Fiber composite material, preparation method and application thereof, flame-retardant product and preparation method thereof

Abstract

The invention relates to the technical field of aerogel flame-retardant materials, and discloses a fiber composite material, a preparation method and application thereof, a flame-retardant product and a preparation method of the flame-retardant product. The fiber composite material is prepared from the following components in percentage by weight: 68 to 78 weight percent of fiber, 21.8 to 32 weight percent of resin and 0.2 to 1 weight percent of organic aerogel. The invention also discloses a preparation method of the fiber composite material. The preparation method comprises the following steps: (1) providing a suspension containing an organic aerogel precursor; (2) performing sol-gel treatment and freezing treatment on the suspension to obtain organic aerogel; and (3) mixing the organic aerogel, the fiber and the resin. When the fiber composite material is applied to a flame-retardant product, the flame retardance of the flame-retardant product can be improved, and the good mechanical property of the flame-retardant product can be kept.

Description

Technical Field

[0001] The present invention relates to the technical field of aerogel flame-retardant materials, and particularly relates to a fiber composite material, a preparation method and application thereof, and a flame-retardant product and a preparation method thereof. Background Art

[0002] With the development of science and technology, the civil engineering construction technology in China has become increasingly advanced, and more and more composite materials have been applied to the civil engineering field. Carbon fiber ribbed bars are a new type of composite material applied to the civil engineering field in recent years, and they have many excellent properties such as corrosion resistance, light weight, and non-magnetic properties that steel does not have. In practical applications, as the main load-bearing structure, the flame-retardant performance of carbon fiber ribbed bars is of utmost importance for the stability in extreme situations such as lightning strikes and fires.

[0003] The manufacturing of carbon fiber ribbed bars mainly uses the pultrusion process. During the pultrusion process, the pultrusion process of the composite material can be improved by adding functional fillers including additive flame retardants. The fillers can not only improve the pultrusion process, ensure the smooth progress of the pultrusion process of the composite material, but also ensure the stability of the composite material performance, improve the performance of the resin matrix, and improve the dynamic and static mechanical properties of the composite material.

[0004] Currently, carbon fiber ribbed bars are often manufactured from mature commercial formula resins. To ensure mechanical properties, the pultrusion process is generally specified by the resin supplier. If the resin is flame-retardantly modified, it will affect the pultrusion process and the performance of the finished product. Moreover, in the prior art, the addition of some additive flame retardants cannot well improve the flame-retardant performance of fiber ribbed bars.

[0005] CN113201201A discloses a flame-retardant and high-toughness carbon fiber composite material for overhead transmission wires. The carbon fiber composite material includes: polyacrylonitrile, single-layer graphene powder, bacterial cellulose, methyl methacrylate, 1,6-dibromohexane, thermosetting resin, nano magnesium hydroxide, and nano aerogel. The carbon fiber composite material has high flame retardancy and toughness. However, the composition of the carbon fiber composite material is relatively complex, the cost is high, and it is not mentioned whether the carbon fiber composite material is suitable for pultrusion process treatment.

[0006] CN110527396A discloses a flame-retardant thermal insulation foam-type coating with a hierarchical pore microstructure and a preparation method thereof. The preparation method includes: dispersing a thickener, a curing agent, a foaming agent, and reinforcing fibers in a solvent to obtain a thickening solution; mixing the thickening solution and an aqueous resin to obtain a mixed solution; and mixing the mixed solution and aerogel powder to obtain a creamy coating. The flame-retardant thermal insulation foam-type coating prepared by the present invention has good sagging and construction properties, and can be coated on vertical surfaces or ceilings, etc., without using adhesives used for thermal insulation boards. It can be seen that this patent also does not mention whether the flame-retardant thermal insulation foam-type coating is applicable to the pultrusion process of fiber threaded bars. Summary of the Invention

[0007] The purpose of the present invention is to overcome the problems existing in the prior art that the improvement method has an insignificant improvement in the flame retardancy of fiber threaded bars, but has a greater impact on the pultrusion process and performance of the product, and to provide a fiber composite material, a preparation method and application thereof, and a flame-retardant product and a preparation method thereof.

[0008] To achieve the above purpose, in a first aspect of the present invention, a fiber composite material is provided. Based on the total weight of the fiber composite material, in the fiber composite material, the content of fibers is 68-78 wt%, the content of resin is 21.8-32 wt%, and the content of organic aerogel is 0.2-1 wt%.

