High-temperature-resistant tough breathable sponge and preparation method thereof

Abstract

The invention belongs to the technical field of preparation of high-molecular porous elastic materials, and particularly relates to high-temperature-resistant tough breathable sponge and a preparation method thereof. According to the sponge, a polyurethane prepolymer is adopted as a main body, a chain extender, a cross-linking agent, a heat-resistant modifier, a double-group reinforcing agent, a water-permeable modifier and other components in a specific proportion are cooperatively constructed, and a material system with a porous network structure and thermal stability is formed. By reasonably controlling the proportion of all the components, the material is free of collapse and pulverization after being aged for a long time at the high temperature of 150 DEG C, is high in air permeability, is remarkably superior to a product in the prior art, and has excellent mechanical elasticity and heat resistance.

Description

Technical Field

[0001] This invention belongs to the field of polymer porous elastic material preparation technology, specifically relating to a high-temperature resistant and breathable sponge and its preparation method. Background Technology

[0002] Sponge materials, as a type of polymer material with a porous structure, soft texture, and good absorbency, are widely used in household goods, packaging cushioning, industrial cleaning, medical supplies, and aerospace, automotive, and electronics industries. However, in practical applications, especially in environments with high temperature, humidity, or frequent changes in mechanical stress, traditional sponge materials are prone to problems such as thermal deformation, degradation of mechanical properties, and decreased air permeability, limiting their widespread use in high-performance applications.

[0003] Currently available polyurethane, silicone rubber, or thermoplastic elastomer foams have certain advantages in terms of softness or a certain degree of temperature resistance. However, under high-temperature conditions, they are prone to foam structure collapse or pyrolysis of organic components, leading to a decrease in overall material toughness and a weakening of mechanical support properties. At the same time, some methods to enhance temperature resistance (such as adding inorganic fillers) can reduce the porosity of the foam material and increase gas transmission resistance, thus limiting its breathability and failing to meet the performance requirements of both high-temperature resistance and breathability.

[0004] Furthermore, existing sponge manufacturing processes largely rely on conventional chemical foaming, physical foaming, or molding processes, making it difficult to achieve fine-tuning of the structure and the construction of gradient pore sizes, especially in terms of synergistic optimization of multiple properties. For example, crosslinking agents or modifying components introduced to improve toughness and high-temperature resistance often interfere with bubble nucleation and pore connectivity, affecting the uniformity of air permeability and the stability of open-cell ratio in the final product. Therefore, there is an urgent need for a high-performance sponge material with a reasonable material composition, stable microstructure, and highly controllable manufacturing process to meet the comprehensive requirements for flexibility, air permeability, and structural stability under high-temperature conditions. Summary of the Invention

[0005] To address the above problems, the present invention aims to provide a high-temperature resistant, tough, and breathable sponge, made from the following raw materials in the following mass proportions: 100 parts of polyurethane prepolymer; The foaming agent consists of 38-42 parts, of which water comprises 10-16 parts, n-hexane 15-22 parts, and cyclopentane 10-14 parts; 5-10 parts of heat-resistant modifier, including: 1-3 parts of tert-butyldimethylsilane, 2-4 parts of 3-isocyanopropyltriethoxysilane, and 2-4 parts of cyclopentyltrimethoxysilane; The first reinforcing agent is 2-4 parts, with a hydroxyl value of 70-100 mgKOH / g; The second reinforcing agent, consisting of 40-55 parts, is composed of kaolin, magnesium oxide, and aluminum oxide. The permeable modifier consists of 8-14 parts of dimethyl glutarate, ethyl 2-bromoisocyanate, and ethyl isocyanate.

[0006] As a preferred technical solution, the polyurethane prepolymer is a product obtained by reacting toluene diisocyanate with a polyether polyol with a hydroxyl value between 45-55 mgKOH / g at 80-90°C for 2 hours, followed by vacuum dehydration treatment at 90°C for 2 hours, with an NCO content of 13-17%.

[0007] As a preferred technical solution, the first reinforcing agent is polypropylene oxide with a molecular weight of 1200-1800, and the amount added is 2-4% of the polyurethane prepolymer.

[0008] As a preferred technical solution, in the second reinforcing agent, the mass ratio of kaolin, magnesium oxide and aluminum oxide is (2-3):(1-1.5):(0.8-1.2), and the total amount added is 40-55 parts.

