High-temperature-resistant and high-wear-resistant bio-based polyurethane membrane casting solution as well as preparation method and application thereof

Abstract

The invention relates to a high-temperature-resistant and high-wear-resistant bio-based polyurethane membrane casting solution as well as a preparation method and application thereof. The high-temperature-resistant and high-wear-resistant bio-based polyurethane membrane casting solution comprises the following components in parts by weight: 60-80 parts of a solvent, 8-12 parts of wear-resistant high-specific-heat particles, 5-10 parts of a pore-foaming agent, 15-30 parts of modified bio-based polyurethane resin, 2-5 parts of a coupling agent, 2-3 parts of a flatting agent, 0.5-3 parts of a penetrating agent and 0.5-1.5 parts of a defoaming agent. Compared with the prior art, the invention adopts bio-based resin and an environment-friendly formula: acetylated lignin, cellulose nanofiber and other modified bio-based polyurethane resin are adopted to replace traditional petroleum-based raw materials, so that the environmental burden is reduced; the use of non-silicon based bio-based antifoams (such as acrylate copolymers, epoxidized vegetable oil derivatives) avoids silicon contamination and maintains the solution clear.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waterproof and moisture-permeable film materials, and particularly relates to a high-temperature-resistant and high-wear-resistant bio-based polyurethane casting film solution as well as a preparation method and application thereof. BACKGROUND

[0002] With the booming development of the global outdoor sports industry and the increasing demand of consumers for functional footwear products, waterproof and moisture-permeable film technology as a key innovation direction in the field of shoe materials has received widespread attention in recent years. Waterproof and moisture-permeable film needs to block the penetration of external liquid water while allowing internal sweat to be discharged in the form of water vapor, thereby maintaining a dry and comfortable environment inside the shoe. However, the performance bottleneck and environmental problems of existing materials are increasingly prominent, and the contradiction between the environmental burden of traditional petroleum-based materials and the functional defects of bio-based materials has become an important challenge to the sustainable development of the industry.

[0003] The waterproof and moisture-permeable films on the market at present mainly rely on polytetrafluoroethylene (PTFE), thermoplastic polyurethane (TPU) and polyether ester (PEE) material systems. Among them, PTFE microporous film occupies a dominant position due to its excellent waterproof and moisture-permeable performance, but its preparation process needs to use perfluorinated compounds (PFCs), which have environmental risks such as non-degradability and bioaccumulation. The European Union REACH regulation has implemented restrictions on some fluorine-containing compounds, forcing the industry to seek environmentally friendly alternatives. The dense type of moisture-permeable film represented by TPU realizes moisture permeability through hydrophilic groups in the molecular chain, but its waterproofness depends on the dense structure, and often needs to be enhanced by composite process (such as pasting high-density fabric) to improve performance, resulting in increased thickness of the finished product and affecting the lightweight demand of shoe materials.

[0004] In recent years, bio-based polyurethane (Bio-PU) has been considered as an ideal alternative to petroleum-based materials due to its renewable raw material sources (such as castor oil, cellulose derivatives) and potential for degradation. Bio-based polyurethane can significantly reduce carbon footprint by replacing petroleum-based monomers with natural polyol parts. However, the molecular structure design of existing bio-based polyurethane resins focuses on improving basic mechanical properties and bio-based content, and pays insufficient attention to key processing and application properties such as high temperature resistance and wear resistance, which limits its application in high-performance shoe materials. (1) Insufficient high temperature resistance limits processing process compatibility The large-scale production of waterproof and moisture-permeable membranes for shoes generally uses high-temperature composite hot pressing process (typical process temperature 120-150°C) to realize rapid adhesion of the membrane layer and the fabric. However, the introduction of natural polyols in the molecular chain of bio-based polyurethane often leads to a decrease in glass transition temperature (Tg) and thermal decomposition temperature (Td). For example, the Tg of castor oil-based polyurethane is usually lower than 80°C, and chain segment relaxation or thermal degradation easily occurs during high-temperature hot pressing, resulting in deformation of the membrane layer, collapse of the moisture-permeable channel, and even peeling off from the substrate. This defect forces manufacturers to reduce the hot pressing temperature or shorten the processing time, but significantly affects the composite adhesion and production efficiency.

