Flame-retardant heat-insulating polyurethane foam material and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to a flame-retardant heat-insulating polyurethane foam material and a preparation method thereof. The flame-retardant heat-insulating polyurethane foam material comprises a component A and a component B, the mass ratio of the component A to the component B is 1: 1; the component A comprises the following raw materials in parts by weight: 100 parts of polyol, 8-15 parts of a flame retardant, 5-8 parts of modified tea saponin, 3-5 parts of a foam stabilizer, 2-4 parts of a catalyst, 1-3 parts of a chain extender and 0.5-1 part of water; and the component B is polyisocyanate. The polyurethane foam material has the advantages of efficient flame retardance, no toxicity and excellent heat-insulating property and mechanical property.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and particularly relates to a flame-retardant and heat-insulating polyurethane foam material and its preparation method. Background Technology

[0002] Soft microporous polyurethane foam is lightweight, can be shaped into any form, and has high energy absorption efficiency, making it the preferred material for "building insulation and long-term sealing" scenarios. Its high-pore three-dimensional mesh structure integrates multiple functions: when made into self-adhesive insulation pipes or sealing strips, it can significantly reduce solid heat conduction, block air convection, and freely expand and contract with temperature differences, maintaining a long-term seal and continuously saving energy.

[0003] However, the high-open-cell structure that endows flexible microporous polyurethane foam with excellent functions also brings serious safety challenges. Air can circulate freely within the foam, causing flames and heat to spread rapidly and easily; simultaneously, its hydrocarbon polymer backbone is inherently flammable and often accompanied by molten dripping during combustion. These inherent defects make it difficult for existing materials to meet increasingly stringent flame-retardant safety standards (such as UL94, GB 8624, etc.), constituting the main technical bottleneck for their widespread application in high-risk scenarios.

[0004] Therefore, in applications with stringent safety requirements, the market urgently needs an innovative material that can fundamentally improve fire safety levels while maintaining excellent mechanical properties and thermal insulation. Developing a polyurethane foam material that is highly flame-retardant, non-toxic, and possesses excellent thermal insulation properties has become a clear technological development direction for overcoming current technological limitations and covering more critical application areas. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a flame-retardant and heat-insulating polyurethane foam material that is highly flame-retardant, non-toxic, and has excellent heat insulation properties.

[0006] One of the objectives of this invention is achieved through the following technical solution: A flame-retardant and heat-insulating polyurethane foam material, comprising component A and component B; wherein the mass ratio of component A to component B is 1:1. By weight, component A comprises the following raw materials: 100 parts of polyol, 8-15 parts of flame retardant, 5-8 parts of modified tea saponin, 3-5 parts of foaming agent, 2-4 parts of catalyst, 1-3 parts of chain extender, and 0.5-1 parts of water. Component B is a polyisocyanate; The structure of the flame retardant in component A is as follows: .

[0007] Furthermore, the preparation process of the flame retardant includes the following steps: (1) Under the protection of an inert gas, 9,9-fluorenediethanol and imidazole were added to tetrahydrofuran, and then phosphorus trichloride was added to react. After the reaction was completed, the mixture was purified to obtain compound 1. The structural formula of compound 1 is: ; (2) Under the protection of an inert gas, N-chlorosuccinimide was added to xylene, and then compound 1 was added to react. After the reaction was completed, the mixture was purified to obtain compound 2. The structural formula of compound 2 is: ; (3) Under the protection of an inert gas and in an ice bath environment, propynyl alcohol and 4-dimethylaminopyridine were added to dichloromethane, followed by the addition of compound 2 and triethylamine. The mixture was heated to room temperature and reacted. After the reaction was completed, the mixture was purified to obtain compound 3. The structural formula of compound 3 is: ; (4) The compound 3 and ethyl azide were added to an aqueous solution of tetrahydrofuran, and then sodium ascorbate and copper sulfate pentahydrate were added to react. After the reaction was completed, the mixture was purified to obtain the flame retardant.

[0008] Furthermore, in step (1), the molar ratio of 9,9-fluorenediethanol, imidazole, and phosphorus trichloride is 1:(1.2-1.5):(0.48-0.52); the reaction temperature is 45-55℃ and the reaction time is 12-24h; in step (2), the molar ratio of compound 1 and N-chlorosuccinimide is 9:(10-11); the reaction time is 2-5h.