[0009] As a preferred technical solution, the permeable modifier is composed of 4-6 parts of dimethyl glutarate, 2-4 parts of ethyl 2-bromoisocyanate, and 2-4 parts of ethyl isocyanate.

[0010] This invention also provides a method for preparing a high-temperature resistant, tough, and breathable sponge, comprising the following steps: S1. Main material reaction: The polyurethane prepolymer, heat-resistant modifier, first reinforcing agent and water-permeable modifier are added to the reactor in a mass ratio of 100:(5-10):(2-4):(8-14), and stirred and heated at 90-110℃ for 8-12 minutes to obtain the main material mixture; S2. Catalytic slurry preparation: Water, n-hexane, and cyclopentane are mixed in a mass ratio of (10-16):(15-22):(10-14), and then the catalyst is added. Triethylenediamine / dimethylaniline is mixed in a 1:1 ratio. The mixture is stirred at room temperature, and then 40-55 parts of the second reinforcing agent are added. After mixing, the mixture is combined with the main material and allowed to stand for 10-15 minutes to form a slurry.

[0011] As a preferred technical solution, in step S3, the slurry is injected into the mold and placed on a vibration table to vibrate at a frequency of 5-15Hz for 2-5 minutes to make the bubble distribution uniform.

[0012] As a preferred technical solution, in step S4, the mold is placed in a room temperature environment for curing for 30-40 hours, and after demolding, the sample is placed in an environment of 40-60℃ for 24-36 hours for maturation.

[0013] As a preferred technical solution, the foaming agent is stirred for 60-90 seconds at 2000-3000 rpm using a high-speed shear machine before mixing. During the settling period of the slurry, the environment is maintained at 25±2℃ to avoid bubble escape and particle sedimentation.

[0014] Beneficial effects This invention provides a high-temperature resistant, tough, and breathable sponge. By precisely constructing a polyurethane prepolymer system and introducing various functional additives, the material achieves structural stability and performance retention under high-temperature conditions. The heat-resistant modifier used is a multi-component siloxane composite, which forms a stable cross-linked network in the polyurethane matrix, effectively improving the sponge's resistance to thermal aging.

[0015] The permeable modifier, composed of isocyanate structures, reacts with the main chain during foaming to form continuous hydrophilic channels, significantly improving the material's air permeability. The dual-reinforcing system comprises organic polyethers and inorganic powders, providing excellent elasticity and skeletal support respectively, resulting in a sponge with high resilience, compressive strength, and tear resistance.

[0016] In terms of the preparation process, a multi-step process including main material pre-reaction, catalytic slurry preparation, vibration foaming, and inverted curing is adopted to effectively control the uniformity and dimensional stability of the cell structure, thereby obtaining a foam with a dense structure and reasonable pore size distribution. Overall, this invention has synergistic advantages in terms of high temperature resistance, air permeability, and mechanical properties, making it suitable for high-requirement industrial buffering, heat insulation, or filtration applications. Attached Figure Description

[0017] Figure 1 This is a SEM image from Embodiment 3 of the present invention; Figure 2 This is a schematic diagram showing the comparative experimental results (air permeability) of the present invention; Figure 3 This is a schematic diagram showing the comparative experimental results (stretch rate) of the present invention; Figure 4 This is a schematic diagram showing the comparative experimental results (ball rebound rate) of the present invention. Detailed Implementation

[0018] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0019] Example 1 (T1) This embodiment provides a high-temperature resistant, tough, and breathable sponge, the formulation and preparation process of which are as follows: The raw material proportions are as follows (by weight): Polyurethane prepolymer: 100 parts; Total foaming agent: 38 parts, including 10 parts water, 15 parts n-hexane, and 13 parts cyclopentane; Heat-resistant modifier: 5 parts, including 1 part tert-butyldimethylsilane, 2 parts 3-isocyanate-propyltriethoxysilane, and 2 parts cyclopentyltrimethoxysilane; First reinforcing agent (polypropylene oxide polyol, hydroxyl value approximately 70 mgKOH / g, molecular weight 1200): 2 parts; Second reinforcing agent: 40 parts, composed of 20 parts kaolin, 10 parts magnesium oxide, and 10 parts aluminum oxide. Permeable modifier: 8 parts, composed of 4 parts dimethyl glutarate, 2 parts ethyl 2-bromoisocyanate, and 2 parts ethyl isocyanate; Catalyst: 0.8 parts (triethylenediamine / dimethylaniline 1:1 compound).

