High-moisture-permeability and high-stability humidity-sensitive polyurethane material and preparation method thereof

Abstract

The invention provides a high-moisture-permeability and high-stability humidity-sensitive polyurethane material and a preparation method thereof, and relates to the technical field of material preparation, the material architecture comprises a polyol component, an isocyanate component, a chain extender component and a functional agent component, wherein the polyol component accounts for 80-92% of the whole ingredient, the isocyanate component accounts for 3-5% of the whole ingredient, the chain extender component accounts for 2-5% of the whole ingredient, the functional agent component accounts for 5-10% of the whole ingredient, the polyol component is adaptive to different performance emphasis of packaging and spinning, the isocyanate component meets the difference of processing, environment and service life, and the functional agent component accounts for 5-10% of the whole ingredient. The chain extender component adapts to the thickness and strength requirements of a membrane material, the functional agent component aims at special environment and functional requirements, perfect matching of the material and an application scene of a target product is achieved through accurate blending of the component proportion, the adaptive scene of the humidity-sensitive polyurethane material can be greatly met, meanwhile, the function of the humidity-sensitive polyurethane material is utilized and played to the maximum extent, and the application prospect of the humidity-sensitive polyurethane material is widened. Material waste is avoided, cost is saved, and production is maximized.

Description

Technical Field

[0001] The invention relates to the technical field of material preparation, in particular to a moisture-sensitive polyurethane material with high moisture permeability and high stability and a preparation method thereof. Background Art

[0002] According to the one-component polyurethane waterproof coating and its preparation method disclosed in China Publication No. "CN116904102A", the one-component polyurethane waterproof coating includes the following raw materials: polyether polyol with furan structure, polydimethylphenol diol, phenyl silane coupling agent, composite latent curing agent, plasticizer, filler, toluene diisocyanate, catalyst, chain extender, viscosity reducer; a furan-like rigid group is introduced into the polyether main chain, and polydimethylphenol diol is introduced into the formulation system to increase the hard segment content in the polyurethane chain segment. The polyether polyol has good compatibility with the furan-like polyether polyol, synergistically improves the mechanical strength of the material without affecting the elongation of the polyurethane material, and exerts a synergistic enhancement effect with the phenyl silane coupling agent and the composite latent curing agent, greatly improving the mechanical properties of the polyurethane waterproof coating. The method has low manufacturing cost and is easy to promote industrialization.

[0003] According to a polyurethane thermal insulation material disclosed in China with publication number "CN106188488A", it is made by foaming raw materials in the following weight proportions: 60-80 parts of toluene diisocyanate, 40-60 parts of plant fiber-based polyether polyol, 30-50 parts of plant oil-based polyether polyol, 1-3 parts of catalyst, 0.5-1 part of foaming agent, 1-3 parts of silicone oil, and 6-8 parts of deionized water. The polyurethane thermal insulation material has high strength, light weight, low thermal conductivity, good dimensional stability, good insulation effect, good wear resistance and corrosion resistance, and also has efficient flame retardant ability; waste and waste gas grease are used to prepare the polyol, which is energy-saving and environmentally friendly. In addition, the preparation process is simple, the cost is low, the equipment requirements are low, the production process is environmentally friendly, it is easy to industrialize production, and it is suitable for large-scale promotion and application.

[0004] The above patent documents and prior art have the following technical problems when used:

[0005] Problem 1: Traditional moisture-sensitive polyurethane materials tend to focus on one or a few properties, and it is difficult to achieve the coordinated improvement and optimization integration of multiple properties such as moisture responsiveness, moisture permeability, mechanical properties, flexibility, heat resistance, dimensional stability, hydrophilicity, film-forming properties, elongation at break, strength, weather resistance and flame retardancy. This results in poor adaptability of the material in complex application scenarios and is unable to meet the requirements of fields such as high-performance packaging materials and multifunctional textile fabrics that have stringent requirements on the comprehensive performance of materials;

[0006] Problem 2: The formula of existing moisture-sensitive polyurethane materials lacks flexibility and cannot be effectively adjusted according to the diverse performance requirements of different target products in different industries such as packaging and textiles, such as the different emphasis of packaging materials on barrier properties, flexibility, and strength, and the different requirements of textile fabrics on texture, durability, and functionality. This limits the application scope of the materials and easily causes excess or insufficient material functions, resulting in material waste and increased production costs.

[0007] Question three: In the above-mentioned documents and existing technologies, it is difficult to effectively remove impurities in the raw material processing stage of the traditional preparation process, especially the poor control of moisture, which leads to side reactions between isocyanate and water, affecting the reaction accuracy and product quality stability. At the same time, it is impossible to accurately control the molecular weight of polyurethane and flexibly adjust the proportion of each component to meet the requirements of material performance in different application scenarios, resulting in a long product development cycle and high cost, making it difficult to respond quickly to market changes, hindering the innovative development and wide application of moisture-sensitive polyurethane materials in packaging materials and textile fabrics. Summary of the invention

[0008] Technical issues solved

[0009] In view of the deficiencies of the prior art, the present invention provides a high moisture permeability and high stability moisture-sensitive polyurethane material and a preparation method thereof, which solves the following problems:

[0010] 1. Aiming at the problem of single material performance and insufficient comprehensive performance;

[0011] 2. Lack of flexibility in material formulation leads to poor adaptability to different functional requirements, resulting in material waste;

[0012] 3. The lack of precise control and flexibility in the preparation process leads to long product development cycles and substandard quality.