[0005] (2) Insufficient wear resistance restricts product service life Shoes are subjected to dynamic friction during use (such as repeated friction between the tongue and the instep, and contact wear between the insole and the socks), and require waterproof and moisture-permeable membranes to have excellent wear resistance (usually tested by DIN EN 530 standard). However, although the increase in the proportion of flexible segments (such as polyester polyols) in bio-based polyurethane is beneficial to moisture permeability, it weakens the hardness and wear resistance of the material. The Taber abrasion value (CS-10 wheel, 1 kg load) of existing bio-based polyurethane membranes is generally higher than 100 mg / 1000 times, which is much higher than the requirement of <30 mg / 1000 times for high-end shoe materials. Insufficient wear resistance leads to microcracks in the membrane layer after long-term use, which destroys the waterproof barrier and accelerates the decay of moisture permeability.

[0006] (3) Performance balance problem hinders functional integration To achieve waterproof and moisture-permeable functions, polyurethane membranes need to simultaneously satisfy high hydrostatic pressure (≥150 kPa) and high moisture permeability (≥8000 g / m 2 / 24h). The hydrophilicity of bio-based polyurethane can be enhanced by introducing polyethylene glycol (PEG) segments, but excessive PEG will reduce the crystallinity of the membrane layer and exacerbate the dimensional instability at high temperatures. In addition, nano-fillers commonly used for wear resistance modification (such as silicon dioxide and silicon carbide) tend to agglomerate in the casting solution, causing blockage of the moisture-permeable channel. In existing technologies, modification schemes for bio-based polyurethane are mostly aimed at optimizing a single performance, and there is a lack of systematic strategies for synergistically regulating the molecular chain structure, cross-linked network, and filler dispersion, resulting in difficulties in balancing waterproofness, moisture permeability, temperature resistance, and wear resistance.

[0007] In summary, the development of bio-based polyurethane casting solutions with excellent high-temperature resistance, wear resistance, and processing performance is still a technical problem to be solved in the field of waterproof and moisture-permeable membrane materials for shoes, and requires systematic innovation in molecular design, composite modification, and processing technology. SUMMARY

[0008] The purpose of this invention is to overcome at least one of the defects of the prior art and provide a high-temperature resistant, high-wear-resistant bio-based polyurethane casting liquid, its preparation method, and its application.

[0009] The objective of this invention can be achieved through the following technical solutions: One of the objectives of this invention is to provide a high-temperature resistant and highly wear-resistant bio-based polyurethane casting solution, comprising the following components in parts by weight: 60-80 parts solvent, 8-12 parts wear-resistant high specific heat particles, 5-10 parts pore-forming agent, 15-30 parts modified bio-based polyurethane resin, 2-5 parts coupling agent, 2-3 parts leveling agent, 0.5-3 parts penetrant, and 0.5-1.5 parts defoamer.

[0010] Furthermore, the solvent is selected from one or more of dimethylformamide, dimethylacetamide, acetone, tetrahydrofuran, or butanone.

[0011] Furthermore, the wear-resistant, high specific heat particles are selected from Al2O3 powder, paraffin / SiO2, and ceramic micro powder, which can absorb heat and delay resin softening when frictional heat accumulates.

[0012] Furthermore, the pore-forming agent is selected from one or more of wood flour, polyvinylpyrrolidone, sodium chloride, nano-titanium dioxide particles, and light calcium carbonate powder. Furthermore, the modified bio-based polyurethane resin is prepared by modifying 65% bio-based polyether thermoplastic polyurethane with a modifier. The modifier is selected from one or more combinations of acetylated lignin (addition amount 1-5%), cellulose nanofibers (addition amount 1-5%), and tannic acid (addition amount 0.5-1%), which can effectively construct the branched network structure of bio-based polyurethane, improve its temperature resistance, and maintain environmental friendliness.

[0013] Furthermore, the leveling agent is selected from one or more of polydimethylsiloxane, polymethylalkylsiloxane, and organically modified polysiloxane.

[0014] Furthermore, the penetrant is selected from one or more of the anionic surfactants OT-50, OT-70, and OT-75.

