A polyurethane derived composite and a method of making the same

Abstract

This invention discloses a polyurethane-derived composite material and its preparation method, relating to the field of polymer composite materials technology. The invention includes heating a polyurethane prepolymer to 60–80°C, adding hydroxylated acrylate and a catalyst, and stirring until the reaction is complete to obtain a modified polyurethane matrix. Modified nano-silica and a silane coupling agent are mixed, ultrasonically dispersed uniformly, and then added to the modified polyurethane matrix, stirred at high speed until complete to form a composite slurry. A crosslinking agent is added to the composite slurry, stirred uniformly, and then injected into a preheated mold. After curing at 80–100°C, the mixture is cooled and demolded to obtain the polyurethane-derived composite material. The preparation process of this invention is easy to control, and the obtained polyurethane-derived composite material simultaneously possesses excellent mechanical properties, weather resistance, and wear resistance, with good product consistency.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, specifically to a polyurethane-derived composite material and its preparation method. Background Technology

[0002] Polyurethane materials, with their excellent elasticity, adhesion, and processability, have been widely used in various fields such as automotive interiors, new energy battery pack sealing, and high-end building materials, becoming an indispensable key polymer material in modern manufacturing. However, traditional polyurethane materials are limited by inherent defects in their molecular structure, resulting in significant performance shortcomings: First, insufficient cross-linking density of molecular chain segments leads to low mechanical strength, with tensile strength generally below 35 MPa, making it difficult to withstand long-term mechanical loads in scenarios such as automotive interiors; second, weak anti-aging properties, easily causing yellowing, cracking, and performance degradation under complex conditions such as high temperatures and ultraviolet radiation inside the vehicle, severely shortening the material's service life; third, poor wear resistance, failing to meet the requirements of high-frequency contact parts in automotive interiors. These defects greatly limit the promotion and application of polyurethane materials in high-end manufacturing scenarios. With the rapid development of automotive lightweighting and the new energy industry, the market demand for high-performance polyurethane-based composite materials is becoming increasingly urgent.

[0003] In existing technologies, improving the performance of polyurethane materials often involves simple filling or conventional modification. For example, in patent application CN121473144A, entitled "A Breathable and Peel-Resistant Waterborne / Solvent-Free Polyurethane Synthetic Leather and Its Preparation Method," the solvent-free polyurethane layer's slurry consists of a carbon dioxide-based polyether prepolymer, color paste, dispersant, isocyanate-modified aerogel, and nanofillers. The waterborne polyurethane surface layer consists of an epoxy resin-modified triethylamine-neutralized carboxylic acid-based waterborne polyurethane emulsion, epoxy-modified aerogel, waterborne color paste, defoamer, and thickener. The polyurethane in this case utilizes conventional methods. Modification methods include filling with nano-kaolin, nano-calcium carbonate, and ultrafine barium sulfate as fillers; another example is the invention patent CN117656637B, entitled "A High Light Resistance Polyurethane Composite Material and Its Preparation Method and Application," which also uses a large amount of functional fillers to improve the mechanical properties or flame retardant properties of the product. These methods generally suffer from problems such as filler agglomeration, weak interfacial bonding between the matrix and filler, and limited performance improvement. They cannot achieve synergistic optimization of mechanical strength, weather resistance, and wear resistance, and cannot meet the stringent requirements of high-end applications such as automotive interiors and new energy battery pack sealing. Therefore, how to make polyurethane materials possess high strength, high weather resistance, and high wear resistance in a simpler and more effective way has become a key technical challenge that urgently needs to be solved in the field of polymer materials. Summary of the Invention