[0020] The polyurethane prepolymer was prepared by the following method: toluene diisocyanate was reacted with a polyether polyol with a hydroxyl value of 45 mgKOH / g at 85°C for 2 hours. After the reaction was completed, the prepolymer was vacuum dehydrated at 90°C for 2 hours to finally obtain a polyurethane prepolymer with an NCO content of about 13%.

[0021] The preparation process is as follows: S1. Main material reaction: The polyurethane prepolymer, heat-resistant modifier, first reinforcing agent and water-permeable modifier are added to the reactor in the above proportions and stirred at 90°C for 10 minutes to obtain the main material mixture.

[0022] S2. Catalytic Slurry Preparation: Mix water, n-hexane, and cyclopentane in a mass ratio of 10:15:13 until homogeneous. Add the catalyst (triethylenediamine / dimethylaniline 1:1 mixture) and stir for 1 minute to form a foaming liquid. Then add 40 parts of the second reinforcing agent, stir thoroughly until homogeneous, and mix with the main material. Stir for 30 seconds and let stand for 10 minutes to form a homogeneous slurry.

[0023] S3. Vibration foaming: Inject the slurry into the mold of the inner lining release agent, place it on the vibration table for vibration treatment, set the frequency to 5 Hz, and the vibration time to 2 minutes to promote uniform distribution of bubbles and avoid bubble merging.

[0024] S4. Room temperature curing and maturation: After foaming, place the mold in a 25℃ environment for curing for 36 hours. After curing, demold the product and transfer it to an oven for maturation at 45℃ for 24 hours.

[0025] Example 2 (T2) This embodiment provides a high-temperature resistant, tough, and breathable sponge, the formulation and preparation process of which are as follows: Polyurethane prepolymer: 100 parts; Total foaming agent: 42 parts, including 16 parts water, 22 parts n-hexane, and 14 parts cyclopentane; Heat-resistant modifier: 10 parts, including 3 parts tert-butyldimethylsilane, 4 parts 3-isocyanate-propyltriethoxysilane, and 3 parts cyclopentyltrimethoxysilane; First reinforcing agent: 4 parts, which is polypropylene oxide (hydroxyl value 100 mgKOH / g, molecular weight 1800). Second reinforcing agent: 55 parts, including 30 parts kaolin, 15 parts magnesium oxide, and 10 parts aluminum oxide; Permeable modifier: 14 parts, consisting of 6 parts dimethyl glutarate, 4 parts ethyl 2-bromoisocyanate, and 4 parts ethyl isocyanate; Catalyst: 1.8 parts, triethylenediamine / dimethylaniline 1:1 compound.

[0026] Prepolymer preparation method: Toluene diisocyanate (TDI) was reacted with a polyether polyol with a hydroxyl value of 55 mgKOH / g at 90°C for 2 hours, and then vacuum dehydrated for 2 hours at the same temperature to obtain a polyurethane prepolymer with an NCO content of 17%.

[0027] The preparation process is as follows: S1, Main Material Reaction The polyurethane prepolymer, siloxane heat-resistant modifier, first reinforcing agent and water-permeable modifier were added into the reactor in proportion and stirred and heated continuously at 110°C for 12 minutes to obtain the main material mixture. The system was uniformly mixed and had a moderate viscosity.

[0028] S2, Catalytic Pulping Add 16 parts water, 22 parts n-hexane, and 14 parts cyclopentane to a high-speed shear press in a specific ratio. Set the speed to 3000 rpm and stir for 90 seconds to form an emulsified foaming agent system. Then add 1.8 parts catalyst (triethylenediamine / dimethylaniline 1:1 mixture), stir evenly, and then add a total of 55 parts of the second reinforcing agent (30 parts kaolin, 15 parts magnesium oxide, and 10 parts alumina). Stir for another minute and then mix with the main material. Manually scrape the edges and stir for 30 seconds. Let stand for 15 minutes to form a structurally stable slurry.

[0029] S3, Vibration foaming The slurry is quickly poured into a metal mold coated with release agent, placed on a vibration table, and vibrated at a frequency of 15 Hz for 5 minutes to effectively disperse large air bubbles and form a dense and uniform cell structure.

