High-strength flame-retardant sound-insulation heat-insulation composite material and preparation method thereof

Abstract

The invention discloses a high-strength flame-retardant sound-insulation heat-insulation composite material and a preparation method thereof, and belongs to the technical field of high polymer materials. The high-strength flame-retardant sound-insulation heat-insulation composite material comprises the following raw materials in parts by weight: 40-60 parts of polyurethane resin, 10-15 parts of polyvinylpyrrolidone, 10-15 parts of ceramic hollow microspheres, 6-10 parts of ceramic fibers, 5-8 parts of a binder, 1-3 parts of a modified flame retardant and 2-4 parts of an anti-aging agent. The high-strength flame-retardant sound-insulation heat-insulation composite material prepared by the invention has excellent heat insulation, sound insulation, tensile property and flame-retardant property.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly relates to a high-strength flame-retardant sound-insulating and heat-insulating composite material and a preparation method thereof. Background Art

[0002] In many fields today, such as construction, aerospace, and automobile manufacturing, the comprehensive performance requirements for materials are becoming increasingly stringent, especially composite materials that need to have high strength, flame retardancy, sound insulation, and heat insulation properties. In the construction field, with the acceleration of the urbanization process, high-rise buildings and intensive residential buildings are emerging continuously, and the performance requirements for composite materials are also increasing continuously.

[0003] However, existing composite materials have many disadvantages when meeting various performance requirements. On the one hand, although many traditional composite materials can meet certain strength requirements, their flame retardant performance is poor. In the face of a fire, they are easy to burn and have poor heat insulation and sound insulation effects. They not only cannot win time for people to escape, but also exacerbate the spread of the fire and the transmission of noise, posing a great threat to people's life safety and living comfort. On the other hand, some composite materials have high strength, but poor sound insulation and heat insulation effects, and cannot effectively isolate external noise and heat, and will transmit external high temperature and noise into the internal space, affecting the use experience. In addition, when some composite materials take into account flame retardancy, sound insulation, and heat insulation properties, their strength will drop significantly, making it difficult to meet the mechanical performance requirements in actual applications, resulting in an imbalance in the overall performance of the material and being unable to operate stably under complex working conditions.

[0004] Chinese Patent No. CN113563771A discloses an anti-cracking sound-insulating composite material and a preparation method thereof. The anti-cracking sound-insulating composite material comprises the following raw materials in parts by weight: 5-20% of hollow glass microspheres, 0.2-0.5% of a modified polycarboxylate water reducer; the vacuum degree of the hollow glass microspheres is 0.2 g / cm 3 , and the particle size is 80 μm; the modified polycarboxylate water reducer is prepared by reacting polycarboxylate water reducer with a silane coupling agent containing an amino group at the end in a weight ratio of 1:2-5 under the action of an organic weak base; the anti-cracking sound-insulating composite material prepared by this patent has excellent sound insulation, heat insulation, strong adhesion, anti-ultraviolet, and is not easy to crack and fall off, etc., but the flame retardant effect of this composite material is poor. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a high-strength flame-retardant sound-insulating and heat-insulating composite material and a preparation method thereof.

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions: A high-strength flame-retardant sound-insulating and heat-insulating composite material, comprising the following raw materials in parts by weight: 40 - 60 parts of polyurethane resin, 10 - 15 parts of polyvinylpyrrolidone, 10 - 15 parts of ceramic hollow microspheres, 6 - 10 parts of ceramic fibers, 5 - 8 parts of binder, 1 - 3 parts of modified flame retardant, 2 - 4 parts of antioxidant; The modified flame retardant is prepared by the following method: S1: Pentaerythritol reacts with 3,6 - dimethyl - 1,4 - dioxane - 2,5 - dione under the catalysis of stannous octoate to form a four - armed star - shaped compound; S2: 2 - Piperazinecarboxylic acid reacts with diphenylphosphinous chloride to form a nitrogen - phosphorus compound; S3: The four - armed star - shaped compound reacts with the nitrogen - phosphorus compound under the action of p - toluenesulfonic acid to form a nitrogen - phosphorus - modified four - armed star - shaped compound; S4: The nitrogen - phosphorus - modified four - armed star - shaped compound reacts with octadecyl dimethyl methoxysilane to form a modified flame retardant.

