Heat-insulating and sound-insulating composite material as well as preparation method and application thereof

Abstract

The invention discloses a heat-insulating and sound-insulating composite material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The heat-insulating and sound-insulating composite material is prepared from the following raw materials in parts by weight: 40 to 60 parts of polyimide resin, 10 to 15 parts of polyvinylpyrrolidone, 15 to 20 parts of ceramic hollow microbeads, 5 to 8 parts of a modified binder, 1 to 3 parts of a modified flame retardant and 5 to 8 parts of a lubricant, the modified binder is prepared by the following steps: reacting 3, 3 '-dichlorobiphenyl-4, 4'-diisocyanate with 2, 2 '-dithiodiethanol to obtain a urethane polymer, reacting the urethane polymer with 8-(trimethoxysilyl) octylamine in triethylamine to obtain an intermediate 1, and finally reacting the intermediate 1 with nonaethylene glycol-anisole. The heat-insulating and sound-insulating composite material prepared by the invention has excellent heat-insulating, sound-insulating and flame-retardant properties, and can be applied to interior trim panels, floors and clapboards of airplanes.

Description

Technical Field

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

[0002] Aviation vehicles such as passenger airplanes need to withstand extremely large temperature differences, external noises, high-altitude lightning strikes, strong radiation and other harsh environments. The heat insulation, sound insulation and flame retardancy of their cabin bodies are the keys to ensuring the structural safety of the airplane and the comfort of passengers. Traditional heat-insulating and sound-insulating materials have significant deficiencies in aspects such as heat insulation, sound insulation and flame retardancy, which limit their use in complex environments. In recent years, significant progress has been made in the application research of composite materials in the field of heat insulation and sound insulation. By combining the excellent properties of different materials, composite materials can achieve both heat insulation and sound insulation effects. However, existing composite materials still face some challenges in practical applications.

[0003] Chinese invention patent with the publication number CN104164024A discloses a semi-interpenetrating network highly foamed flame-retardant polyvinyl chloride alloy material, which is composed of polyvinyl chloride resin, polymer toughening agent, flame-retardant plasticizer, halogen-free flame retardant, heat stabilizer, cross-linking agent, foaming agent and reactive monomer. This polyvinyl chloride alloy material can be used as a heat preservation, heat insulation and sound insulation material. However, the flame retardant effect of this composite material is poor.

[0004] Therefore, it is of great significance to develop a composite material with good flame retardant performance, heat insulation and sound insulation performance to meet the needs of modern industrial and construction fields. Summary of the Invention

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

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions: A heat-insulating and sound-insulating composite material, comprising the following raw materials in parts by weight: Polyimide resin: 40-60 parts, polyvinylpyrrolidone: 10-15 parts, ceramic hollow microspheres: 15-20 parts, modified binder: 5-8 parts, modified flame retardant: 1-3 parts, lubricant: 5-8 parts; The modified binder is first obtained by reacting 3,3'-dichlorobiphenyl-4,4'-diisocyanate with 2,2'-dithiodiethanol to obtain a urethane polymer, then reacting with 8-(trimethoxysilyl)octylamine in triethylamine to obtain intermediate 1, and finally reacting with nonaethylene glycol monophenyl ether to prepare.

[0007] The modified binder is prepared by the following method: S1: 3,3'-Dichlorobiphenyl-4,4'-diisocyanate and 2,2'-dithiobisethanol react at 30 - 50 °C for 4 - 6 h under the catalysis of dibutyltin dilaurate to obtain a urethane polymer. The reaction equation is as follows: 。

[0008] S2: The urethane polymer reacts with 8-(trimethoxysilyl)octylamine at room temperature for 10 - 12 h under the action of triethylamine to obtain Intermediate 1. The reaction equation is as follows: 。

[0009] S3: Intermediate 1 and nonaethylene glycol monophenyl ether react under reflux for 10 - 15 h under the action of potassium carbonate to obtain a modified binder. The reaction equation is as follows: 。

[0010] In step S1, the molar ratio of the feed of 3,3'-dichlorobiphenyl-4,4'-diisocyanate, 2,2'-dithiobisethanol, and dibutyltin dilaurate is (1.2 - 1.5):1:(0.01 - 0.05).