[0009] Furthermore, in step (3), the molar ratio of propynyl alcohol, 4-dimethylaminopyridine, compound 2, and triethylamine is 1:(0.1-0.2):(1.3-1.5):(1.2-1.4); the reaction time is 1-3 h; in step (4), the molar ratio of compound 3, ethyl azide, sodium ascorbate, and copper sulfate pentahydrate is 1:(1-1.2):(0.22-0.3):(0.12-0.18); the reaction time is 16-24 h.

[0010] Furthermore, the preparation process of the modified tea saponin includes the following steps: S1. Add tea saponin and tert-butyl (2-(2-(2-(2-bromoethoxy)ethoxy)ethyl)carbamate to N,N-dimethylformamide, add potassium tert-butoxide under ice bath conditions, heat to room temperature and react. After the reaction is completed, purify to obtain pretreated tea saponin 1. S2. Trifluoroacetic acid is added to dichloromethane, and the pretreated tea saponin 1 is added under ice bath conditions. The mixture is heated to room temperature and reacted. After the reaction is completed, the reaction solution is concentrated to obtain pretreated tea saponin 2. S3. The pretreated tea saponin 2, 4-formylbenzenesulfonic acid and p-toluenesulfonic acid are added to toluene for reaction. After the reaction is completed, the mixture is purified to obtain the modified tea saponin.

[0011] Furthermore, in step S1, the mass ratio of tea saponin, (2-(2-(2-bromoethoxy)ethoxy)ethyl)carbamate tert-butyl ester, and potassium tert-butoxide is 12:(4-6):(3-5); the reaction time is 12-24 h; in step S2, the mass ratio of pretreated tea saponin 1 and trifluoroacetic acid is 1:(0.8-1); the reaction time is 3-5 h.

[0012] Furthermore, in step S3, the mass ratio of the pretreated tea saponin 2, 4-formylbenzenesulfonic acid, and p-toluenesulfonic acid is 13:(3-5):(0.1-0.2); the reaction time is 3-5 hours.

[0013] Furthermore, the polyol in component A is composed of polycarbonate diol CD-200 and polypropylene glycol PPG-4000 in a mass ratio of 1:(1-1.5); the chain extender is composed of pentaerythritol and triethanolamine in a mass ratio of 1:1; the catalyst is triethylenediamine or dimethylethanolamine; and the foam stabilizer is silicone surfactant AK-8812.

[0014] Furthermore, the polyol in component A is composed of polycarbonate diol CD-200 and polypropylene glycol PPG-4000 in a mass ratio of 1:1.2; the catalyst is triethylenediamine.

[0015] Furthermore, the polyisocyanate in component B is toluene diisocyanate or isophorone diisocyanate.

[0016] Furthermore, the polyisocyanate mentioned in component B is toluene diisocyanate.

[0017] The second objective of this invention is to provide a simple method for preparing flame-retardant and heat-insulating polyurethane foam material.

[0018] The second objective of this invention is achieved by the following technical solution: The preparation method of the above-mentioned flame-retardant and heat-insulating polyurethane foam material includes the following steps: Component A is prepared by mixing the raw materials of component A evenly according to the stated weight proportions; component B is prepared by mixing component A evenly according to the stated mass ratio, followed by foaming, curing, and aging.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The flame-retardant and heat-insulating polyurethane foam material of the present invention has the advantages of high flame retardancy, non-toxicity, and excellent heat insulation and mechanical properties.

[0020] 2. This invention improves the thermal insulation and resilience of the material by adding modified tea saponin. The role of modified tea saponin in the polyurethane foaming process is multi-stage: First, the polarity mutation brought about by the sulfonic acid groups introduced by the dilution of the ethoxy spatial arm induces high-density nucleation. Subsequently, the potential intramolecular electrostatic interaction (reversible ion pairs between Schiff bases and sulfonate groups) provides an electrostatic barrier to inhibit bubble coalescence. Furthermore, its active groups (Schiff bases) participate in the cross-linking reaction of polyurethane, thereby fixing the cell structure and enhancing the toughness of the skeleton, thus improving the thermal insulation and resilience of the polyurethane foam material.