[0007] In step S1, the molar ratio of pentaerythritol to 3,6 - dimethyl - 1,4 - dioxane - 2,5 - dione is 1:(12 - 20).

[0008] In step S2, the molar ratio of 2 - piperazinecarboxylic acid to diphenylphosphinous chloride is 1:(2 - 2.5).

[0009] In step S3, the molar ratio of the four - armed star - shaped compound to the nitrogen - phosphorus compound is 1:(1.8 - 2.2).

[0010] In step S4, the molar ratio of the nitrogen - phosphorus - modified four - armed star - shaped compound to octadecyl dimethyl methoxysilane is 1:(2 - 2.5).

[0011] The binder is prepared by the following method: A1: Castor oil reacts with formic acid and H2O2 to form an epoxide; A2: The epoxide reacts with (1,4 - phenylenebis(1,3,2 - dioxaborolane - 2,4 - diyl)) dimethanethiol to form a binder.

[0012] In step A1, the mass ratio of castor oil to formic acid is 1:3.

[0013] In step A2, the mass ratio of the epoxide to (1,4 - phenylenebis(1,3,2 - dioxaborolane - 2,4 - diyl)) dimethanethiol is 2:1.

[0014] The antioxidant is one of UV - 531 and UV - 326.

[0015] A preparation method of a high - strength flame - retardant, sound - insulating and heat - insulating composite material includes the following steps: (1) Weigh by parts by weight: 40 - 60 parts of polyurethane resin, 10 - 15 parts of polyvinylpyrrolidone, 10 - 15 parts of ceramic hollow microspheres, 6 - 10 parts of ceramic fibers, 5 - 8 parts of binder, 1 - 3 parts of modified flame retardant, and 2 - 4 parts of antioxidant; (2) Mix the polyurethane resin, polyvinylpyrrolidone, binder, modified flame retardant, and antioxidant to obtain mixture A; Grind the ceramic fibers and add them to the ceramic hollow microspheres for mixing to obtain mixture B; (3) Mix mixture A and mixture B evenly, extrude through an extruder, and cool and shape to obtain a high-strength flame-retardant, sound-insulating, and heat-insulating composite material.

[0016] Due to the above technical solutions, the beneficial effects of the present invention include: (1) The modified flame retardant prepared in the present invention achieves efficient flame retardancy through the synergistic flame retardancy of nitrogen and phosphorus and the star-shaped topological structure. At the same time, the introduction of silane significantly improves the dispersion uniformity and interfacial stability of the flame retardant in the matrix through steric hindrance dispersion and chemical bonding.

[0017] (2) The binder in the present invention constructs a highly cross-linked network through thiol-epoxy click reaction, and utilizes the dynamic flexibility of the long-chain alkyl group of castor oil and the reversible fracture and recombination of borate bonds. The synergistic effect significantly improves the tensile properties of the heat-insulating and sound-insulating materials. Detailed implementation mode

[0018] The following is further illustrated in conjunction with examples, but the present invention is not limited to these examples.

[0019] Example 1 Preparation of modified flame retardant: S1: Under nitrogen protection, add 1200 g of DMF, 0.1 mol of pentaerythritol, and 1.2 mol of 3,6-dimethyl-1,4-dioxane-2,5-dione to the reactor, stir and mix evenly, heat up to 130 °C, stir for 15 min, then add 10 g of catalyst stannous octoate, react for 20 h, then cool to room temperature, carry out vacuum distillation at 60 °C for 2 h to obtain a crude product. Add the crude product to 500 ml of chloroform, stir and mix evenly, then add 500 ml of cold methanol, let it stand to precipitate, filter, and then wash three times with methanol (500 ml each time), and vacuum dry at 60 °C for 5 h to obtain a four-armed star compound with a number average molecular weight of 1762; The reaction equation is shown as follows: .