[0004] The purpose of this invention is to provide a polyurethane-derived composite material and its preparation method, so that the polyurethane material has high strength, high weather resistance, and high wear resistance.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a polyurethane-derived composite material, comprising the following steps: S1 is made by weighing the following raw materials in parts by weight: 40-60 parts of MDI type polyurethane prepolymer, 5-10 parts of hydroxylated acrylate, 8-15 parts of modified nano silica, 2-5 parts of silane coupling agent, 0.5-2 parts of catalyst, and 1-3 parts of crosslinking agent. S2 heats the polyurethane prepolymer to 60-80°C and holds it at that temperature. Then, hydroxylated acrylate and a catalyst are added, and the mixture is stirred until the reaction is complete to obtain the modified polyurethane matrix. S3 mixes modified nano-silica with a silane coupling agent, disperses it evenly by ultrasonication, and then adds it to the modified polyurethane matrix, stirring at high speed to form a composite slurry. S4 adds a crosslinking agent to the composite slurry, stirs it evenly, pours it into a preheated mold, keeps it at 80-100℃ for curing, and then cools and demolds it to obtain a polyurethane-derived composite material.

[0006] Preferably, in step S1 above, the hydroxylated acrylate is 2-hydroxyethyl acrylate; the modified nano silica is nano silica with a surface modified by a silane coupling agent; the catalyst is dibutyltin dilaurate; and the crosslinking agent is trimethylolpropane.

[0007] Preferably, in step S2 above, the stirring speed is 300-500 r / min, and the stirring time is 2-4 h. The molecular structure is characterized by infrared spectroscopy to confirm that the grafting reaction is complete.

[0008] Preferably, in step S3 above, the ultrasonic dispersion frequency is 20-30 kHz, the ultrasonic treatment lasts for 30-60 min, the high-speed stirring speed is 800-1000 r / min, and the stirring lasts for 1-2 h.

[0009] Preferably, in step S4 above, the mold preheating temperature is 50-60°C, the curing time is 3-5 hours, and the temperature is maintained stable by a temperature control system during the curing process.

[0010] Preferably, the above preparation method further includes post-processing and testing. The obtained polyurethane-derived composite material is cooled to room temperature and then demolded. The tests include tensile strength, weather resistance, and abrasion resistance.

[0011] Another technical solution provided by the present invention: a polyurethane-derived composite material prepared by the above preparation method.

[0012] Preferably, the tensile strength of the above composite material is ≥50MPa, and its weather resistance is improved by more than 60% compared with polyurethane materials that do not contain hydroxylated acrylate and silane coupling agents and use unmodified nano-silica.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. This polyurethane-derived composite material uses hydroxylated acrylate as a novel graft monomer, breaking through the performance limitations of traditional graft monomers. It can precisely optimize the distribution and crosslinking density of polyurethane molecular chain segments, effectively overcoming the anti-aging bottleneck of traditional polyurethane materials. Actual testing shows that the material prepared using this method has weather resistance improved by more than 60% compared to traditional polyurethane, effectively resisting the effects of high temperature, ultraviolet radiation, and other complex working conditions in automotive interior scenarios, completely solving the problems of yellowing, cracking, and performance degradation of traditional materials. The material is suitable for high-end scenarios such as automotive interiors and new energy battery pack sealing, filling the gap in the domestic high-end product market and effectively reducing supply chain security risks in related industries.

[0014] 2. This polyurethane-derived composite material uses silane coupling agent-modified nano-silica to solve the problems of filler agglomeration and weak interfacial bonding, increasing the interfacial bonding strength between the filler and the matrix by more than 30%, and improving the tensile strength of the material by 40% compared with traditional polyurethane, reaching more than 50MPa. It can stably withstand the long-term mechanical load of automotive interiors and meet the needs of high-end applications. In addition, the modified nano-silica showed an equally important role in the weather resistance test, indicating that it and hydroxylated acrylate are indispensable. The two work synergistically under the preparation method of this invention to obtain the above-mentioned excellent weather resistance.

[0015] 3. The preparation method of this polyurethane-derived composite material accurately identifies the key control points of each step, which can ensure product consistency; the optimized design of the composite molding process and the development of low-temperature and high-efficiency molding technology effectively avoid the problems of bubbles and delamination that are easy to be generated inside the material in traditional molding processes, and achieve stable and controllable material performance.