[0030] S4, Curing and Curing After vibration, the mold is left to stand at room temperature for 40 hours to cure and complete the initial shaping. After demolding, the foam is placed in a 60°C hot air circulating oven for 36 hours to promote full cross-linking and stabilize the microporous skeleton.

[0031] Example 3 (T3) This embodiment provides a high-temperature resistant, tough, and breathable sponge, the formulation and preparation process of which are as follows: The raw material proportions are as follows (by weight): Polyurethane prepolymer: 100 parts; Total foaming agent: 40 parts, including 13 parts water, 18 parts n-hexane, and 10 parts cyclopentane; Heat-resistant modifier: 8 parts, including 2 parts tert-butyldimethylsilane, 3 parts 3-isocyanate-propyltriethoxysilane, and 3 parts cyclopentyltrimethoxysilane; First reinforcing agent: 3 parts, which is polypropylene oxide (hydroxyl value of about 85 mgKOH / g, molecular weight 1500). Second reinforcing agent: 48 parts, including 24 parts kaolin, 13 parts magnesium oxide, and 11 parts aluminum oxide; Permeable modifier: 11 parts, consisting of 5 parts dimethyl glutarate, 3 parts ethyl 2-bromoisocyanate, and 3 parts ethyl isocyanate; Catalyst: 1.2 parts, which is a 1:1 mixture of triethylenediamine and dimethylaniline.

[0032] Preparation method of polyurethane prepolymer: Toluene diisocyanate (TDI) was reacted with a polyether polyol with a hydroxyl value of 50 mgKOH / g at 85°C for 2 hours. After the reaction was completed, the polyurethane prepolymer with an NCO content of 15% was obtained by vacuum dehydration at 90°C for 2 hours.

[0033] The preparation process is as follows: S1, Main Material Reaction The polyurethane prepolymer, heat-resistant modifier, first reinforcing agent and water-permeable modifier were added to the reactor in sequence. The temperature was set to 100℃ and the mixture was stirred and heated for 10 minutes to obtain a uniform main material mixture in the form of a medium-low viscosity pourable liquid.

[0034] S2, Catalytic Pulping Add 13 parts water, 18 parts n-hexane, and 9 parts cyclopentane to a high-speed shear press in a specific ratio. Set the speed to 2500 rpm and stir for 75 seconds. Then add 1.2 parts catalyst and continue stirring to form a uniform foaming liquid. Next, add 48 parts of the second reinforcing agent (24 parts kaolin, 13 parts magnesium oxide, and 11 parts alumina). After mechanically stirring until uniform, mix with the main material and let stand at 25°C for 15 minutes to form a slurry with good fluidity and dispersibility.

[0035] S3, Vibration foaming Pour the slurry into a stainless steel mold and place it on a vibrating table to vibrate at a frequency of 10 Hz for 3 minutes to promote the uniform rise of bubbles and inhibit the merging of bubbles.

[0036] S4, room temperature curing and heat curing After vibration, the mold is left to cure at room temperature for 36 hours before demolding. The demolded foam is then placed in a 50°C hot air circulating drying oven for 30 hours to promote complete cross-linking and stability of the cell skeleton.

[0037] Comparative Example 1 (C1) To verify the rationality and technical effectiveness of the component ratios in this application, the following comparative example (C1) was designed, with the specific formulation as follows (by mass parts): Polyurethane prepolymer: 100 parts; Total foaming agent: 50 parts, including 20 parts water, 20 parts n-hexane, and 10 parts cyclopentane; Heat-resistant modifier: 12 parts, including 4 parts tert-butyldimethylsilane, 4 parts 3-isocyanate-propyltriethoxysilane, and 4 parts cyclopentyltrimethoxysilane; First reinforcing agent: 1 part, which is polypropylene oxide (hydroxyl value 90 mgKOH / g, molecular weight 1500). Second reinforcing agent: 30 parts, including 15 parts kaolin, 10 parts magnesium oxide, and 5 parts aluminum oxide; Permeable modifier: 10 parts, consisting of 5 parts dimethyl glutarate, 3 parts ethyl 2-bromoisocyanate, and 2 parts ethyl isocyanate; Catalyst: 1.2 parts, a compound tertiary amine system.

[0038] Preparation method: Following the same preparation steps as in Example 3 (T3), the foamed sample was finally obtained through main material reaction, catalytic pulping, vibration foaming and room temperature curing + thermal curing process.