[0009] In a second aspect of the present invention, a method for preparing a fiber composite material is provided. The method includes:

[0010] (1) Providing a suspension containing an organic aerogel precursor;

[0011] (2) Performing sol-gel treatment and freezing treatment on the suspension to obtain an organic aerogel;

[0012] (3) Mixing the organic aerogel, fibers, and resin to obtain the fiber composite material.

[0013] In a third aspect of the present invention, an application of the fiber composite material described in the first aspect or the fiber composite material prepared by the method described in the second aspect in a flame-retardant product is provided.

[0014] Among them, the pultrusion speed is 30-50 cm / min, and the temperature is 100-200 °C.

[0015] Through the above technical solution, by controlling the relative contents of fibers, resin and organic aerogel in the fiber composite material of the present invention, not only can the flame retardancy of the composite material be significantly improved, but also the pultrusion process of the composite material and the mechanical properties of the composite material after pultrusion are not affected. The flame retardancy performance tests were carried out on the products prepared in Examples 1-5 of the present invention. It can be seen from the test results (as shown in Table 1) that, compared with Comparative Examples 1-2, the organic aerogel contained in the fiber composite material of the present invention can significantly improve the flame retardancy performance of the fiber composite material; in addition, it can also be seen from Table 1 that after the fiber composite material is prepared into a threaded rib by the pultrusion process, the organic aerogel existing as a flame retardant additive has little influence on the mechanical properties of the threaded rib. Detailed Description of the Invention

[0016] In the ranges disclosed herein, the endpoints and any value are not limited to the exact range or value. 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, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0017] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0018] The limiting oxygen index of the fiber composite material was measured according to the ASTM D2863-2009 standard. The limiting oxygen index (LOI) of the fiber composite material was tested using a limiting oxygen index tester. Specifically, the fiber composite material sample was placed in the combustion chamber, and the oxygen content in the atmosphere was adjusted to find the lowest oxygen concentration that could maintain combustion. Among them, the sample size was 130*10*4 mm, and each sample was tested 3 times, and the average value was taken.

[0019] The flame retardancy performance of the fiber composite material was measured according to the ASTM D3801 standard. Specifically, a vertical burning (UL-94) test was carried out on the fiber composite material sample. Among them, the sample size was 130*10*4 mm, and each sample was tested 3 times, and the average value was taken.

[0020] The tensile property test of the fiber composite material was carried out using a YF-900 computer tensile testing machine, and the test speed was 2.0 mm / min. Among them, at least 3 parallel samples were tested for each sample, and the average value was taken.

[0021] In the first aspect of the present invention, a fiber composite material is provided. Based on the total weight of the fiber composite material, in the fiber composite material, the content of fibers is 68 - 78 wt%, the content of resin is 21.8 - 32 wt%, and the content of organic aerogel is 0.2 - 1 wt%.

[0022] According to the present invention, by controlling the relative contents of fibers, resin, and organic aerogel in the fiber composite material of the present invention, not only can the flame retardancy of the composite material be significantly improved, but also the pultrusion process of the composite material and the mechanical properties of the composite material after pultrusion are not affected.

[0023] According to the present invention, based on the total weight of the fiber composite material, in the fiber composite material, the content of fibers is 70 - 72 wt%, the content of resin is 27.5 - 29.6 wt%, and the content of organic aerogel is 0.4 - 0.5 wt%.

[0024] According to the present invention, in order to enable the composite material to have better mechanical properties, preferably, the fiber is at least one of glass fiber, carbon fiber, and basalt fiber, and further preferably, the fiber is carbon fiber.

[0025] Preferably, the resin is at least one of epoxy resin, vinyl resin, polyimide resin, unsaturated polyester, and phenolic resin, and further preferably, the resin is epoxy resin.

[0026] According to the present invention, in order to significantly improve the flame retardancy of the fiber composite material while ensuring good mechanical properties of the fiber composite material, preferably, the organic aerogel is phosphated cellulose aerogel and / or cellulose aerogel, and further preferably, it is phosphated cellulose aerogel.

[0027] The present invention has no particular limitation on the source of the phosphated cellulose, which can be obtained by commercial purchase or prepared by any existing method.

[0028] Preferably, based on the total weight of the phosphated cellulose aerogel, the phosphorus content in the phosphated cellulose aerogel is 2 - 17 wt%, preferably 5 - 16 wt%.

