Composition for preparing flame-retardant material, flame-retardant material as well as preparation method and application of flame-retardant material

Abstract

The invention relates to the field of aerogel flame-retardant materials, and discloses a composition for preparing a flame-retardant material, the flame-retardant material and a preparation method and application of the flame-retardant material, and the composition comprises resin, a fiber material and phosphorus pentoxide-silicon dioxide composite aerogel; based on the weight of the composition, the content of the resin is 16.5 to 29 wt%, the content of the phosphorus pentoxide-silicon dioxide composite aerogel is 0.025 to 0.15 wt%, and the content of the fiber material is 70 to 82 wt%. The flame-retardant material prepared from the composition has excellent tensile strength and also has excellent flame retardance.

Description

Technical Field

[0001] The invention relates to the technical field of aerogel flame retardant materials, and in particular to a composition for preparing a flame retardant material, a flame retardant material, and a preparation method and application thereof. Background Art

[0002] Wind turbine blades are the most important components for capturing wind energy during wind power generation. They work in all-weather conditions at high altitudes all year round, bearing heavy loads and operating in harsh environments. Once a blade is struck by lightning and catches fire, even if it can be discovered in time through the monitoring system, it is difficult to take timely remedial measures because the wind turbine is located in a harsh climate and sparsely populated area. As the main load-bearing component, the flame retardant performance of the blade main beam is particularly important, which can ensure that the blade does not deform to the greatest extent, ensure that the hub and other structures of the wind turbine are not damaged, and minimize the repair costs and serious losses in power generation.

[0003] Pultrusion has become the main process for manufacturing wind turbine blade beams. The addition of functional fillers can not only improve the pultrusion process, ensure the smooth progress of the pultrusion process, and ensure the stability of the composite material performance, but also improve the performance of the resin matrix and improve the dynamic and static mechanical properties of the composite material. However, the existing functional fillers cannot take into account both the mechanical properties and flame retardant properties of the composite material. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem of poor flame retardant properties and mechanical properties of flame retardant materials in the prior art, and to provide a composition for preparing a flame retardant material, a flame retardant material, and a preparation method and application thereof. The composition contains phosphorus pentoxide-silicon dioxide composite aerogel, so that the prepared flame retardant material has excellent flame retardant properties and mechanical properties.

[0005] In order to achieve the above-mentioned object, the first aspect of the present invention provides a composition for preparing a flame retardant material, wherein the composition comprises a resin, a fiber material and a phosphorus pentoxide-silicon dioxide composite aerogel;

[0006] Based on the weight of the composition, the content of the resin is 16.5-29wt%, the content of the phosphorus pentoxide-silicon dioxide composite aerogel is 0.025wt%-0.15wt%, and the content of the fiber material is 70-82wt%.

[0007] A second aspect of the present invention provides a flame retardant material, wherein the flame retardant material is prepared from the above-mentioned composition for preparing a flame retardant material.

[0008] A third aspect of the present invention provides a method for preparing a flame retardant material, wherein the flame retardant material is obtained by mixing the components of the composition for preparing the flame retardant material and then heating and molding the mixture.

[0009] A fourth aspect of the present invention provides a composition for preparing the flame retardant material, or the use of the flame retardant material in a main beam of a wind turbine blade.

[0010] Through the above technical scheme, a composition for preparing a flame retardant material and a flame retardant material and a preparation method and application thereof provided by the present invention have the following beneficial effects.

[0011] The composition for preparing the flame retardant material of the present invention contains phosphorus pentoxide-silicon dioxide composite aerogel, which has good heat insulation performance and can prevent further heat transfer; further, during the combustion process, the composite aerogel promotes the dehydration and carbonization of the resin and fiber material matrix, improves the carbonization rate of the material, and forms a stable carbon layer; phosphorus pentoxide and the water generated by the combustion of resin generate metaphosphoric acid and pyrophosphoric acid, which effectively inhibits the smoldering of carbon. The flame retardant material prepared by the composition has excellent tensile strength and excellent flame retardant performance; the flame retardant material of the present invention is used for the main beam of the wind turbine blade, which can meet the stability of the main beam of the wind turbine blade in an emergency. DETAILED DESCRIPTION

[0012] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0013] In the present invention, unless otherwise specified, the "first" and "second" do not indicate a sequence or a limitation on the materials or steps, but are only used to distinguish that they are not the same materials or steps. For example, in "first pH" and "second pH", "first" and "second" are only used to indicate that they are not the same pH.

