Bio-based phosphorus-containing intrinsic flame-retardant polyurethane roadway support for coal mine

Abstract

The invention belongs to the technical field of composite materials, relates to a bio-based phosphorus-containing intrinsic flame-retardant polyurethane roadway support for a coal mine, and aims to overcome the defects of an existing support structure in the aspects of material selection, fiber laying layer design and flame retardance. The support is made of a continuous fiber reinforced flame-retardant antistatic polyurethane composite material, wherein polyurethane resin is formed by reacting and curing diphenylmethane diisocyanate and a polyol mixed solution containing bio-based phosphorus-containing polyol, polyester polyol, a flame retardant and an antistatic agent. By introducing the bio-based phosphorus-containing polyol, efficient intrinsic flame retardance is realized, and meanwhile, the mechanical property of the composite material is kept. The supporting structure has the advantages of light weight, high strength, corrosion resistance, static electricity resistance, environmental friendliness, sustainability and the like, is suitable for complex and severe environments of an underground coal mine, and provides powerful guarantee for mine safety production.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials and relates to a bio-based phosphorus-containing intrinsically flame-retardant polyurethane roadway support for coal mines. Background Art

[0002] In the field of coal mine underground engineering, the safety and stability of the support structure are the cornerstones to ensure the safe production of the mine and safeguard the lives of miners. Due to the complex and changeable environment in coal mines, harsh conditions such as high temperature, high humidity, and high salt pose extremely high requirements for the performance of support materials. Traditionally, metal materials, especially steel support structures, are mostly used for coal mine underground support structures. However, the application of metal materials in coal mines has many limitations.

[0003] Firstly, the weight of metal materials is relatively large, which directly increases the self-weight of the support structure, bringing great inconvenience to the transportation and installation of the mine. In the narrow space and complex roadways of coal mines, the transportation and installation of heavy support structures are not only time-consuming and laborious but also increase the risks of mine operations. In addition, the corrosion resistance of metal materials is poor. Especially in high-humidity and high-salt environments, metal materials are prone to rust and corrosion, resulting in a decrease in the strength and stability of the support structure, thereby affecting the safe production of the mine.

[0004] To address the deficiencies of metal material support structures, composite material support structures have gradually come into view. Composite materials, with their characteristics of light weight and high strength, have shown great application potential in coal mine underground support. Compared with metal materials, composite material support structures have a lower density and a higher specific strength, which means that under the same load-bearing capacity, composite material support structures can significantly reduce their self-weight and lower the transportation and installation costs. At the same time, composite materials also have good corrosion resistance and can resist the erosion of harsh environments in coal mines, extending the service life of the support structure.

[0005] However, there are still many problems in the design and preparation of existing composite material support structures. In terms of fiber layup design, currently, composite material support structures mainly adopt methods such as orthogonal layup, unidirectional layup, or π / 4 layup. Although these traditional layup designs improve the strength and stiffness of composite materials to a certain extent, they perform poorly in impact resistance and delamination resistance. In the complex stress environment of coal mines, a single layup design often fails to meet the dual requirements of strength and toughness for the support structure. Especially when subjected to impact or vibration, composite material support structures are prone to delamination or rupture, resulting in support failure.

[0006] In addition to fiber layup design, existing composite support structures also have obvious deficiencies in flame retardancy. Since there are flammable and explosive gases and dust in coal mines, the support structure must have good flame retardancy to prevent fire accidents. However, most of the currently widely used flame retardants are halogen-containing flame retardants, such as brominated flame retardants. These flame retardants will release toxic gases when burning, causing serious pollution to the working environment in coal mines and even endangering the lives of workers. In addition, the use of halogen-containing flame retardants does not conform to the concepts of green environmental protection and sustainable development, restricting their wide application in support structures in coal mines.

[0007] Specifically, halogen-containing flame retardants will generate a large amount of hydrogen halide gas and toxic smoke during the combustion process. These gases and smokes are not only harmful to the human body but also damage the mine ventilation system, further exacerbating the spread and harm of the fire. At the same time, the production and use of halogen-containing flame retardants will also cause environmental pollution, not meeting the requirements of modern industry for environmental protection and sustainable development.

