A bio-based polyurethane cushioning material

Abstract

The present application relates to the technical field of polyurethane, in particular to a kind of bio-based polyurethane cushion material.The material is prepared by bio-based polyurethane prepolymer foaming, curing.The bio-based polyurethane prepolymer is obtained by the reaction of branched polyol containing quaternary ammonium salt, polytetrahydrofuran ether diol modified attapulgite, soybean oil based polyol, polytetrahydrofuran ether diol, isophorone diisocyanate and other raw materials.The bio-based polyurethane cushion material provided by the present application has high compressive strength and compressive modulus, hysteresis loss rate is less than 20%, elastic recovery rate is higher than 99%, and excellent resilience and energy absorption capacity are shown, which has excellent adaptability and durability in the field of high resilience and lightweight design.

Description

Technical Field

[0001] This invention relates to the field of polyurethane technology, and more particularly to a bio-based polyurethane cushioning material. Background Technology

[0002] With the continuous advancement of science and technology and the rapid development of industry, the demand for high-performance materials is increasing, especially in the field of cushioning materials. Traditional polyurethane materials are widely used in automotive, construction, electronics, and medical fields due to their excellent elasticity, wear resistance, and processability. However, under high temperature, high pressure, or long-term use environments, traditional polyurethane materials often experience a decline in mechanical properties and a weakening of elastic recovery ability, limiting their application in certain high-end fields.

[0003] In recent years, with increasing environmental awareness and the demand for sustainable development, bio-based materials have gradually become a research hotspot. Bio-based polyurethane materials have attracted widespread attention due to their renewable and biodegradable properties. However, bio-based polyurethane materials generally lag behind petroleum-based polyurethane materials in terms of mechanical properties and elastic recovery, which has become a major obstacle to their widespread application.

[0004] To overcome this technical challenge, researchers began exploring ways to improve the performance of bio-based polyurethane materials through modification. Attapulgite, a natural mineral filler, is widely used in the modification of polymer materials due to its unique layered structure and excellent mechanical properties. However, the poor compatibility between attapulgite and the polyurethane matrix leads to unsatisfactory dispersibility and reinforcing effect in polyurethane materials. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a bio-based polyurethane cushioning material to improve the mechanical properties and elastic recovery of bio-based polyurethane.

[0006] To achieve the above objectives, the present invention provides a bio-based polyurethane cushioning material, which is obtained by foaming and curing a bio-based polyurethane prepolymer;

[0007] Preferably, the foaming is performed at 30-40℃ for 10-15 minutes.

[0008] Preferably, the curing is performed at room temperature for 20-28 hours.

[0009] The preparation steps of the bio-based polyurethane prepolymer are as follows:

[0010] (1) Under nitrogen protection, diethanolamine and pentaerythritol tetraacrylate were dissolved in methanol and stirred at room temperature for 20-28 h. After the reaction was completed, the solvent was removed by vacuum distillation, and the crude product was purified by column chromatography to obtain a branched polyol containing tertiary amine.

[0011] (2) Under nitrogen protection, the branched polyol containing tertiary amine and hydroquinone were dissolved in dichloromethane, stirred evenly, and benzyl chloride was added dropwise. The reaction system was heated to 40-50℃ and stirred under reflux for 20-28h. After the reaction was completed, the solid was cooled and precipitated. The solid was washed and dried under vacuum to obtain the branched polyol containing quaternary ammonium salt.

[0012] (3) Add the branched polyol containing quaternary ammonium salt and polytetrahydrofuran ether diol to a mixed solution of deionized water and anhydrous ethanol, stir evenly, add attapulgite, heat to 70-80℃, reflux and stir for 5-7h, after the reaction is completed, filter under reduced pressure, wash, and vacuum dry to obtain modified attapulgite.

[0013] (4) Mix soybean oil-based polyol, polytetrahydrofuran ether diol, modified attapulgite, stannous octoate, dimethylcyclohexylamine and deionized water, stir once, then add isophorone diisocyanate and polyether modified silicone oil, stir a second time to obtain bio-based polyurethane prepolymer.