[0014] In one aspect, the present invention provides a composition for preparing a flame retardant material, wherein the composition comprises a resin, a fiber material and a phosphorus pentoxide-silicon dioxide composite aerogel;

[0015] Based on the weight of the composition, the content of the resin is 16.5-29wt%, the content of the phosphorus pentoxide-silicon dioxide composite aerogel is 0.025wt%-0.15wt%, and the content of the fiber material is 70-82wt%.

[0016] In the present invention, the composition for preparing the flame retardant material contains phosphorus pentoxide-silicon dioxide composite aerogel, which has good heat insulation performance and can prevent further heat transfer; further, during the combustion process, the composite aerogel promotes the dehydration and carbonization of the resin and fiber material matrix, improves the carbonization rate of the material, and forms a stable carbon layer; phosphorus pentoxide and the water generated by the combustion of resin generate metaphosphoric acid and pyrophosphoric acid, which effectively inhibits the smoldering of carbon. When the amount of each component in the composition is controlled to meet the above range, the flame retardant material prepared by the composition has excellent tensile strength and excellent flame retardant performance.

[0017] In the present invention, the total content of the resin, phosphorus pentoxide-silicon dioxide composite aerogel and fiber material is 100wt%.

[0018] Further, based on the weight of the composition, the content of the resin is 22-27wt%, the content of the phosphorus pentoxide-silicon dioxide composite aerogel is 0.05wt%-0.1wt%, and the content of the fiber material is 74-80wt%.

[0019] According to the present invention, the content of phosphorus pentoxide in the phosphorus pentoxide-silicon dioxide composite aerogel is 25-80wt%.

[0020] In the present invention, when the content of phosphorus pentoxide in the composite aerogel meets the above requirements, it is beneficial to improve the flame retardant properties and mechanical properties of the flame retardant material.

[0021] Furthermore, in the phosphorus pentoxide-silicon dioxide composite aerogel, the content of phosphorus pentoxide is 50-75wt%.

[0022] According to the present invention, the average particle size of the phosphorus pentoxide-silicon dioxide composite aerogel is 1-100 μm.

[0023] In the present invention, when the average particle size of the composite aerogel meets the above range, the prepared flame retardant material has better flame retardant properties.

[0024] Furthermore, the average particle size of the phosphorus pentoxide-silicon dioxide composite aerogel is 5-50 μm.

[0025] According to the present invention, the resin is an epoxy resin.

[0026] In the present invention, there is no particular limitation on the type of the epoxy resin, and the epoxy resin may be any conventional epoxy resin in the art.

[0027] According to the present invention, the fiber material is glass fiber and / or carbon fiber.

[0028] Furthermore, the fiber material is carbon fiber.

[0029] According to a preferred embodiment of the present invention, the method for preparing the phosphorus pentoxide-silicon dioxide composite aerogel comprises:

[0030] (1) mixing a silicon source, a phosphorus source, ethanol and water, adjusting the pH to a first pH, stirring, adjusting the pH to a second pH, and aging to obtain a wet gel;

[0031] (2) The wet gel is immersed in ethanol, dried, and ground to obtain the phosphorus pentoxide-silicon dioxide composite aerogel.

[0032] According to a preferred embodiment of the present invention, in step (1), the silicon source is selected from at least one of ethyl orthosilicate, methyl orthosilicate, methyltriethoxysilane and polysiloxane.

[0033] Furthermore, the silicon source is tetraethyl orthosilicate.

[0034] According to a preferred embodiment of the present invention, the phosphorus source is at least one selected from triethyl phosphate, triethyl phosphite, diethyl phosphate, ethyl phosphite, ethyl methyl phosphite and ethyl methyl phosphate.

[0035] Furthermore, the phosphorus source is triethyl phosphate.

[0036] According to a preferred embodiment of the present invention, the mass ratio of the silicon source, the phosphorus source, the ethanol and the water is 1:0.1-1:1-3:0.1-1.

[0037] In the present invention, when the amounts of silicon source, phosphorus source, ethanol and water meet the above mass ratio, the prepared phosphorus pentoxide-silicon dioxide composite aerogel is used to prepare a composition of flame retardant materials, which is conducive to obtaining flame retardant materials with high mechanical properties and high flame retardant properties.

[0038] Furthermore, the mass ratio of the silicon source, phosphorus source, ethanol and water is 1:0.5-0.9:2-2.6:0.4-0.6.