[0021] 3. This invention enhances the flame retardant properties and mechanical strength of materials by adding flame retardants. The mechanism of action of the flame retardant is manifested in two aspects: In terms of flame retardant performance, the flame retardant is used in conjunction with pentaerythritol in the formulation. Upon heating, the phosphorus fragment catalyzes the formation of char, while the nitrogen fragment releases non-flammable gas, dilutes and expands, and the carbon skeleton stabilizes the char layer. This synergistic effect constructs a stable intumescent flame retardant system, enabling the material to meet the UL-94 V-0 flame retardant standard. The ester groups and triazole rings in the flame retardant are hydrogen-bonded to the polyurethane chain segments, and the rigid skeleton of the spirofluorene locks the molecules, effectively preventing the migration of the flame retardant in the polyurethane material and improving flame retardant durability and stability. In terms of mechanical strength, the flame retardant is uniformly dispersed in the polyurethane matrix at the molecular level at room temperature. The rigid skeleton of the spirofluorene and phosphorus heterocycles constitutes "micro-reinforcing nodes," effectively supporting the cell structure and giving the material excellent tensile strength; the ethyl acetate groups on the side chain produce an internal plasticizing effect, improving the chain segment mobility, which not only offsets the brittleness that the rigid components may cause, but also improves the elongation at break of the material, ensuring flexibility in the processing and application stages. Attached Figure Description

[0022] Figure 1 This is the infrared spectrum of tea saponin from Example 4; Figure 2 This is the infrared spectrum of the modified tea saponin prepared in Example 4. Detailed Implementation

[0023] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.

[0024] In this invention, component A contains a polyol composed of polycarbonate diol CD-200 (hydroxyl value 56±2 mg KOH / g) and polypropylene glycol PPG-4000 (hydroxyl value 28±2 mg KOH / g) in a mass ratio of 1:1.2; a catalyst is triethylenediamine; a chain extender is composed of pentaerythritol and triethanolamine in a mass ratio of 1:1; and a foam stabilizer is an organosilicon surfactant AK-8812. The polyisocyanate in component B is toluene diisocyanate.

[0025] Example 1 A flame retardant, the preparation process of which includes the following steps: ; (1) Under a nitrogen atmosphere, 9,9-fluorenediethanol (CAS: 4425-93-8, 10 mmol) and imidazole (13 mmol) were added to 30 mL of tetrahydrofuran. After stirring evenly, phosphorus trichloride (5 mmol) was added, and the mixture was heated to 50 °C and reacted for 16 h. After the reaction was completed, the reaction solution was cooled to room temperature, washed with deionized water, and the tetrahydrofuran phase was dried to obtain compound 1. The NMR and mass spectrometry results of compound 1 are as follows: ; (2) Under a nitrogen atmosphere, N-chlorosuccinimide (NCS, 10.5 mmol) was dissolved in 50 mL of xylene, and then intermediate 1 (9 mmol) was added. The reaction was carried out at room temperature for 4 h. After the reaction was completed, the reaction solution was filtered and concentrated to obtain compound 2. The NMR and mass spectrometry results of compound 2 are as follows: ; (3) Under a nitrogen atmosphere and in an ice bath environment, propynyl alcohol (10 mmol) and 4-dimethylaminopyridine (DMAP, 1.5 mmol) were added to 10 mL of dichloromethane, followed by compound 2 (14 mmol) and triethylamine (13 mmol). The mixture was gradually heated to room temperature and reacted for 2 h. The reaction solution was quenched with saturated ammonium chloride solution, and the aqueous phase was extracted with dichloromethane. The organic layers were combined, washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography (30 v%, ethyl acetate / hexane) to obtain compound 3. The NMR and mass spectrometry results of compound 3 are as follows: ; (4) Compound 3 (10 mmol) and ethyl azide (CAS: 637-81-0, 11 mmol) were added to 20 mL of tetrahydrofuran and 20 mL of deionized water, followed by sodium ascorbate (2.5 mmol) and copper sulfate pentahydrate (1.6 mmol). The reaction was carried out at room temperature for 20 h. After the reaction was completed, the reaction solution was diluted with dichloromethane and washed with water. The organic layers were combined and washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography (40 v%, ethyl acetate / hexane) to obtain the flame retardant. The NMR and mass spectrometry results of the flame retardant are as follows: .