[0014] Preferably, in step (1), the weight ratio of diethanolamine, pentaerythritol tetraacrylate and methanol is 2.8:2:8-12.

[0015] Preferably, the eluent used in step (1) for column chromatography purification is a mixture of ethyl acetate and petroleum ether in a volume ratio of 1:50.

[0016] Preferably, in step (2), the weight ratio of the branched polyol containing tertiary amine, hydroquinone, dichloromethane and benzyl chloride is 1.5-4.5:0.5-2.5:5-15:0.5-1.5.

[0017] Preferably, in step (3), the weight ratio of branched polyol containing quaternary ammonium salt, polytetrahydrofuran ether diol, deionized water, anhydrous ethanol and attapulgite is 1.5-4.5:0.5-4:100-150:100-150:5-15.

[0018] Preferably, the weight-average molecular weight of the polytetrahydrofuran ether diol in step (3) is 500-700.

[0019] Preferably, in step (4), the weight ratio of soybean oil-based polyol, polytetrahydrofuran ether diol, modified attapulgite, stannous octoate, dimethylcyclohexylamine, deionized water, isophorone diisocyanate, and polyether-modified silicone oil is 40-60:20-40:5-15:0.4-0.6:2-3:3-5:40-70:3-8.

[0020] Preferably, the weight-average molecular weight of polytetrahydrofuran ether diol in step (4) is 1500-2500.

[0021] Preferably, the soybean oil-based polyol in step (4) has a hydroxyl value of 240-260 mg KOH / g and a viscosity of 11000-13000 mPa·s.

[0022] Preferably, in step (4), the first stirring is carried out at a speed of 2000-3000 r / min for 60-100 s, and the second stirring is carried out at a speed of 1000-2000 r / min for 30-60 s.

[0023] The beneficial effects of this invention are:

[0024] This invention provides a bio-based polyurethane cushioning material with high compressive strength and compressive modulus, enabling it to effectively resist deformation under external pressure and provide reliable support and protection for various applications. Its hysteresis loss rate is less than 20%, and its elastic recovery rate is higher than 99%, indicating that the material can quickly return to its original shape after deformation, exhibiting excellent resilience and energy absorption capacity. These properties make this material exhibit superior adaptability and durability in fields requiring high resilience and lightweight design.

[0025] Furthermore, by intercalating attapulgite with branched polyols containing quaternary ammonium salts and low molecular weight polytetrahydrofuran ether diol, the mechanical and elastic properties of the prepared polyurethane cushioning material were significantly improved. This modification method effectively improved the compatibility between attapulgite and the polyurethane matrix, promoted the formation of the polyurethane network, and thus more effectively dispersed stress under load, reducing the risk of permanent deformation. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0027] In the specific embodiments of the present invention, the attapulgite clay is powdered and passed through a 200-mesh sieve; the soybean oil-based polyol has a hydroxyl value of 252 mg KOH / g and a viscosity of 12000 mPa·s; the polytetrahydrofuran ether diol was purchased from Shandong Weishang Chemical Co., Ltd.; and the polyether-modified silicone oil is Dow Corning DC193.

[0028] Example 1:

[0029] (1) Under nitrogen protection, 2.8 g of diethanolamine and 2 g of pentaerythritol tetraacrylate were dissolved in 8 g of methanol and stirred at room temperature for 20 h. After the reaction was completed, the solvent was removed by vacuum distillation. The crude product was purified by column chromatography (elution agent was ethyl acetate / petroleum ether, volume ratio 1:50) to obtain a branched polyol containing tertiary amine.

[0030] (2) Under nitrogen protection, 1.5g of branched polyol containing tertiary amine and 0.5g of hydroquinone were dissolved in 5g of dichloromethane. After stirring evenly, 0.5g of benzyl chloride was added dropwise. The reaction system was heated to 40°C and stirred under reflux for 20h. After the reaction was completed, the solid was cooled and precipitated. The product was washed with diethyl ether and dried under vacuum to obtain branched polyol containing quaternary ammonium salt.