[0029] In the present invention, the phosphorus content of the organic aerogel is determined by the Kjeldahl method. The specific method is: adding ammonium ions and measuring the absorbance at 740 nm by spectrophotometry.

[0030] According to the present invention, in order to improve the dispersibility of the organic aerogel in the composite material and enable it to better play the role of a flame retardant additive, preferably, the particle size of the organic aerogel is 300 - 2000 mesh, and further preferably, it is 325 - 800 mesh.

[0031] The particle size of the organic aerogel of the present invention is obtained by sieving test.

[0032] According to the present invention, in order to enable the product made of the fiber composite material to have good mechanical properties, be able to serve as the main load-bearing structure in applications, and ensure stability under extreme conditions such as lightning strikes and fires, preferably, the limiting oxygen index of the fiber composite material is 20-60%, preferably 30-50%; the UL-94 determination grade is V-2 to V-0, preferably V-1 to V-0; the tensile strength is 1800-2200 MPa, preferably 2089-2134 MPa.

[0033] In the present invention, the composition of the fiber composite material is obtained by calculating the feeding amount.

[0034] The present invention does not particularly limit the preparation method of the fiber composite material, as long as the fiber composite material with the above composition can be obtained. According to a preferred embodiment of the present invention, the second aspect of the present invention provides a method for preparing a fiber composite material, and the method includes:

[0035] (1) Providing a suspension containing an organic aerogel precursor;

[0036] (2) Subjecting the suspension to sol-gel treatment and freezing treatment to obtain an organic aerogel;

[0037] (3) Mixing the organic aerogel, fibers and resin to obtain the fiber composite material.

[0038] According to the preparation method of the present invention, the suspension containing the organic aerogel precursor is subjected to sol-gel and freezing treatment to obtain an organic aerogel with a smaller particle size, and then mixed with fibers and resin to obtain a fiber composite material with significantly improved flame retardancy.

[0039] According to the preparation method of the present invention, in order to significantly improve the flame retardancy of the obtained fiber composite material and ensure that the mechanical properties of the fiber composite material are not affected, preferably, in step (1), the organic aerogel precursor is phosphated cellulose and / or cellulose, and further preferably phosphated cellulose.

[0040] According to the preparation method of the present invention, in order to uniformly disperse the organic aerogel precursor in the suspension and obtain an aerogel with a small and uniform particle size through subsequent sol-gel and freezing treatment of the suspension, preferably, in step (1), the mass concentration of the suspension is 1-10%, preferably 1%.

[0041] According to the preparation method of the present invention, in order to make the organic aerogel precursor disperse more uniformly in the solution, preferably, in step (1), the way to provide the suspension containing the organic aerogel precursor includes: stirring the solution containing the organic aerogel precursor.

[0042] Further preferably, the stirring process includes: first stirring at a speed of 6000 - 8000 rpm for 10 - 20 min; then stirring at a speed of 200 - 300 rpm for 20 - 40 min.

[0043] According to the present invention, preferably, in step (2), the conditions for the sol - gel treatment include: the temperature is room temperature, preferably 25 - 35 °C, and the time is 24 - 48 h.

[0044] According to the preparation method of the present invention, in order to obtain a better - performance aerogel, preferably, in step (2), the way of the freezing treatment includes: the freezing temperature is - 200 °C to - 100 °C, and the time is 15 - 30 min; the freeze - drying temperature is - 80 °C to - 70 °C, and the time is 24 - 48 h.

[0045] According to the preparation method of the present invention, preferably, in step (2), after the freezing treatment, there is also a step of freeze - grinding to obtain aerogel powder.

[0046] Further preferably, the temperature of the freeze - grinding is - 80 °C to - 70 °C, and the time is 1 - 5 h.

[0047] According to the preparation method of the present invention, in order to improve the dispersibility of the prepared organic aerogel in the composite material and make it better play the role of a flame - retardant additive, preferably, in step (2), the particle size of the obtained aerogel powder is 300 - 2000 mesh, and further preferably 325 - 800 mesh.

[0048] According to the preparation method of the present invention, in order to make the prepared composite material have better mechanical properties, preferably, in step (3), the fiber is at least one of glass fiber, carbon fiber, and basalt fiber, and further preferably, the fiber is carbon fiber.