[0020] S2: Under nitrogen protection and in an ice bath, add 200 ml of dichloromethane and 0.2 mol of diphenylphosphinyl chloride to the reactor, stir and mix evenly, then slowly dropwise add 100 ml of a dichloromethane solution of 2-piperazinecarboxylic acid (0.1 mol of 2-piperazinecarboxylic acid dissolved in 100 ml of dichloromethane) over 20 min, then slowly dropwise add 0.3 mol of triethylamine over 10 min. After the addition is complete, reflux for 4 h, then cool to room temperature, perform vacuum distillation at 35 °C for 45 min, wash three times with deionized water (200 ml each time), filter, and dry in vacuo at 60 °C for 4 h to obtain the nitrogen-phosphorus compound; the reaction equation is shown as follows: 。

[0021] S3: Under nitrogen protection, add 1200 g of toluene, 0.1 mol of the four-armed star compound, and 0.18 mol of the nitrogen-phosphorus compound to the reactor, stir and mix evenly, heat to 80 °C, then add 15 g of p-toluenesulfonic acid, react for 6 h (remove the generated water using a water separator during the reaction), then cool to room temperature, slowly add saturated sodium bicarbonate solution to adjust the pH to neutral, stir well for 30 min, let it stand for phase separation, transfer the organic phase to a rotary evaporator, perform vacuum distillation at 60 °C for 4 h, and dry in vacuo at 70 °C for 10 h to obtain the nitrogen-phosphorus modified four-armed star compound; the number-average molecular weight is 2633; the reaction equation is shown as follows: 。

[0022] S4: Add 800 ml of toluene and 0.1 mol of the nitrogen-phosphorus modified four-armed star compound to the reactor, stir for 1 h, then add 0.2 mol of octadecyl dimethyl methoxysilane and 0.2 mol of triethylamine, react at 60 °C for 6 h, then centrifuge, wash three times with deionized water (500 ml each time), filter, and dry in vacuo at 70 °C for 12 h to obtain the modified flame retardant; the number-average molecular weight is 3224; the reaction equation is shown as follows: 。

[0023] Example 2 Preparation of the modified flame retardant: S1: Under nitrogen protection, add 1200 g of DMF, 0.1 mol of pentaerythritol, and 1.6 mol of 3,6-dimethyl-1,4-dioxane-2,5-dione to the reactor, stir and mix evenly, heat to 130 °C, stir for 15 min, then add 10 g of the catalyst stannous octoate, react for 24 h, then cool to room temperature, perform vacuum distillation at 60 °C for 2 h to obtain the crude product. Add the crude product to 500 ml of chloroform, stir and mix evenly, then add 500 ml of cold methanol, let it stand to precipitate, filter, then wash three times with methanol (500 ml each time), and dry in vacuo at 60 °C for 5 h to obtain the four-armed star compound, with a number-average molecular weight of 2318; S2: Under nitrogen protection and in an ice bath, add 200 ml of dichloromethane and 0.22 mol of diphenylphosphinyl chloride to the reactor, stir and mix evenly, then slowly dropwise add a dichloromethane solution of 100 ml of 2-piperazinecarboxylic acid (0.1 mol of 2-piperazinecarboxylic acid dissolved in 100 ml of dichloromethane) over 20 min, then slowly dropwise add 0.3 mol of triethylamine over 10 min. After the addition is complete, reflux for 5 h, then cool to room temperature, distill under reduced pressure at 35 °C for 45 min, wash three times with deionized water (200 ml each time), filter, and dry in vacuo at 60 °C for 4 h to obtain the nitrogen-phosphorus compound; S3: Under nitrogen protection, add 1200 g of toluene, 0.1 mol of the four-armed star compound, and 0.2 mol of the nitrogen-phosphorus compound to the reactor, stir and mix evenly, heat to 90 °C, then add 15 g of p-toluenesulfonic acid, and react for 5 h (using a water separator to remove the generated water during the reaction). After cooling to room temperature, slowly add saturated sodium bicarbonate solution to adjust the pH to neutral, stir well for 30 min, let it stand for phase separation, transfer the organic phase to a rotary evaporator, distill under reduced pressure at 60 °C for 4 h, and dry in vacuo at 70 °C for 10 h to obtain the nitrogen-phosphorus modified four-armed star compound; The number average molecular weight is 3291; S4: Add 800 ml of toluene and 0.1 mol of the nitrogen-phosphorus modified four-armed star compound to the reactor, stir for 1 h, then add 0.22 mol of octadecyl dimethyl methoxysilane and 0.2 mol of triethylamine, react at 70 °C for 5 h, then centrifuge, wash three times with deionized water (500 ml each time), filter, and dry in vacuo at 70 °C for 12 h to obtain the modified flame retardant; The number average molecular weight is 3913.