[0031] (3) 1.5g of branched polyol containing quaternary ammonium salt and 0.5g of polytetrahydrofuran ether diol with a weight average molecular weight of 650 were added to a mixed solution of 100g deionized water and 100g anhydrous ethanol. After stirring evenly, 5g of attapulgite was added, heated to 70℃, and stirred under reflux for 5h. After the reaction was completed, the mixture was filtered under reduced pressure. The resulting solid was washed with water and ethanol in sequence, and finally dried under vacuum to obtain modified attapulgite.

[0032] (4) Mix 40g of soybean oil-based polyol, 20g of polytetrahydrofuran ether diol with a weight average molecular weight of 2000, 5g of modified attapulgite, 0.4g of stannous octoate, 2g of dimethylcyclohexylamine and 3g of deionized water, stir at 2000r / min for 60s, then add 40g of isophorone diisocyanate and 3g of polyether modified silicone oil, stir at 1000r / min for 30s to obtain bio-based polyurethane prepolymer;

[0033] (5) The bio-based polyurethane prepolymer was poured into a mold for foaming at 30°C for 10 min, and then cured at room temperature for 20 h to obtain the bio-based polyurethane buffer material.

[0034] Example 2:

[0035] (1) Under nitrogen protection, 2.8 g of diethanolamine and 2 g of pentaerythritol tetraacrylate were dissolved in 10 g of methanol and stirred at room temperature for 24 h. After the reaction was completed, the solvent was removed by vacuum distillation. The crude product was purified by column chromatography (elution was ethyl acetate / petroleum ether, volume ratio 1:50) to obtain a branched polyol containing tertiary amine.

[0036] (2) Under nitrogen protection, 3g of branched polyol containing tertiary amine and 1g of hydroquinone were dissolved in 8g of dichloromethane. After stirring evenly, 1g of benzyl chloride was added dropwise. The reaction system was heated to 45°C and stirred under reflux for 24h. After the reaction was completed, the solid was cooled and precipitated. The product was washed with diethyl ether and dried under vacuum to obtain branched polyol containing quaternary ammonium salt.

[0037] (3) 3g of branched polyol containing quaternary ammonium salt and 2g of polytetrahydrofuran ether diol with a weight average molecular weight of 650 were added to a mixed solution of 120g deionized water and 120g anhydrous ethanol. After stirring evenly, 10g of attapulgite was added, heated to 75°C, and stirred under reflux for 6h. After the reaction was completed, the mixture was filtered under reduced pressure. The resulting solid was washed with water and ethanol in sequence, and finally dried under vacuum to obtain modified attapulgite.

[0038] (4) Mix 50g soybean oil-based polyol, 30g polytetrahydrofuran ether diol with a weight average molecular weight of 2000, 10g modified attapulgite, 0.5g stannous octoate, 2.5g dimethylcyclohexylamine and 4g deionized water, stir at 2500r / min for 80s, then add 55g isophorone diisocyanate and 5g polyether modified silicone oil, stir at 1500r / min for 45s to obtain bio-based polyurethane prepolymer;

[0039] (5) The bio-based polyurethane prepolymer was poured into a mold for foaming at 35°C for 12 min, and then cured at room temperature for 24 h to obtain the bio-based polyurethane buffer material.

[0040] Example 3:

[0041] (1) Under nitrogen protection, 2.8 g of diethanolamine and 2 g of pentaerythritol tetraacrylate were dissolved in 12 g of methanol and stirred at room temperature for 28 h. After the reaction was completed, the solvent was removed by vacuum distillation. The crude product was purified by column chromatography (elution was ethyl acetate / petroleum ether, volume ratio 1:50) to obtain a branched polyol containing tertiary amine.