[0016] 4. This polyurethane-derived composite material and its preparation method have successfully broken through core technologies such as precise modification of polyurethane molecules and filler interface reinforcement. This effectively solves the industry pain points of existing technologies, such as filler agglomeration, weak interfacial bonding, and limited performance improvement. It promotes technological innovation in the polyurethane materials field, significantly improves the R&D and industrialization level of high-performance composite materials in my country, provides key material support for strategic emerging industries such as automotive lightweighting and new energy, effectively reduces enterprises' dependence on imported materials, significantly reduces industrial procurement costs, and helps related industries reduce costs, increase efficiency, and upgrade. At the same time, it can drive the development of upstream and downstream raw materials, equipment, and other related industrial chains, creating significant economic and social benefits and possessing broad industrial application prospects. Detailed Implementation

[0017] The method for preparing the polyurethane-derived composite material of the present invention includes the following steps: Weigh the following raw materials by weight: 40-60 parts of MDI-type polyurethane prepolymer, 5-10 parts of hydroxylated acrylate, 8-15 parts of modified nano-silica, 2-5 parts of silane coupling agent, 0.5-2 parts of catalyst, and 1-3 parts of crosslinking agent. In a preferred embodiment, the hydroxylated acrylate is 2-hydroxyethyl acrylate, whose core function is to graft and modify the polyurethane molecules, precisely optimize the distribution state and crosslinking density of the polyurethane molecular chain segments, thereby significantly improving the anti-aging performance and mechanical strength of the material, and effectively solving the shortcoming of the weak anti-aging ability of traditional polyurethane materials. In a preferred embodiment, the modified nano-silica is nano-silica with a surface modified by a silane coupling agent. The modification treatment can effectively solve the industry problem of filler agglomeration in the prior art, significantly enhance the interfacial bonding force between the filler and the polyurethane matrix, and thus simultaneously improve the wear resistance and tensile strength of the material, achieving synergistic performance optimization. In a preferred embodiment, the catalyst is dibutyltin dilaurate, the crosslinking agent is trimethylolpropane, and the silane coupling agent plays a modifying role. The above components work synergistically and in good coordination, which can ensure the full progress of filler modification and molecular grafting reaction, and also ensure the molding effect and performance stability of the material.

[0018] The polyurethane prepolymer is heated to 60-80℃ and kept at a constant temperature. Hydroxylated acrylate and catalyst are added and stirred until the reaction is complete. Specifically, the stirring speed can be 300-500 r / min. The completeness of the reaction can be confirmed by characterizing the molecular structure by infrared spectroscopy, or by stirring for 2-4 hours. After the reaction, the modified polyurethane matrix is ​​obtained. The modified nano-silica is mixed with a silane coupling agent and ultrasonically dispersed evenly. For reference, the ultrasonic frequency should be 20-30 kHz and the ultrasonication time should be 30-60 min. Then it is added to the modified polyurethane matrix and stirred at high speed for 1-2 h, for example, at 800-1000 r / min, to obtain the composite slurry. A crosslinking agent is added to the composite slurry, and after stirring evenly, it is poured into a preheated mold. For reference, the mold preheating temperature can be selected as 50-60℃. After curing at 80-100℃, the polyurethane-derived composite material is obtained by cooling and demolding. The curing time is generally 3-5 hours. During the curing process, the temperature can be kept stable by a temperature control system to avoid affecting the material performance due to temperature fluctuations. Further, after the obtained polyurethane-derived composite material is cooled to room temperature, it is demolded and subjected to comprehensive testing of the material using professional equipment such as a universal testing machine and an aging test chamber, in accordance with the relevant testing standards for automotive interior materials. The testing methods for tensile strength, weather resistance, and abrasion resistance are as follows: tensile strength is tested according to GB / T 1040.1-2006 "Determination of tensile properties of plastics - Part 1: General Rules", weather resistance is tested according to GB / T 16422.2-2014 "Laboratory exposure test method for plastics - Part 2: Xenon arc lamp", and abrasion resistance is tested according to GB / T 2726-2005 "Physical and mechanical tests of leather - Determination of abrasion resistance".