[0026] Example 2 A flame retardant, the preparation process of which includes the following steps: (1) Under a nitrogen atmosphere, 9,9-fluorenediethanol (10 mmol) and imidazole (12 mmol) were added to 30 mL of tetrahydrofuran, stirred evenly, and then phosphorus trichloride (4.8 mmol) was added. The temperature was raised to 45 °C and reacted for 24 h. After the reaction was completed, the reaction solution was cooled to room temperature, washed with deionized water, and the tetrahydrofuran phase was dried to obtain compound 1. The NMR and mass spectrometry results of compound 1 were the same as those in Example 1. (2) Under a nitrogen atmosphere, NCS (10 mmol) was dissolved in 50 mL of xylene, and then intermediate 1 (9 mmol) was added. The reaction was carried out at room temperature for 2 h. After the reaction was completed, the reaction solution was filtered and concentrated to obtain compound 2. The NMR and mass spectrometry results of compound 2 were the same as those in Example 1. (3) Under a nitrogen atmosphere and in an ice bath environment, propynyl alcohol (10 mmol) and DMAP (1 mmol) were added to 10 mL of dichloromethane, followed by compound 2 (13 mmol) and triethylamine (12 mmol). The mixture was gradually heated to room temperature and reacted for 1-3 h. The reaction solution was quenched with saturated ammonium chloride solution, and then the aqueous phase was extracted with dichloromethane. The organic layers were combined and washed with saturated brine, dried with anhydrous sodium sulfate, and purified by column chromatography (30 v%, ethyl acetate / hexane) to obtain compound 3. The NMR and mass spectrometry results of compound 3 were the same as in Example 1. (4) Compound 3 (10 mmol) and ethyl azide (10 mmol) were added to 20 mL of tetrahydrofuran and 20 mL of deionized water, and then sodium ascorbate (2.2 mmol) and copper sulfate pentahydrate (1.2 mmol) were added. The reaction was carried out at room temperature for 16 h. After the reaction was completed, the reaction solution was diluted with dichloromethane and washed with water. The organic layers were combined and washed with saturated brine, dried with anhydrous sodium sulfate, and purified by column chromatography (40 v%, ethyl acetate / hexane) to obtain the flame retardant. The NMR and mass spectrometry results of the flame retardant were the same as those in Example 1.

[0027] Example 3 A flame retardant, the preparation process of which includes the following steps: (1) Under a nitrogen atmosphere, 9,9-fluorenediethanol (10 mmol) and imidazole (15 mmol) were added to 30 mL of tetrahydrofuran, stirred evenly, and then phosphorus trichloride (5.2 mmol) was added. The temperature was raised to 55 °C and reacted for 12 h. After the reaction was completed, the reaction solution was cooled to room temperature, washed with deionized water, and the tetrahydrofuran phase was dried to obtain compound 1. The NMR and mass spectrometry results of compound 1 were the same as those in Example 1. (2) Under a nitrogen atmosphere, NCS (11 mmol) was dissolved in 50 mL of xylene, and then intermediate 1 (9 mmol) was added. The reaction was carried out at room temperature for 5 h. After the reaction was completed, the reaction solution was filtered and concentrated to obtain compound 2. The NMR and mass spectrometry results of compound 2 were the same as those in Example 1. (3) Under a nitrogen atmosphere and in an ice bath environment, propynyl alcohol (10 mmol) and DMAP (2 mmol) were added to 10 mL of dichloromethane, followed by compound 2 (15 mmol) and triethylamine (14 mmol). The mixture was gradually heated to room temperature and reacted for 3 h. The reaction solution was quenched with saturated ammonium chloride solution, and then the aqueous phase was extracted with dichloromethane. The organic layers were combined and washed with saturated brine, dried with anhydrous sodium sulfate, and purified by column chromatography (30 v%, ethyl acetate / hexane) to obtain compound 3. The NMR and mass spectrometry results of compound 3 were the same as in Example 1. (4) Compound 3 (10 mmol) and ethyl azide (12 mmol) were added to 20 mL of tetrahydrofuran and 20 mL of deionized water, and then sodium ascorbate (3 mmol) and copper sulfate pentahydrate (1.8 mmol) were added. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the reaction solution was diluted with dichloromethane and washed with water. The organic layers were combined and washed with saturated brine, dried with anhydrous sodium sulfate, and purified by column chromatography (40 v%, ethyl acetate / hexane) to obtain the flame retardant. The NMR and mass spectrometry results of the flame retardant were the same as those in Example 1.