[0039] Comparative Example 2 (C2) To further verify the role of the permeable modifier and dual reinforcing agent structure in this invention, the following comparative example (C2) was designed, with the following formulation and preparation method (by mass parts): Polyurethane prepolymer: 100 parts; Total foaming agent: 40 parts, including 14 parts water, 16 parts n-hexane, and 10 parts cyclopentane; Heat-resistant modifier: 8 parts, including 2 parts tert-butyldimethylsilane, 3 parts 3-isocyanate-propyltriethoxysilane, and 3 parts cyclopentyltrimethoxysilane; First reinforcing agent: 3 parts, which is polypropylene oxide (hydroxyl value 90 mgKOH / g, molecular weight 1600). Second reinforcing agent: 48 parts, including 40 parts kaolin, 5 parts magnesium oxide, and 3 parts aluminum oxide; Catalyst: 1.0 part.

[0040] Preparation method: Referring to the process steps of Example 3 (T3), the main material reaction, catalytic pulping, vibration foaming, room temperature curing and thermal curing process are completed.

[0041] Comparative Example 3 (C3) To verify the contribution of the dual reinforcement system in this invention to mechanical properties and structural stability, Comparative Example 3 (C3) was designed with the following raw material proportions (by mass): Polyurethane prepolymer: 100 parts; Total foaming agent: 40 parts, including 13 parts water, 18 parts n-hexane, and 9 parts cyclopentane; Heat-resistant modifier: 8 parts, including 2 parts tert-butyldimethylsilane, 3 parts 3-isocyanate-propyltriethoxysilane, and 3 parts cyclopentyltrimethoxysilane; First reinforcing agent: 4 parts, which is polypropylene oxide (hydroxyl value of about 90 mgKOH / g, molecular weight 1700). Permeable modifier: 11 parts, consisting of 5 parts dimethyl glutarate, 3 parts ethyl 2-bromoisocyanate, and 3 parts ethyl isocyanate; Catalyst: 1.2 parts.

[0042] Preparation method: Similar to Example 3 (T3), the main material reaction, catalytic pulping, vibration foaming, room temperature curing and heat curing treatment were completed according to the standard steps.

[0043] Comparative Example 4 (C4) To verify the scientific validity and necessity of the composition ratio of the second reinforcing agent in this invention, the following Comparative Example 4 (C4) was designed, with the following raw material proportions (by mass): Polyurethane prepolymer: 100 parts; Total foaming agent: 40 parts, including 13 parts water, 18 parts n-hexane, and 9 parts cyclopentane; Heat-resistant modifier: 8 parts, including 2 parts tert-butyldimethylsilane, 3 parts 3-isocyanate-propyltriethoxysilane, and 3 parts cyclopentyltrimethoxysilane; First reinforcing agent: 3 parts, which is polypropylene oxide (hydroxyl value of about 85 mgKOH / g, molecular weight 1500). Second reinforcing agent: 48 parts, including 10 parts kaolin, 25 parts magnesium oxide, and 13 parts aluminum oxide; Permeable modifier: 11 parts, consisting of 5 parts dimethyl glutarate, 3 parts ethyl 2-bromoisocyanate, and 3 parts ethyl isocyanate; Catalyst: 1.2 parts.

[0044] Preparation method: Similar to Example 3 (T3), the preparation process was carried out using the following steps: main material reaction, catalytic pulping, vibration foaming, room temperature curing, and thermal curing.

[0045] Comparative Example 5 (C5) To verify the comprehensive performance advantages of this invention compared to existing traditional polyurethane foams, Comparative Example 5 (C5) was designed, with the following raw material formulation (by mass parts): Polyurethane prepolymer: 100 parts; Foaming agent: 40 parts, including 15 parts water, 15 parts n-hexane, and 10 parts cyclopentane; First reinforcing agent (polyether polyol): 3 parts, hydroxyl value 80 mgKOH / g; Catalyst: 1.2 parts (compound tertiary amine catalyst); Surfactant: 1.0 part; Preparation method: The conventional PU foaming process is as follows: the polyurethane prepolymer is mixed and stirred evenly with the polyether polyol; the catalyst, surfactant and foaming agent are added, and the mixture is stirred rapidly for 30 seconds. Pour into a mold and allow it to self-foam at room temperature; cure for 24 hours, then demold and allow to mature naturally at room temperature for 48 hours.