[0042] (2) Under nitrogen protection, 4.5g of branched polyol containing tertiary amine and 2.5g of hydroquinone were dissolved in 15g of dichloromethane. After stirring evenly, 1.5g of benzyl chloride was added dropwise. The reaction system was heated to 50°C and stirred under reflux for 28h. After the reaction was completed, the solid was cooled and precipitated. The product was washed with diethyl ether and dried under vacuum to obtain branched polyol containing quaternary ammonium salt.

[0043] (3) 4.5g of branched polyol containing quaternary ammonium salt and 4g of polytetrahydrofuran ether diol with a weight average molecular weight of 650 were added to a mixed solution of 150g deionized water and 150g anhydrous ethanol. After stirring evenly, 15g of attapulgite was added, heated to 80℃, and stirred under reflux for 7h. After the reaction was completed, the mixture was filtered under reduced pressure. The resulting solid was washed with water and ethanol in sequence, and finally dried under vacuum to obtain modified attapulgite.

[0044] (4) Mix 60g of soybean oil-based polyol, 40g of polytetrahydrofuran ether diol with a weight average molecular weight of 2000, 15g of modified attapulgite, 0.6g of stannous octoate, 3g of dimethylcyclohexylamine and 5g of deionized water, stir at 3000r / min for 100s, then add 70g of isophorone diisocyanate and 8g of polyether modified silicone oil, stir at 2000r / min for 60s to obtain bio-based polyurethane prepolymer;

[0045] (5) The bio-based polyurethane prepolymer was poured into a mold for foaming at 40°C for 15 min, and then cured at room temperature for 28 h to obtain the bio-based polyurethane buffer material.

[0046] Comparative Example 1:

[0047] The difference between Comparative Example 1 and Example 2 is that the branched polyol containing quaternary ammonium salt in step (3) is replaced with a branched polyol containing tertiary amine;

[0048] The specific steps are as follows:

[0049] (1) Under nitrogen protection, 2.8 g of diethanolamine and 2 g of pentaerythritol tetraacrylate were dissolved in 10 g of methanol and stirred at room temperature for 24 h. After the reaction was completed, the solvent was removed by vacuum distillation. The crude product was purified by column chromatography (elution was ethyl acetate / petroleum ether, volume ratio 1:50) to obtain a branched polyol containing tertiary amine.

[0050] (2) 3g of branched polyol containing tertiary amine and 2g of polytetrahydrofuran ether diol with a weight average molecular weight of 650 were added to a mixed solution of 120g deionized water and 120g anhydrous ethanol. After stirring evenly, 10g of attapulgite was added, heated to 75°C, and stirred under reflux for 6h. After the reaction was completed, the mixture was filtered under reduced pressure. The resulting solid was washed with water and ethanol in sequence, and finally dried under vacuum to obtain modified attapulgite.

[0051] (3) Mix 50g soybean oil-based polyol, 30g polytetrahydrofuran ether diol with a weight average molecular weight of 2000, 10g modified attapulgite, 0.5g stannous octoate, 2.5g dimethylcyclohexylamine and 4g deionized water, stir at 2500r / min for 80s, then add 55g isophorone diisocyanate and 5g polyether modified silicone oil, stir at 1500r / min for 45s to obtain bio-based polyurethane prepolymer;

[0052] (4) The bio-based polyurethane prepolymer was poured into a mold for foaming at 35°C for 12 min, and then cured at room temperature for 24 h to obtain the bio-based polyurethane buffer material.

[0053] Comparative Example 2:

[0054] The difference between Comparative Example 2 and Example 2 is that the polytetrahydrofuran ether diol with a weight average molecular weight of 650 in step (3) is replaced with polytetrahydrofuran ether diol with a weight average molecular weight of 2000.

[0055] The specific steps are as follows:

[0056] (1) Under nitrogen protection, 2.8 g of diethanolamine and 2 g of pentaerythritol tetraacrylate were dissolved in 10 g of methanol and stirred at room temperature for 24 h. After the reaction was completed, the solvent was removed by vacuum distillation. The crude product was purified by column chromatography (elution was ethyl acetate / petroleum ether, volume ratio 1:50) to obtain a branched polyol containing tertiary amine.