[0019] The present invention will be further described in detail below with reference to several embodiments. The following are not all embodiments of the present invention and should not be regarded as an absolute limitation on the scope of protection.

[0020] The raw materials used in the following examples and comparative examples include: Polyurethane prepolymer (MDI type): Covestro Hydroxylated acrylates (2-hydroxyethyl acrylate): BASF Modified Nano-Silica: Fujian Yuanxiang New Materials Co., Ltd. Silane coupling agent: Anhui Sibao Organosilicon New Materials Co., Ltd. Crosslinking agent (trimethylolpropane): Shanghai Yuanye Biotechnology Co., Ltd. Catalyst (Dibutyltin Dilaurate): Anhui Sibao Organosilicon New Materials Co., Ltd. Example 1: The following components are taken by weight: 52 parts polyurethane prepolymer, 7.5 parts hydroxylated acrylate, 11.8 parts modified nano silica, 2.8 parts silane coupling agent, 1.2 parts dibutyltin dilaurate, and 1.9 parts trimethylolpropane.

[0021] The preparation steps are as follows: (1) Molecular modification: The polyurethane prepolymer was put into the reactor, heated to 72°C and kept at a constant temperature. Hydroxylated acrylate and dibutyltin dilaurate were added and stirred at 420 r / min for 3.2 h. The molecular grafting reaction was confirmed to be sufficient and complete by infrared spectroscopy (FT-IR) to obtain the modified polyurethane matrix.

[0022] (2) Filler composite: The modified nano silica and silane coupling agent are mixed evenly and placed in an ultrasonic disperser. The mixture is ultrasonically dispersed at a frequency of 26 kHz for 48 min. Then, the dispersed filler system is slowly injected into the modified polyurethane matrix. The stirring speed is increased to 920 r / min and stirring is continued for 1.6 h to form a uniform and stable composite slurry.

[0023] (3) Molding and curing: Add trimethylolpropane to the composite slurry, stir evenly and quickly inject into the mold preheated to 56°C, move the mold into the curing oven and keep it at 91°C for 4.2 hours. During this period, the temperature inside the oven is strictly maintained through the temperature control system.

[0024] (4) Post-processing and testing: After cooling to room temperature, demold to obtain the finished composite material; The finished product test results show that the tensile strength is 52.3MPa, the weather resistance is 65.8% higher than that of traditional polyurethane, and the wear resistance meets relevant standards, which can meet the requirements of high-end automotive interiors.

[0025] Example 2: The following components are taken in parts by weight: 45.5 parts of polyurethane prepolymer, 6.2 parts of hydroxylated acrylate, 10.3 parts of modified nano silica, 2.6 parts of silane coupling agent, 0.85 parts of dibutyltin dilaurate, and 1.6 parts of trimethylolpropane.

[0026] The preparation steps are as follows: (1) Molecular modification: The polyurethane prepolymer was put into the reactor, heated to 66 °C and kept at a constant temperature. Hydroxylated acrylate and dibutyltin dilaurate were added, and the mixture was stirred at 360 r / min for 2.6 h. The molecular grafting reaction was confirmed to be complete by infrared spectroscopy.

[0027] (2) Filler composite: Nano silica and modifier are mixed evenly and placed in an ultrasonic disperser for ultrasonic dispersion for 36 min. Then, it is injected into the modified polyurethane matrix and stirred continuously at a speed of 860 r / min for 1.3 h to form a uniform composite slurry.

[0028] (3) Molding and curing: Add crosslinking agent to the composite slurry, stir evenly and then inject into a mold preheated to 53°C. Move the mold into the curing oven and keep it at 86°C for 3.6 hours to maintain the temperature inside the oven.