[0015] Furthermore, the defoamer is selected from one or more of the following: acrylate copolymer defoamers (such as polyacrylates and vinyl polymers), polyether non-silicone modified defoamers (such as polyoxypropylene-polyoxyethylene block copolymers), and vegetable oil derivative defoamers (such as castor oil and soybean oil products modified by esterification / epoxidation).

[0016] The second objective of this invention is a method for preparing the high-temperature resistant and high-wear-resistant bio-based polyurethane casting solution as described above, comprising: S1. Add solvent, wear-resistant high specific heat particles and pore-forming agent to the reaction vessel and stir until uniform to obtain the first mixture; S2. Add modified bio-based polyurethane resin and coupling agent to the first mixture obtained in S1, and stir again until uniform to obtain the second mixture. S3. Add leveling agent, penetrant and defoamer to the second mixture obtained in S2, and stir until uniform to obtain high temperature resistant and high wear resistant bio-based polyurethane casting liquid.

[0017] The third objective of this invention is to apply the high-temperature resistant and high-wear-resistant bio-based polyurethane casting liquid described above to waterproof and breathable membranes.

[0018] The high-temperature resistant, high-wear-resistant bio-based polyurethane casting solution described in this invention can be applied to the preparation of waterproof and breathable membranes via a blade coating-phase inversion process. Specifically, the casting solution is uniformly coated onto a release paper or fabric substrate, controlling the wet film thickness to be 60-80 μm; it is immediately immersed in a coagulation bath (water / N,N-dimethylformamide volume ratio 8:2) and coagulated at 25-30°C for 2-5 min, during which polyurethane precipitates and solidifies from the solution, while a pore-forming agent forms a micro-nano porous structure within the membrane; it is then washed with water at 30-40°C for 20-30 min to remove residual solvent, followed by drying at 80-100°C for 5-7 min to obtain a high-temperature resistant, high-wear-resistant, waterproof and breathable composite membrane.

[0019] Compared with the prior art, the present invention has the following advantages: (1) This invention uses bio-based resin and environmentally friendly formulation: modified bio-based polyurethane resin such as acetylated lignin and cellulose nanofibers are used to replace traditional petroleum-based raw materials to reduce the environmental burden; non-silicone bio-based defoamers (such as acrylate copolymers and epoxidized vegetable oil derivatives) are used to avoid silicon pollution and keep the solution clear.

[0020] (2) This invention utilizes a synergistic improvement technology for temperature resistance and wear resistance: adding wear-resistant high specific heat particles such as Al2O3 and paraffin / SiO2 absorbs heat during friction, delays resin softening, and enhances wear resistance. By modifying the polyurethane molecular chain with tannic acid and cellulose nanofibers, a cross-linked network is formed, which inhibits molecular chain movement at high temperatures and improves temperature resistance.

[0021] (3) The present invention optimizes the processing technology: first, solid particles (wear-resistant particles, pore-forming agent) are added to the solvent for homogeneous dispersion, and then the resin is added gradually to avoid agglomeration problems caused by a sudden increase in viscosity. By using solvent combination (such as DMF + acetone) and low filler content (8-12% wear-resistant particles), the viscosity of the casting solution is maintained within the processable range (<10000cP).

[0022] (4) The present invention utilizes moisture permeability enhancement technology: using porous materials such as wood flour and nano TiO2 as pore-forming agents to optimize the microporous structure inside the membrane and balance waterproof and moisture permeability performance.

[0023] (5) The present invention utilizes interface bonding strengthening technology: coupling agents such as aminosilane and lactic acid modified titanate are used to enhance the interface bonding between the filler and the resin, thereby improving dispersibility and mechanical properties.

[0024] (6) The present invention balances cost and performance: performance improvement and cost control are achieved by using low addition amounts (0.5-5%) of nano-sized particles (such as Al2O3 powder) and bio-based modifiers (such as tannic acid); and by combining chemical crosslinking, physical blending and nanofilling, the single high-cost modification method (such as the whole nano system) is avoided.

[0025] (7) The present invention proposes a long-term stability solution: high specific heat particles absorb heat and the branched cross-linked structure delays the thermal motion of molecular chains at high temperatures, improves thermomechanical properties, and ensures a long service life. Attached Figure Description

[0026] Figure 1 Here is a surface SEM image of the bio-based membrane prepared in Example 1; Figure 2 A cross-sectional SEM image of the bio-based membrane prepared in Example 1; Figure 3 The surface SEM image of the bio-based membrane prepared for Comparative Example 1.