[0049] According to the preparation method of the present invention, preferably, in step (3), the resin is at least one of vinyl resin, polyimide resin, unsaturated polyester, and phenolic resin, and further preferably, it is epoxy resin.

[0050] According to the preparation method of the present invention, preferably, in step (3), the weight ratio of fiber, resin, and organic aerogel is 68 - 78:21.8 - 32:0.2 - 1, and preferably 70 - 72:27.5 - 29.6:0.4 - 0.5.

[0051] The third aspect of the present invention provides an application of the fiber composite material described in the first aspect or the fiber composite material prepared by the method described in the second aspect in a flame-retardant product.

[0052] According to the present invention, the flame-retardant product is a threaded rib obtained by subjecting the fiber composite material to a pultrusion process.

[0053] Preferably, the pultrusion speed is 30 - 50 cm / min and the temperature is 100 - 200 °C. More preferably, the pultrusion speed can be 50 cm / min and the temperature can be 110 °C.

[0054] The present invention will be described in detail below through examples.

[0055] Cellulose nanocrystals with a purity of 99% were purchased from Shanghai Petrochemical.

[0056] Epoxy resin, model OLIN-550E.

[0057] Carbon fiber, model SPC-40S, was purchased from Shanghai Petrochemical.

[0058] The phosphated cellulose used in the examples was prepared by the preparation examples.

[0059] The composition of the fiber composite was calculated from the feed amounts in the specific examples.

[0060] The particle size of the aerogel was determined by sieving.

[0061] Preparation Example 1

[0062] (1) 6.24 g of urea was melted under a N2 atmosphere at 140 °C, then 1 g of cellulose nanocrystals and 2 g of phosphorous acid were added, and the reaction was carried out at 140 °C for 4 h to obtain Product 1;

[0063] (2) Product 1 was dissolved in a small amount of deionized water, then absolute ethanol was added, and manual stirring was carried out to precipitate a solid, which was then filtered by suction to obtain phosphated cellulose 1.

[0064] Preparation Example 2

[0065] According to the method of Preparation Example 1, except that in step (1), the amount of phosphorous acid used was 3 g, and the reaction conditions were: reaction at 142.5 °C for 4.5 h, and finally phosphated cellulose 2 was obtained.

[0066] Preparation Example 3

[0067] According to the method of Preparation Example 1, except that in step (1), the amount of phosphorous acid used was 4 g, and the reaction conditions were: reaction at 145 °C for 5 h, and finally phosphated cellulose 3 was obtained.

[0068] Preparation Example 4

[0069] According to the method of Preparation Example 1, except that in step (1), the amount of phosphorous acid used is 5 g, and the reaction conditions are: reacting at 147.5 °C for 5.5 h, and finally obtaining phosphated cellulose 4.

[0070] Preparation Example 5

[0071] According to the method of Preparation Example 1, except that in step (1), the amount of phosphorous acid used is 6 g, and the reaction conditions are: reacting at 150 °C for 6 h, and finally obtaining phosphated cellulose 5.

[0072] Example 1

[0073] (1) Mix 1 g of phosphated cellulose 1 with 99 g of deionized water, disperse it with a high-speed disperser at a speed of 6000 r / min for 10 min, and then stir it with a magnetic stirrer at a speed of 200 r / min for 20 min to remove air bubbles, obtaining a uniformly dispersed phosphated cellulose suspension;

[0074] (2) Pour the phosphated cellulose suspension prepared in step (1) into a mold, carry out sol-gel at 25 °C for 24 h to form a hydrogel; put the mold into a liquid nitrogen bucket, freeze it at -196 °C for 15 min until completely frozen, and freeze-dry it at -70 °C for 48 h to obtain a phosphated cellulose aerogel, and freeze-crush it at -70 °C for 2 h, and pass through a 325-mesh sieve to obtain a phosphated cellulose aerogel powder;

[0075] (3) Mix the phosphated cellulose aerogel powder prepared in step (2) into epoxy resin, stir evenly, pour the resin into the glue tank of a pultrusion machine, and use carbon fiber to prepare a threaded rib. The contents of each component are shown in Table 1, the mold specification is Φ16 mm * 600 mm, and post-cure is carried out in a furnace with a length of 90 cm in turn. The curing temperatures in each furnace are 200 °C, 200 °C, 180 °C, 180 °C, 190 °C, 190 °C respectively, and the pultrusion speed is 40 cm / min, obtaining threaded rib 1.