[0028] Example 4 A modified tea saponin, the preparation process includes the following steps:

[0029] S1. 12g of tea saponin (Mn=1223.54) and 5g of (2-(2-(2-bromoethoxy)ethoxy)ethyl)carbamate tert-butyl ester (CAS: 165963-71-3) were added to 100mL of anhydrous N,N-dimethylformamide and stirred evenly in an ice bath. Then, 4g of potassium tert-butoxide was added and stirred evenly. The mixture was then heated to room temperature and reacted for 18h. After the reaction was completed, the reaction solution was washed successively with 2mol / L hydrochloric acid solution, 10wt% sodium bicarbonate solution and saturated brine. The organic phase was dried with anhydrous sodium sulfate, filtered and concentrated to obtain pretreated tea saponin 1. S2. Add 9g of trifluoroacetic acid to 100mL of dichloromethane, add 10g of the pretreated tea saponin 1 in an ice bath environment, stir evenly, and then heat to room temperature for 4h. After the reaction is completed, concentrate the reaction solution to obtain pretreated tea saponin 2. S3. Add 13g of the pretreated tea saponin 2 (Mn=1358.65), 4g of 4-formylbenzenesulfonic acid (CAS: 5363-54-2), and 0.15g of p-toluenesulfonic acid to 100mL of toluene and react at room temperature for 4h. After the reaction is complete, add 10mL of acetonitrile to the reaction solution, filter the reaction solution, and dry the resulting filter cake to obtain the modified tea saponin.

[0030] Example 5 A modified tea saponin, the preparation process includes the following steps: S1. 12g of tea saponin and 4g of (2-(2-(2-bromoethoxy)ethoxy)ethyl)carbamate tert-butyl ester were added to 100mL of anhydrous N,N-dimethylformamide and stirred evenly in an ice bath environment. Then, 3g of potassium tert-butoxide was added and stirred evenly. The mixture was then heated to room temperature and reacted for 12h. After the reaction was completed, the reaction solution was washed successively with 2mol / L hydrochloric acid solution, 10wt% sodium bicarbonate solution and saturated brine. The organic phase was dried with anhydrous sodium sulfate, filtered and concentrated to obtain pretreated tea saponin 1. S2. Add 8g of trifluoroacetic acid to 100mL of dichloromethane, add 10g of the pretreated tea saponin 1 in an ice bath environment, stir evenly, and then heat to room temperature for 3h. After the reaction is completed, concentrate the reaction solution to obtain pretreated tea saponin 2. S3. Add 13g of the pretreated tea saponin, 2g of 4-formylbenzenesulfonic acid, and 0.1g of p-toluenesulfonic acid to 100mL of toluene and react at room temperature for 3h. After the reaction is complete, add 10mL of acetonitrile to the reaction solution, filter the reaction solution, and dry the resulting filter cake to obtain the modified tea saponin.

[0031] Example 6 A modified tea saponin, the preparation process includes the following steps: S1. 12g of tea saponin and 6g of (2-(2-(2-bromoethoxy)ethoxy)ethyl)carbamate tert-butyl ester were added to 100mL of anhydrous N,N-dimethylformamide and stirred evenly in an ice bath environment. Then, 5g of potassium tert-butoxide was added and stirred evenly. The mixture was then heated to room temperature and reacted for 24h. After the reaction was completed, the reaction solution was washed successively with 2mol / L hydrochloric acid solution, 10wt% sodium bicarbonate solution, and saturated brine. The organic phase was dried with anhydrous sodium sulfate, filtered, and concentrated to obtain pretreated tea saponin 1. S2. Add 10g of trifluoroacetic acid to 100mL of dichloromethane, add 10g of the pretreated tea saponin 1 in an ice bath environment, stir evenly, and then heat to room temperature for 5h. After the reaction is completed, concentrate the reaction solution to obtain pretreated tea saponin 2. S3. Add 13g of the pretreated tea saponin, 2g of 4-formylbenzenesulfonic acid, and 0.2g of p-toluenesulfonic acid to 100mL of toluene and react at room temperature for 5h. After the reaction is complete, add 10mL of acetonitrile to the reaction solution, filter the reaction solution, and dry the resulting filter cake to obtain the modified tea saponin.