[0011] In step S2, the mass ratio of the feed of triethylamine, 8-(trimethoxysilyl)octylamine, and the urethane polymer is (10 - 16):(8 - 15):35.

[0012] In step S3, the mass ratio of the feed of potassium carbonate, Intermediate 1, and nonaethylene glycol monophenyl ether is (4 - 9):40:(6 - 12).

[0013] The modified flame retardant is prepared by the following method: M1: 1,4-Phenylenediboronic acid reacts with 9-octadecen-1-ol to obtain a borate compound. The reaction equation is as follows: 。

[0014] M2: The carbon-carbon double bond of the borate compound generates an epoxide under the action of H2O2 and formic acid. The reaction equation is as follows: 。

[0015] M3: The epoxide reacts with 3-aminopropyltrimethylsilane to obtain a hydroxylamine compound. The reaction equation is as follows: 。

[0016] M4: The hydroxylamine compound reacts with diphenylphosphinous chloride to obtain a modified flame retardant. The reaction equation is as follows: 。

[0017] The lubricant is one of stearamide and ethylene bisstearamide.

[0018] A method for preparing a heat-insulating and sound-insulating composite material includes the following steps: N1: Weigh by parts by weight: polyimide resin: 40 - 60 parts, polyvinylpyrrolidone: 10 - 15 parts, ceramic hollow microspheres: 15 - 20 parts, modified binder: 5 - 8 parts, modified flame retardant: 1 - 3 parts, lubricant: 5 - 8 parts; N2: Mix the polyimide resin, polyvinylpyrrolidone, modified binder, modified flame retardant, and lubricant in a low-speed mixer to obtain a premix. N3: Add the ceramic hollow microspheres to the premix and mix evenly, then melt and extrude at 380 - 400 °C through a twin-screw extruder, and cool and form to obtain the heat-insulating and sound-insulating composite material.

[0019] An application of the heat-insulating and sound-insulating composite material in aircraft interior panels, floors, and partitions.

[0020] Due to the above technical solutions, the beneficial effects of the present invention include: (1) In the present invention, a urethane polymer is obtained by reacting 3,3'-dichlorobiphenyl-4,4'-diisocyanate with 2,2'-dithioglycol, then an intermediate 1 is obtained by reacting with 8-(trimethoxysilyl)octylamine in triethylamine, and finally a modified binder is prepared by reacting with nonaethylene glycol monophenyl ether.

[0021] (2) In the present invention, a borate compound is obtained by reacting 1,4-benzenediboronic acid with 9-octadecen-1-ol, an epoxide is formed under the action of H2O2 and formic acid, then a hydroxylamine compound is obtained by reacting with 3-aminopropyltrimethoxysilane, and finally a modified flame retardant is obtained by reacting with diphenylphosphinous chloride.

[0022] (3) The heat-insulating and sound-insulating composite material prepared by the present invention has excellent heat-insulating, sound-insulating, and flame-retardant properties and can be applied to aircraft interior panels, floors, and partitions. Specific embodiments

[0023] The following is further illustrated with reference to embodiments, but the present invention is not limited to these embodiments.

[0024] Example 1 Preparation of the modified binder: S1: Under nitrogen protection, 800 ml of DMF, 1.2 mol of 3,3'-dichlorobiphenyl-4,4'-diisocyanate, and 1 mol of 2,2'-dithiobisethanol were successively added to a reactor, stirred and mixed evenly, 0.01 mol of dibutyltin dilaurate was added, the temperature was raised to 30 °C, and the reaction was carried out for 6 h. 800 ml of deionized water was added to precipitate solids, filtered, washed with 500 ml of deionized water, and vacuum dried at 50 °C for 6 h to obtain a urethane polymer; S2: Under an ice bath, 800 ml of tetrahydrofuran, 100 g of triethylamine, and 80 g of 8-(trimethoxysilyl)octylamine were stirred and mixed evenly, 800 ml of a tetrahydrofuran solution containing 350 g of urethane polymer was added dropwise, and the addition was completed in 2 h. The temperature was raised to room temperature, and the reaction was carried out for 10 h. It was distilled under reduced pressure at 40 °C for 3 h, 800 ml of dichloromethane was added, washed twice with deionized water (500 ml each time), dried with 80 g of anhydrous sodium sulfate and filtered, and distilled under reduced pressure at 35 °C for 2 h to obtain Intermediate 1; S3: 1000 ml of DMF, 40 g of potassium carbonate, 400 g of Intermediate 1, and 60 g of nonaethylene glycol monophenyl ether were successively added to a reactor, the temperature was raised to reflux, and the reaction was carried out for 10 h. After cooling to room temperature, 600 ml of methanol was added to precipitate solids, filtered, washed twice with deionized water (600 ml each time), and vacuum dried at 60 °C for 24 h to obtain a modified binder.

