Highly flame retardant unsaturated polyester resin matrix composite and method for producing same

Abstract

The present application relates to the technical field of high polymer composite material, in particular to a high flame-retardant unsaturated polyester resin matrix composite material and a preparation method thereof, which is composed of the following components in parts by mass: phosphorus-containing unsaturated polyester resin 90-110 parts, bisphenol A type epoxy resin 8-12 parts, composite premix slurry 160-190 parts and other components, the present application is compounded by the specific modified phosphorus-containing resin and the multi-component composite premix slurry system, and is assisted by the corresponding curing initiation system, wherein the composite premix slurry contains organic modified clay, nano-cellulose colloidal water suspension and various flame-retardant and smoke-suppressing functional components, compared with the prior art, the composite material effectively inhibits the sedimentation and stratification of solid fillers, improves the anti-cracking performance in low temperature environment, simultaneously realizes the synergistic improvement of flame retardancy and smoke suppression, and has good processing rheological property, has a wide application prospect, and is particularly suitable for mine roadway support, tunnel reinforcement and building anchoring and other fields.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, and in particular to a highly flame-retardant unsaturated polyester resin matrix composite material and its preparation method. Background Technology

[0002] Unsaturated polyester resin, as the core matrix material for building adhesives, especially anchoring agents, is widely used in fields such as mine roadway support, tunnel reinforcement, and rebar installation in building structures due to its advantages such as fast curing speed, high strength, and strong adhesion to rock mass.

[0003] However, unsaturated polyester resin is flammable and is extremely easy to burn in complex working conditions such as high temperature, open flame or electric spark in underground mines. When burning, it releases a large amount of heat and produces smoke and toxic gases, which poses a serious threat to the life safety of construction workers.

[0004] In existing technologies, traditional methods to improve the flame retardant properties of unsaturated polyester resins typically involve adding inorganic flame retardant fillers such as aluminum hydroxide and ammonium polyphosphate. While this method can achieve effective flame retardancy, the amount of inorganic filler required to reach 40%-60% of the resin mass leads to a sharp increase in the viscosity of the resin system, severe filler sedimentation and stratification, and a significant increase in the brittleness of the cured product. Furthermore, the anchoring agent is prone to cracking and failure at low temperatures. In addition, high-filler-content flame retardants still produce a large amount of smoke during combustion, which can easily cause asphyxiation and injury in confined underground spaces. The problem of balancing flame retardant efficiency and smoke suppression performance has never been effectively solved.

[0005] Therefore, based on the relevant technologies mentioned above, there is an urgent need to develop a high flame-retardant unsaturated polyester resin matrix composite material and its preparation method. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a high flame retardant unsaturated polyester resin matrix composite material and its preparation method, so as to solve the problems of easy sedimentation and delamination of fillers, difficulty in achieving both flame retardancy and smoke suppression, and low-temperature brittleness of cured products in the prior art.

[0007] To achieve the above objectives, the present invention provides a high flame-retardant unsaturated polyester resin matrix composite material and its preparation method.

[0008] A high flame-retardant unsaturated polyester resin matrix composite material is composed of the following components in parts by weight: 90-110 parts of phosphorus-containing unsaturated polyester resin, 8-12 parts of bisphenol A type epoxy resin, 160-190 parts of composite premix, 0.5-1.5 parts of curing agent dicyandiamide micro powder, 3-5 parts of release agent, 8-15 parts of curing initiator benzoyl peroxide, and 15-25 parts of calcium carbonate. The phosphorus-containing unsaturated polyester resin is generated by reacting propylene glycol, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, phthalic anhydride and maleic anhydride.

[0009] Preferably, the preparation steps of the phosphorus-containing unsaturated polyester resin are as follows: Under a nitrogen atmosphere, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, phthalic anhydride, and maleic anhydride are added to propylene glycol. The mixture is heated to 140-150°C, stirred at 80-100 rpm for 1-2 hours, then heated to 190-200°C at a rate of 10-15°C / h and held for 3-5 hours. After the reaction is complete, the mixture is cooled to 160-170°C, and hydroquinone, an inhibitor of polymerization, is added. The mixture is then cooled to 90-100°C, and styrene is added. The stirring speed is increased to 100-150 rpm, and the mixture is stirred for 40-60 minutes. After stirring is complete, the mixture is cooled to 20-30°C to obtain a phosphorus-containing unsaturated polyester resin.

[0010] By embedding phosphorus-containing flame-retardant groups into the unsaturated polyester backbone through copolymerization, the flame-retardant properties of the unsaturated resin are improved. This overcomes the shortcomings of traditional physical additive flame retardants, such as uneven dispersion, easy migration, and impact on mechanical properties. In addition, the viscosity of the resin can be controlled by segmented temperature-controlled polycondensation process, and the synergistic effect between styrene and the polymerization inhibitor can ensure the storage stability and processing adaptability of the resin at room temperature, laying the foundation for the subsequent preparation of highly flame-retardant composite materials.

[0011] Preferably, the mass ratio of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, phthalic anhydride, maleic anhydride, propylene glycol, polymerization inhibitor, and styrene is 0.3-0.4:0.55-0.65:1:0.72-0.92:0.0006-0.0012:0.85-0.95.

[0012] Preferably, the preparation steps of the release agent are as follows: Step A1: Add triethyl phosphate to a beaker, heat to 60-70℃, stir at 30-50 rpm for 20-30 minutes, and after stirring is complete, hot triethyl phosphate solution is obtained; Step A2: Add calcium stearate to a melting tank, heat to 150-160℃, rotate at 40-60 rpm, hold for 30-40 min, heating rate 6-8℃ / min, increase rotation speed to 800-1000 rpm, add hot triethyl phosphate solution, stir for 15-25 min, after stirring is complete, place in a spray granulation tower, nozzle pressure 0.3-0.5MPa, inlet air temperature 0-5℃, outlet air temperature 10-15℃, sieve to obtain release agent.

[0013] Triethyl phosphate has plasticizing and lubricating properties, while calcium stearate has both demolding and thermal stabilizing functions. The two are melt-composite and then spray-granulated to obtain uniform particles, which make them easy to disperse and prevent clumping during the mixing of composite materials. In addition, the low-temperature air-cooling process can prevent the active ingredients from being decomposed by heat, ensuring the stability of the subsequent demolding effect and not affecting the subsequent curing reaction.

[0014] Preferably, the mass ratio of calcium stearate to hot triethyl phosphate solution in step A2 is 0.4-0.5:1.