[0032] Example 7 A flame-retardant and heat-insulating polyurethane foam material includes component A and component B; wherein the mass ratio of component A to component B is 1:1; and component B is a polyisocyanate. By weight, component A comprises the following raw materials: 100 parts of polyol, 12 parts of flame retardant from Example 1, 6 parts of modified tea saponin from Example 4, 4 parts of foaming agent, 3 parts of catalyst, 2 parts of chain extender, and 0.7 parts of water.

[0033] The preparation method of the above-mentioned flame-retardant and heat-insulating polyurethane foam material includes the following steps: Weigh each raw material of component A according to the above weight proportions and mix them evenly to obtain component A; mix component B and component A at the foaming machine gun head according to the above mass ratio, and transport them to the foaming continuous line for foaming and curing at room temperature.

[0034] Example 8 A flame-retardant and heat-insulating polyurethane foam material includes component A and component B; wherein the mass ratio of component A to component B is 1:1; and component B is a polyisocyanate. By weight, component A comprises the following raw materials: 100 parts of polyol, 8 parts of flame retardant from Example 2, 5 parts of modified tea saponin from Example 5, 3 parts of foaming agent, 2 parts of catalyst, 1 part of chain extender, and 0.5 parts of water.

[0035] The preparation method of the above-mentioned flame-retardant and heat-insulating polyurethane foam material includes the following steps: Weigh each raw material of component A according to the above weight proportions and mix them evenly to obtain component A; mix component B and component A at the foaming machine gun head according to the above mass ratio, and transport them to the foaming continuous line for foaming and curing at room temperature.

[0036] Example 9 A flame-retardant and heat-insulating polyurethane foam material includes component A and component B; wherein the mass ratio of component A to component B is 1:1; and component B is a polyisocyanate. By weight, component A comprises the following raw materials: 100 parts of polyol, 15 parts of flame retardant of Example 3, 8 parts of modified tea saponin of Example 6, 5 parts of foaming agent, 4 parts of catalyst, 3 parts of chain extender, and 1 part of water.

[0037] The preparation method of the above-mentioned flame-retardant and heat-insulating polyurethane foam material includes the following steps: Weigh each raw material of component A according to the above weight proportions and mix them evenly to obtain component A; mix component B and component A at the foaming machine gun head according to the above mass ratio, and transport them to the foaming continuous line for foaming and curing at room temperature.

[0038] Comparative Example 1 Based on Example 7, tea saponin was used to replace the modified tea saponin in Component A of Example 4 to form Comparative Example 1.

[0039] Comparative Example 2 Based on Example 7, the flame retardant of Example 1 in Component A is omitted to form Comparative Example 2.

[0040] Experimental Example 1 The tea saponin and modified tea saponin of Example 4 were analyzed by Fourier transform infrared spectroscopy (FT-IR), and the results are as follows: Figure 1 As shown.

[0041] Figure 1 This is the infrared spectrum of tea saponin from Example 4. Figure 2 This is the infrared spectrum of the modified tea saponin obtained in Example 4. (Observation) Figure 1-2 It is known that, compared to tea saponin, modified tea saponin has a lower content of 1652 cm⁻¹. -1 The characteristic peak of the stretching vibration of Schiff base C=N appears at 1600 cm⁻¹. -1 1500cm -1 The characteristic peak at 1205 cm⁻¹ belongs to the C=C stretching vibration of the benzene ring. -1 The characteristic peak at 1080 cm⁻¹ is attributed to the asymmetric stretching vibration of the S=O bond in the sulfonic acid group; -1 The characteristic peak at 620 cm⁻¹ is attributed to the asymmetric stretching vibration of the ether bond COC; -1 The characteristic peaks are attributed to the symmetric stretching vibrations of the S=O bonds in the sulfonic acid group; these results indicate that the modified tea saponin was successfully prepared.