[0025] Example 2 Preparation of modified binder: S1: Under nitrogen protection, 800 ml of DMF, 1.3 mol of 3,3'-dichlorobiphenyl-4,4'-diisocyanate, and 1 mol of 2,2'-dithiobisethanol were successively added to a reactor, stirred and mixed evenly, 0.03 mol of dibutyltin dilaurate was added, the temperature was raised to 40 °C, and the reaction was carried out for 5 h. 800 ml of deionized water was added to precipitate solids, filtered, washed with 500 ml of deionized water, and vacuum dried at 50 °C for 6 h to obtain a urethane polymer; S2: Under an ice bath, 800 ml of tetrahydrofuran, 150 g of triethylamine, and 120 g of 8-(trimethoxysilyl)octylamine were stirred and mixed evenly, 800 ml of a tetrahydrofuran solution containing 350 g of urethane polymer was added dropwise, and the addition was completed in 2 h. The temperature was raised to room temperature, and the reaction was carried out for 11 h. It was distilled under reduced pressure at 40 °C for 3 h, 800 ml of dichloromethane was added, washed twice with deionized water (500 ml each time), dried with 80 g of anhydrous sodium sulfate and filtered, and distilled under reduced pressure at 35 °C for 2 h to obtain Intermediate 1; S3: Add 1000 ml of DMF, 80 g of potassium carbonate, 400 g of Intermediate 1, and 110 g of nonaethylene glycol monophenyl ether into a reactor in sequence. Heat up to reflux and react for 14 h. Cool to room temperature, add 600 ml of methanol to precipitate solids, filter, wash twice with deionized water (600 ml each time), and dry in vacuum at 60 °C for 24 h to obtain the modified binder.

[0026] Example 3 Preparation of the modified binder: S1: Under nitrogen protection, add 800 ml of DMF, 1.5 mol of 3,3'-dichlorobiphenyl-4,4'-diisocyanate, and 1 mol of 2,2'-dithioglycol into a reactor in sequence. Stir and mix evenly, add 0.05 mol of dibutyltin dilaurate, heat up to 50 °C, and react for 4 h. Add 800 ml of deionized water to precipitate solids, filter, wash with 500 ml of deionized water, and dry in vacuum at 50 °C for 6 h to obtain the urethane polymer. S2: Under an ice bath, mix 800 ml of tetrahydrofuran, 160 g of triethylamine, and 150 g of 8-(trimethoxysilyl) octylamine evenly, and dropwise add 800 ml of a tetrahydrofuran solution containing 350 g of the urethane polymer dropwise over 2 h. After the addition is complete, raise the temperature to room temperature and react for 12 h. Distill under reduced pressure at 40 °C for 3 h, add 800 ml of dichloromethane, wash twice with deionized water (500 ml each time), dry with 80 g of anhydrous sodium sulfate and filter, and distill under reduced pressure at 35 °C for 2 h to obtain Intermediate 1. S3: Add 1000 ml of DMF, 90 g of potassium carbonate, 400 g of Intermediate 1, and 120 g of nonaethylene glycol monophenyl ether into a reactor in sequence. Heat up to reflux and react for 15 h. Cool to room temperature, add 600 ml of methanol to precipitate solids, filter, wash twice with deionized water (600 ml each time), and dry in vacuum at 60 °C for 24 h to obtain the modified binder.