[0027] Figure 4 SEM image of the bio-based membrane prepared in Comparative Example 1 after hot pressing at 180℃. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0029] In the following embodiments, the specific steps of the bio-based polyether thermoplastic polyurethane and its preparation method, in parts by weight, are as follows: S1. Add 45-55 parts of castor oil-based polyether polyol (Changhua Chemical, BP-1390) to a dry reactor, dehydrate under vacuum at 100-110℃ for 2 hours, cool to 75-80℃, and slowly add 22-28 parts of bio-based PDI (Mitsui Chemicals, D-3725N). React under nitrogen protection for 1.5-2 hours to form an end-NCO prepolymer (NCO mass fraction controlled at 4.5-5.5%). S2. Cool the prepolymer to 60-65℃, add 9-13 parts of BDO and 0.15-0.35 parts of dibutyltin dilaurate, stir and react for 30-40 minutes, and control the viscosity of the system to 5000-8000 mPa·s. S3. Add 0.2-0.5 parts of antioxidant (BASF 1010), keep warm at 65-70℃ for 1 hour, and extrude and granulate to obtain polyether thermoplastic polyurethane with 65% bio-based content.

[0030] Example 1 This embodiment provides a method for preparing a high-temperature resistant and highly wear-resistant bio-based polyurethane casting solution, the specific steps of which are as follows: (1) Add 60 parts of acetone, 10 parts of Al2O3 powder (particle size 10-20μm), and 5 parts of polyvinylpyrrolidone (BASF K30) to reactor 1 and stir at high speed to obtain a uniform solution. (2) Preparation of modified bio-based polyurethane resin: The self-synthesized bio-based polyether thermoplastic polyurethane with a content of 65% was added to the reactor 2 and stirred. After heating to 80°C, cellulose nanofibers accounting for 3% of the bio-based polyurethane resin were added and stirred for 1 h. (3) Add 22 parts of the modified bio-based polyurethane resin and 1% of aminosilane coupling agent (Shin-Etsu Chemical KBE-603) from the above reaction vessel 2 to the reaction vessel 1 and stir at 80°C for 1 h; (4) Add 1.5 parts of organic modified polysiloxane leveling agent (MONENG-1080 from Moneng Chemical), 1 part of penetrant OT-50 (L-OT-50 from Jiangsu Maoheng Chemical), and 0.5 parts of polyether non-silicone modified defoamer (BYK-052 from BYK Chemical) to the above reaction vessel 1 and stir thoroughly to obtain a uniform and clear solution, which is the high-temperature resistant and high-wear-resistant bio-based polyurethane casting liquid. The surface SEM image and cross-sectional SEM image are shown below. Figures 1-2 .

[0031] The casting solution is uniformly coated onto the release paper or fabric substrate, and the wet film thickness is controlled to be 60-80μm. Immediately immerse it in a coagulation bath (water / N,N-dimethylformamide volume ratio 8:2) and coagulate at 25-30℃ for 2-5min. Polyurethane precipitates and solidifies from the solution, while the pore-forming agent forms a micro-nano porous structure in the membrane. Wash with water at 30-40℃ for 20-30min to remove residual solvent, and then dry at 80-100℃ for 5-7min to obtain a high-temperature resistant, high-wear resistant, waterproof and breathable composite membrane.

[0032] Depend on Figure 1As can be seen, the film surface is smooth, dense, and free of obvious defects. This indicates that the leveling agent and defoamer effectively controlled the surface tension during the film-forming process, proving that the nano-Al2O3 particles achieved good dispersion in the resin matrix under the bridging effect of the aminosilane coupling agent, without significant agglomeration. The uniform surface structure is the microscopic basis for the material to achieve high wear resistance.

[0033] Depend on Figure 2 As can be seen, a uniform, continuous, and interconnected micro-nano porous structure has formed inside the membrane. This confirms that the porogen, under the optimized phase transformation process, has successfully constructed ideal moisture permeability channels. This regular pore structure is the fundamental reason for the membrane's high moisture permeability; the wear-resistant particles are firmly embedded in the pore walls, playing a role in strengthening the framework and improving the material's mechanical strength.