[0015] Preferably, the preparation steps of the composite premixed pulp are as follows: Step B1: Add the organically modified bentonite to styrene, stir at 300-500 rpm for 15-25 min, increase the speed to 800-1000 rpm, add the nanocellulose colloidal aqueous suspension, heat to 30-40℃, stir for 35-45 min, and after stirring is complete, a pregel is obtained. Step B2: Add calcium lignosulfonate and ammonium polyphosphate to the pregel, stir at 500-600 rpm for 10-20 min, then add melamine, modified magnesium aluminum hydrotalcite, slag powder and aluminum hydroxide in sequence, stir for 20-30 min, and when the mixture is complete, reduce the pressure to -0.08 to -0.09 MPa, increase the speed to 1000-1200 rpm, raise the temperature to 40-50℃, and shear for 40-60 min. When the shearing is complete, restore the pressure to normal to obtain the composite premixed slurry. The mass ratio of the organically modified bentonite, styrene, and nanocellulose colloidal aqueous suspension is 0.1-0.3:0.6-1.2:1. The mass ratio of calcium lignosulfonate, ammonium polyphosphate, pregel, melamine, modified magnesium aluminum hydrotalcite, slag powder and aluminum hydroxide is 0.6-1.2:0.8-1.6:1:0.6-0.9:0.8-1.2:1.5-2.5:4-6.

[0016] Preferably, the preparation steps of the organically modified bentonite in step B1 are as follows: Step C1: Add calcium-based bentonite to deionized water, stir at 400-600 rpm for 2-3 hours. After stirring, let stand for 30-40 minutes, then pass through a 200-mesh sieve to obtain bentonite slurry. Step C2: Add 10wt% sodium carbonate aqueous solution to bentonite slurry, heat to 60-70℃, stir for 1.5-2.5h at 400-600rpm, and after stirring is complete, cool to 45-55℃ to obtain sodium-based bentonite slurry. Step C3: Add dodecyl dimethyl ammonium chloride to deionized water, heat to 60-70℃, stir for 8-12 minutes at 300-400 rpm, add sodium-based bentonite slurry, heat to 75-85℃, keep the temperature for 2-3 hours, after the reaction is complete, filter and dehydrate, wash with deionized water, vacuum dry, and pulverize to a particle size of 35-45 μm to obtain organic modified bentonite; The mass ratio of calcium-based bentonite to deionized water in step C1 is 0.1-0.12:1; The mass ratio of the sodium carbonate aqueous solution to the bentonite slurry in step C2 is 0.035-0.055:1; The mass ratio of dodecyl dimethyl ammonium chloride, deionized water and sodium bentonite slurry in step C3 is 0.25-0.35:0.2-0.3:1.

[0017] Preferably, the preparation steps of the nanocellulose colloidal aqueous suspension in step B1 are as follows: Add nanocellulose to deionized water, heat to 20-30℃, stir for 15-25 minutes at 200-400 rpm, place in a high-speed shear homogenizer, cool to 6-10℃, homogenize for 20-30 minutes at 8000-12000 rpm to obtain nanocellulose colloidal aqueous suspension. The mass ratio of nanocellulose to deionized water is 0.050-0.054:1.

[0018] Preferably, the preparation steps of the modified magnesium-aluminum hydrotalcite in step B2 are as follows: Step D1: Add magnesium aluminum hydrotalcite to deionized water, stir at 400-500 rpm for 6-8 minutes, increase the speed to 800-1000 rpm and stir for 20-30 minutes. Once stirring is complete, hydrotalcite slurry is obtained. Step D2: Add deionized water to anhydrous ethanol, stir evenly at 200-300 rpm, add glacial acetic acid, adjust the pH to 4.3-4.7, heat to 25-35℃, add silane coupling agent KH-550, stir for 25-35 min, and after stirring is complete, the hydrolysate is obtained. Step D3: Add the hydrolysate to the hydrotalcite slurry, heat to 60-70℃, rotate at 600-800 rpm, stir and react for 2-3 hours. After the reaction is complete, cool to 40-50℃, dehydrate under vacuum, wash with deionized water, dry under vacuum, and pulverize to obtain modified magnesium aluminum hydrotalcite with a particle size D90≤5μm. The mass ratio of magnesium aluminum hydrotalcite to deionized water in step D1 is 0.2-0.3:1; The mass ratio of anhydrous ethanol, deionized water and silane coupling agent KH-550 in step D2 is 1:0.06-0.1:0.008-0.012; The mass ratio of the hydrolysate to the hydrotalcite slurry in step D3 is 0.3-0.4:1.

[0019] A method for preparing a highly flame-retardant unsaturated polyester resin matrix composite material, the specific steps of which are as follows: Step S1: Add phosphorus-containing unsaturated polyester resin to the composite premix slurry, heat to 25-35℃, stir at 200-300 rpm for 20-30 minutes, add bisphenol A type epoxy resin and curing agent dicyandiamide micro powder, increase the speed to 300-400 rpm, stir for 15-25 minutes, then reduce the speed to 200-300 rpm, add release agent, stir for 8-12 minutes, after stirring is complete, vacuum degas to obtain the mixture; Step S2: Add the curing initiator benzoyl peroxide and calcium carbonate to the mixture, heat to 20-30℃, stir for 3-5 minutes at a speed of 150-250 rpm, and the composite material is obtained after stirring.

[0020] The mass ratio of phosphorus-containing unsaturated polyester resin, composite premixed slurry, bisphenol A type epoxy resin, curing agent dicyandiamide micro powder and release agent in step S1 is 90-110:160-190:8-12:0.5-1.5:3-5; The mass ratio of curing initiator, calcium carbonate and mixture in step S2 is 0.08-0.15:0.15-0.25:1.

[0021] The beneficial effects of this invention are: This invention provides a high flame-retardant unsaturated polyester resin matrix composite material and its preparation method. The invention involves compounding a specific modified phosphorus-containing resin with a multi-component composite premixed slurry system and supplementing it with a corresponding curing initiation system. The composite premixed slurry contains organic modified clay, nanocellulose colloidal aqueous suspension, and various flame-retardant and smoke-suppressing functional components. Compared with the prior art, this composite material effectively inhibits the sedimentation and stratification of solid fillers, improves crack resistance under low-temperature conditions, and achieves a synergistic improvement in flame retardancy and smoke suppression. It also exhibits good processing rheology and has broad application prospects, particularly suitable for fields such as mine roadway support, tunnel reinforcement, and building anchoring. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a bar chart of the limiting oxygen index in this invention; Figure 2 This is a bar chart of the maximum smoke density test in this invention; Figure 3 This is a bar chart of the bending strength test in this invention; Figure 4 This is a bar chart showing the impact strength tests at room temperature and low temperature in this invention. Figure 5 This is a bar chart showing the settlement rate in this invention; Figure 6 This is a bar chart showing the maximum instantaneous force value in this invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0025] Example 1: Preparation of an organically modified bentonite: S1: Add 100g of calcium-based bentonite to 1000g of deionized water, stir at 400rpm for 3 hours, let stand for 30 minutes after stirring, and pass through a 200-mesh sieve to obtain bentonite slurry. S2: Add 3.5g of 10wt% sodium carbonate aqueous solution to 100g of bentonite slurry, heat to 60℃, stir for 2.5h at 400rpm, and after stirring is complete, cool to 55℃ to obtain sodium-based bentonite slurry. S3: Add 25g of dodecyl dimethyl ammonium chloride to 20g of deionized water, heat to 60℃, stir for 12min at 300rpm, add 100g of sodium-based bentonite slurry, heat to 85℃, keep the temperature for 2h, after the reaction is complete, filter and dehydrate, wash with deionized water, vacuum dry, and pulverize to a particle size of 45μm to obtain organic modified bentonite.