[0008] In summary, there are significant problems and deficiencies in the material selection, fiber layup design, and flame retardancy of existing support structures in coal mines. Traditional metal material support structures are heavy and have poor corrosion resistance; while existing composite support structures are lightweight and high-strength, but still need to be improved in fiber layup design and flame retardancy. Therefore, how to develop a support structure that is both lightweight and high-strength, and has good impact resistance, delamination resistance, and environmentally friendly flame retardancy has become an urgent technical problem to be solved in the field of support structures in coal mines. Summary of the Invention

[0009] In view of this, the purpose of the present invention is to provide a bio-based phosphorus-containing inherently flame-retardant polyurethane roadway support for coal mines to solve the existing problems.

[0010] To achieve the above purpose, the present invention provides the following technical solution: A bio-based phosphorus-containing inherently flame-retardant polyurethane roadway support for coal mines, the material of the roadway support is a continuous fiber-reinforced flame-retardant and antistatic polyurethane composite material, and the flame-retardant and antistatic polyurethane composite material is composed of polyurethane resin and glass fiber; the polyurethane resin includes components A and B. Among them, component A is diphenylmethane diisocyanate, and component B is a polyol mixture obtained by mixing polyester polyol, bio-based phosphorus-containing polyol, flame retardant, and antistatic agent in a set ratio; the structural formula of the bio-based phosphorus-containing polyol is as follows:

[0011] Among them, 2-4 compounds with structural formula II are contained in R1 to R11, and the rest are The structural formula II is:

[0012]

[0013] Optionally, the preparation method of the roadway support includes the following steps:

[0014] Step 1: The traction fiber passes through the oven and the yarn dividing plate respectively and is drawn into the mold; the traction felt / cloth enters the mold;

[0015] Step 2: Prepare the bio-based phosphorus-containing polyol, and mix it with the polyester polyol, flame retardant, and antistatic agent in proportion to obtain the B component, and add the A and B components to the two-component resin mixer;

[0016] Step 3: Turn on the mold heating device for 1.5 h to fully heat the mold;

[0017] Step 4: Turn on the oven and start the traction device;

[0018] Step 5: Turn on the glue injection machine and the cutting machine;

[0019] Step 6: The resin and glass fiber are cured through the mold to obtain a flame-retardant and antistatic bio-based phosphorus-containing intumescent polyurethane profile, which is cut to a fixed length by the cutting machine.

[0020] Optionally, in Step 2, the method for preparing the bio-based phosphorus-containing polyol includes the following steps:

[0021] (1) Add phytic acid and ammonia water to the reaction kettle in sequence, dissolve with water and then heat to 30-80 °C, carry out condensation reflux reaction for 20-200 min, and obtain the intermediate of Structural Formula III after purification and drying;

[0022] (2) Add the compound of Structural Formula II to the flask equipped with a condensation device, add an organic solvent and then heat to 30 °C - 100 °C to dissolve, and at 25 °C - 150 °C, add the intermediate of Structural Formula III obtained in step (1) and react for 1 h - 10 h, then remove the solvent, and obtain the bio-based phosphorus-containing polyol after drying;

[0023] The said structural formula is Among them, R13 - R24 contain 2 - 4 H+, and the rest are

[0024] The said Structural Formula II is

[0025] Optionally, in step (1), the molar ratio of the phytic acid to the ammonia water is 1:8 - 10.

[0026] Optionally, in step (2), the molar ratio of the compound of Structural Formula II to the intermediate of Structural Formula III is 2 - 4:1.

[0027] Optionally, the antistatic agent is one or a mixture composed of one or more of 1,3-dimethylimidazolium tetrafluoroborate, N-octylpyridinium bromide, N-butyl-N-methylpiperidinium bromide, N-butyl-N-methylpyrrolidinium bromide, tributylmethylammonium chloride, N-ethyl, methylmorpholinium bromide, and tributylethylphosphonium bromide ionic liquids.

[0028] Optionally, in step 3, the mold heating temperature is 150°C - 210°C, divided into two zones or three zones. The temperature at the front end of the mold is 150°C - 170°C, the middle section is 170°C - 190°C, and the rear section is 190°C - 210°C.

[0029] Optionally, in step 4, the oven temperature is 60°C - 150°C.

[0030] Optionally, the fiber drawing speed is 0.2 - 2 m / min, and the injection pressure is 0.5 - 1 MPa.