[0034] Example 2 This embodiment provides a method for preparing a high-temperature resistant and highly wear-resistant bio-based polyurethane casting solution, the specific steps of which are as follows: (1) Add 63 parts of dimethylformamide, 8 parts of ceramic micro powder (particle size ≤ 5 μm), and 7 parts of light calcium carbonate powder (particle size 1-3 μm) to reactor 1 and perform high-speed homogenization stirring to obtain a uniform solution; (2) Preparation of modified bio-based polyurethane resin: The self-synthesized polyether thermoplastic polyurethane with a bio-based content of 65% was added to the reactor 2 and stirred. After heating to 60°C, acetylated lignin accounting for 1% of the bio-based polyurethane resin was added and stirred for 1.5 h. (3) Add 20 parts of the modified bio-based polyurethane resin and 1% of aminosilane (Shin-Etsu Chemical KBE-603) from reactor 2 to reactor 1 and stir at 60°C for 1 h. (4) Add 1 part of polydimethylsiloxane leveling agent (BYK-077), 0.5 part of penetrant OT-70 (L-OT-70 of Jiangsu Maoheng Chemical), and 0.5 part of polyacrylate vinyl polymer defoamer (TEGOFoamex 810) to the above reaction vessel 1 and stir thoroughly to obtain a uniform and clear solution, which is a high temperature resistant and high wear resistant bio-based polyurethane casting liquid.

[0035] The casting solution is uniformly coated onto the release paper or fabric substrate, and the wet film thickness is controlled to be 60-80μm. Immediately immerse it in a coagulation bath (water / N,N-dimethylformamide volume ratio 8:2) and coagulate at 25-30℃ for 2-5min. Polyurethane precipitates and solidifies from the solution, while the pore-forming agent forms a micro-nano porous structure in the membrane. Wash with water at 30-40℃ for 20-30min to remove residual solvent, and then dry at 80-100℃ for 5-7min to obtain a high-temperature resistant, high-wear resistant, waterproof and breathable composite membrane.

[0036] Example 3 This embodiment provides a method for preparing a high-temperature resistant and highly wear-resistant bio-based polyurethane casting solution, the specific steps of which are as follows: (1) Add 40 parts of dimethylacetamide, 20 parts of dimethylformamide, 5 parts of Al2O3 powder (particle size 10-20μm), 3 parts of paraffin / SiO2 phase change microcapsules (Zhejiang Ruifeng Capsule Technology PCM-28), and 8 parts of nano titanium dioxide particles (particle size 15-30nm) to reactor 1 and stir at high speed to obtain a uniform solution; (2) Preparation of modified bio-based polyurethane resin: Add the self-synthesized bio-based polyether thermoplastic polyurethane with a content of 65% to the reactor 2 and stir. After heating to 80°C, add tannic acid accounting for 0.5% of the bio-based polyurethane resin and stir for 1 hour. (3) Add 21 parts of the modified bio-based polyurethane resin and 1% of lactic acid modified titanate (Aladdin CAS: 79110-90-0) from the above reaction vessel 2 to the reaction vessel 1 and stir at 80°C for 1 h; (4) Add 2 parts of organic modified polysiloxane leveling agent (BYK-333), 0.5 parts of penetrant OT-50 (L-OT-50 of Jiangsu Maoheng Chemical), and vegetable oil derivative defoamer (MOUSSEX 7141HL-V of Oupeng Chemical) to the above reaction vessel 1 and stir thoroughly to obtain a uniform and clear solution, which is a high temperature resistant and high wear resistant bio-based polyurethane casting liquid.

[0037] The casting solution is uniformly coated onto the release paper or fabric substrate, and the wet film thickness is controlled to be 60-80μm. Immediately immerse it in a coagulation bath (water / N,N-dimethylformamide volume ratio 8:2) and coagulate at 25-30℃ for 2-5min. Polyurethane precipitates and solidifies from the solution, while the pore-forming agent forms a micro-nano porous structure in the membrane. Wash with water at 30-40℃ for 20-30min to remove residual solvent, and then dry at 80-100℃ for 5-7min to obtain a high-temperature resistant, high-wear resistant, waterproof and breathable composite membrane.