[0042] Experimental Example 2 The properties of the materials prepared according to the embodiments and comparative examples of the present invention were tested, as follows: Resilience: Tested according to GB / T6670-2008, the experimental results are shown in Table 1; Flame retardant performance: Tested according to GB / T2406.2-2009, the test results are shown in Table 1; UL-94 Vertical Burning Test (UL-94): Tested according to ASTM D3801-2023, the test results are shown in Table 1; Mechanical properties: Tensile strength and elongation at break were tested according to GB / T6344-2008, and the experimental results are shown in Table 1. Thermal insulation: Tested according to GB / T10295-2008, the experimental results are shown in Table 1.

[0043] Table 1

[0044] As shown in Table 1, the material prepared in Example 7 has high flame retardant properties, resilience, mechanical strength, and thermal insulation properties.

[0045] Compared to Example 7, the material prepared in Comparative Example 1 showed significantly reduced thermal insulation and resilience. This experimental result demonstrates that modified tea saponin can improve the thermal insulation and resilience of the material. The role of modified tea saponin in the polyurethane foaming process is multi-stage: First, the polarity mutation brought about by the sulfonic acid groups introduced through ethoxy spatial arm dilution induces high-density nucleation. Subsequently, it provides an electrostatic barrier to inhibit bubble coalescence through potential intramolecular electrostatic interactions (reversible ion pairs between Schiff bases and sulfonate groups). Furthermore, its active groups (Schiff bases) participate in the cross-linking reaction of polyurethane, thereby fixing the cell structure and enhancing the skeleton toughness, thus improving the thermal insulation and resilience of the polyurethane foam material.

[0046] Compared to Example 7, the flame retardant properties and mechanical strength of the material prepared in Comparative Example 2 were significantly reduced. This experimental result demonstrates that flame retardants can improve the flame retardant properties and mechanical strength of materials. The mechanism of action of the flame retardant is reflected in two aspects: In terms of flame retardant properties, the flame retardant is used in conjunction with pentaerythritol in the formulation. Upon heating, the phosphorus fragment is catalyzed into char, the nitrogen fragment releases non-flammable gas for dilution and expansion, and the carbon skeleton stabilizes the char layer. The synergistic effect constructs a stable intumescent flame retardant system, enabling the material to meet the UL-94 V-0 flame retardant standard. The ester groups and triazole rings in the flame retardant are linked to the polyurethane chain segments by hydrogen bonds, and the rigid skeleton of the spirocyclic fluorene locks the molecule, effectively preventing the migration of the flame retardant in the polyurethane material and improving flame retardant durability and stability. In terms of mechanical strength, the flame retardant is uniformly dispersed in the polyurethane matrix at the molecular level at room temperature. The rigid framework of spirofluorene and phosphorus heterocycles forms "micro-reinforcing nodes" that effectively support the cell structure and endow the material with excellent tensile strength. The ethyl acetate groups on the side chains produce an internal plasticizing effect, which improves the chain segment mobility, offsets the brittleness that may be caused by the rigid components, improves the elongation at break of the material, and ensures the flexibility of the material during processing and application.

[0047] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A flame-retardant and heat-insulating polyurethane foam material, characterized in that, It includes component A and component B; the mass ratio of component A to component B is 1:1; By weight, component A comprises the following raw materials: 100 parts of polyol, 8-15 parts of flame retardant, 5-8 parts of modified tea saponin, 3-5 parts of foaming agent, 2-4 parts of catalyst, 1-3 parts of chain extender, and 0.5-1 parts of water. Component B is a polyisocyanate; The structure of the flame retardant in component A is as follows: 。 2. The flame-retardant and heat-insulating polyurethane foam material according to claim 1, characterized in that, The preparation process of the flame retardant includes the following steps: (1) Under the protection of an inert gas, 9,9-fluorenediethanol and imidazole were added to tetrahydrofuran, and then phosphorus trichloride was added to react. After the reaction was completed, the mixture was purified to obtain compound 1. The structural formula of compound 1 is: ； (2) Under the protection of an inert gas, N-chlorosuccinimide was added to xylene, and then compound 1 was added to react. After the reaction was completed, the mixture was purified to obtain compound 2. The structural formula of compound 2 is: ； (3) Under the protection of an inert gas and in an ice bath environment, propynyl alcohol and 4-dimethylaminopyridine were added to dichloromethane, followed by the addition of compound 2 and triethylamine. The mixture was heated to room temperature and reacted. After the reaction was completed, the mixture was purified to obtain compound 3. The structural formula of compound 3 is: ； (4) The compound 3 and ethyl azide were added to an aqueous solution of tetrahydrofuran, and then sodium ascorbate and copper sulfate pentahydrate were added to react. After the reaction was completed, the mixture was purified to obtain the flame retardant.