[0026] Example 2: Preparation of an organically modified bentonite: S1: Add 110g of calcium-based bentonite to 1000g of deionized water, stir at 500rpm for 2.5h, let stand for 35min, and pass through a 200-mesh sieve to obtain bentonite slurry. S2: Add 4.5g of 10wt% sodium carbonate aqueous solution to 100g of bentonite slurry, heat to 65℃, stir for 2 hours at 500rpm, and after stirring is complete, cool to 50℃ to obtain sodium-based bentonite slurry. S3: Add 30g of dodecyl dimethyl ammonium chloride to 25g of deionized water, heat to 65℃, stir for 10min at 350rpm, add 100g of sodium-based bentonite slurry, heat to 80℃, keep the temperature for 2.5h, after the reaction is complete, filter and dehydrate, wash with deionized water, vacuum dry, and pulverize to a particle size of 40μm to obtain organic modified bentonite.

[0027] Example 3: Preparation of an organically modified bentonite: S1: Add 120g of calcium-based bentonite to 1000g of deionized water, stir at 600rpm for 2 hours, let stand for 40 minutes, and pass through a 200-mesh sieve to obtain bentonite slurry. S2: Add 5.5g of 10wt% sodium carbonate aqueous solution to 100g of bentonite slurry, heat to 70℃, stir for 1.5h at 600rpm, and after stirring is complete, cool to 45℃ to obtain sodium-based bentonite slurry. S3: Add 35g of dodecyl dimethyl ammonium chloride to 30g of deionized water, heat to 70℃, stir for 8min at 400rpm, add 100g of sodium-based bentonite slurry, heat to 75℃, keep the reaction at this temperature for 3h, after the reaction is complete, filter and dehydrate, wash with deionized water, vacuum dry, and pulverize to a particle size of 35μm to obtain organic modified bentonite.

[0028] Example 4: Preparation of a nanocellulose colloidal aqueous suspension: Add 50g of nanocellulose to 1000g of deionized water, heat to 20℃, stir for 25min at 200rpm, place in a high-speed shear homogenizer, cool to 10℃, homogenize at 8000rpm for 30min to obtain a nanocellulose colloidal aqueous suspension.

[0029] Example 5: Preparation of a nanocellulose colloidal aqueous suspension: Add 52g of nanocellulose to 1000g of deionized water, heat to 25℃, stir for 20min at 300rpm, place in a high-speed shear homogenizer, cool to 8℃, homogenize at 10000rpm for 25min to obtain a nanocellulose colloidal aqueous suspension.

[0030] Example 6: Preparation of a nanocellulose colloidal aqueous suspension: Add 54g of nanocellulose to 1000g of deionized water, heat to 30℃, stir for 15min at 400rpm, place in a high-speed shear homogenizer, cool to 6℃, homogenize at 12000rpm for 20min to obtain a nanocellulose colloidal aqueous suspension.

[0031] Example 7: Preparation of a modified magnesium aluminum hydrotalcite: S1: Add 200g of magnesium aluminum hydrotalcite to 1000g of deionized water, stir at 400rpm for 8min, increase the speed to 800rpm and stir for 30min. Once stirring is complete, the hydrotalcite slurry is obtained. S2: Add 6g of deionized water to 100g of anhydrous ethanol, stir evenly at 200rpm, add glacial acetic acid, adjust the pH to 4.3-4.7, heat to 35℃, add 0.8g of silane coupling agent KH-550, stir for 25min, and after stirring is complete, the hydrolysate is obtained. S3: Add 30g of hydrolysate to 100g of hydrotalcite slurry, heat to 60℃, stir at 800rpm for 2h until the reaction is complete, cool to 50℃, dehydrate under vacuum, wash with deionized water, dry under vacuum, and pulverize to obtain modified magnesium aluminum hydrotalcite with a particle size D90≤5μm.

[0032] Example 8: Preparation of a modified magnesium aluminum hydrotalcite: S1: Add 250g of magnesium aluminum hydrotalcite to 1000g of deionized water, stir at 450rpm for 7min, increase the speed to 900rpm and stir for 25min. Once stirring is complete, the hydrotalcite slurry is obtained. S2: Add 8g of deionized water to 100g of anhydrous ethanol, stir evenly at 250rpm, add glacial acetic acid, adjust the pH to 4.3-4.7, heat to 30℃, add 1g of silane coupling agent KH-550, stir for 30min, and after stirring is complete, the hydrolysate is obtained. S3: Add 35g of hydrolysate to 100g of hydrotalcite slurry, heat to 65℃, rotate at 700rpm, stir and react for 2.5h. After the reaction is complete, cool to 45℃, dehydrate under vacuum, wash with deionized water, dry under vacuum, and pulverize. The particle size D90≤5μm is obtained to obtain modified magnesium aluminum hydrotalcite.

[0033] Example 9: Preparation of a modified magnesium aluminum hydrotalcite: S1: Add 300g of magnesium aluminum hydrotalcite to 1000g of deionized water, stir at 500rpm for 6min, increase the speed to 1000rpm and stir for 20min. Once stirring is complete, the hydrotalcite slurry is obtained. S2: Add 10g of deionized water to 100g of anhydrous ethanol, stir evenly at 300rpm, add glacial acetic acid, adjust the pH to 4.3-4.7, heat to 25℃, add 1.2g of silane coupling agent KH-550, stir for 35min, and after stirring is complete, the hydrolysate is obtained. S3: Add 40g of hydrolysate to 100g of hydrotalcite slurry, heat to 70℃, stir at 600rpm for 3h until the reaction is complete, cool to 40℃, dehydrate under vacuum, wash with deionized water, dry under vacuum, and pulverize to obtain modified magnesium aluminum hydrotalcite with a particle size D90≤5μm.