[0039] According to a preferred embodiment of the present invention, the temperature of the first mixing is 20-30° C., and the time of the first mixing is 15-30 min.

[0040] According to a preferred embodiment of the present invention, the first pH is 1-3.

[0041] In the present invention, there is no particular limitation on the method for adjusting pH, and conventional means for adjusting pH in the art may be used, such as using a 0.05-0.15 mol / L hydrochloric acid solution.

[0042] According to a preferred embodiment of the present invention, the stirring temperature is 20-30° C., and the stirring time is 1-3 h.

[0043] According to a preferred embodiment of the present invention, the second pH is 5.5-6.

[0044] In the present invention, there is no particular limitation on the method for adjusting pH, and conventional means for adjusting pH in the art may be used, such as using 0.05-0.15 mol / L NH 3 ·H 2 O.

[0045] According to a preferred embodiment of the present invention, the aging time is 24-48 hours.

[0046] According to a preferred embodiment of the present invention, in step (2), the immersion time is 1-5 days.

[0047] In the present invention, the wet gel is immersed in ethanol, and the ethanol is replaced every 12 hours.

[0048] According to a preferred embodiment of the present invention, the drying is carried out by supercritical carbon dioxide drying.

[0049] In the present invention, the pressure PC of the supercritical carbon dioxide drying is 10 MPa and the temperature TC is 318.15K.

[0050] A second aspect of the present invention provides a flame retardant material, wherein the flame retardant material is prepared from the above-mentioned composition for preparing a flame retardant material.

[0051] In the present invention, the flame retardant material has excellent tensile strength and excellent flame retardant properties; using the flame retardant material of the present invention for the main beam of a wind turbine blade can ensure the stability of the main beam of the wind turbine blade in an emergency situation.

[0052] According to the present invention, the tensile strength of the flame retardant material is greater than or equal to 2000 MPa.

[0053] Furthermore, the tensile strength of the flame retardant material is greater than or equal to 2300 MPa.

[0054] According to the present invention, the flame retardant material has a grade of V-1, V-0 or V-2 as determined by UL-94.

[0055] Furthermore, the flame retardant material has a grade of V-1 or V-0 as determined by UL-94.

[0056] According to the present invention, the limited oxygen index of the flame retardant material is greater than or equal to 20%.

[0057] Furthermore, the flame retardant material has an oxygen limiting index greater than or equal to 35%.

[0058] In the present invention, there is no special requirement for the size of the flame retardant material, for example, it can be 100-1500mm*10-150mm*2-10mm.

[0059] A third aspect of the present invention provides a method for preparing a flame retardant material, wherein the flame retardant material is obtained by mixing the components of the composition for preparing the flame retardant material and then heating and molding the mixture.

[0060] According to the present invention, the temperature of the heating molding is 140-200°C.

[0061] According to the present invention, the heating and forming speed is 30-50 cm / min.

[0062] According to a preferred embodiment of the present invention, a flame retardant material is prepared by a pultrusion method, the method comprising: mixing the metal-doped silica aerogel with a resin, and then mixing with a fiber material for pultrusion. Preferably, the temperature of the first zone of the pultruder is 140-160°C, the temperature of the second zone is 150-180°C, and the temperature of the third zone is 150-200°C. Preferably, the pultrusion speed is 30-50 cm / min.

[0063] In the present invention, the temperature of the first zone, the temperature of the second zone and the temperature of the third zone are in an increasing trend.

[0064] A fourth aspect of the present invention provides a composition for preparing the flame retardant material, or the use of the flame retardant material in a main beam of a wind turbine blade.

[0065] The present invention will be described in detail below through examples.

[0066] In the following examples, the limiting oxygen index (LOI) of aerogel is tested using a limiting oxygen index tester according to ASTM D2863-2009 standard. The aerogel sample is placed in a combustion chamber, and the oxygen content in the atmosphere is adjusted to find the minimum oxygen concentration that can maintain combustion. Sample size: 130*10*4mm, each sample is tested 3 times, and the average value is taken.

[0067] UL-94 The aerogel samples were subjected to vertical combustion (UL-94) test according to ASTM D3801 standard. The sample size was 130*10*4mm. Each test was performed 3 times and the average value was taken.

[0068] The tensile strength was tested on a YF-900 computer tensile testing machine. At least three parallel samples were tested for each sample and the average value was taken. The test speed was 2.0 mm / min.