[0076] Measure the limiting oxygen index, flame retardant performance and tensile performance of threaded rib 1, and the measurement results are shown in Table 2.

[0077] Example 2

[0078] (1) Mix 1 g of phosphated cellulose 2 with 99 g of deionized water, disperse it with a high-speed disperser at a speed of 6500 r / min for 12.5 min, and then stir it with a magnetic stirrer at a speed of 225 r / min for 25 min to remove air bubbles, obtaining a uniformly dispersed phosphated cellulose suspension;

[0079] (2) Pour the phosphated cellulose suspension prepared in step (1) into a mold, and carry out sol-gel for 30 h at 25 °C to form a hydrogel; put the mold into a liquid nitrogen bucket, freeze it at -197 °C for 20 min until completely frozen, and freeze-dry it at -70 °C for 48 h to obtain phosphated cellulose aerogel, and freeze-crush it at -70 °C for 2 h to obtain phosphated cellulose aerogel powder;

[0080] (3) Mix the phosphated gel prepared in step (2) into the resin and stir evenly. Pour the resin into the glue tank of a pultrusion machine, and use carbon fiber to prepare the threaded rib. The contents of each component are shown in Table 1. The mold specification is Φ16mm*600mm. Carry out post-curing in a furnace with a length of 90 cm in sequence. The curing temperatures in each furnace are 200 °C, 200 °C, 180 °C, 180 °C, 190 °C, and 190 °C respectively, and the pultrusion speed is 40 cm / min to obtain the threaded rib 2.

[0081] Measure the limiting oxygen index, flame retardancy and tensile properties of the threaded rib material 2, and the measurement results are shown in Table 2.

[0082] Example 3

[0083] (1) Mix 1 g of phosphated cellulose 3 with 99 g of deionized water, disperse it with a high-speed disperser at a speed of 7000 r / min for 15 min, and then stir it with a magnetic stirrer at a speed of 250 r / min for 30 min to remove air bubbles, obtaining a uniformly dispersed phosphated cellulose suspension;

[0084] (2) Pour the phosphated cellulose suspension prepared in step (1) into a mold, and carry out sol-gel for 36 h at 27 °C to form a hydrogel; put the mold into a liquid nitrogen bucket, freeze it at -200 °C for 30 min until completely frozen, and freeze-dry it at -70 °C for 48 h to obtain phosphated cellulose aerogel, and freeze-crush it at -70 °C for 2 h to obtain phosphated cellulose aerogel powder;

[0085] (3) Mix the phosphated gel prepared in step (2) into the resin and stir evenly. Pour the resin into the glue tank of a pultrusion machine, and use carbon fiber to prepare the threaded rib. The contents of each component are shown in Table 1. The mold specification is Φ16mm*600mm. Carry out post-curing in a furnace with a length of 90 cm in sequence. The curing temperatures in each furnace are 200 °C, 200 °C, 180 °C, 180 °C, 190 °C, and 190 °C respectively, and the pultrusion speed is 40 cm / min to obtain the threaded rib 3.

[0086] Measure the limiting oxygen index, flame retardancy and tensile properties of the threaded rib material 3, and the measurement results are shown in Table 2.

[0087] Example 4

[0088] (1) Mix 1 g of phosphated cellulose 4 with 99 g of deionized water, disperse it for 17.5 min with a high-speed disperser at a speed of 7500 r / min, and then stir it for 35 min with a magnetic stirrer at a speed of 275 r / min to remove air bubbles, obtaining a uniformly dispersed phosphated cellulose suspension;

[0089] (2) Pour the phosphated cellulose suspension prepared in step (1) into a mold, carry out sol-gel for 42 h at a temperature of 35 °C to form a hydrogel; put the mold into a liquid nitrogen bucket, freeze it for 28 min at 198 °C until completely frozen, and freeze-dry it at -70 °C for 48 h to obtain a phosphated cellulose aerogel, and freeze-crush it at -70 °C for 2 h to obtain a phosphated cellulose aerogel powder;

[0090] (3) Mix the phosphated gel prepared in step (2) into the resin, stir evenly, pour the resin into the glue tank of a pultrusion machine, and use carbon fiber to prepare a threaded rib. The content of each component is shown in Table 1, the mold specification is Φ16 mm * 600 mm, and post-cure is carried out in a furnace with a length of 90 cm in turn. The curing temperatures in each furnace are 200 °C, 200 °C, 180 °C, 180 °C, 190 °C, and 190 °C respectively, and the pultrusion speed is 40 cm / min to obtain a threaded rib 4.