3. The flame-retardant and heat-insulating polyurethane foam material according to claim 2, characterized in that, In step (1), the molar ratio of 9,9-fluorenediethanol, imidazole, and phosphorus trichloride is 1:(1.2-1.5):(0.48-0.52); the reaction temperature is 45-55℃ and the reaction time is 12-24h; in step (2), the molar ratio of compound 1 and N-chlorosuccinimide is 9:(10-11); the reaction time is 2-5h.

4. The flame-retardant and heat-insulating polyurethane foam material according to claim 2, characterized in that, In step (3), the molar ratio of propynyl alcohol, 4-dimethylaminopyridine, compound 2, and triethylamine is 1:(0.1-0.2):(1.3-1.5):(1.2-1.4); the reaction time is 1-3 h. In step (4), the molar ratio of compound 3, ethyl azide, sodium ascorbate, and copper sulfate pentahydrate is 1:(1-1.2):(0.22-0.3):(0.12-0.18); the reaction time is 16-24 h.

5. The flame-retardant and heat-insulating polyurethane foam material according to claim 1, characterized in that, The preparation process of the modified tea saponin includes the following steps: S1. Add tea saponin and tert-butyl (2-(2-(2-(2-bromoethoxy)ethoxy)ethyl)carbamate to N,N-dimethylformamide, add potassium tert-butoxide under ice bath conditions, heat to room temperature and react. After the reaction is completed, purify to obtain pretreated tea saponin 1. S2. Trifluoroacetic acid is added to dichloromethane, and the pretreated tea saponin 1 is added under ice bath conditions. The mixture is heated to room temperature and reacted. After the reaction is completed, the reaction solution is concentrated to obtain pretreated tea saponin 2. S3. The pretreated tea saponin 2, 4-formylbenzenesulfonic acid and p-toluenesulfonic acid are added to toluene for reaction. After the reaction is completed, the mixture is purified to obtain the modified tea saponin.

6. The flame-retardant and heat-insulating polyurethane foam material according to claim 5, characterized in that, In step S1, the mass ratio of tea saponin, (2-(2-(2-bromoethoxy)ethoxy)ethyl)carbamate tert-butyl ester, and potassium tert-butoxide is 12:(4-6):(3-5); the reaction time is 12-24 h. In step S2, the mass ratio of pretreated tea saponin 1 and trifluoroacetic acid is 1:(0.8-1); the reaction time is 3-5 h.

7. The flame-retardant and heat-insulating polyurethane foam material according to claim 5, characterized in that, In step S3, the mass ratio of the pretreated tea saponin 2, 4-formylbenzenesulfonic acid and p-toluenesulfonic acid is 13:(3-5):(0.1-0.2); the reaction time is 3-5 h.

8. The flame-retardant and heat-insulating polyurethane foam material according to claim 1, characterized in that, The polyol in component A is composed of polycarbonate diol CD-200 and polypropylene glycol PPG-4000 in a mass ratio of 1:(1-1.5); the chain extender is composed of pentaerythritol and triethanolamine in a mass ratio of 1:1; the catalyst is triethylenediamine or dimethylethanolamine; and the foam stabilizer is silicone surfactant AK-8812.

9. The flame-retardant and heat-insulating polyurethane foam material according to claim 1, characterized in that, The polyisocyanate mentioned in component B is toluene diisocyanate or isophorone diisocyanate.

10. A method for preparing a flame-retardant and heat-insulating polyurethane foam material as described in any one of claims 1-9, characterized in that, Includes the following steps: Component A is prepared by mixing the raw materials of component A evenly according to the stated weight proportions; component B is prepared by mixing component A evenly according to the stated mass ratio, followed by foaming, curing, and aging.

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