[0034] Example 10: Preparation of a composite premixed pulp: S1: Add 10g of organically modified bentonite (Example 1) to 60g of styrene, stir at 300rpm for 25min, increase the speed to 800rpm, add 100g of nanocellulose colloidal aqueous suspension (Example 4), heat to 40℃, stir for 35min, and after stirring is complete, a pregel is obtained. S2: Add 60g of calcium lignosulfonate and 80g of ammonium polyphosphate to 100g of pregel, stir at 500rpm for 20min, then add 60g of melamine, 80g of modified magnesium aluminum hydrotalcite (Example 7), 150g of slag powder and 400g of aluminum hydroxide in sequence, stir for 20min, and the mixture is complete. Reduce the pressure to -0.09MPa, increase the speed to 1000rpm, raise the temperature to 50℃, and shear for 40min. After shearing is complete, restore the pressure to normal to obtain the composite premixed slurry.

[0035] Example 11: Preparation of a composite premixed pulp: S1: Add 20g of organically modified bentonite (Example 2) to 90g of styrene, stir at 400rpm for 20min, increase the speed to 900rpm, add 100g of nanocellulose colloidal aqueous suspension (Example 5), heat to 35℃, stir for 40min, and after stirring is complete, a pregel is obtained; S2: Add 90g of calcium lignosulfonate and 120g of ammonium polyphosphate to 100g of pregel, stir at 550rpm for 15min, then add 75g of melamine, 100g of modified magnesium aluminum hydrotalcite (Example 8), 200g of slag powder and 500g of aluminum hydroxide in sequence, stir for 25min, and the mixture is complete. Reduce the pressure to -0.085MPa, increase the speed to 1100rpm, raise the temperature to 45℃, and shear for 50min. After shearing is complete, restore the pressure to normal to obtain the composite premixed slurry.

[0036] Example 12: Preparation of a composite premixed pulp: S1: Add 30g of organically modified bentonite (Example 3) to 120g of styrene, stir at 500rpm for 15min, increase the speed to 1000rpm, add 100g of nanocellulose colloidal aqueous suspension (Example 6), heat to 30℃, stir for 45min, and after stirring is complete, a pregel is obtained. S2: Add 120g of calcium lignosulfonate and 160g of ammonium polyphosphate to 100g of pregel, stir at 600rpm for 10min, then add 90g of melamine, 120g of modified magnesium aluminum hydrotalcite (Example 9), 250g of slag powder and 600g of aluminum hydroxide in sequence, stir for 30min, and the mixture is complete. Reduce the pressure to -0.08MPa, increase the speed to 1200rpm, raise the temperature to 40℃, and shear for 60min. After shearing is complete, restore the pressure to normal to obtain the composite premixed slurry.

[0037] Example 13: Preparation of a release agent: S1: Add 200g of triethyl phosphate to a beaker, heat to 70℃, stir at 30rpm for 30min, and after stirring is complete, hot triethyl phosphate solution is obtained. S2: Add 40g of calcium stearate to a melting tank, heat to 150℃, rotate at 60rpm, hold for 30min, heating rate 8℃ / min, increase rotation speed to 800rpm, add 100g of hot triethyl phosphate solution, stir for 25min, after stirring is complete, place in a spray granulation tower, nozzle pressure 0.3MPa, inlet air temperature 5℃, outlet air temperature 10℃, sieve to obtain release agent.

[0038] Example 14: Preparation of a release agent: S1: Add 200g of triethyl phosphate to a beaker, heat to 60℃, stir at 50rpm for 20min, and after stirring is complete, hot triethyl phosphate solution is obtained. S2: Add 45g of calcium stearate to a melting tank, heat to 160℃, rotate at 40rpm, hold for 40min, heating rate 6℃ / min, increase rotation speed to 1000rpm, add 100g of hot triethyl phosphate solution, stir for 15min, after stirring is complete, place in a spray granulation tower, nozzle pressure 0.5MPa, inlet air temperature 0℃, outlet air temperature 15℃, sieve to obtain release agent.

[0039] Example 15: Preparation of a release agent: S1: Add 200g of triethyl phosphate to a beaker, heat to 65℃, stir at 40rpm for 25min, and after stirring is complete, hot triethyl phosphate solution is obtained. S2: Add 50g of calcium stearate to a melting tank, heat to 155℃, rotate at 50rpm, hold for 35min, heating rate 7℃ / min, increase rotation speed to 900rpm, add 100g of hot triethyl phosphate solution, stir for 20min, after stirring is complete, place in a spray granulation tower, nozzle pressure 0.4MPa, inlet air temperature 3℃, outlet air temperature 13℃, sieve to obtain release agent.

[0040] Example 16: Preparation of a phosphorus-containing unsaturated polyester resin: Under a nitrogen atmosphere, 30g of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, 55g of phthalic anhydride, and 100g of maleic anhydride were added to 72g of propylene glycol. The mixture was heated to 140℃, stirred at 100rpm for 1h, and then heated to 200℃ at a rate of 10℃ / h for 5h. After the reaction was complete, the mixture was cooled to 160℃, and 0.06g of hydroquinone, an inhibitor of polymerization, was added. The mixture was then cooled to 100℃, and 85g of styrene was added. The stirring speed was increased to 100rpm for 60min. After stirring was complete, the mixture was cooled to 20℃ to obtain a phosphorus-containing unsaturated polyester resin.

[0041] Example 17: Preparation of a phosphorus-containing unsaturated polyester resin: Under a nitrogen atmosphere, 35g of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, 60g of phthalic anhydride, and 100g of maleic anhydride were added to 82g of propylene glycol. The mixture was heated to 145℃, stirred at 90 rpm for 1.5h, then heated to 195℃ at a rate of 13℃ / h and held for 4h. After the reaction was complete, the mixture was cooled to 165℃, and 0.09g of hydroquinone, an inhibitor of polymerization, was added. The mixture was then cooled to 95℃, and 90g of styrene was added. The stirring speed was increased to 130 rpm and the mixture was stirred for 50min. After stirring was complete, the mixture was cooled to 25℃ to obtain a phosphorus-containing unsaturated polyester resin.

[0042] Example 18: Preparation of a phosphorus-containing unsaturated polyester resin: Under a nitrogen atmosphere, 40g of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, 65g of phthalic anhydride, and 100g of maleic anhydride were added to 92g of propylene glycol. The mixture was heated to 150°C and stirred at 80 rpm for 2 hours. The temperature was then increased to 190°C at a rate of 15°C / h and maintained for 3 hours. After the reaction was complete, the temperature was lowered to 170°C, and 0.12g of hydroquinone, an inhibitor of polymerization, was added. The temperature was then lowered to 90°C, and 95g of styrene was added. The stirring speed was increased to 150 rpm and the mixture was stirred for 40 minutes. After stirring was complete, the temperature was lowered to 30°C to obtain a phosphorus-containing unsaturated polyester resin.