[0031] Optionally, the cross-section of the support structure is U-shaped and consists of a composite support bending section, a composite support straight section, a joint weld, a U-shaped steel, and a cable clamp. Among them, the composite support bending section and the composite support straight section are made of composite materials.

[0032] The beneficial effects of the present invention are as follows:

[0033] 1. High-efficiency inherent flame retardancy, preventing the precipitation of flame retardants: The present invention uses bio-based phosphorus-containing polyols. By directly incorporating bio-based DOPO derivatives into the polyurethane molecular chain, an inherently flame-retardant and antistatic polyurethane composite material is formed. When this material burns, it can self-crosslink and expand to form a dense carbon layer, and crosslink with the pyrolysis small molecules of the polymer to generate a carbon layer with high thermal stability, effectively isolating oxygen and heat and inhibiting flame propagation. At the same time, at high temperatures, the phosphorus-containing polyols crosslink with the pyrolysis small molecules of the polyurethane to generate a carbon layer with high thermal stability, further enhancing the flame retardant effect. The flame retardancy can reach UL94 V-0 level and meet the MT113 standard. Compared with traditional additive flame retardants, the inherent flame retardant design eliminates the problem of flame retardant precipitation, significantly improves the flame retardant efficiency, and ensures the long-term stability of the flame retardant performance of the material; at the same time, it reduces the dosage of additive flame retardants and improves the mechanical properties of the flame-retardant polyurethane composite material.

[0034] 2. Excellent mechanical properties: Through continuous glass fiber reinforcement technology and the chemical bonding of bio-based phosphorus-containing polyols and polyurethane resin, reducing the dosage of additive flame retardants, the roadway support of the present invention has excellent mechanical properties. Tests show that the tensile strength of the composite material prepared by the pultrusion process is ≥1200 MPa, and the flexural strength is ≥1200 MPa. The introduction of DOPO derivatives reduces or eliminates the use of additive flame retardants, not only enhancing the rigidity of the molecular chain but also improving the overall strength of the composite material, enabling it to withstand greater loads and impacts, and effectively extending the service life of the idler.

[0035] 3. Lightweight design: The density of the polyurethane composite material is only about one-fourth of that of the steel roadway support, realizing the lightweight design of the support. This not only reduces the overall weight of the support but also lowers the transportation and installation costs.

[0036] 4. Excellent corrosion resistance: This support can resist the erosion of various corrosive media such as acids, alkalis, and salts. Its corrosion resistance is better than that of metal supports and is especially suitable for the complex and harsh environment in coal mines. Its excellent corrosion resistance effectively extends the service life of the support and reduces the maintenance cost.

[0037] 5. Excellent antistatic performance: The synergistic effect of the bio-based phosphorus-containing polyol and the antistatic agent can make the surface resistivity of the support ≤ 3×108Ω, meeting the MT113 standard. It can effectively prevent the accumulation of static electricity and reduce the fire risk caused by static sparks. This characteristic significantly improves the safety of the idler in the complex environment of coal mines.

[0038] 6. Environmental protection and sustainability: The bio-based binary terminal hydroxyl DOPO derivative flame retardant of the present invention adopts a halogen-free and environmentally friendly design. The synthesis monomers (such as phytic acid) are widely sourced and renewable, reducing the carbon footprint in the production process and the dependence on non-renewable resources. Compared with traditional halogen-containing flame retardants, the present invention avoids the generation of toxic gases during combustion, meets the requirements of green manufacturing and sustainable development, and has remarkable environmental friendliness.

[0039] 7. High production efficiency: Using a large amount of additive flame retardants to achieve a good flame retardant effect will affect the curing time and quality of polyurethane, resulting in a slow pultrusion speed (below 0.25m / min). Since the bio-based phosphorus-containing polyol used in the present invention participates in the reaction of polyurethane and belongs to inherent flame retardancy, it has no impact on the reaction of polyurethane, with a fast pultrusion speed and high production efficiency.