[0069] The content of phosphorus pentoxide in the composite aerogel is calculated by the following formula according to the amount of raw materials used.

[0070]

[0071] The average particle size of the composite aerogel was measured by a laser particle size analyzer.

[0072] In the following preparation examples, embodiments and comparative examples, the epoxy resin is a commercial product of olin company with a brand number of 550E. The carbon fiber is a commercial product of Shanghai Petrochemical Company with a brand number of SPC-40S. The carbon fiber is 48K carbon fiber.

[0073] Unless otherwise specified, the equipment, materials, etc. used in the following preparation examples, embodiments and comparative examples can be obtained from public commercial sources.

[0074] Preparation Example 1

[0075] Preparation of composite aerogel: 3.3g of tetraethyl orthosilicate, 1.7g of triethyl phosphate, 1.5g of deionized water and 7g of ethanol were mixed, with the mass ratio of silicon source, phosphorus source, ethanol and water being 1:0.52:2.12:0.45, stirred at 25°C for 15min, adjusted to pH 2 with 0.1mol / L hydrochloric acid, and continued to stir at 25°C for 1h. Adjusted pH to 5.5 with 0.05mol / L NH3·H2O, aged for 36h to form wet gel, and then immersed in ethanol for 5 days, replacing ethanol every 12h. Finally, supercritical carbon dioxide drying (PC=10MPa and TC=318.15K) was used to obtain phosphorus pentoxide-silicon dioxide composite aerogel Q1. The composite aerogel Q1 was ground into powder with an average particle size of 13μm.

[0076] Preparation Example 2

[0077] Preparation of composite aerogel: 2.9g of tetraethyl orthosilicate, 2g of triethyl phosphate, 1.6g of deionized water and 7g of ethanol were mixed, with the mass ratio of silicon source, phosphorus source, ethanol and water being 1:0.69:2.41:0.55, stirred at 25°C for 15min, adjusted to pH 2 with 0.1mol / L hydrochloric acid, and continued to stir at 25°C for 3h. Adjusted pH to 5.5 with 0.05mol / L NH3·H2O, aged for 42h to form wet gel, and then immersed in ethanol for 5 days, replacing ethanol every 12h. Finally, supercritical carbon dioxide drying (PC=10MPa and TC=318.15K) was used to obtain phosphorus pentoxide-silicon dioxide composite aerogel Q2. The composite aerogel Q2 was ground into powder with an average particle size of 10μm.

[0078] Preparation Example 3

[0079] Preparation of composite aerogel: 2.7g of tetraethyl orthosilicate, 2.3g of triethyl phosphate, 1.6g of deionized water and 7g of ethanol were mixed, with the mass ratio of silicon source, phosphorus source, ethanol and water being 1:0.85:2.59:0.59, stirred at 25°C for 15min, adjusted to pH 3 with 0.1mol / L hydrochloric acid, and continued to stir at 25°C for 1h. Adjust pH to 5.5 with 0.05mol / L NH3·H2O, aged for 48h to form wet gel, and then immersed in ethanol for 5 days, replacing ethanol every 12h. Finally, supercritical carbon dioxide drying (PC=10MPa and TC=318.15K) was used to obtain phosphorus pentoxide-silicon dioxide composite aerogel Q3. The composite aerogel Q3 was ground into powder with an average particle size of 6.5μm.

[0080] Preparation Example 4

[0081] Preparation of composite aerogel: 4.25g of tetraethyl orthosilicate, 0.74g of triethyl phosphate, 1.4g of deionized water and 6.8g of ethanol were mixed, and the mass ratio of silicon source, phosphorus source, ethanol and water was 1:0.17:1.6:0.33. Stirred at 25℃ for 15min, adjusted pH to 1 with 0.1mol / L hydrochloric acid, and continued stirring at 25℃ for 1h. Adjusted pH to 5.5 with 0.05mol / L NH3·H2O, aged for 24h to form wet gel, and then immersed in ethanol for 5 days, replacing ethanol every 12h. Finally, supercritical carbon dioxide drying (PC=10MPa and TC=318.15K) was used to obtain phosphorus pentoxide-silicon dioxide composite aerogel Q4. The composite aerogel Q4 was ground into powder with an average particle size of 44μm.