[0043] Example 19: A method for preparing a highly flame-retardant unsaturated polyester resin matrix composite material: S1: Add 90g of phosphorus-containing unsaturated polyester resin (Example 16) to 160g of composite premix slurry (Example 10), heat to 25°C, stir at 300 rpm for 20 min, add 8g of bisphenol A type epoxy resin and 0.5g of curing agent dicyandiamide powder, increase the speed to 400 rpm, stir for 15 min, then reduce the speed to 300 rpm, add 3g of release agent (Example 13), stir for 8 min, after stirring is complete, vacuum degas to obtain the mixture; S2: Add 8g of curing initiator benzoyl peroxide and 15g of calcium carbonate to 100g of the mixture, heat to 20℃, stir for 5 minutes at 150rpm, and the composite material is obtained after stirring.

[0044] Example 20: A method for preparing a high flame-retardant unsaturated polyester resin matrix composite material: S1: Add 100g of phosphorus-containing unsaturated polyester resin (Example 17) to 175g of composite premix slurry (Example 11), heat to 30°C, stir at 250 rpm for 25 min, add 10g of bisphenol A type epoxy resin and 1g of curing agent dicyandiamide micro powder, increase the speed to 350 rpm, stir for 20 min, then reduce the speed to 250 rpm, add 4g of release agent (Example 14), stir for 10 min, after stirring is completed, vacuum degassing to obtain the mixture; S2: Add 11.5g of curing initiator benzoyl peroxide and 20g of calcium carbonate to 100g of mixture, heat to 25℃, stir for 4min at 200rpm, and the composite material is obtained after stirring is completed.

[0045] Example 21: A method for preparing a high flame-retardant unsaturated polyester resin matrix composite material: S1: Add 110g of phosphorus-containing unsaturated polyester resin (Example 18) to 190g of composite premix slurry (Example 12), heat to 35°C, stir at 200 rpm for 30 min, add 12g of bisphenol A epoxy resin and 1.5g of curing agent dicyandiamide powder, increase the speed to 300 rpm, stir for 25 min, then reduce the speed to 200 rpm, add 5g of release agent (Example 15), stir for 12 min, after stirring is complete, vacuum degas to obtain the mixture; S2: Add 15g of curing initiator benzoyl peroxide and 25g of calcium carbonate to 100g of the mixture, heat to 30℃, stir for 3 minutes at 250 rpm, and the composite material is obtained after stirring is completed.

[0046] Example 22: A method for preparing a high flame-retardant unsaturated polyester resin matrix composite material: S1: Add 90g of phosphorus-containing unsaturated polyester resin (Example 16) to 160g of composite premix slurry (Example 10), heat to 25°C, stir at 300 rpm for 20 min, add 8g of bisphenol A epoxy resin, 2g of γ-methacryloyloxypropyltrimethoxysilane and 0.5g of curing agent dicyandiamide powder, increase the speed to 400 rpm, stir for 15 min, then reduce the speed to 300 rpm, add 3g of release agent (Example 13) and 5g of active silica powder, stir for 8 min, after stirring is complete, vacuum degas to obtain the mixture; S2: Add 8g of curing initiator benzoyl peroxide and 15g of calcium carbonate to 100g of the mixture, heat to 20℃, stir for 5 minutes at 150rpm, and the composite material is obtained after stirring.

[0047] Comparative Example 1: Compared with Example 19, this comparative example did not add nanocellulose colloidal aqueous suspension during the preparation of composite premixed slurry. All other steps and parameters were the same, and will not be repeated here. The final composite material was obtained.

[0048] Comparative Example 2: Compared with Example 19, this comparative example only replaces "phosphorus-containing unsaturated polyester resin" with "196# resin". All other steps and parameters are the same, and will not be repeated here. The final composite material is obtained.

[0049] Comparative Example 3: Compared with Example 19, this comparative example did not add modified magnesium aluminum hydrotalcite during the preparation of the composite premixed slurry. Instead, it used an equal mass of aluminum hydroxide. All other steps and parameters were the same, and will not be repeated here. The final composite material was obtained.

[0050] Comparative Example 4: This comparative example differs from Example 19 only in that the "release agent" is replaced with "calcium stearate powder". All other steps and parameters are the same, and will not be repeated here. The final composite material is obtained.

[0051] Comparative Example 5: Compared with Example 19, this comparative example only replaces "composite premixed slurry" with "a mixture of aluminum hydroxide and ammonium polyphosphate". The aluminum hydroxide and ammonium polyphosphate are mixed at a mass ratio of 5:1. All other steps and parameters are the same, and will not be repeated in this comparative example. The final composite material is obtained.

[0052] Performance testing: Acid value determination of phosphorus-containing unsaturated polyester resin 1. During the 190-200℃ incubation reaction of Examples 16-18, take 1.0g of sample from the reactor every 1 hour, cool to room temperature, add to 50mL of a mixed solvent of toluene and anhydrous ethanol (toluene to anhydrous ethanol volume ratio of 1:1), heat to 40-50℃, shake to dissolve, add 2-3 drops of phenolphthalein indicator, and then add 0.1mol / L potassium hydroxide standard solution for titration until the solution turns slightly red and does not fade within 30s. Record the volume of KOH consumed, V (mL). At the same time, perform a blank experiment and record the blank consumption volume, V0 (mL). 2. Acid value (AV) calculation formula:

[0053] In the formula: C is the concentration of KOH standard solution (mol / L), m is the sample mass (g), and 56.1 is the molar mass of KOH; 3. When the difference in acid value between two consecutive samples (interval ≥ 30 min) is ≤ 1.0 mg / g, and the acid value drops to the range of 28-35 mg KOH / g, the endpoint of the polycondensation reaction is determined to have been reached.

[0054] Table 1. Acid value determination results

[0055] Flame retardancy test: Limiting oxygen index (reference) Figure 1 ) The JF-3 oxygen index analyzer was used in accordance with the GB / T 2406.2-2009 testing standard. The composite materials of Examples 19-22 and Comparative Examples 1-5 were respectively cut into 120mm×10mm×4mm samples, tested using an oxygen index meter, and the final oxygen index value (LOI) was recorded. Three samples were tested repeatedly. Vertical flammability test Referring to the GB / T 2408-2021 testing standard, the CZF-3 type horizontal and vertical combustion tester was used; 1. Take the composite materials of Examples 19-22 and Comparative Examples 1-5 respectively, cut them into 125mm×13mm×3mm samples, and test them using a horizontal and vertical combustion tester. Repeat the test on 5 samples. 2. Place the sample perpendicular to the fixture, with a layer of degreased cotton at the bottom. Ignite the bottom of the sample and record the first flaming burning time t1. After the flame goes out, ignite it again and record the second flaming burning time t2 and the second flameless burning time t3. At the same time, record whether the burning drips ignite the degreased cotton below.