[0040] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:

[0042] Figure 1 is a schematic diagram of the U-shaped support structure of the present invention;

[0043] Figure 2 is the forming process diagram of the U-shaped support structure of the present invention;

[0044] Figure 3 This is the cross-sectional view of the roadway support of the present invention. Specific embodiments

[0045] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0046] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation on the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0047] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation on the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0048] Please refer to Figures 1 to 3 , a bio-based phosphorus-containing intrinsically flame-retardant polyurethane roadway support for coal mines of the present invention. The material of the roadway support is a continuous fiber-reinforced flame-retardant and antistatic polyurethane composite material. The flame-retardant and antistatic polyurethane composite material is composed of polyurethane resin and glass fiber; the polyurethane resin includes components A and B. Among them, component A is diphenylmethane diisocyanate, and component B is a polyol mixture obtained by mixing polyester polyol, bio-based phosphorus-containing polyol, flame retardant, and antistatic agent in a set ratio;

[0049] Among them, the component A can select MDI for pultrusion such as 4,4'-MDI, modified MDI, polymeric MDI (PMDI), etc., and the polyester polyol in the component B can select adipic acid-based polyester polyol, phthalic anhydride (PA)-based polyester polyol, hydrolysis-resistant polyester polyol and other polyols for pultrusion;

[0050] The mixing ratio of the flame retardant and the bio-based phosphorus-containing polyol is determined according to the flame retardant grade requirements. For example, to achieve V0-level flame retardancy, the mass ratio of the polyester polyol to the bio-based phosphorus-containing polyol is 72:28; to meet the MT113 flame retardancy requirement, the mass ratio of the polyester polyol to the bio-based phosphorus-containing polyol is: 63:37.

[0051] The antistatic agent can select one or a mixture of more than one of 1,3-dimethylimidazolium tetrafluoroborate, N-octylpyridinium bromide, N-butyl-N-methylpiperidinium bromide, N-butyl-N-methylpyrrolidinium bromide, tributylmethylammonium chloride, N-ethyl,methylmorpholinium bromide and tributylethylphosphonium bromide ionic liquids, as well as carbon fiber, etc. According to the different surface resistances achieved, the dosage of the antistatic agent is different. For example, when the surface resistance reaches 109Ω, the polyol mixture: antistatic agent is 72:28; when the surface resistance reaches 108Ω, the polyol mixture: antistatic agent is 65:35; when the surface resistance < 108Ω, carbon fiber is used on the surface.

[0052] The structural formula Ⅰ of the bio-based phosphorus-containing polyol is:

[0053] Among them, R1 to R11 contain 2 to 4 compounds of structural formula Ⅱ, and the rest are The said structural formula Ⅱ is:

[0054]

[0055] The preparation method of the roadway support includes the following steps:

[0056] Step 1: The traction fiber passes through the oven and the yarn splitting board and is drawn into the mold respectively; the traction felt / cloth enters the mold;

[0057] Step 2: Prepare the bio-based phosphorus-containing polyol, and mix it with the polyester polyol, flame retardant and antistatic agent in proportion to obtain the component B, and add the components A and B to the two-component resin mixer;

[0058] Step 3: Turn on the mold heating device for 1.5 h to fully heat the mold;

[0059] Step 4: Turn on the oven and start the traction device;

[0060] Step 5: Turn on the glue injection machine and the cutting machine;

[0061] Step 6: The resin and glass fiber are cured by a mold to obtain a flame-retardant and antistatic bio-based phosphorus-containing intrinsically flame-retardant polyurethane profile, which is cut to a fixed length by a cutting machine.

[0062] In Step 2, the method for preparing the bio-based phosphorus-containing polyol includes the following steps:

[0063] (1) Phytic acid and ammonia water are sequentially added to a reaction kettle, dissolved in water and heated to 30-80°C, and subjected to condensation reflux reaction for 20-200 min. After purification and drying, an intermediate of Structural Formula III is obtained;

[0064] (2) The compound of Structural Formula II is added to a flask equipped with a condensation device, dissolved by adding an organic solvent and heated to 30°C - 100°C. At 25°C - 150°C, the intermediate of Structural Formula III obtained in step (1) is added and reacted for 1 h - 10 h, then the solvent is removed, and the bio-based phosphorus-containing polyol can be obtained after drying;

[0065] The structural formula is Among them, 2 - 4 of H+ are contained in R13 - R24, and the rest are

[0066] The structural formula II is

[0067] In step (1), the molar ratio of phytic acid to ammonia water is 1:8 - 10.

[0068] In step (2), the molar ratio of the compound of Structural Formula II to the intermediate of Structural Formula III is 2 - 4:1.