[0082] Preparation Example 5

[0083] Preparation of composite aerogel: 3.7g of tetraethyl orthosilicate, 1.3g of triethyl phosphate, 1.5g of deionized water and 6.9g of ethanol were mixed, and the mass ratio of silicon source, phosphorus source, ethanol and water was 1:0.35:1.86:0.41. Stirred at 25℃ for 15min, adjusted pH to 1 with 0.1mol / L hydrochloric acid, and continued stirring at 25℃ for 1h. Adjust pH to 5.5 with 0.05mol / L NH3·H2O, aged for 30h to form wet gel, and then immersed the wet gel in ethanol for 5 days, replacing ethanol every 12h. Finally, supercritical carbon dioxide drying (PC=10MPa and TC=318.15K) was used to obtain phosphorus pentoxide-silicon dioxide composite aerogel Q5. The composite aerogel Q5 was ground into powder with an average particle size of 25μm.

[0084] Preparation Example 6

[0085] Phosphorus pentoxide-silicon dioxide composite aerogel Q6 was prepared according to Preparation Example 1, except that the amount of triethyl phosphate was 0.4 g.

[0086] Preparation Example 7

[0087] Phosphorus pentoxide-silicon dioxide composite aerogel Q7 was prepared according to Preparation Example 4, except that the prepared aerogel was ground and sieved, and the average particle size of the composite aerogel Q7 was 100 μm.

[0088] Comparative Preparation Example 1

[0089] Preparation of composite aerogel: 5g of tetraethyl orthosilicate, 1.3g of deionized water and 6.6g of ethanol were mixed, with the mass ratio of silicon source, ethanol and water being 1:1.32:0.26, stirred at 25°C for 15min, adjusted to pH 1 with 0.1mol / L hydrochloric acid, and continued to stir at 25°C for 1h. The pH was adjusted to 5.5 with 0.05mol / L NH3·H2O, aged for 24h to form a wet gel; the wet gel was then immersed in ethanol for 5 days, with the ethanol replaced every 12h. Finally, the silica aerogel DQ1 was obtained by supercritical carbon dioxide drying (PC=10MPa and TC=318.15K). The aerogel DQ1 was ground into powder with an average particle size of 44μm.

[0090] Table 1

[0091] Aerogel Phosphorus pentoxide content / wt% Average particle size / μm Q1 58 13 Q2 65 10 Q3 70 6.5 Q4 32 44 Q5 49 25 Q6 20 44 Q7 65 100 DQ1 0 44

[0092] Example 1

[0093] The prepared composite aerogel Q1 was mixed into the epoxy resin and stirred evenly. The resin was poured into the glue tank of the pultruder. The carbon fiber was used to prepare the pultruded sheet. The content of each component is shown in Table 2. The mold specification is 120mm*5mm*900mm. The three-zone temperatures are 155℃, 170℃, and 190℃ respectively. The pultrusion speed is 40cm / min. The flame retardant material A1 was obtained. The performance parameters of A1 are shown in Table 3.

[0094] Embodiment 2-9

[0095] The flame retardant material was prepared according to the preparation method of Example 1. The contents of the components are shown in Table 2. The performance parameters of the flame retardant material are shown in Table 3.

[0096] Comparative Example 1

[0097] The flame retardant material was prepared according to the preparation method of Example 1, except that the phosphorus pentoxide-silicon dioxide composite aerogel was not added.

[0098] Comparative Example 2

[0099] The flame retardant material was prepared according to the preparation method of Example 1, except that the phosphorus pentoxide-silicon dioxide composite aerogel 1 was replaced with an equal volume of talcum powder.

[0100] Comparative Example 3

[0101] The flame retardant material was prepared according to the preparation method of Example 1, except that the phosphorus pentoxide-silicon dioxide composite aerogel 1 was replaced by an equal volume of silicon dioxide aerogel DQ1.

[0102] Comparative Example 4

[0103] The flame retardant material was prepared according to the preparation method of Example 1. The contents of the components are shown in Table 2. The performance parameters of the flame retardant material are shown in Table 3.

[0104] Table 2

[0105]

[0106] Table 3

[0107]

[0108]

[0109] *Fail refers to failure to meet V-0, V-1 and V-2 ratings in UL-94 testing.

[0110] From the results, it can be seen that compared with the comparative example, the flame retardant material prepared in the present invention has better comprehensive performance. Comparative example 2 is a traditional preparation method for wind turbine main beams. Compared with comparative example 2, the tensile strength of the flame retardant material of the present application does not change much, indicating that the flame retardant material of the present invention has better tensile strength.