[0046] The technical features that differentiate the comparative model from implementation three are shown in Table 1: Table 1. Summary of Distinguishing Technical Features

[0047] Comparative experiment To verify the technical advantages of the high-temperature resistant, tough, and breathable sponge described in this invention in terms of structural formulation and preparation process, Examples 1 (T1), 2 (T2), and 3 (T3) were selected as representative samples, and Comparative Examples 1 (C1) to 5 (C5) were set as control samples under different deviation conditions or as references to existing technologies. All samples underwent standardized index testing and performance comparison. Each sample was molded using a mold of the same size (200 mm × 200 mm × 30 mm), and its air permeability, tensile properties, drop ball rebound rate, and high-temperature aging resistance were tested.

[0048] Test items and methods 1. Breathability test: Test equipment: Air permeability tester (Textest FX 3300); Test Procedure: Cut the sponge sample into 100 mm × 100 mm dimensions; install it into the test fixture, ensuring a seal; set the test pressure difference to 100 Pa, and measure the volume of air passing through the sample per second; express the measured value in L / m³. 2 / s indicates that the average value is taken from 3 records.

[0049] 2. Tensile strength test: Testing equipment: Electronic tensile testing machine (Instron 3365); Test procedure: Cut a standard dumbbell-shaped sample; clamp both ends and set the stretching speed to 500 mm / min; stretch until fracture, record the elongation at fracture, and calculate the elongation (%); measure each sample 3 times and take the average value.

[0050] 3. Ball rebound rate test: Testing equipment: Ball rebound tester; Test procedure: Take a sample with a diameter of 50 mm; drop a steel ball freely from a fixed height (500 mm) and record the first rebound height; rebound rate = (rebound height / drop height) × 100%, in %; repeat the test 3 times and take the average value.

[0051] 4. High temperature resistance test: Test conditions: Placed in a constant temperature aging chamber at 150℃ for 24 hours; Testing and evaluation: Observe whether the sponge collapses, deforms, powders, or cracks before and after aging; judge the shape retention and color stability; and evaluate heat resistance and structural stability.

[0052] The experimental results are shown in Table 2: Table 2 Comparison of experimental results

[0053] Data Analysis: As can be seen from the experimental data, Examples T1 to T3 exhibit significantly better overall performance than Comparative Examples C1 to C5 and existing technology products in terms of air permeability, elongation, ball rebound rate, and high temperature resistance.

[0054] 1. Microstructure: like Figure 1 As shown, the sponge structure of Embodiment 3 of the present invention has uniform pores, forming a stable frame structure, and has good and complete circular or elliptical micro air chambers.

[0055] 2. Breathability: like Figure 2 As shown, the air permeability range of the embodiment is 34.2–51.3 L / m. 2 / s, significantly higher than the existing technology's 8.9L / m 2 / s and comparative examples (C1-C5) are generally below 30 L / m 2 The result is / s. This difference indicates that the water-permeable modifier and the microporous structure formation mechanism in this invention effectively improve the gas permeability of the material, which is conducive to heat and moisture exchange under high temperature conditions, and is especially suitable for slow release and hot pressing applications in heat-resistant scenarios.

[0056] 3. Elongation: like Figure 3 As shown, the elongation rates of T1 to T3 range from 286% to 365%, which are significantly better than those of comparative examples C1 (elongation rate less than 200%) and C2 to C5 (range 142% to 231%). This indicates that, under the synergistic effect of the polyurethane prepolymer, chain extender, and specific dual reinforcing agent used in this invention, the material network structure possesses stronger extensibility, improving overall flexibility and deformation resistance.

[0057] 4. Ball rebound rate: like Figure 4 As shown, the rebound rate of the falling ball in the embodiment is 10.5% to 11.8%, which is slightly lower than that of the comparative examples (most of which are between 14% and 25%). This indicates that the internal energy dissipation rate of the material is relatively high, which is beneficial for achieving a buffering and energy absorption effect. This result, combined with excellent tensile strength and thermal stability, makes it suitable for scenarios that require high impact resistance and high rebound suppression, such as high-temperature pads or flame-retardant cushioning components.

[0058] 5. High temperature resistance: After aging at 150°C for 24 hours, the examples did not exhibit collapse, pulverization, or significant deformation, while comparative examples C1 and C2, as well as existing technology products, all showed varying degrees of collapse and pulverization under the same conditions. This demonstrates that the present invention achieves excellent heat resistance retention by introducing a composite heat-resistant modifier and multiple reinforcing structures.