[0029] (4) Post-processing and testing: After cooling to room temperature, demold to obtain the finished composite material; The finished product test results show that the tensile strength is 50.7MPa, the weather resistance is 62.5% higher than that of traditional polyurethane, and the wear resistance meets relevant standards, which can meet the requirements of high-end automotive interiors.

[0030] Example 3: The following components are taken by weight: 58.2 parts of polyurethane prepolymer, 9.3 parts of hydroxylated acrylate, 14.5 parts of modified nano silica, 4.2 parts of silane coupling agent, 1.8 parts of dibutyltin dilaurate, and 2.7 parts of trimethylolpropane.

[0031] The preparation steps are as follows: (1) Molecular modification: The polyurethane prepolymer was put into the reactor, heated to 78°C and kept at a constant temperature. Hydroxylated acrylate and dibutyltin dilaurate were added and stirred at 480 r / min for 3.8 h. The molecular grafting reaction was confirmed to be sufficient and complete by infrared spectroscopy (FT-IR) to obtain the modified polyurethane matrix.

[0032] (2) Filler composite: The modified nano silica and silane coupling agent are mixed evenly and placed in an ultrasonic disperser. The mixture is ultrasonically dispersed at a frequency of 29 kHz for 55 min. Then the dispersed filler system is slowly injected into the modified polyurethane matrix. The stirring speed is increased to 980 r / min and stirring is continued for 1.9 h to form a uniform composite slurry.

[0033] (3) Molding and curing: Add trimethylolpropane to the composite slurry, stir evenly and quickly inject into the mold preheated to 59°C, move the mold into the curing oven and keep it at 98°C for 4.8 hours. During this period, the temperature inside the oven is kept stable by the temperature control system.

[0034] (4) Post-processing and testing: After cooling to room temperature, demold to obtain the finished composite material; The finished product test results show that the tensile strength is 54.7MPa, the weather resistance is 68.3% higher than that of traditional polyurethane, and the wear resistance meets relevant standards, which can meet the requirements of high-end automotive interiors.

[0035] Example 4: The following components are taken by weight: 41.3 parts polyurethane prepolymer, 5.2 parts hydroxylated acrylate, 8.5 parts modified nano silica, 2.2 parts silane coupling agent, 0.6 parts dibutyltin dilaurate, and 1.2 parts trimethylolpropane.

[0036] The preparation steps are as follows: (1) Molecular modification: The polyurethane prepolymer was heated to 62 °C and kept at a constant temperature. Hydroxylated acrylate and catalyst were added, and the reaction was stirred at 320 r / min for 2.2 h. The grafting reaction was confirmed to be complete by infrared spectroscopy.

[0037] (2) Filler composite: Nano silica and modifier are mixed evenly and ultrasonically dispersed in an ultrasonic disperser for 32 min. Then, it is injected into the modified polyurethane matrix and stirred continuously at a speed of 820 r / min for 1.1 h to form a uniform composite slurry.

[0038] (3) Molding and curing: Add crosslinking agent to the composite slurry, stir evenly and then inject into a mold preheated to 51 ℃. Move the mold into the curing oven and keep it at 82 ℃ for 3.2 h to maintain the temperature inside the oven.

[0039] (4) Post-processing and testing: After cooling to room temperature, demold to obtain the finished composite material; The finished product test results show that the tensile strength is 50.2MPa, the weather resistance is 60.5% higher than that of traditional polyurethane, and the wear resistance meets relevant standards, which can meet the requirements of high-end automotive interiors.

[0040] Comparative Example 1 (using hydroxylated acrylates not present in this invention): The following components are taken by weight: 52 parts polyurethane prepolymer, 7.5 parts ordinary acrylate, 11.8 parts modified nano silica, 2.8 parts silane coupling agent, 1.2 parts dibutyltin dilaurate, and 1.9 parts trimethylolpropane.

[0041] The preparation steps are exactly the same as in Example 1.