[0091] Measure the limiting oxygen index, flame retardancy and tensile properties of the threaded rib material 4, and the measurement results are shown in Table 2.

[0092] Example 5

[0093] (1) Mix 1 g of phosphated cellulose 1 with 99 g of deionized water, disperse it for 20 min with a high-speed disperser at a speed of 8000 r / min, and then stir it for 40 min with a magnetic stirrer at a speed of 300 r / min to remove air bubbles, obtaining a uniformly dispersed phosphated cellulose suspension;

[0094] (2) Pour the phosphated cellulose suspension prepared in step (1) into a mold, carry out sol-gel for 48 h at a temperature of 25 °C to form a hydrogel; put the mold into a liquid nitrogen bucket, freeze it for more than 20 min at 199 °C until completely frozen, and freeze-dry it at -70 °C for 48 h to obtain a phosphated cellulose aerogel, and freeze-crush it at -70 °C for 2 h to obtain a phosphated cellulose aerogel powder;

[0095] (3) Mix the phosphating gel prepared in step (2) into the resin, stir evenly, pour the resin into the glue tank of the pultrusion machine, and use carbon fiber to prepare the threaded rib. The contents of each component are shown in Table 1. The mold specification is Φ16mm * 600mm, and post-curing is carried out in a furnace with a length of 90 cm. The curing temperatures in each furnace are 200 °C, 200 °C, 180 °C, 180 °C, 190 °C, and 190 °C respectively, and the pultrusion speed is 40 cm / min to obtain the threaded rib 5.

[0096] Measure the limiting oxygen index, flame retardant performance, and tensile performance of the threaded rib material 5. The measurement results are shown in Table 2.

[0097] Comparative Example 1

[0098] Comparative Example 1 was operated according to Example 1. The difference from Example 1 was that carbon fiber and epoxy resin were directly used for pultrusion. The contents of each component are shown in Table 1 to obtain the threaded rib 6.

[0099] Measure the limiting oxygen index, flame retardant performance, and tensile performance of the threaded rib material 6. The measurement results are shown in Table 2.

[0100] Comparative Example 2

[0101] Comparative Example 2 was operated according to Example 1. The difference from Example 1 was that carbon fiber and epoxy resin added with talcum powder were used for pultrusion. The contents of each component are shown in Table 1 to obtain the threaded rib 7.

[0102] Measure the limiting oxygen index, flame retardant performance, and tensile performance of the threaded rib material 7. The measurement results are shown in Table 2.

[0103] Table 1

[0104]

[0105] Table 2

[0106]

[0107] Note: The phosphorus content refers to the content of phosphorus in the phosphated cellulose aerogel based on the total weight of the phosphated cellulose aerogel.

[0108] As can be seen from Table 1, compared with Comparative Example 1, in Comparative Example 2 and Examples 1-5, the addition of the flame retardant additive has little effect on the tensile strength of the fiber threaded ribs. The limiting oxygen index of the fiber threaded ribs prepared in Examples 1-5 is much higher than that of the fiber threaded ribs prepared in Comparative Example 1 and Comparative Example 2, indicating that the phosphated cellulose aerogel material prepared in the examples has a good flame retardant effect on the fiber threaded ribs, and its flame retardant performance increases with the increase of the phosphorus content. This is not only because the good heat insulation performance of the aerogel material prevents the further transfer of heat, but also because phosphorous acid is oxidized to phosphoric acid during combustion, and further becomes metaphosphoric acid and pyrophosphoric acid, which promotes the dehydration and carbonization of the matrix material, increases the char yield of the collective material, and forms a stable carbon layer; and the metaphosphoric acid and pyrophosphoric acid formed on the surface of the carbon layer by combustion can passivate the oxidizable active centers on the carbon, thereby inhibiting the smoldering of the carbon and achieving an excellent flame retardant effect.

[0109] As can be seen from the above examples and comparative examples, by adding an organic aerogel to the fiber composite material, the flame retardant performance of the composite material can be significantly improved; in addition, by controlling the relative contents of the fiber, resin and organic aerogel in the fiber composite material, the present invention can not only achieve the improvement of the flame retardancy of the composite material, but also does not affect the pultrusion process of the composite material and the mechanical properties of the composite material after pultrusion.