[0024] Example 3 Preparation of the modified flame retardant: S1: Under nitrogen protection, add 1200 g of DMF, 0.1 mol of pentaerythritol and 2 mol of 3,6-dimethyl-1,4-dioxane-2,5-dione to the reactor, stir and mix evenly, heat to 130 °C, stir for 15 min, then add 10 g of the catalyst stannous octoate, react for 26 h, then cool to room temperature, distill under reduced pressure at 60 °C for 2 h to obtain the crude product. Add the crude product to 500 ml of chloroform, stir and mix evenly, then add 500 ml of cold methanol, let it stand to precipitate, filter, then wash three times with methanol (500 ml each time), and dry in vacuo at 60 °C for 5 h to obtain the four-armed star compound; The number average molecular weight is 2984; S2: Under nitrogen protection and in an ice bath, add 200 ml of dichloromethane and 0.25 mol of diphenylphosphinic chloride to the reactor, stir and mix evenly, then slowly dropwise add 100 ml of a dichloromethane solution of 2-piperazinecarboxylic acid (0.1 mol of 2-piperazinecarboxylic acid dissolved in 100 ml of dichloromethane), the dropping takes 20 min, then slowly dropwise add 0.3 mol of triethylamine, the dropping takes 10 min. After the dropping is complete, reflux for 6 h, then cool to room temperature, distill under reduced pressure at 35 °C for 45 min, wash three times with deionized water (200 ml each time), filter, and dry in vacuum at 60 °C for 4 h to obtain a nitrogen-phosphorus compound; S3: Under nitrogen protection, add 1200 g of toluene, 0.1 mol of a four-armed star compound, and 0.22 mol of the nitrogen-phosphorus compound to the reactor, stir and mix evenly, heat up to 100 °C, then add 15 g of p-toluenesulfonic acid, react for 4 h (remove the generated water using a water separator during the reaction), then cool to room temperature, slowly add saturated sodium bicarbonate solution to adjust the pH to neutral, stir well for 30 min, let it stand for liquid separation, transfer the organic phase to a rotary evaporator, distill under reduced pressure at 60 °C for 4 h, and dry in vacuum at 70 °C for 10 h to obtain a nitrogen-phosphorus modified four-armed star compound; The number-average molecular weight is 4060; S4: Add 800 ml of toluene and 0.1 mol of the nitrogen-phosphorus modified four-armed star compound to the reactor, stir for 1 h, then add 0.25 mol of octadecyl dimethyl methoxysilane and 0.2 mol of triethylamine, react at 80 °C for 4 h, then centrifuge, wash 3 times with deionized water (500 ml each time), filter, and dry in vacuum at 70 °C for 12 h to obtain a modified flame retardant; The number-average molecular weight is 4681.