[0027] Example 4 Preparation of the modified flame retardant: M1: Add 1000 ml of DMF and 2 mol of 9-octadecen-1-ol into a reactor, stir for 10 min, add 0.5 mol of 1,4-benzenediboronic acid in batches (divided into 8 portions, with an interval of 15 min each time), and react at room temperature for 24 h. Filter to obtain solids, wash twice with DMF (500 ml each time), and dry in vacuum at 90 °C for 24 h to obtain the borate compound. M2: Add 800 ml of ethyl acetate, 300 g of the borate compound, and 30 g of strong acid cation exchange resin into a reaction flask, heat up to 60 °C, and dropwise add a mixed solution of 195 g of 30 wt% H2O2 and 45 g of formic acid over 30 min. After the addition is complete, react for 6 h. Cool to room temperature, wash three times with deionized water (400 ml each time), and distill under reduced pressure at 50 °C for 3 h to obtain the epoxy compound. M3: Under nitrogen protection, 500 ml of tetrahydrofuran, 0.5 mol of triethylamine, 0.1 mol of epoxide and 0.4 mol of 3-aminopropyltrimethylsilane were successively added to a reactor, stirred and mixed evenly, refluxed for 10 h, cooled to room temperature, washed 3 times with 300 ml of saturated brine, distilled under reduced pressure at 40 °C for 3 h to remove tetrahydrofuran, and dried at 70 °C for 10 h to obtain a hydroxylamine compound; M4: Under an ice bath, 500 ml of tetrahydrofuran, 0.5 mol of triethylamine and 0.1 mol of the hydroxylamine compound were added to a reaction flask, 0.4 mol of diphenylphosphinic chloride was added dropwise, and the addition was completed in 1 h. The temperature was raised to room temperature and the reaction was carried out for 8 h. It was washed three times with saturated brine (300 ml each time), and distilled under reduced pressure at 40 °C for 3 h to obtain a modified flame retardant. The nuclear magnetic resonance hydrogen spectrum data are as follows: 1 H NMR (500 MHz,Chloroform-d) δ 7.73-7.69 (m, 20H), 7.56-7.52 (m, 8H), 7.49-7.45 (m, 16H),4.02 (q, J=6.3 Hz, 4H), 3.73 (t, J=5.4 Hz, 8H), 3.02-2.95 (m, 4H), 2.62 (d, J=7.1 Hz, 8H), 2.55 (s, 4H), 1.68 (dtd, J=14.6, 8.5, 6.3 Hz, 4H), 1.57 (tt, J=7.3, 5.4 Hz, 8H), 1.54-1.48 (m, 4H), 1.47-1.19 (m, 104H), 0.91-0.87 (m, 12H),0.57 (t, J=8.1 Hz, 8H), 0.11 (s, 36H).

[0028] Example 5 Preparation of heat-insulating and sound-insulating composite material: N1: Weigh by weight: polyimide resin: 400 g, polyvinylpyrrolidone: 100 g, ceramic hollow microspheres: 150 g, modified binder (prepared in Example 1): 50 g, modified flame retardant (prepared in Example 4): 10 g, stearamide: 50 g; N2: The polyimide resin, polyvinylpyrrolidone, modified binder, modified flame retardant and lubricant were mixed in a low-speed mixer to obtain a premix; N3: Ceramic hollow microspheres were added to the premix, mixed evenly, and melt-extruded at 380 °C by a twin-screw extruder, and cooled and formed to obtain a heat-insulating and sound-insulating composite material.

[0029] Example 6 Preparation of heat-insulating and sound-insulating composite material: N1: Weigh by weight: polyimide resin: 550 g, polyvinylpyrrolidone: 140 g, ceramic hollow microspheres: 180 g, modified binder (prepared in Example 2): 70 g, modified flame retardant (prepared in Example 4): 20 g, ethylene bisstearamide: 70 g; N2: Mix the polyimide resin, polyvinylpyrrolidone, modified binder, modified flame retardant, and lubricant in a low-speed mixer to obtain a premix; N3: Add the ceramic hollow microspheres to the premix, mix evenly, and melt-extrude at 395 °C through a twin-screw extruder, then cool and shape to obtain the heat-insulating and sound-insulating composite material.