[0056] 3. Criteria for determining flame retardancy rating

[0057] Maximum smoke density test: (reference) Figure 2 ) The JCY-2 smoke density tester was used in accordance with the test procedures of GB / T 8323.2-2008. 1. Take the composite materials from Examples 19-22 and Comparative Examples 1-5 respectively, cut them into 75mm×75mm×3mm samples, place them on a stainless steel sample holder with the aluminum foil-covered side facing down, and use a smoke density meter with an irradiation heat flux of 25kW / m². 2 The flame was applied to the sample surface for 20 minutes, and the transmittance T (%) was recorded. 2. Calculate the smoke density (Ds):

[0058] In the formula: 132: Proportionality constant; T: Light transmittance, % 10: Offset.

[0059] Table 2 Flame retardancy test results of the examples and comparative examples

[0060] Mechanical property testing Bending strength test: (Reference) Figure 3 ) Referring to the GB / T 9341-2008 testing standard, the CMT5504 universal testing machine was used; 1. Take the composite materials of Examples 19-22 and Comparative Examples 1-5 respectively, and cut them into 80mm×10mm×4mm samples; 2. Place the specimen on the universal testing machine with a span of 64 mm, a loading speed of 2 mm / min, and a preload force of 5 N until the specimen breaks or the stress drops to less than 50% of its maximum value. Record the maximum bending force F. max (N), repeat 3 times; 3. Calculate the bending strength σf:

[0061] in: σf: Bending strength, MPa; F max Maximum bending force, N; L: Spacing, 64mm; b: Sample width, 10mm; h: Sample thickness, 4 mm; Impact strength test of simply supported beam: (Reference) Figure 4 ) Referring to the GB / T 1043.1-2008 testing standard, the XJ-50D type simply supported beam impact testing machine was used; 1. Take the composite materials of Examples 19-22 and Comparative Examples 1-5 respectively, and cut them into 80mm×10mm×4mm samples; 2. Place the specimen in the impact testing machine with a span of 62mm, raise the pendulum to the specified height, and use an energy of 7.5J. Let the pendulum fall freely to impact the specimen and record the energy W absorbed when the specimen breaks. Repeat the test 10 times. 3. Calculate the impact strength a cU :

[0062] in: a cU Impact strength of a simply supported beam without notches, kJ / m 2 ; W: Energy absorbed during sample fracture, in J; b: Sample width, 10mm; h: Sample thickness, 4 mm; Table 3. Mechanical property test results of the examples and comparative examples

[0063] Anti-settlement performance test: (Reference) Figure 5 ) A constant temperature and humidity chamber is used; 1. Take 80 mL of each of the mixtures from Examples 19-22 and Comparative Examples 1-5, pour them into a 100 mL graduated cylinder, record the initial height as H0 (mm), place them in a constant temperature and humidity chamber, heat to 23±2℃, let stand for 48h±0.5h, and then take them out. 2. Observe whether the mixture shows stratification, and use a ruler to measure the height H of the bottom settling layer. s (mm); 3. Calculate the settlement rate S (%):

[0064] Low-temperature crack resistance test: (Reference) Figure 4 ) 1. Take the composite materials of Examples 19-22 and Comparative Examples 1-5 respectively, cut them into 80mm×10mm×4mm samples, put them in a constant temperature chamber, cool them to -20℃±2℃, and continue for 48±1h, then take them out. 2. Observe and record whether there are visible cracks and whether whitening occurs; Judgment criteria: No cracks, no whitening: qualified; Minor cracks or localized whitening: Record the location and extent; Obvious through-cracks: Unacceptable, poor low-temperature crack resistance; 3. Conduct tests according to GB / T 1043.1-2008 standard and calculate the low-temperature impact strength α. -20 (kJ / m 2 Repeat this process at least three times and take the average value. 4. Calculate the impact strength retention rate R (%):

[0065] Table 4 Performance test results of the examples and comparative examples

[0066] Demolding performance test: (Reference) Figure 6 ) 1. Cool the molds containing the cured samples of Examples 19-22 and Comparative Examples 1-5 to room temperature respectively. Remove the mold side plates to allow the ejection mechanism to contact the back of the sample. Use the push rod of a tension gauge to push the sample and record the maximum instantaneous force value when the sample just moves, denoted as F. d (N), and record whether the sample breaks, repeat 3 times; 2. Qualitative rating: Excellent: Smooth and intact surface, no mold residue, F d ≤100N; Good: Slightly roughened surface, small amount of powdery residue from the mold, 100 < F d ≤150N; Poor: Surface shows obvious adhesion and defects, with a lot of mold residue. d >150N; Table 5. Test results of demolding performance of the examples and comparative examples