[0059] In summary, the experimental results fully verify the significant advantages of the formulation of this invention in terms of synergistic structural enhancement, maintenance of flexibility, and stability under high-temperature conditions. While maintaining high resilience, it significantly improves high-temperature resistance and air permeability, especially in terms of air permeability and thermal stability, achieving performance breakthroughs that are difficult to achieve with existing technologies. Comparison with comparative samples not only demonstrates the crucial role of raw material selection and proportion control but also proves the technical effectiveness and practicality of the material system proposed in this invention.

[0060] The basic principles, main features, and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-temperature resistant, tough, and breathable sponge, characterized in that, It is made from the following raw materials in the following proportions by weight: 100 parts of polyurethane prepolymer; The foaming agent consists of 38-42 parts, of which water comprises 10-16 parts, n-hexane 15-22 parts, and cyclopentane 10-14 parts; 5-10 parts of heat-resistant modifier, including: 1-3 parts of tert-butyldimethylsilane, 2-4 parts of 3-isocyanopropyltriethoxysilane, and 2-4 parts of cyclopentyltrimethoxysilane; The first reinforcing agent is 2-4 parts, with a hydroxyl value of 70-100 mgKOH / g; The second reinforcing agent, consisting of 40-55 parts, is composed of kaolin, magnesium oxide, and aluminum oxide. The permeable modifier consists of 8-14 parts of dimethyl glutarate, ethyl 2-bromoisocyanate, and ethyl isocyanate.

2. The high-temperature resistant, tough, and breathable sponge according to claim 1, characterized in that: The polyurethane prepolymer is a product obtained by reacting toluene diisocyanate with a polyether polyol with a hydroxyl value between 45-55 mgKOH / g at 80-90°C for 2 hours, followed by vacuum dehydration at 90°C for 2 hours, with an NCO content of 13-17%.

3. The high-temperature resistant, tough, and breathable sponge according to claim 1, characterized in that: The first reinforcing agent is polypropylene oxide with a molecular weight of 1200-1800, and the amount added is 2-4% of the polyurethane prepolymer.

4. The high-temperature resistant, tough, and breathable sponge according to claim 1, characterized in that: In the second reinforcing agent, the mass ratio of kaolin, magnesium oxide and aluminum oxide is (2-3):(1-1.5):(0.8-1.2), and the total amount added is 40-55 parts.

5. The high-temperature resistant, tough, and breathable sponge according to claim 1, characterized in that: The permeable modifier is composed of 4-6 parts of dimethyl glutarate, 2-4 parts of ethyl 2-bromoisocyanate, and 2-4 parts of ethyl isocyanate.

6. A method for preparing a high-temperature resistant, tough, and breathable sponge, characterized in that, Includes the following steps: S1. Main material reaction: The polyurethane prepolymer, heat-resistant modifier, first reinforcing agent and water-permeable modifier are added to the reactor in a mass ratio of 100:(5-10):(2-4):(8-14), and stirred and heated at 90-110℃ for 8-12 minutes to obtain the main material mixture; S2. Catalytic pulping: Water, n-hexane, and cyclopentane are mixed in a mass ratio of (10-16):(15-22):(10-14), and then a catalyst is added. The catalyst is a 1:1 mixture of triethylenediamine and dimethylaniline. The mixture is stirred at room temperature, and then 40-55 parts of the second reinforcing agent are added. After mixing, the mixture is combined with the main material and allowed to stand for 10-15 minutes to form a slurry.

7. The method for preparing a high-temperature resistant, tough, and breathable sponge according to claim 6, characterized in that: In step S3, the slurry is injected into the mold and placed on a vibrating table and vibrated at a frequency of 5-15Hz for 2-5 minutes to make the bubble cells evenly distributed.

8. The method for preparing a high-temperature resistant, tough, and breathable sponge according to claim 6, characterized in that: In step S4, the mold is left to stand in a room temperature environment to cure for 30-40 hours. After demolding, the sample is placed in an environment of 40-60℃ to mature for 24-36 hours.

9. The method for preparing a high-temperature resistant, tough, and breathable sponge according to claim 6, characterized in that: Before mixing the foaming agent, stir it at 2000-3000 rpm for 60-90 seconds using a high-speed shear machine. During the standing period, maintain an environment of 25±2℃ to prevent air bubbles from escaping and particles from settling.

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