[0057] (2) Under nitrogen protection, 3g of branched polyol containing tertiary amine and 1g of hydroquinone were dissolved in 8g of dichloromethane. After stirring evenly, 1g of benzyl chloride was added dropwise. The reaction system was heated to 45°C and stirred under reflux for 24h. After the reaction was completed, the solid was cooled and precipitated. The product was washed with diethyl ether and dried under vacuum to obtain branched polyol containing quaternary ammonium salt.

[0058] (3) 3g of branched polyol containing quaternary ammonium salt and 2g of polytetrahydrofuran ether diol with a weight average molecular weight of 2000 were added to a mixed solution of 120g deionized water and 120g anhydrous ethanol. After stirring evenly, 10g of attapulgite was added, heated to 75°C, and stirred under reflux for 6h. After the reaction was completed, the mixture was filtered under reduced pressure. The resulting solid was washed with water and ethanol in sequence, and finally dried under vacuum to obtain modified attapulgite.

[0059] (4) Mix 50g soybean oil-based polyol, 30g polytetrahydrofuran ether diol with a weight average molecular weight of 2000, 10g modified attapulgite, 0.5g stannous octoate, 2.5g dimethylcyclohexylamine and 4g deionized water, stir at 2500r / min for 80s, then add 55g isophorone diisocyanate and 5g polyether modified silicone oil, stir at 1500r / min for 45s to obtain bio-based polyurethane prepolymer;

[0060] (5) The bio-based polyurethane prepolymer was poured into a mold for foaming at 35°C for 12 min, and then cured at room temperature for 24 h to obtain the bio-based polyurethane buffer material.

[0061] Comparative Example 3:

[0062] The difference between Comparative Example 3 and Example 2 is that the branched polyol containing quaternary ammonium salt in step (3) is replaced with hexadecyltrimethylammonium chloride;

[0063] The specific steps are as follows:

[0064] (1) Add 3g of hexadecyltrimethylammonium chloride and 2g of polytetrahydrofuran ether diol with a weight average molecular weight of 650 to a mixed solution of 120g deionized water and 120g anhydrous ethanol. After stirring evenly, add 10g of attapulgite, heat to 75°C, reflux and stir for 6h. After the reaction is complete, filter under reduced pressure. Wash the obtained solid with water and ethanol in sequence, and finally dry under vacuum to obtain modified attapulgite.

[0065] (2) Mix 50g soybean oil-based polyol, 30g polytetrahydrofuran ether diol with a weight average molecular weight of 2000, 10g modified attapulgite, 0.5g stannous octoate, 2.5g dimethylcyclohexylamine and 4g deionized water, stir at 2500r / min for 80s, then add 55g isophorone diisocyanate and 5g polyether modified silicone oil, stir at 1500r / min for 45s to obtain bio-based polyurethane prepolymer;

[0066] (3) The bio-based polyurethane prepolymer was poured into a mold for foaming at 35°C for 12 min, and then cured at room temperature for 24 h to obtain the bio-based polyurethane buffer material.

[0067] Comparative Example 4:

[0068] The difference between Comparative Example 4 and Example 2 is that the modified attapulgite in step (3) is replaced with attapulgite.

[0069] The specific steps are as follows:

[0070] (1) Mix 50g soybean oil-based polyol, 30g polytetrahydrofuran ether diol with a weight average molecular weight of 2000, 10g attapulgite, 0.5g stannous octoate, 2.5g dimethylcyclohexylamine and 4g deionized water, stir at 2500r / min for 80s, then add 55g isophorone diisocyanate and 5g polyether modified silicone oil, stir at 1500r / min for 45s to obtain bio-based polyurethane prepolymer;

[0071] (2) The bio-based polyurethane prepolymer was poured into a mold for foaming at 35°C for 12 min, and then cured at room temperature for 24 h to obtain the bio-based polyurethane buffer material.