[0025] Example 4 Preparation of the binder: A1: Add 200 ml of DMF, 10 g of castor oil, and 2 g of strong acid cation exchange resin to the reactor, stir and mix evenly, heat up to 50 °C, then mix 30 g of formic acid and 90 g of 30 wt% H2O2 solution evenly, slowly dropwise add the mixed solution of formic acid and H2O2 solution, the dropping takes 20 min, react for 8 h, then cool to room temperature, transfer the upper clear liquid to a separatory funnel, extract three times with petroleum ether (300 ml each time), distill under reduced pressure at 50 °C for 5 h to obtain an epoxy compound; The reaction equation is shown as follows: 。

[0026] A2: Under nitrogen protection, add 200 ml of anhydrous DMF, 20 g of epoxy compound, and 10 g of (1,4-phenylenebis(1,3,2-dioxaborolane-2,4-diyl)) dimethanethiol into the reactor, stir and mix evenly, then add 5 g of triethylamine, heat up to 80 °C and react for 6 h, then cool down to room temperature, then add 1 M hydrochloric acid to adjust the pH value to 7, add 200 ml of ice water and stir, precipitate is separated out, filtered, and dried in vacuum at 60 °C for 6 h to obtain the binder; the reaction equation is shown as follows: 。

[0027] Example 5 Preparation of high-strength flame-retardant sound-insulating and heat-insulating composite material: (1)Weigh: 400 g of polyurethane resin, 100 g of polyvinylpyrrolidone, 100 g of ceramic hollow microspheres, 60 g of ceramic fibers, 50 g of binder (prepared in Example 4), 10 g of modified flame retardant (prepared in Example 1), and 20 g of antioxidant (UV-531); (2)Mix the polyurethane resin, polyvinylpyrrolidone, binder, modified flame retardant, and antioxidant, with a stirring speed of 500 r / min and stir for 30 min to obtain mixture A; grind the ceramic fibers and add them to the ceramic hollow microspheres for mixing, with a stirring speed of 800 r / min and stir for 50 min to obtain mixture B; (3)Mix mixture A and mixture B evenly, with a stirring speed of 600 r / min and stir for 40 min, extrude through a twin-screw extruder, and the temperatures of the feeding section, compression section, homogenization section, and die orifice are 150 °C, 170 °C, 185 °C, and 170 °C respectively, and cool and form to obtain the high-strength flame-retardant sound-insulating and heat-insulating composite material.

[0028] Example 6 Preparation of high-strength flame-retardant sound-insulating and heat-insulating composite material: (1)Weigh by weight: 500 g of polyurethane resin, 120 g of polyvinylpyrrolidone, 120 g of ceramic hollow microspheres, 80 g of ceramic fibers, 60 g of binder (prepared in Example 4), 20 g of modified flame retardant (prepared in Example 2), and 30 g of antioxidant (UV-326); (2)Mix the polyurethane resin, polyvinylpyrrolidone, binder, modified flame retardant, and antioxidant, with a stirring speed of 500 r / min and stir for 30 min to obtain mixture A; grind the ceramic fibers and add them to the ceramic hollow microspheres for mixing, with a stirring speed of 800 r / min and stir for 50 min to obtain mixture B; (3) Mix mixture A and mixture B evenly, with a stirring speed of 600 r / min, stir for 40 min, extrude through a twin-screw extruder, and the temperatures of the feeding section, compression section, homogenization section and die orifice are 150 °C, 170 °C, 185 °C and 170 °C respectively, and cool and form to obtain a high-strength flame-retardant sound-insulating and heat-insulating composite material.