[0042] Test results: The tensile strength of the finished product is 38.6 MPa, and the weather resistance is improved by 28.3% compared with traditional polyurethane; however, the abrasion resistance does not meet the relevant standards and cannot meet the requirements of high-end automotive interiors.

[0043] Comparative Example 2 (using commercially available ordinary nano-silica): The following components are taken by weight: 52 parts polyurethane prepolymer, 7.5 parts hydroxylated acrylate, 11.8 parts unmodified nano silica, 2.8 parts silane coupling agent, 1.2 parts dibutyltin dilaurate, and 1.9 parts trimethylolpropane.

[0044] The preparation steps are exactly the same as in Example 1.

[0045] Test results: The tensile strength of the finished product is 42.1 MPa, and the weather resistance is improved by 35.7% compared with traditional polyurethane. However, due to the lack of modification of the nanofiller, the filler agglomeration is serious, the interfacial bonding is weak, the material is prone to cracking, and the wear resistance does not meet the requirements of high-end automotive interiors.

[0046] Comparative Example 3 (using conventional preparation process): The following components are taken by weight: 52 parts polyurethane prepolymer, 7.5 parts hydroxylated acrylate, 11.8 parts modified nano silica, 2.8 parts silane coupling agent, 1.2 parts dibutyltin dilaurate, and 1.9 parts trimethylolpropane.

[0047] Preparation steps: The ultrasonic dispersion step is omitted. The filler is directly mixed and stirred with the modified polyurethane matrix. The molding and curing temperature is adjusted to 110℃ and the curing time is shortened to 2h. The remaining steps are the same as in Example 1.

[0048] Test results: The tensile strength of the finished product is 45.3 MPa, and the weather resistance is improved by 42.5% compared with traditional polyurethane. However, due to the failure to use the composite molding process of this invention, there are obvious bubbles and delamination inside the material, resulting in unstable mechanical properties and poor wear resistance, which cannot meet the needs of high-end application scenarios.

[0049] Comparative Example 4 (without hydroxylated acrylates and silane coupling agents, using commercially available ordinary nano silica): The following components are taken in parts by weight: 60 parts of polyurethane prepolymer, 15 parts of unmodified nano silica, 1.5 parts of catalyst, 2 parts of crosslinking agent, without grafted monomers and modifiers.

[0050] Preparation steps: The conventional melt mixing and molding curing process is adopted. The molding curing temperature is 100℃ and the curing time is 4h.

[0051] Test results: The tensile strength is 34.8 MPa, the weather resistance is not significantly improved, and the wear resistance is poor. It can only be used in low-end scenarios and cannot meet the needs of high-end automotive interiors.

[0052] Table 1 Performance test results of Examples 1-4 and Comparative Examples 1-4

[0053] As can be seen from the comparison of the performance test results of the examples and comparative examples in Table 1 above, the present invention, by using hydroxylated acrylate grafted monomers and silane coupling agents to modify nano-silica, combined with an optimized composite molding process, can significantly improve the tensile strength, weather resistance, and wear resistance of polyurethane-derived composite materials. It effectively solves the inherent shortcomings of traditional polyurethane materials, such as low mechanical strength, weak aging resistance, and poor wear resistance. At the same time, it successfully overcomes the industry problems of filler agglomeration, weak interfacial bonding, and limited performance improvement in existing improved technologies.

[0054] Among them, Comparative Example 1 did not use hydroxylated acrylate, and its weather resistance was significantly reduced; Comparative Example 2, although using hydroxylated acrylate, only slightly improved weather resistance and tensile strength compared to Comparative Example 1, confirming that in the method of the present invention, hydroxylated acrylate and modified nano-silica have a certain synergistic effect. It is possible that the modification of the silica surface makes it form a stronger bond with the polyurethane modified by hydroxylated acrylate, rather than a normal filling relationship; Comparative Example 3 used existing common preparation processes, which could not accurately control the quality of each step as in the present invention, resulting in the final product not achieving the desired effect. In fact, this is a waste of resources caused by the imperfection and lack of precision in past manufacturing technology, and this relatively rough process led to a deviation in the understanding of raw materials, causing many detours in production; Comparative Example 4 used traditional polyurethane materials, and its various properties were far lower than those of the embodiments of the present invention.