[0072] Performance testing:

[0073] The mechanical properties of the polyurethane cushioning material were tested and analyzed using a universal testing machine, according to the ASTM D3574-05 method. The specimen size was 50 mm × 25 mm (diameter × thickness), and the compression rate was 50 mm / min.

[0074] Compression hardness: The polyurethane cushioning material was subjected to a 50% compression hardness test. The compression modulus was determined according to the standard method of GB / T8813-2008. The results are shown in Table 1.

[0075] Hysteresis loss and elastic recovery: Hysteresis loss test was performed on polyurethane cushioning material. The foam was rapidly compressed to 75% strain, and then the stress was unloaded at the same rate until the indenter returned to its original position. The hysteresis loss rate and elastic recovery rate of the foam were calculated according to the following formulas. The results are shown in Table 1.

[0076]

[0077] Table 1 Performance Test Results

[0078]

[0079]

[0080] Data Analysis:

[0081] As can be seen from the data in Examples 1-3 of Table 1, the bio-based polyurethane cushioning material prepared by this invention exhibits high compressive strength and compressive modulus, indicating that the material displays excellent mechanical properties under external pressure. This high strength and high modulus mean that the material can effectively resist deformation and provide good support and protection under impact or compression. Furthermore, its hysteresis loss rate is less than 20%, and its elastic recovery rate is higher than 99%, indicating that the material can quickly return to its original shape after deformation, exhibiting excellent resilience and energy absorption capacity. These properties make this bio-based polyurethane cushioning material exhibit superior adaptability and durability in various applications, especially in situations requiring high resilience and lightweight design.

[0082] As can be seen from the data in Example 2 and Comparative Example 1 in Table 1, compared with branched polyols containing tertiary amines, branched polyols containing quaternary ammonium salts can effectively improve the compressive strength and compressive modulus of polyurethane buffer materials. Most importantly, they significantly reduce the hysteresis loss rate and improve the elastic recovery rate. This is mainly because the quaternary ammonium salt in the branched polyols can be intercalated into the interlayer of attapulgite through ion exchange. On the one hand, this increases the interlayer spacing of attapulgite, and on the other hand, the introduction of polyols allows attapulgite to crosslink with diisocyanates through the interlayer polyols, thereby improving the mechanical properties and elastic characteristics of the polyurethane material. Specifically, the introduction of quaternary ammonium salts not only enhances the compatibility between attapulgite and the polyurethane matrix, but also promotes the formation of the polyurethane network. The uniformly dispersed intercalated modified attapulgite in the polyurethane network can more effectively disperse stress under load, reducing the permanent deformation of the material.

[0083] As can be seen from the data in Example 2 and Comparative Example 2 in Table 1, the low molecular weight polytetrahydrofuran ether diol can more effectively improve the cushioning performance of polyurethane cushioning materials during intercalation modification. This is mainly because the low molecular weight polytetrahydrofuran ether diol has lower steric hindrance and can be more effectively intercalated into attapulgite, thereby forming a more stable cross-linked structure with the branched polyol containing quaternary ammonium salt and diisocyanate. This helps to improve the flexibility and impact resistance of polyurethane materials, enabling the materials to better recover their shape when subjected to external forces, reducing the risk of damage and deformation.

[0084] As can be seen from the data in Example 2 and Comparative Example 3 in Table 1, compared with the traditional hexadecyltrimethylammonium chloride intercalation modification, the branched polyol containing quaternary ammonium salt prepared by the present invention can significantly improve the compression performance and recovery performance of polyurethane buffer materials. This is mainly because the branched polyol containing quaternary ammonium salt effectively adjusts the interlayer spacing of attapulgite and improves the compatibility of attapulgite in the polyurethane matrix.