[0110] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A fiber composite material, characterized in that, Based on the total weight of the fiber composite material, in the fiber composite material, the content of fibers is 68 - 78 wt%, the content of resin is 21.8 - 32 wt%, and the content of organic aerogel is 0.2 - 1 wt%.

2. The fiber composite material according to claim 1, wherein Based on the total weight of the fiber composite material, in the fiber composite material, the content of fibers is 70 - 72 wt%, the content of resin is 27.5 - 29.6 wt%, and the content of organic aerogel is 0.4 - 0.5 wt%.

3. The fiber composite material according to claim 1 or 2, wherein, The fibers are at least one of glass fiber, carbon fiber, and basalt fiber, preferably carbon fiber; Preferably, the resin is at least one of epoxy resin, vinyl resin, polyimide resin, unsaturated polyester, and phenolic resin, preferably epoxy resin; Preferably, the organic aerogel is phosphoric acid cellulose aerogel and / or cellulose aerogel, preferably phosphoric acid cellulose aerogel; Preferably, the particle size of the organic aerogel is 325 - 2000 mesh, preferably 325 - 800 mesh; Preferably, based on the total weight of the phosphoric acid cellulose aerogel, the content of phosphorus in the phosphoric acid cellulose aerogel is 2 - 17 wt%, preferably 5 - 16 wt%.

4. The fiber composite material according to any one of claims 1 to 3, wherein, The limiting oxygen index of the fiber composite material is 20 - 60%, preferably 30 - 50%; the UL - 94 determination grade is V - 2 to V - 0, preferably V - 1 to V - 0; the tensile strength is 1800 - 2200 MPa, preferably 2089 - 2134 MPa.

5. A method for preparing a fiber composite material, characterized in that, The method includes: (1) Providing a suspension containing an organic aerogel precursor; (2) Performing sol - gel treatment and freezing treatment on the suspension to obtain an organic aerogel; (3) Mixing the organic aerogel, fibers, and resin to obtain the fiber composite material.

6. The method according to claim 5, wherein, In step (1), the organic aerogel precursor is phosphoric acid cellulose and / or cellulose, preferably phosphoric acid cellulose; Preferably, based on the total weight of the phosphoric acid cellulose aerogel, the content of phosphorus in the phosphoric acid cellulose aerogel is 2 - 17 wt%, preferably 5 - 16 wt%; and / or, the mass concentration of the suspension is 1 - 10%; and / or, the way of providing a suspension containing an organic aerogel precursor includes: stirring a solution containing an organic aerogel precursor; Preferably, the stirring process includes: first stirring at a speed of 6000 - 8000 rpm for 10 - 20 min; then stirring at a speed of 200 - 300 rpm for 20 - 40 min.

7. The method according to claim 5 or 6, wherein In step (2), the conditions of the sol - gel treatment include: the temperature is 25 - 35 °C, and the time is 24 - 48 h; and / or, the way of the freezing treatment includes: the freezing temperature is - 200 °C to - 100 °C, and the time is 15 - 30 min; the freeze - drying temperature is - 80 °C to - 70 °C, and the time is 24 - 48 h.

8. The method according to any one of claims 5-7, wherein, In step (2), after the freezing treatment, there is also a step of freeze - grinding to obtain an aerogel powder; Preferably, the temperature of the freeze - grinding is - 80 °C to - 70 °C, and the time is 1 - 5 h; Preferably, the particle size of the aerogel powder is 325 - 2000 mesh, preferably 325 - 800 mesh.

9. The method according to any one of claims 5-8, wherein In step (3), the resin is at least one of epoxy resin, vinyl resin, polyimide resin, unsaturated polyester, and phenolic resin, preferably epoxy resin; and / or, the fiber is at least one of glass fiber, carbon fiber, and basalt fiber, preferably carbon fiber; and / or, the weight ratio of the fiber, resin, and organic aerogel is 68 - 78: 21.8 - 32: 0.2 - 1, preferably 70 - 72: 27.5-29.6：0.4-0.5。 10. Use of the fiber composite material according to any one of claims 1 - 4 or the fiber composite material prepared by the method according to any one of 5 - 9 in a flame-retardant product; Preferably, the flame-retardant product is a threaded rib.

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