[0069] The antistatic agent is a mixture composed of one or more of 1,3-dimethylimidazolium tetrafluoroborate, N-octylpyridinium bromide, N-butyl-N-methylpiperidinium bromide, N-butyl-N-methylpyrrolidinium bromide, tributylmethylammonium chloride, N-ethyl, methylmorpholinium bromide, and tributylethylphosphonium bromide ionic liquids.

[0070] In Step 3, the mold heating temperature is 150°C - 210°C, divided into two zones or three zones. The temperature at the front end of the mold is 150°C - 170°C, the middle section is 170°C - 190°C, and the rear section is 190°C - 210°C. In Step 4, the oven temperature: the oven temperature is 60°C - 150°C. The fiber traction speed is 0.2 - 2 m / min, and the injection pressure is 0.5 - 1 MPa.

[0071] In the present invention, the cross-section of the support structure is U-shaped and consists of a composite support bending section, a composite support straight section, a joint welding, a U-shaped steel, and a cable clip. Among them, the composite support bending section and the composite support straight section are made of composite materials.

[0072] 1. Example 1 (basic formula)

[0073] Formulation: Polyol 24.2 phr, bio-based phosphorus-containing polyol 15.4 phr, antistatic agent 15.4 phr; MDI: 45 phr; Glass fiber: 80 wt%.

[0074] Process: Pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0075] 2. Example 2 (High flame-retardant formulation)

[0076] Formulation: Polyol 14.6 phr, bio-based phosphorus-containing polyol 20.4 phr, antistatic agent 20 phr; MDI: 45 phr; Glass fiber: 80 wt%.

[0077] Process: Pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0078] 3. Example 3

[0079] Formulation: Polyol 16.6 phr, bio-based phosphorus-containing polyol 13 phr, additive flame retardant (aluminum hydroxide) 10 phr, antistatic agent 15.4 phr; MDI: 45 phr; Glass fiber: 80 wt%.

[0080] Process: Pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0081] 4. Example 4

[0082] Formulation: Polyol 34.6 phr, bio-based phosphorus-containing polyol 20.4 phr, antistatic agent surface carbon fiber; MDI: 45 phr; Glass fiber: 80 wt%.

[0083] Process: Pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0084] 5. Comparative Example 1 (Omit phosphorus-containing polyol)

[0085] Formulation: Polyol 55 phr, MDI: 45 phr; Glass fiber: 80 wt%.

[0086] Process: Pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0087] 6. Comparative Example 2

[0088] Formulation: Polyol 14.6 phr, additive flame retardant (aluminum hydroxide) 25 phr, antistatic agent 15.4 phr; MDI: 45 phr; Glass fiber: 80 wt%.

[0089] Process: Pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0090] Test the products made in the above examples, and the test results are shown in the following table:

[0091]

[0092] Note: Since the bio-based phosphorus-containing polyol participates in the reaction, this characteristic can not only ensure that the composite material prepared without adding an additive flame retardant can achieve the flame retardant effect (the flame retardancy can reach MT113), but also maintain the mechanical properties of the composite material. At the same time, when adding a large amount of other additives (such as an antistatic agent, making the surface resistance ≤ 3×108 Ω), the mechanical properties of the composite material only decrease slightly, as shown in Example 2; reducing the amount of bio-based phosphorus-containing polyol and antistatic agent can prepare composite materials with different flame retardant and antistatic specifications. For example, in Example 1, the flame retardant performance of the composite material reaches V0, the surface resistance reaches 3.8×109 Ω, and the mechanical properties are excellent; since the bio-based phosphorus-containing polyol has a high price, in order to reduce costs, using a method of mixing bio-based phosphorus-containing polyol with an additive flame retardant or completely using an additive flame retardant to prepare the composite material will reduce the mechanical properties of the composite material, such as in Example 3 and Comparative Example 2; in order to further reduce the surface resistance of the composite material profile, using carbon fiber on the surface of the composite material can make the surface resistance ≤ 103 Ω, and the mechanical properties are almost the same as those of the non-flame retardant and antistatic composite material, such as in Example 4.