[0111] The limiting oxygen index of the embodiment of the present application is much higher than that of the comparative example, indicating that the phosphorus pentoxide-silicon dioxide composite aerogel has a good flame retardant effect on flame retardant materials. The composite aerogel has good thermal insulation performance and can prevent further heat transfer; further, during the combustion process, the composite aerogel promotes the dehydration and carbonization of the resin and fiber material matrix, improves the carbonization rate of the material, and forms a stable carbon layer; phosphorus pentoxide and the water produced by the combustion of resin generate metaphosphoric acid and pyrophosphoric acid, which synergize the passivation of the oxidizable active center on the carbon and effectively inhibit the smoldering of the carbon.

[0112] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A composition for preparing a flame retardant material, characterized in that: The composition comprises resin, fiber material and phosphorus pentoxide-silicon dioxide composite aerogel; Based on the weight of the composition, the content of the resin is 16.5-29wt%, the content of the phosphorus pentoxide-silicon dioxide composite aerogel is 0.025wt%-0.15wt%, and the content of the fiber material is 70-82wt%.

2. The composition according to claim 1, wherein Based on the weight of the composition, the content of the resin is 22-27wt%, the content of the phosphorus pentoxide-silicon dioxide composite aerogel is 0.05wt%-0.1wt%, and the content of the fiber material is 74-80wt%; Preferably, the phosphorus pentoxide-silicon dioxide composite aerogel has a phosphorus pentoxide content of 25-80wt%, preferably 50-75wt%; Preferably, the average particle size of the phosphorus pentoxide-silicon dioxide composite aerogel is 1-100 μm, preferably 5-50 μm.

3. The composition according to claim 1 or 2, wherein The resin is epoxy resin; Preferably, the fiber material is glass fiber and / or carbon fiber, preferably carbon fiber.

4. The composition according to any one of claims 1 to 3, wherein The preparation method of the phosphorus pentoxide-silicon dioxide composite aerogel comprises: (1) mixing a silicon source, a phosphorus source, ethanol and water, adjusting the pH to a first pH, stirring, adjusting the pH to a second pH, and aging to obtain a wet gel; (2) The wet gel is immersed in ethanol, dried, and ground to obtain the phosphorus pentoxide-silicon dioxide composite aerogel.

5. The composition according to claim 4, wherein In step (1), the silicon source is selected from at least one of tetraethyl orthosilicate, methyl orthosilicate, methyltriethoxysilane and polysiloxane, preferably tetraethyl orthosilicate; Preferably, the phosphorus source is selected from at least one of triethyl phosphate, triethyl phosphite, diethyl phosphate, ethyl phosphite, ethyl methyl phosphite and ethyl methyl phosphate, preferably triethyl phosphate; Preferably, the mass ratio of the silicon source, phosphorus source, ethanol and water is 1:0.1-1:1-3:0.1-1, preferably 1:0.5-0.9:2-2.6:0.4-0.6; Preferably, the temperature of the first mixing is 20-30°C, and the time of the first mixing is 15-30min; Preferably, the first pH is 1-3; Preferably, the stirring temperature is 20-30°C and the stirring time is 1-3h; Preferably, the second pH is 5.5-6; Preferably, the aging time is 24-48 hours.

6. The composition according to claim 4 or 5, wherein In step (2), the immersion time is 1-5 days; Preferably, the drying is carried out using supercritical carbon dioxide drying.

7. A flame retardant material, characterized in that: The flame retardant material is prepared from the composition for preparing a flame retardant material according to any one of claims 1 to 6; Preferably, the tensile strength of the flame retardant material is greater than or equal to 2000 MPa, preferably greater than or equal to 2300 MPa; Preferably, the flame retardant material has a grade of V-1, V-0 or V-2 as determined by UL-94, preferably V-1 or V-0; Preferably, the flame retardant material has an oxygen limiting index greater than or equal to 20%, preferably greater than or equal to 35%.

8. A method for preparing a flame retardant material, characterized in that: The flame retardant material is obtained by mixing the components of the composition for preparing the flame retardant material according to any one of claims 1 to 6 and then heating and molding the mixture.

9. The preparation method according to claim 8, wherein: The heating temperature is 140-200°C. Preferably, the heating and forming speed is 30-50 cm / min.

10. The composition for preparing a flame retardant material according to any one of claims 1 to 6, or the use of the flame retardant material according to claim 7 in a main beam of a wind turbine blade.

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