[0067] Data Analysis: As can be seen from Tables 2-5, the high flame retardant unsaturated polyester resin matrix composite material prepared by the present invention has better flame retardancy, mechanical properties, low temperature crack resistance and demolding performance. In contrast, Comparative Example 1, due to the absence of nanocellulose colloidal aqueous suspension in the preparation of the composite premixed slurry, resulted in incomplete construction of the organic and inorganic network structure, inability of the flame retardant and filler to be uniformly suspended, increased sedimentation rate, decreased LOI, and Ds. max The temperature rose to 112°C, but the low-temperature impact strength was only 7.2 kJ / m³. 2Furthermore, the surface turns white and the bending strength drops to 71.0 MPa. This is because the high aspect ratio of nanocellulose is an important supporting structure for the construction of organic and inorganic network structures. Therefore, it cannot support the particles and inhibit particle sedimentation. At the same time, it loses its toughening and catalytic carbonization synergistic effect, and the carbon layer becomes less dense. In addition, the lack of hydrogen bond bridging microcracks at low temperature leads to debonding and whitening, and the mechanical reinforcement effect also disappears. Comparative Example 2, due to the replacement of phosphorus-containing unsaturated polyester resin with ordinary 196# resin, resulted in a lack of chemically bonded phosphorus flame-retardant elements in the resin matrix, leading to a severe deterioration in flame-retardant performance. The LOI was only 22.8%, V-2 rating, and Ds max The impact strength was as high as 182, but dropped to 11.2 kJ / m. 2 At low temperatures, fine cracks appeared, and the settling rate was still as high as 10.2%. The reason is that phosphorus in the phosphorus-containing resin is chemically bonded to the polyester main chain. During combustion, it decomposes to generate phosphate esters, which promotes the dehydration of the matrix into carbon. At the same time, it releases ·PO free radicals in the gas phase to inhibit combustion. However, ordinary 196# resin does not have this chemically bonded flame-retardant structure. It relies solely on additive flame retardants, which drastically reduces the flame-retardant efficiency. The LOI is close to the threshold of combustible materials. In addition, the polarity of 196# resin and composite premixed slurry is mismatched and the compatibility is poor, forming a large number of interface defects, which induces low-temperature cracks and a decrease in toughness. Furthermore, the deterioration of compatibility also weakens the system's ability to homogenize and stabilize the filler, resulting in a still high settling rate. Comparative Example 3, due to the absence of modified magnesium aluminum hydrotalcite and its substitution with an equal mass of ordinary aluminum hydroxide, resulted in a decrease in LOI to 27.6%, and Ds max The temperature rose to 102, but the low-temperature impact strength was only 8.5 kJ / m. 2 The product exhibits localized whitening and a flexural strength of 80.4 MPa. This is because ammonium polyphosphate can catalyze the formation of a stable carbon frame in the modified hydrotalcite layer, while melamine foaming and expansion can generate a high-strength expanded carbon layer. The lack of modified hydrotalcite makes it difficult to construct a stable expanded carbon layer, resulting in insufficient flame retardant and smoke suppression effects. At the same time, ordinary aluminum hydroxide is not surface-modified, resulting in weak interfacial bonding with the matrix and becoming a stress concentration point. This leads to debonding and whitening at low temperatures and a significant reduction in impact toughness. In addition, the decreased interfacial load transfer efficiency also drags down the flexural strength. Comparative Example 4, by simply replacing the release agent with ordinary calcium stearate powder and not using the triethyl phosphate composite spray granulation release agent of this invention, resulted in a significant decrease in release performance. The release force reached 145N, with a poor rating, and there was excessive surface adhesion, mold residue, and the low-temperature impact strength dropped to 8.6kJ / m. 2The sample showed slight whitening in some areas, and the sedimentation rate increased slightly to 5.1%. This was because the calcium stearate powder was unevenly dispersed and severely agglomerated, making it impossible to form a complete and uniform lubricating film at the mold interface, resulting in demolding failure. At the same time, the agglomerated particles caused local stress concentration at low temperatures, which promoted the initiation of microcracks and whitening, and deteriorated the toughness. In addition, the uneven powder failed to provide effective internal lubrication, which weakened the inhibition of filler sedimentation, and the sedimentation rate was higher than that of the example. Comparative Example 5, by replacing the entire composite premixed slurry with a simple mixture of aluminum hydroxide and ammonium polyphosphate (a mass ratio of aluminum hydroxide to ammonium polyphosphate of 5:1), resulted in severe filler sedimentation, extremely poor flame retardant properties, and a comprehensive deterioration of mechanical properties. Significant through-cracks appeared at low temperatures. This was because the organic-inorganic network suspension carrier constructed by organic modified bentonite and nanocellulose, as well as the multi-component synergistic flame retardant system of melamine, slag powder, and modified hydrotalcite, were completely lost. A solid expanded char layer could not be formed, and the filler rapidly delaminated. At the same time, the mechanisms of nanocellulose toughening, hydrotalcite interface enhancement, and slag powder dense filling were lacking. Low-temperature stress directly triggered macroscopic through-cracks. In addition, all performance indicators of Comparative Example 5 deteriorated comprehensively, which fully demonstrates the indispensable synergistic effect of each component in the composite premixed slurry. Example 22, based on Example 19, additionally added γ-methacryloxypropyltrimethoxysilane and activated silica powder. The silane coupling agent reacts at one end with the hydroxyl groups on the surface of inorganic fillers such as calcium carbonate, aluminum hydroxide, and slag powder, and at the other end with the unsaturated polyester resin and epoxy resin matrix, thereby significantly enhancing the interfacial bonding force between the filler and the resin matrix. Furthermore, the activated silica powder, as a rigid micro / nano filler, can further fill network pores and increase packing density. Simultaneously, the low coefficient of thermal expansion of the silica powder itself helps improve low-temperature dimensional stability. In addition, the synergistic effect of both ingredients allows Example 22 to maintain high flame retardancy and low smoke density while increasing flexural strength by approximately 3.7% compared to Example 19 (impact strength increased by approximately 8.9%, low-temperature impact strength increased by approximately 12.1%, sedimentation rate further reduced to 3.1%, and demolding force reduced to 75 N).

[0068] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

[0069] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A high flame-retardant unsaturated polyester resin matrix composite material, characterized in that, It is composed of the following components in parts by weight: 90-110 parts of phosphorus-containing unsaturated polyester resin, 8-12 parts of bisphenol A type epoxy resin, 160-190 parts of composite premix, 0.5-1.5 parts of curing agent dicyandiamide micro powder, 3-5 parts of release agent, 8-15 parts of curing initiator benzoyl peroxide, and 15-25 parts of calcium carbonate. The phosphorus-containing unsaturated polyester resin is generated by reacting propylene glycol, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, phthalic anhydride and maleic anhydride.

2. The high flame-retardant unsaturated polyester resin matrix composite material according to claim 1, characterized in that, The preparation steps of the phosphorus-containing unsaturated polyester resin are as follows: Under a nitrogen atmosphere, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, phthalic anhydride, and maleic anhydride are added to propylene glycol. The mixture is heated to 140-150°C, stirred at 80-100 rpm for 1-2 hours, then heated to 190-200°C at a rate of 10-15°C / h and held for 3-5 hours. After the reaction is complete, the mixture is cooled to 160-170°C, and hydroquinone, an inhibitor of polymerization, is added. The mixture is then cooled to 90-100°C, and styrene is added. The stirring speed is increased to 100-150 rpm, and the mixture is stirred for 40-60 minutes. After stirring is complete, the mixture is cooled to 20-30°C to obtain a phosphorus-containing unsaturated polyester resin.

3. The high flame-retardant unsaturated polyester resin matrix composite material according to claim 2, characterized in that, The mass ratio of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, phthalic anhydride, maleic anhydride, propylene glycol, polymerization inhibitor, and styrene is 0.3-0.4:0.55-0.65:1:0.72-0.92:0.0006-0.0012:0.85-0.

95.

4. The high flame-retardant unsaturated polyester resin matrix composite material according to claim 1, characterized in that, The preparation steps of the release agent are as follows: Step A1: Add triethyl phosphate to a beaker, heat to 60-70℃, stir at 30-50 rpm for 20-30 minutes, and after stirring is complete, hot triethyl phosphate solution is obtained; Step A2: Add calcium stearate to a melting tank, heat to 150-160℃, rotate at 40-60 rpm, hold for 30-40 min, heating rate 6-8℃ / min, increase rotation speed to 800-1000 rpm, add hot triethyl phosphate solution, stir for 15-25 min, after stirring is complete, place in a spray granulation tower, nozzle pressure 0.3-0.5MPa, inlet air temperature 0-5℃, outlet air temperature 10-15℃, sieve to obtain release agent.

5. The high flame-retardant unsaturated polyester resin matrix composite material according to claim 4, characterized in that, The mass ratio of calcium stearate to hot triethyl phosphate solution in step A2 is 0.4-0.5:

1.