[0029] Example 7 Preparation of high-strength flame-retardant sound-insulating and heat-insulating composite material: (1) Weigh by weight: 600 g of polyurethane resin, 150 g of polyvinylpyrrolidone, 150 g of ceramic hollow microspheres, 100 g of ceramic fibers, 80 g of binder (prepared in Example 4), 30 g of modified flame retardant (prepared in Example 3), 40 g of antioxidant (UV-531); (2) Mix the polyurethane resin, polyvinylpyrrolidone, binder, modified flame retardant, and antioxidant, with a stirring speed of 500 r / min, stir for 30 min to obtain mixture A; grind the ceramic fibers and add them to the ceramic hollow microspheres for mixing, with a stirring speed of 800 r / min, stir for 50 min to obtain mixture B; (3) Mix mixture A and mixture B evenly, with a stirring speed of 600 r / min, stir for 40 min, extrude through a twin-screw extruder, and the temperatures of the feeding section, compression section, homogenization section and die orifice are 150 °C, 170 °C, 185 °C and 170 °C respectively, and cool and form to obtain a high-strength flame-retardant sound-insulating and heat-insulating composite material.

[0030] Comparative Example 1 The raw material composition and preparation method of the high-strength flame-retardant sound-insulating and heat-insulating composite material are basically the same as those in Example 6, except that the modified flame retardant is replaced with an equal weight of the nitrogen-phosphorus modified four-armed star compound prepared in step S3 of Example 2.

[0031] Comparative Example 2 The raw material composition and preparation method of the high-strength flame-retardant sound-insulating and heat-insulating composite material are basically the same as those in Example 6, except that the modified flame retardant is replaced with an equal weight of the modified flame retardant prepared by the following method: The preparation method of the modified flame retardant is basically the same as that in Example 2, except that the addition amount of the nitrogen-phosphorus compound in step S3 is increased to 0.4 mol.

[0032] Comparative Example 3 The raw material composition and preparation method of the high-strength flame-retardant sound-insulating and heat-insulating composite material are basically the same as those in Example 6, except that the modified flame retardant is replaced with an equal weight of the modified flame retardant prepared by the following method: The preparation method of the modified flame retardant is basically the same as that of Example 2, except that in step S4, octadecyldimethylmethoxysilane is replaced with an equimolar amount of methoxy(dimethyl)octylsilane.

[0033] Comparative Example 4 The raw material composition and preparation method of the high-strength flame-retardant sound-insulating and heat-insulating composite material are basically the same as those of Example 6, except that the modified flame retardant is replaced with a modified flame retardant prepared by the following method in an equal weight: The preparation method of the modified flame retardant is basically the same as that of Example 2, except that in step S2, 2-piperazinecarboxylic acid is replaced with an equimolar amount of (S)-3-piperidinecarboxylic acid.

[0034] Comparative Example 5 The raw material composition and preparation method of the high-strength flame-retardant sound-insulating and heat-insulating composite material are basically the same as those of Example 6, except that the binder is replaced with a binder prepared by the following method in an equal weight: The preparation method of the binder is basically the same as that of Example 4, except that in step A1, castor oil is replaced with an equal mass of glycerol monooleate.

[0035] Comparative Example 6 The raw material composition and preparation method of the high-strength flame-retardant sound-insulating and heat-insulating composite material are basically the same as those of Example 6, except that the binder is replaced with a binder prepared by the following method in an equal weight: The preparation method of the binder is basically the same as that of Example 4, except that in step A1, castor oil is replaced with an equal mass of glycerol dilinoleate.

[0036] Comparative Example 7 The raw material composition and preparation method of the high-strength flame-retardant sound-insulating and heat-insulating composite material are basically the same as those of Example 6, except that the binder is replaced with a binder prepared by the following method in an equal weight: The preparation method of the binder is basically the same as that of Example 4, except that in step A2, (1,4-phenylenebis(1,3,2-dioxaborolane-2,4-diyl))dimethanethiol is replaced with an equal mass of 1,4-benzenedimethanethiol.