[0085] As can be seen from the data in Example 2 and Comparative Example 4 in Table 1, compared with the direct addition of attapulgite, the attapulgite modified by intercalation with branched polyols containing quaternary ammonium salts and polytetrahydrofuran ether diol with a weight average molecular weight of 650 can significantly improve the compression performance and recovery performance of polyurethane buffer materials. This is mainly because the branched polyols containing quaternary ammonium salts and polytetrahydrofuran ether diol coordinate and regulate the interlayer structure of attapulgite and promote the formation of polyurethane network structure.

[0086] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A bio-based polyurethane cushioning material, characterized in that, It is obtained by foaming and curing bio-based polyurethane prepolymer; The preparation steps of the bio-based polyurethane prepolymer are as follows: (1) Under nitrogen protection, diethanolamine and pentaerythritol tetraacrylate were dissolved in methanol and stirred at room temperature for 20-28 h. After the reaction was completed, the solvent was removed by vacuum distillation and the crude product was purified by column chromatography to obtain a branched polyol containing tertiary amine. (2) Under nitrogen protection, the branched polyol containing tertiary amine and hydroquinone were dissolved in dichloromethane, stirred evenly, and benzyl chloride was added dropwise. The reaction system was heated to 40-50℃ and stirred under reflux for 20-28h. After the reaction was completed, the solid was cooled and precipitated. It was washed and dried under vacuum to obtain the branched polyol containing quaternary ammonium salt. (3) Add the branched polyol containing quaternary ammonium salt and polytetrahydrofuran ether diol to a mixed solution of deionized water and anhydrous ethanol, stir evenly, add attapulgite, heat to 70-80℃, reflux and stir for 5-7h, after the reaction is complete, filter under reduced pressure, wash, and vacuum dry to obtain modified attapulgite. (4) Mix soybean oil-based polyol, polytetrahydrofuran ether diol, modified attapulgite, stannous octoate, dimethylcyclohexylamine and deionized water, stir once, then add isophorone diisocyanate and polyether modified silicone oil, stir twice to obtain bio-based polyurethane prepolymer. In step (1), the weight ratio of diethanolamine, pentaerythritol tetraacrylate and methanol is 2.8:2:8-12; In step (2), the weight ratio of branched polyol containing tertiary amine, hydroquinone, dichloromethane, and benzyl chloride is 1.5-4.5:0.5-2.5:5-15:0.5-1.5; In step (3), the weight ratio of branched polyol containing quaternary ammonium salt, polytetrahydrofuran ether diol, deionized water, anhydrous ethanol and attapulgite is 1.5-4.5:0.5-4:100-150:100-150:5-15. The weight-average molecular weight of polytetrahydrofuran ether diol in step (3) is 500-700. In step (4), the weight ratio of soybean oil-based polyol, polytetrahydrofuran ether diol, modified attapulgite, stannous octoate, dimethylcyclohexylamine, deionized water, isophorone diisocyanate, and polyether-modified silicone oil is 40-60:20-40:5-15:0.4-0.6:2-3:3-5:40-70:3-8.

2. The bio-based polyurethane cushioning material according to claim 1, characterized in that, In step (1), the eluent used for column chromatography purification is a mixture of ethyl acetate and petroleum ether in a volume ratio of 1:

50.

3. The bio-based polyurethane cushioning material according to claim 1, characterized in that, The weight-average molecular weight of polytetrahydrofuran ether diol in step (4) is 1500-2500.

4. The bio-based polyurethane cushioning material according to claim 1, characterized in that, In step (4), the hydroxyl value of the soybean oil-based polyol is 240-260 mg KOH / g, and the viscosity is 11000-13000 mPa·s.

5. The bio-based polyurethane cushioning material according to claim 1, characterized in that, In step (4), the first stirring is: stirring at a speed of 2000-3000 r / min for 60-100 s, and the second stirring is: stirring at a speed of 1000-2000 r / min for 30-60 s.

6. The bio-based polyurethane cushioning material according to claim 1, characterized in that, The foaming process is as follows: foaming at 30-40℃ for 10-15 minutes.

7. The bio-based polyurethane cushioning material according to claim 1, characterized in that, The curing process involves curing at room temperature for 20-28 hours.

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