[0055] Example 5 Following the exact same parameters and steps as in Example 1, five additional sets of preparations were conducted under the same environmental conditions, with different time periods, different operators, and to observe product consistency.

[0056] Comparative Example 5 Following the exact same parameters and steps as Comparative Example 3, five additional sets of preparations were conducted under the same conditions, with different time periods, different operators, and the same environmental conditions, and the same tests were performed to observe product consistency.

[0057] The test results of Example 5 and Comparative Example 5 are as follows: Table 2 Performance test results of Example 5 and Comparative Example 5

[0058] As can be seen from the comparison of the performance test results of the embodiments and comparative examples in Table 2 above, the method of the present invention obviously has higher product consistency and is more stable in terms of tensile strength and weather resistance. In contrast, it is difficult to control the differences between different batches of products prepared by ordinary processes. This is because the preparation method of the present invention accurately finds the key control points of each step and can also achieve effective control for the operation of different personnel.

[0059] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

[0060] Any aspects of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A process for the preparation of a polyurethane derived composite material, characterized in that, Includes the following steps: S1 is made by weighing the following raw materials in parts by weight: 40-60 parts of MDI type polyurethane prepolymer, 5-10 parts of hydroxylated acrylate, 8-15 parts of modified nano silica, 2-5 parts of silane coupling agent, 0.5-2 parts of catalyst, and 1-3 parts of crosslinking agent. S2 heats the polyurethane prepolymer to 60-80°C and holds it at that temperature. Then, hydroxylated acrylate and a catalyst are added, and the mixture is stirred until the reaction is complete to obtain the modified polyurethane matrix. S3 mixes modified nano-silica with a silane coupling agent, disperses it evenly by ultrasonication, and then adds it to the modified polyurethane matrix, stirring at high speed to form a composite slurry. S4 adds a crosslinking agent to the composite slurry, stirs it evenly, pours it into a preheated mold, keeps it at 80-100℃ for curing, and then cools and demolds it to obtain a polyurethane-derived composite material.

2. A process for the preparation of a polyurethane derived composite material according to claim 1, characterized in that: In step S1, the hydroxylated acrylate is 2-hydroxyethyl acrylate; the modified nano silica is nano silica with a surface modified by a silane coupling agent; the catalyst is dibutyltin dilaurate; and the crosslinking agent is trimethylolpropane.

3. The method for preparing a polyurethane-derived composite material according to claim 1, characterized in that: In step S2, the stirring speed is 300-500 r / min, and the stirring time is 2-4 h. The molecular structure is characterized by infrared spectroscopy to confirm that the grafting reaction is complete.

4. The method for preparing a polyurethane-derived composite material according to claim 1, characterized in that: In step S3, the ultrasonic dispersion frequency is 20-30kHz, and the ultrasonic treatment lasts for 30-60 minutes; the high-speed stirring speed is 800-1000r / min, and the stirring lasts for 1-2 hours.

5. The method for preparing a polyurethane-derived composite material according to claim 1, characterized in that: In step S4, the mold preheating temperature is 50-60℃, the curing time is 3-5 hours, and the temperature is kept stable by a temperature control system during the curing process.

6. The method for preparing a polyurethane-derived composite material according to claim 1, characterized in that: The preparation method also includes post-processing and testing. The obtained polyurethane-derived composite material is cooled to room temperature and then demolded. The tests include tensile strength, weather resistance, and abrasion resistance.

7. A polyurethane-derived composite material prepared by the preparation method according to any one of claims 1 to 6.

8. The polyurethane-derived composite material according to claim 6, characterized in that: The composite material has a tensile strength ≥50MPa and its weather resistance is improved by more than 60% compared with polyurethane materials without hydroxylated acrylate and silane coupling agent and using unmodified nano-silica.

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