[0037] The polyurethane resin used in this application is WANNATE® 6087F produced by Wanhua Chemical Group Co., Ltd.; the polyvinylpyrrolidone is PVP K30; the ceramic hollow microspheres are of the E-SPHERES model and are produced by Dalian Yibang Technology Co., Ltd.; the ceramic fiber is the 1050-type ceramic fiber of Shandong Haoyang Energy Saving Materials Co., Ltd., with the fiber diameter evenly distributed between 2 - 4 μm, the Al2O3 content being 46 wt%, and the SiO2 content being 52 wt%; the strongly acidic cation exchange resin is a polymer of divinylbenzene and sodium vinylbenzenesulfonate, with the trade name Amberlite® IMAC HP1110 resin, and is produced by Sinopharm Chemical Reagent Co., Ltd.

[0038] The high-strength flame-retardant sound-insulating and heat-insulating composite materials prepared in Examples 5 - 7 and Comparative Examples 1 - 7 were subjected to tensile property tests in accordance with GB / T 1040.1 - 2006; the flame-retardant properties were tested using a horizontal and vertical burning tester in accordance with the ASTM-D3801 standard, with the sample size being 127 mm × 13 mm × 10 mm; the thermal conductivity was tested in accordance with GB / T 10295 - 2008; the sound-insulating performance was tested in accordance with the method of GB / Z27764 - 2011 (sound source frequency 400 Hz); the test results are shown in Table 1.

[0039] Table 1 Data table of performance tests

[0040] It can be seen from Examples 5, 6, and 7 in Table 1 that the high-strength flame-retardant sound-insulating and heat-insulating composite material prepared by the present invention has good mechanical properties, flame-retardant properties, heat insulation, and sound-insulating properties.

[0041] The modified flame retardant prepared in this application has a unique star-shaped molecular structure. This structure has higher thermal stability and can form a denser cross-linked carbon layer than linear polymers at high temperatures; at the same time, the star-shaped molecular structure realizes good dispersion of nitrogen and phosphorus elements through chemical bonding, and produces a synergistic flame-retardant effect in the gas phase and condensed phase during combustion, forming a dense three-dimensional network carbon layer. In addition, the introduction of silane further promotes the formation of a dense silicon-carbon composite carbon layer, effectively isolating the transfer of heat and oxygen; the introduced octadecyl dimethyl methoxysilane improves the dispersion and compatibility of the flame retardant in the matrix. The octadecyl long chain prevents the agglomeration of flame retardant molecules through physical steric hindrance, promotes its dispersion in the matrix material, and avoids stress concentration caused by excessive local concentration. Good dispersion and compatibility prevent the flame retardant from causing stress cracking as "defect points" and improve the tensile strength of the material.

[0042] The epoxy groups in the binder prepared in this application form a three-dimensional network structure with the boron-containing crosslinking agent. A high-crosslinking-density skeleton is constructed through thiol-epoxy click reaction, significantly improving the tensile strength. At the same time, the long fatty chains of castor oil endow the molecular segments with dynamic flexibility, avoiding brittle fracture of the traditional rigid crosslinking system. The borate ester bond (B-O) contained in the binder has reversible dynamic characteristics, can be broken and recombined under external force, absorb energy and prevent stress concentration, making the material exhibit high ductility during stretching. The temperature responsiveness of the borate ester bond enables its dynamic recombination at high temperatures to relieve thermal stress; at low temperatures, the crosslinking network remains rigid to avoid brittle cracking.