[0093] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A bio-based phosphorus-containing inherently flame-retardant polyurethane roadway support for coal mines, characterized in that: The material for the roadway support is a continuous fiber-reinforced flame-retardant and antistatic polyurethane composite material. The flame-retardant and antistatic polyurethane composite material is composed of polyurethane resin and glass fiber. The polyurethane resin includes components A and B. Component A is diphenylmethane diisocyanate, and component B is a polyol mixture obtained by mixing polyester polyol, bio-based phosphorus-containing polyol, flame retardant, and antistatic agent in a set ratio. The structural formula of the bio-based phosphorus-containing polyol is as follows: Among R1 to R11, there are 2 to 4 compounds of structural formula II, and the rest are The structural formula II is:

2. A bio-based phosphorus-containing intrinsically flame-retardant polyurethane roadway support for coal mines according to claim 1, characterized in that, The preparation method of the roadway support includes the following steps: Step 1: The traction fibers pass through the oven and the yarn splitting board respectively and are drawn into the mold; the traction felt / cloth enters the mold; Step 2: Prepare the bio-based phosphorus-containing polyol, and mix it with polyester polyol, flame retardant, and antistatic agent in proportion to obtain component B, and add components A and B to the two-component resin mixer; Step 3: Turn on the mold heating device for 1.5 h to fully heat the mold; Step 4: Turn on the oven and start the traction device; Step 5: Turn on the glue injection machine and the cutting machine; Step 6: The resin and glass fiber are cured through the mold to obtain a flame-retardant, antistatic, bio-based phosphorus-containing intrinsically flame-retardant polyurethane profile, which is cut to a fixed length by the cutting machine.

3. A bio-based phosphorus-containing inherently flame-retardant polyurethane roadway support for coal mines according to claim 1, wherein, In step 2, the method for preparing the bio-based phosphorus-containing polyol includes the following steps: (1) Add phytic acid and ammonia water to the reaction kettle in sequence. After adding water and dissolving, heat it to 30 - 80 °C, and carry out condensation reflux reaction for 20 - 200 min. After purification and drying, obtain the intermediate with structural formula III; (2) Add the compound with structural formula II to the flask equipped with a condensation device, add an organic solvent and heat it to 30 °C - 100 °C to dissolve. At 25 °C - 150 °C, add the intermediate with structural formula III obtained in step (1) and react for 1 h - 10 h, then remove the solvent. After drying, the bio-based phosphorus-containing polyol can be obtained; The structural formula is Among them, R13 to R24 contain 2 to 4 H+, and the rest are The structural formula II is 4. A bio-based phosphorus-containing intrinsically flame-retardant polyurethane roadway support for coal mines according to claim 3, characterized in that, In step (1), the molar ratio of phytic acid to ammonia water is 1:8 - 10.

5. A bio-based phosphorus-containing inherently flame-retardant polyurethane roadway support for coal mines according to claim 3, characterized in that, In step (2), the molar ratio of the compound with structural formula II to the intermediate with structural formula III is 2 - 4:

1.

6. A bio-based phosphorus-containing inherently flame-retardant polyurethane roadway support for coal mines according to claim 3, characterized in that, The antistatic agent is a mixture composed of one or more of 1,3-dimethylimidazolium tetrafluoroborate, N-octylpyridinium bromide, N-butyl-N-methylpiperidinium bromide, N-butyl-N-methylpyrrolidinium bromide, tributylmethylammonium chloride, N-ethyl,methylmorpholinium bromide, and tributylethylphosphonium bromide ionic liquids.

7. A bio-based phosphorus-containing inherently flame-retardant polyurethane roadway support for coal mines according to claim 2, characterized in that, In step 3, the mold heating temperature is 150 °C - 210 °C, divided into two zones or three zones. The temperature at the front end of the mold is 150 °C - 170 °C, the middle section is 170 °C - 190 °C, and the rear section is 190 °C - 210 °C.

8. A bio-based phosphorus-containing inherently flame-retardant polyurethane roadway support for coal mines according to claim 2, characterized in that, In step 4, the oven temperature: the oven temperature is 60 °C - 150 °C.

9. The bio-based phosphorus-containing inherently flame-retardant polyurethane roadway support for coal mines according to claim 2, wherein The fiber traction speed is 0.2 - 2 m / min, and the glue injection pressure is 0.5 - 1 MPa.

10. A bio-based phosphorus-containing inherently flame-retardant polyurethane roadway support for coal mines according to claim 1, characterized in that, The cross-section of the support structure is U-shaped and is composed of a composite material support bending section, a composite material support straight section, a joint welding, a U-shaped steel, and a cable clip. Among them, the composite material support bending section and the composite material support straight section adopt composite materials.

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