[0030] Example 7 Preparation of heat-insulating and sound-insulating composite material: N1: Weigh by weight: polyimide resin: 600 g, polyvinylpyrrolidone: 150 g, ceramic hollow microspheres: 200 g, modified binder (prepared in Example 3): 80 g, modified flame retardant (prepared in Example 4): 30 g, ethylene bisstearamide: 80 g; N2: Mix the polyimide resin, polyvinylpyrrolidone, modified binder, modified flame retardant, and lubricant in a low-speed mixer to obtain a premix; N3: Add the ceramic hollow microspheres to the premix, mix evenly, and melt-extrude at 400 °C through a twin-screw extruder, then cool and shape to obtain the heat-insulating and sound-insulating composite material.

[0031] Comparative Example 1 The raw material composition and preparation method of the heat-insulating and sound-insulating composite material are basically the same as those in Example 6, except that the modified binder (prepared in Example 2) is replaced with an equal weight of Intermediate 2 (prepared in Example 2) as the binder.

[0032] Comparative Example 2 The raw material composition and preparation method of the heat-insulating and sound-insulating composite material are basically the same as those in Example 6, except that the modified binder is replaced with an equal weight of the modified binder prepared by the following method: The preparation method of the modified binder is basically the same as that in Example 2, except that 2,2'-dithioglycol in step S1 is replaced with an equal molar amount of 1,6-hexanediol.

[0033] Comparative Example 3 The raw material composition and preparation method of the heat-insulating and sound-insulating composite material are basically the same as those in Example 6, except that the modified binder is replaced with an equal weight of the modified binder prepared by the following method: The preparation method of the modified binder is basically the same as that in Example 2, except that 8-(trimethoxysilyl)octylamine in step S2 is replaced with an equal mass of octylamine.

[0034] Comparative Example 4 The raw material composition and preparation method of the heat-insulating and sound-insulating composite material are basically the same as those of Example 6, except that the modified binder is replaced with a modified binder prepared by the following method in an equal weight: The preparation method of the modified binder is basically the same as that of Example 2, except that the nonaethylene glycol monobenzyl ether in step S3 is replaced with dodecyl heptaethylene glycol ether in an equal mass.

[0035] Comparative Example 5 The raw material composition and preparation method of the heat-insulating and sound-insulating composite material are basically the same as those of Example 6, except that the modified flame retardant (prepared in Example 4) is replaced with a hydroxylamine compound (prepared in Example 4) in an equal weight.

[0036] Comparative Example 6 The raw material composition and preparation method of the heat-insulating and sound-insulating composite material are basically the same as those of Example 6, except that the modified flame retardant (prepared in Example 4) 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 4, except that 1,4-benzenediboronic acid in step M1 is replaced with heptane-1,7-diyldiboronic acid in an equal molar amount.

[0037] Comparative Example 7 The raw material composition and preparation method of the heat-insulating and sound-insulating composite material are basically the same as those of Example 6, except that the modified flame retardant (prepared in Example 4) 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 4, except that 3-aminopropyltrimethylsilane in step M3 is replaced with 4,4-dimethyl-1-pentanamine in an equal molar amount.

[0038] The polyimide resin used in this application has the model 6051 and is produced by Shanghai Xuji Electric Co., Ltd.; the molecular weight of polyvinylpyrrolidone is PVP K30; the ceramic hollow microspheres have the model E-SPHERES and are produced by Dalian Yibang Technology Co., Ltd.; 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.; the heptane-1,7-diyldiboronic acid used in Comparative Example 5 is named Heptane-1,7-diyldiboronic acid in English, CAS: 1498308-80-7.

[0039] The heat-insulating and sound-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; combustion was determined by the oxygen index method in accordance with GB / T 2406.1-2008; the thermal coefficient was tested in accordance with GB / T 10295-2008; the sound-insulating performance was tested by the method in accordance with GB / Z 27764-2011 (sound source frequency 400 Hz); the test results are shown in Table 1.

[0040] The heat-insulating and sound-insulating composite materials prepared in Examples 5-7 and Comparative Examples 1-4 were subjected to a destructive test, and the specific method was as follows: A square iron block with a size of 1.5 cm×0.5 cm was used to impact the heat-insulating and sound-insulating composite material evenly (impact once every 8 cm 2 ), the impact pressure each time was 0.35 MPa, and after the impact, the mechanical properties were tested after standing for 24 h. The test results are shown in Table 1.

[0041] Table 1 Data table of performance test

[0042] It can be seen from Examples 5, 6, and 7 in Table 1 that the heat-insulating and sound-insulating composite materials prepared by the present invention have good mechanical properties, flame retardant properties, heat insulation, and sound insulation properties.