[0043] As described above, the above are only the preferred embodiments of the present invention and are not used to limit the present invention. However, for those of ordinary skill in the art, without departing from the scope of the technical solution of the present invention, any slight changes, modifications and equivalent changes evolved by using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A high-strength flame-retardant, sound-insulating and heat-insulating composite material, characterized in that, It comprises raw materials in the following parts by weight: 40 - 60 parts of polyurethane resin, 10 - 15 parts of polyvinylpyrrolidone, 10 - 15 parts of ceramic hollow microspheres, 6 - 10 parts of ceramic fibers, 5 - 8 parts of binder, 1 - 3 parts of modified flame retardant, 2 - 4 parts of antioxidant; The modified flame retardant is prepared by the following method: S1: Pentaerythritol reacts with 3,6 - dimethyl - 1,4 - dioxane - 2,5 - dione under the catalysis of stannous octoate to form a four - armed star - shaped compound; S2: 2 - Piperazinecarboxylic acid reacts with diphenylphosphinic chloride to form a nitrogen - phosphorus compound; S3: The four - armed star - shaped compound reacts with the nitrogen - phosphorus compound under the action of p - toluenesulfonic acid to form a nitrogen - phosphorus - modified four - armed star - shaped compound; S4: The nitrogen - phosphorus - modified four - armed star - shaped compound reacts with octadecyl dimethyl methoxysilane to form a modified flame retardant.

2. The high-strength flame-retardant sound-insulating and heat-insulating composite material according to claim 1, characterized in that, In step S1, the feeding molar ratio of pentaerythritol to 3,6 - dimethyl - 1,4 - dioxane - 2,5 - dione is 1:(12 - 20).

3. A high-strength flame-retardant, sound-insulating and heat-insulating composite material according to claim 1, characterized in that, In step S2, the feeding molar ratio of 2 - piperazinecarboxylic acid to diphenylphosphinic chloride is 1:(2 - 2.5).

4. A high-strength flame-retardant, sound-insulating and heat-insulating composite material according to claim 1, characterized in that, In step S3, the feeding molar ratio of the four - armed star - shaped compound to the nitrogen - phosphorus compound is 1:(1.8 - 2.2).

5. A high-strength flame-retardant sound-insulating and heat-insulating composite material according to claim 1, characterized in that, In step S4, the feeding molar ratio of the nitrogen - phosphorus - modified four - armed star - shaped compound to octadecyl dimethyl methoxysilane is 1:(2 - 2.5).

6. A high-strength flame-retardant sound-insulating and heat-insulating composite material according to claim 1, characterized in that, The binder is prepared by the following method: A1: Castor oil reacts under the action of formic acid and H2O2 to form an epoxide; A2: The epoxide reacts with (1,4 - phenylenebis(1,3,2 - dioxaborolane - 2,4 - diyl)) dimethanethiol to form a binder.

7. An intumescent flame retardant sound insulation and heat insulation composite material according to claim 6, characterized in that, In step A1, the feeding mass ratio of castor oil to formic acid is 1:

3.

8. A high-strength flame-retardant sound-insulating and heat-insulating composite material according to claim 6, characterized in that, In step A2, the feeding mass ratio of the epoxide to (1,4 - phenylenebis(1,3,2 - dioxaborolane - 2,4 - diyl)) dimethanethiol is 2:

1.

9. A high-strength flame-retardant sound-insulating and heat-insulating composite material according to claim 1, characterized in that, The antioxidant is one of UV - 531 and UV - 326.

10. A method for preparing the high-strength flame-retardant sound-insulating and heat-insulating composite material according to any one of claims 1-9, characterized in that, It includes the following steps: (1) Weigh by parts by weight: 40 - 60 parts of polyurethane resin, 10 - 15 parts of polyvinylpyrrolidone, 10 - 15 parts of ceramic hollow microspheres, 6 - 10 parts of ceramic fibers, 5 - 8 parts of binder, 1 - 3 parts of modified flame retardant, 2 - 4 parts of antioxidant; (2) Mix polyurethane resin, polyvinylpyrrolidone, binder, modified flame retardant, and antioxidant to obtain mixture A; Grind ceramic fibers and add them to ceramic hollow microspheres for mixing to obtain mixture B; (3) Mix mixture A and mixture B evenly, extrude through an extruder, and cool and form to obtain a high - strength flame - retardant, sound - insulating and heat - insulating composite material.

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