6. The high flame-retardant unsaturated polyester resin matrix composite material according to claim 1, characterized in that, The preparation steps of the composite premixed pulp are as follows: Step B1: Add the organically modified bentonite to styrene, stir at 300-500 rpm for 15-25 min, increase the speed to 800-1000 rpm, add the nanocellulose colloidal aqueous suspension, heat to 30-40℃, stir for 35-45 min, and after stirring is complete, a pregel is obtained. Step B2: Add calcium lignosulfonate and ammonium polyphosphate to the pregel, stir at 500-600 rpm for 10-20 min, then add melamine, modified magnesium aluminum hydrotalcite, slag powder and aluminum hydroxide in sequence, stir for 20-30 min, and when the mixture is complete, reduce the pressure to -0.08 to -0.09 MPa, increase the speed to 1000-1200 rpm, raise the temperature to 40-50℃, and shear for 40-60 min. When the shearing is complete, restore the pressure to normal to obtain the composite premixed slurry. By constructing an organic-inorganic network structure with organically modified bentonite and nanocellulose, and using it as a carrier, multiple flame-retardant synergistic components are uniformly suspended in the resin matrix, thus solving the problems of easy sedimentation, stratification, and poor processing rheology of traditional high-filler flame-retardant systems. At the same time, the phosphorus-nitrogen-metal hydroxide intumescent flame-retardant system in this premixed slurry rapidly forms a dense char layer during combustion, with significant smoke suppression and anti-dripping effects. Furthermore, due to the improved interfacial compatibility between the flame retardant and the matrix, the low-temperature crack resistance of the cured product is greatly improved, making it particularly suitable for harsh environments such as mine tunnels. The mass ratio of the organically modified bentonite, styrene, and nanocellulose colloidal aqueous suspension is 0.1-0.3:0.6-1.2:

1. The mass ratio of calcium lignosulfonate, ammonium polyphosphate, pregel, melamine, modified magnesium aluminum hydrotalcite, slag powder and aluminum hydroxide is 0.6-1.2:0.8-1.6:1:0.6-0.9:0.8-1.2:1.5-2.5:4-6.

7. The high flame-retardant unsaturated polyester resin matrix composite material according to claim 6, characterized in that, The preparation steps of the organically modified bentonite described in step B1 are as follows: Step C1: Add calcium-based bentonite to deionized water, stir at 400-600 rpm for 2-3 hours. After stirring, let stand for 30-40 minutes, then pass through a 200-mesh sieve to obtain bentonite slurry. Step C2: Add 10wt% sodium carbonate aqueous solution to bentonite slurry, heat to 60-70℃, stir for 1.5-2.5h at 400-600rpm, and after stirring is complete, cool to 45-55℃ to obtain sodium-based bentonite slurry. Step C3: Add dodecyl dimethyl ammonium chloride to deionized water, heat to 60-70℃, stir for 8-12 minutes at 300-400 rpm, add sodium-based bentonite slurry, heat to 75-85℃, keep the temperature for 2-3 hours, after the reaction is complete, filter and dehydrate, wash with deionized water, vacuum dry, and pulverize to a particle size of 35-45 μm to obtain organic modified bentonite; The mass ratio of calcium-based bentonite to deionized water in step C1 is 0.1-0.12:1; The mass ratio of the sodium carbonate aqueous solution to the bentonite slurry in step C2 is 0.035-0.055:1; The mass ratio of dodecyl dimethyl ammonium chloride, deionized water and sodium bentonite slurry in step C3 is 0.25-0.35:0.2-0.3:

1.

8. The high flame-retardant unsaturated polyester resin matrix composite material according to claim 6, characterized in that, The preparation steps of the nanocellulose colloidal aqueous suspension in step B1 are as follows: Add nanocellulose to deionized water, heat to 20-30℃, stir for 15-25 minutes at 200-400 rpm, place in a high-speed shear homogenizer, cool to 6-10℃, homogenize for 20-30 minutes at 8000-12000 rpm to obtain nanocellulose colloidal aqueous suspension. The mass ratio of nanocellulose to deionized water is 0.050-0.054:

1.

9. The high flame-retardant unsaturated polyester resin matrix composite material according to claim 6, characterized in that, The preparation steps of the modified magnesium aluminum hydrotalcite described in step B2 are as follows: Step D1: Add magnesium aluminum hydrotalcite to deionized water, stir at 400-500 rpm for 6-8 minutes, increase the speed to 800-1000 rpm and stir for 20-30 minutes. Once stirring is complete, hydrotalcite slurry is obtained. Step D2: Add deionized water to anhydrous ethanol, stir evenly at 200-300 rpm, add glacial acetic acid, adjust the pH to 4.3-4.7, heat to 25-35℃, add silane coupling agent KH-550, stir for 25-35 min, and after stirring is complete, the hydrolysate is obtained. Step D3: Add the hydrolysate to the hydrotalcite slurry, heat to 60-70℃, rotate at 600-800 rpm, stir and react for 2-3 hours. After the reaction is complete, cool to 40-50℃, dehydrate under vacuum, wash with deionized water, dry under vacuum, and pulverize to obtain modified magnesium aluminum hydrotalcite with a particle size D90≤5μm. The mass ratio of magnesium aluminum hydrotalcite to deionized water in step D1 is 0.2-0.3:1; The mass ratio of anhydrous ethanol, deionized water and silane coupling agent KH-550 in step D2 is 1:0.06-0.1:0.008-0.012; The mass ratio of the hydrolysate to the hydrotalcite slurry in step D3 is 0.3-0.4:

1.

10. A method for preparing a high flame-retardant unsaturated polyester resin matrix composite material according to any one of claims 1-9, characterized in that, The specific steps of the preparation method are as follows: Step S1: Add phosphorus-containing unsaturated polyester resin to the composite premix slurry, heat to 25-35℃, stir at 200-300 rpm for 20-30 minutes, add bisphenol A type epoxy resin and curing agent dicyandiamide micro powder, increase the speed to 300-400 rpm, stir for 15-25 minutes, then reduce the speed to 200-300 rpm, add release agent, stir for 8-12 minutes, after stirring is complete, vacuum degas to obtain the mixture; Step S2: Add the curing initiator benzoyl peroxide and calcium carbonate to the mixture, heat to 20-30℃, stir for 3-5 minutes at a speed of 150-250 rpm, and after stirring is complete, the composite material is obtained; The mass ratio of phosphorus-containing unsaturated polyester resin, composite premixed slurry, bisphenol A type epoxy resin, curing agent dicyandiamide micro powder and release agent in step S1 is 90-110:160-190:8-12:0.5-1.5:3-5; The mass ratio of curing initiator, calcium carbonate and mixture in step S2 is 0.08-0.15:0.15-0.25:1.

Images