[0038] Comparative Example 1 This comparative example is basically the same as Example 1, except that Al2O3 powder and coupling agent are not added in this comparative example. The surface SEM image of the sample prepared in Comparative Example 1 is shown below. Figure 3 SEM images after hot pressing at 180℃ are shown below. Figure 4 .

[0039] Depend on Figure 3 It can be seen that obvious unevenness and agglomerates appear on the membrane surface. This proves that in the absence of a coupling agent, the dispersibility of the solid component in the matrix deteriorates.

[0040] Depend on Figure 4It can be seen that the microporous structure inside the membrane has severely collapsed. This proves that without the endothermic buffering effect of the high specific heat Al2O3 particles and the interfacial bonding force enhanced by the coupling agent, the membrane material cannot withstand the high-temperature processing environment, and its microstructure is damaged. This invention significantly improves the high-temperature resistance of the product through the synergistic effect of wear-resistant high specific heat particles and coupling agents.

[0041] Table 1 The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A high-temperature resistant, high-wear-resistant bio-based polyurethane casting solution, characterized in that, It includes the following components in parts by weight: 60-80 parts solvent, 8-12 parts wear-resistant high specific heat particles, 5-10 parts pore-forming agent, 15-30 parts modified bio-based polyurethane resin, 2-5 parts coupling agent, 2-3 parts leveling agent, 0.5-3 parts penetrant, and 0.5-1.5 parts defoamer.

2. The high-temperature resistant and high-wear-resistant bio-based polyurethane casting solution according to claim 1, characterized in that, The solvent is selected from one or more of dimethylformamide, dimethylacetamide, acetone, tetrahydrofuran, or butanone.

3. The high-temperature resistant and high-wear-resistant bio-based polyurethane casting solution according to claim 1, characterized in that, The wear-resistant, high specific heat particles are selected from one of Al2O3 powder, paraffin / SiO2, and ceramic micro powder.

4. The high-temperature resistant and high-wear-resistant bio-based polyurethane casting solution according to claim 1, characterized in that, The pore-forming agent is selected from one or more of wood flour, polyvinylpyrrolidone, sodium chloride, nano-titanium dioxide particles, and light calcium carbonate powder.

5. The high-temperature resistant and high-wear-resistant bio-based polyurethane casting solution according to claim 1, characterized in that, The modified bio-based polyurethane resin is made by modifying polyether-type thermoplastic polyurethane with a bio-based content of 65% with a modifier, wherein the modifier is selected from one or more of acetylated lignin, cellulose nanofibers, and tannic acid.

6. The high-temperature resistant and high-wear-resistant bio-based polyurethane casting solution according to claim 1, characterized in that, The leveling agent is selected from one or more of polydimethylsiloxane, polymethylalkylsiloxane, and organically modified polysiloxane.

7. The high-temperature resistant and high-wear-resistant bio-based polyurethane casting solution according to claim 1, characterized in that, The penetrant is selected from one or more of the anionic surfactants OT-50, OT-70, and OT-75.

8. The high-temperature resistant and high-wear-resistant bio-based polyurethane casting solution according to claim 1, characterized in that, The defoamer is selected from one or more of the following: acrylate copolymer defoamers (such as polyacrylates and vinyl polymers), polyether non-silicone modified defoamers (such as polyoxypropylene-polyoxyethylene block copolymers), and vegetable oil derivative defoamers (such as castor oil and soybean oil products modified by esterification / epoxidation).

9. A method for preparing a high-temperature resistant, high-wear-resistant bio-based polyurethane casting solution as described in any one of claims 1-8, characterized in that, include: S1. Add solvent, wear-resistant high specific heat particles and pore-forming agent to the reaction vessel and stir until uniform to obtain the first mixture; S2. Add modified bio-based polyurethane resin and coupling agent to the first mixture obtained in S1, and stir again until uniform to obtain the second mixture. S3. Add leveling agent, penetrant and defoamer to the second mixture obtained in S2, and stir until uniform to obtain high temperature resistant and high wear resistant bio-based polyurethane casting liquid.

10. The application of a high-temperature resistant, high-wear-resistant bio-based polyurethane casting solution as described in any one of claims 1-8 on a waterproof and breathable membrane.

Images