[0043] The modified binder prepared in this application contains a rigid aromatic ring structure and a flexible dynamic disulfide segment. The highly conjugated rigid planar structure of the benzene ring can significantly improve the tensile strength of the material; the presence of dynamic disulfide bonds allows chain segments to slip during the stretching process, which can delay fracture; and it can undergo reversible fracture and recombination through redox reactions, enabling it to have a self-healing function, and the material can still maintain high performance after the impact test. By introducing a long-chain ether bond segment with a high degree of rotational freedom, the molecular chains are arranged disorderly. Since heat is mainly transmitted through lattice vibration, heat is scattered frequently during the transmission process, thereby reducing the thermal conductivity of the material; the siloxane in the modified binder can form Si-O-Si covalent bonds with the surface hydroxyl groups of ceramic hollow microspheres, improving the dispersibility of ceramic hollow microspheres, and thus improving the mechanical properties, heat insulation, and sound insulation properties of the material.

[0044] The modified binders used in Comparative Example 1 and Comparative Example 2 did not introduce long-chain ether bond segments and disulfide bonds respectively, and the tensile properties of the composite materials decreased. The sulfur-containing binder prepared in this application plays a flame retardant role by promoting the crosslinking and carbonization of the matrix during combustion, reducing the fire intensity and improving the safety of the material. While Comparative Example 2 did not introduce disulfide bonds, and the flame retardant effect was poor.

[0045] The Si-O-Si covalent bond formed between the siloxane in the modified binder and the hydroxyl groups on the surface of ceramic hollow microspheres has a relatively high bond energy and is not easily broken under impact. However, the binder in Comparative Example 3 does not contain siloxane and cannot form Si-O-Si covalent bonds, resulting in poor impact fracture performance.

[0046] The modified binder used in Comparative Example 4 is a modified binder synthesized by replacing nonaethylene glycol monobenzyl ether with dodecyl heptaethylene glycol ether. The reason for its poor performance is that the polyimide structure contains a large number of rigid aromatic ring structures. Compared with the modified binder containing benzene rings in this application, the benzene rings can enhance the interfacial stress transfer with the polyimide matrix through π-π stacking, thereby improving the tensile properties of the composite materials in this application.

[0047] In this application, a borate-based four-armed flame retardant is prepared with 1,4-benzenediboronic acid as the center. The borate can achieve efficient flame retardancy through multi-path synergy: in the condensed phase, its thermal decomposition generates glassy boron oxides (such as B2O3) to cover the surface of the material, isolating oxygen and heat; at the same time, it catalyzes the dehydration of the polymer to form a dense carbon layer, significantly reducing the heat release rate and increasing the limiting oxygen index (LOI); in the gas phase, the released water vapor dilutes the combustible gas, and the boron oxide radicals (BO·) quench the active radicals (H·, OH·) of the combustion chain reaction, inhibiting flame spread; its endothermic decomposition behavior can absorb a large amount of heat, delay the temperature rise of the material, and enhance the thermal stability of the matrix through hydrogen bonding or coordination. This flame retardant contains silicon atoms and has a low surface energy, making it easy for the flame retardant to migrate to the surface of the matrix at the initial stage of combustion, and then form stable inorganic compounds such as SiO2 and SiC to cover the surface of the substrate, achieving the purpose of inhibiting flame spread. In addition, this flame retardant contains a diphenylphosphinoyl structure and amino groups. The borate, phosphorus, and nitrogen can form high-temperature-resistant B-P-O or BN structures, synergistically improving the flame retardancy efficiency. Each of the four arms of the flame retardant structure contains a diphenylphosphinoyl structure. Due to the stretching effect of the four-arm structure, the dispersion performance of this flame retardant is higher when added to the composite material compared to adding diphenylphosphinoyl alone.

[0048] The modified flame retardant prepared in Comparative Example 6 uses heptane-1,7-diyl di(boronic acid) instead of 1,4-benzenediboronic acid to synthesize the modified flame retardant. Its alkyl aliphatic chain may form a loose and porous carbon layer, resulting in a decline in the barrier effect. The benzene ring conjugated bond structure in the modified flame retardant prepared in this application enables it to remain stable at high temperatures, forming a heat-resistant carbon layer to effectively block the transfer of oxygen and heat.

