] Table 1 Sand fixation performance of Examples 1 to 5 and Comparative Examples 1 to 2

[0065] As can be seen from Table 1, the composite sand-fixing barrier provided by the present invention can fix the moisture in the sand, reduce the near-surface wind speed and sand transport rate, and at the same time increase the content of organic matter and total nitrogen in the sand, and can achieve a good sand-fixing and sand-preventing effect; the present invention uses wood and bamboo fibers to make sand barriers, which are naturally degradable and green and environmentally friendly; wood and bamboo absorb a large amount of carbon dioxide through photosynthesis during their natural growth, and play a role in carbon fixation. They are used as sand barriers and can effectively fix carbon in the desert. The bamboo fiber used in Example 2 has better flexibility than the wood fiber used in Example 1, can improve the flexibility of the composite material (board), increase the ability to swing with the wind, and increase the vibration amplitude of the board, and has a better wind-proof and sand-fixing effect; Example 4 increases the content of polyurethane particles compared to Example 1, improves the flexibility of the fiber composite material board, increases the ability to swing with the wind, and increases the vibration amplitude of the board, and has a better wind-proof and sand-fixing effect.

[0066] Through on-site measurements using a sand collector and a wind speed profiler and a wind tunnel simulation experiment, compared with Example 2, the sand-raising wind speed in Example 3 can be reduced by about 68%, calculated as (68-0)×100%÷68=68%; the sand transport rate can be reduced by 80.76%, calculated as (2.386-0.459)×100%÷2.386=80.76%; the organic matter content in the sand is increased by 2%, calculated as (2.34-0.35)×100%÷2.34=85.04%.

[0067] The following is a comparison of the effects of the sand barriers set up in Examples 1 and 3 and Comparative Example 1 after half a year: Example 1 has a good wind-proof and sand-fixing effect after more than half a year, and has not fallen over; Fig.10 This is a photo of the composite sand barrier set up in Example 1 after half a year of use ( Fig.10 This is a picture from January, so the plants are withered and yellow).

[0068] After more than half a year, Example 3 still has a good wind-proof and sand-fixing effect without lodging; Fig.11 This is a photo of the composite sand barrier set up in Example 3 after half a year of use ( Fig.11 This is a picture from January, so the plants are withered and yellow).

[0069] Comparative Example 1 After more than half a year, due to the strong wind, the grass grid sand barrier collapsed very seriously, and had almost no ability to prevent wind and fix sand; Fig.12 This is a photo of the grass grid sand barrier set up in Comparative Example 1 after being used for half a year.

[0070] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A fiber composite material, characterized in that: Including the following raw materials in percentage by mass: Modified fiber 55~80%; Flexibility agent 10~20%; Fertilizer slow-release agent 5~10%; Adhesive 5~15%; The modified fiber comprises natural fiber and a silane interfacial modifier grafted on the surface of the natural fiber.

2. The fiber composite material according to claim 1, characterized in that: The natural fiber includes one or more of wood fiber, bamboo fiber, hemp fiber and seaweed fiber; the length of the natural fiber is less than or equal to 500 μm, and the diameter of the natural fiber is less than or equal to 250 μm; The silane interface modifier includes one or more of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, 1H,1H,2H,2Hperfluorodecyltrichlorosilane, 1H,1H,2H,2Hperfluorooctyltrichlorosilane and 1H,1H,2H,2Hperfluorodecyltriethoxysilane.

3. The fiber composite material according to claim 1, characterized in that: The flexibilizer includes polyurethane particles, polyurethane fibers, polypropylene fibers or polyester fibers.

4. The fiber composite material according to claim 1, characterized in that: The adhesive includes one or more of urea-formaldehyde resin adhesive, phenol-formaldehyde resin adhesive, melamine-modified urea-formaldehyde resin adhesive, epoxy resin adhesive and isocyanate adhesive.

5. The fiber composite material according to claim 1, characterized in that: The fertilizer slow-release agent includes one or more of sulfur-coated urea, urea formaldehyde, isobutylene diurea, oxalamide fertilizer, nitrifying urease inhibitor fertilizer and resin-coated urea.

6. The method for preparing the fiber composite material according to any one of claims 1 to 5, comprising the following steps: The natural fiber and the silane interfacial modifier are first mixed and dehydrated to obtain modified fiber; The adhesive is atomized and sprayed onto the surface of the modified fiber, and then mixed with a flexibilizer and a fertilizer slow-release agent to obtain a mixed material; The mixed material is formed and then hot-pressed to obtain the fiber composite material.

7. The preparation method according to claim 6, characterized in that: The temperature of the dehydration reaction is 50-150°C, and the time of the dehydration reaction is 30-150min; The atomization pressure is 1-10 MPa; The thickness of the blank after forming is 3 to 50 cm; The temperature of the hot pressing is 100-180° C., and the holding time of the hot pressing is 0.5-5 min.

8. Use of the fiber composite material according to any one of claims 1 to 5 or the fiber composite material prepared by the preparation method according to claim 6 or 7 in the preparation of sand barriers.

9. A composite sand-fixing barrier, characterized in that: Includes sand barriers and sand-dwelling plants; The sand barrier material is the fiber composite material described in any one of claims 1 to 5 or the fiber composite material prepared by the preparation method described in claim 6 or 7.

10. The composite sand-fixing barrier according to claim 9, characterized in that: The sand-dwelling plants include one or more of Haloxylon ammodendron, Nitraria tangutorum, Caragana korshinskii, Cyperus rotundus, Calligonum mongolica and Artemisia ordosica; The sand barrier may be in the form of strip, grid or arc; When the sand barrier is in the form of strips, the sand-dwelling plants are planted in the intervals between adjacent strips; When the sand barrier is in a grid-type form, the sand-dwelling plants are planted in the middle area of ​​the grid-type sand barrier; When the sand barrier is in the shape of an arc, the sand-dwelling plants are planted in the interval areas between adjacent arc zones.

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