[0049] 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, within the scope of the technical solution of the present invention, any minor changes, modifications, and equivalent variations made by using the above-disclosed technical content are all equivalent embodiments of the present invention. At the same time, any changes, modifications, and variations of any equivalent changes made to the above embodiments based on the substantial technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A heat-insulating and sound-insulating composite material, characterized in that, It comprises raw materials in the following parts by weight: Polyimide resin: 40 - 60 parts, polyvinylpyrrolidone: 10 - 15 parts, ceramic hollow microspheres: 15 - 20 parts, modified binder: 5 - 8 parts, modified flame retardant: 1 - 3 parts, lubricant: 5 - 8 parts; The modified binder is first obtained by reacting 3,3'-dichlorobiphenyl-4,4'-diisocyanate and 2,2'-dithioglycol to get a urethane polymer, then reacting with 8-(trimethoxysilyl)octylamine in triethylamine to obtain intermediate 1, and finally reacting with nonaethylene glycol monophenyl ether to prepare it.

2. The heat-insulating and sound-insulating composite material according to claim 1, wherein The modified binder is prepared by the following method: S1: 3,3'-Dichlorobiphenyl-4,4'-diisocyanate and 2,2'-dithioglycol react at 30 - 50 °C for 4 - 6 h under the catalysis of dibutyltin dilaurate to obtain a urethane polymer; S2: The urethane polymer reacts with 8-(trimethoxysilyl)octylamine at room temperature for 10 - 12 h under the action of triethylamine to obtain intermediate 1; S3: Intermediate 1 and nonaethylene glycol monophenyl ether react under reflux for 10 - 15 h under the action of potassium carbonate to obtain the modified binder.

3. The heat-insulating and sound-insulating composite material according to claim 2, characterized in that, In step S1, the feeding molar ratio of 3,3'-dichlorobiphenyl-4,4'-diisocyanate, 2,2'-dithioglycol, and dibutyltin dilaurate is (1.2 - 1.5):1:(0.01 - 0.05).

4. An insulating and soundproof composite material according to claim 2, characterized in that, In step S2, the feeding mass ratio of triethylamine, 8-(trimethoxysilyl)octylamine, and the urethane polymer is (10 - 16):(8 - 15):

35.

5. An insulating and soundproof composite material according to claim 2, characterized in that, In step S3, the feeding mass ratio of potassium carbonate, intermediate 1, and nonaethylene glycol monophenyl ether is (4 - 9):40:(6 - 12).

6. An insulating and soundproof composite material according to claim 1, characterized in that, The modified flame retardant is prepared by the following method: M1: 1,4-Phenylenediboronic acid reacts with 9-octadecen-1-ol to obtain a borate compound; M2: The carbon-carbon double bond of the borate compound generates an epoxy compound under the action of H2O2 and formic acid; M3: The epoxy compound reacts with 3-aminopropyltrimethoxysilane to obtain a hydroxylamine compound; M4: The hydroxylamine compound reacts with diphenylphosphinic chloride to obtain the modified flame retardant.

7. An insulating and soundproof composite material according to claim 1, characterized in that, The lubricant is one of stearamide and ethylene bisstearamide.

8. A method for preparing the heat-insulating and sound-insulating composite material according to any one of claims 1-7, characterized in that, It includes the following steps: N1: Weigh by parts by weight: polyimide resin: 40 - 60 parts, polyvinylpyrrolidone: 10 - 15 parts, ceramic hollow microspheres: 15 - 20 parts, modified binder: 5 - 8 parts, modified flame retardant: 1 - 3 parts, lubricant: 5 - 8 parts; N2: Mix the polyimide resin, polyvinylpyrrolidone, modified binder, modified flame retardant, and lubricant in a low-speed mixer to obtain a premix; N3: Add ceramic hollow microspheres to the premix and mix evenly, and extrude it by a twin-screw extruder at 380 - 400 °C, then cool and form to obtain a heat-insulating and sound-insulating composite material.

9. Application of the heat-insulating and sound-insulating composite material as claimed in claims 1 - 7 in aircraft interior panels, floors, and partitions.

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