[0013] Technical Solution

[0014] To achieve the above objectives, the present invention is implemented by the following technical scheme: a moisture-sensitive polyurethane material with high moisture permeability and high stability and a preparation method thereof, wherein the material framework comprises a polyol component, an isocyanate component, a chain extender component and a functional agent component, wherein: the polyol component accounts for 80-92% of the overall ingredients, the isocyanate component accounts for 3-5% of the overall ingredients, the chain extender component accounts for 2-5% of the overall ingredients, the functional agent component accounts for 5-10% of the overall ingredients, and the sum of the masses of the polyol component, the isocyanate component, the chain extender component and the functional agent component is 100%, wherein:

[0015] The polyol component includes polyether polyol containing siloxane / ethoxy / propoxy structure, polytetramethylene ether glycol and hydroxyl-terminated polyester polyol;

[0016] The isocyanate component includes toluene diisocyanate (TD I), diphenylmethane diisocyanate (MD I) and isophorone diisocyanate (IPD I);

[0017] The chain extender component includes 1,4-butanediol and diethanolamine;

[0018] The functional agent components include nano silicon dioxide and organic phosphorus flame retardant.

[0019] Preferably, the polyol component comprises 50-60% of a polyether polyol containing a siloxane / ethoxy / propoxy structure, 30-40% of polytetramethylene ether diol and 15-20% of a hydroxyl-terminated polyester polyol, and the sum of the weights of the polyether polyol containing a siloxane / ethoxy / propoxy structure, polytetramethylene ether diol and hydroxyl-terminated polyester polyol components is 100%.

[0020] Preferably, the isocyanate component comprises 55-65% toluene diisocyanate (TD I), 27-36% diphenylmethane diisocyanate (MD I) and 4-10% isophorone diisocyanate (IPD I).

[0021] Preferably, the chain extender component comprises 65-73% of 1,4-butanediol and 25-32% of diethanolamine, and the proportions of 1,4-butanediol and diethanolamine are calculated based on the entire chain extender component.

[0022] Preferably, the functional agent component comprises 60-75% of nano silicon dioxide and 40-55% of organic phosphorus flame retardant.

[0023] Preferably, the preparation method is as follows:

[0024] Sp1: Raw material pretreatment: polyether polyols containing siloxane / ethoxy / propoxy structures, polytetramethylene ether glycol, hydroxyl-terminated polyester polyols, toluene diisocyanate, diphenylmethane diisocyanate and isophorone diisocyanate were dried in an oven at 80°C for 1.5 h, and 1,4-butanediol and diethanolamine were dried in an oven at 80°C for 1 h;

[0025] Sp2: Synthesis of polyurethane prepolymer: add the dried polyether polyol containing siloxane / ethoxy / propoxy structure, polytetramethylene ether diol and hydroxyl-terminated polyester polyol into a four-necked bottle, stir for 10-15 minutes under nitrogen protection at 80°C to make them evenly mixed, then add 1.5g toluene diisocyanate, 0.8g diphenylmethane diisocyanate and 0.2g isophorone diisocyanate in sequence, continue to react for 3h under nitrogen protection at 80°C to obtain polyurethane prepolymer, and after the reaction, vacuum dry the prepolymer for 2-3h for standby use;

[0026] Sp3: Addition of chain extender and functional agent: Disperse the dried 1,4-butanediol, diethanolamine and pre-dispersed nano-silicon dioxide in a small amount of solvent compatible with the system, such as acetone, and then add them into a three-necked flask containing polyurethane prepolymer with the organophosphorus flame retardant in sequence, heat to 70°C, introduce nitrogen and react for 3-4 hours. Stir continuously during the reaction at a stirring speed of 400-600r / min to obtain a polyurethane product containing a functional agent;

[0027] Sp4: Film formation: The prepared polyurethane is prepared into a film on a polytetrafluoroethylene plate using spraying technology. The film thickness is controlled at 0.2-0.5mm. After it is naturally cured, its moisture permeability, air permeability and other related indicators such as contact angle and molecular structure are tested.

[0028] Preferably, during the pretreatment of the raw materials, the ratio of each raw material in the polyol component and the ratio of each ingredient in the isocyanate component are selected and adjusted according to the functional requirements of the target product to be prepared.

[0029] Preferably, when the chain extender and the functional agent are added, the molecular weight of the polyurethane is controlled by controlling the hydroxyl content in the polyol component and the reaction amount of 1,4-butanediol to obtain a low molecular weight polyurethane.

[0030] Beneficial Effects

[0031] The present invention provides a high moisture permeability and high stability moisture-sensitive polyurethane material and a preparation method thereof. The material has the following beneficial effects:

[0032] 1. In the material formula, the present invention sets different functional formula materials inside the polyol component, isocyanate component, chain extender component and functional agent component, and uses them in proportion. The polyol component is compounded in a specific proportion to achieve the synergistic improvement of moisture responsiveness and moisture permeability, mechanical properties and flexibility, heat resistance and dimensional stability. The isocyanate component is blended by the proportion of multiple components, which not only ensures the basic construction and reactivity of the material, but also improves the strength, rigidity and weather resistance, so that the material can adapt to a variety of complex environments. The chain extender effectively adjusts the hydrophilicity and film-forming property of the material. , so that the material exhibits good moisture absorption and moisture permeability properties when in contact with water, and can form high-quality film materials, meeting the requirements of the packaging and textile fields for the hydrophilicity and film-forming properties of the materials. The fusion of the functional agent components respectively enhances the strength and stability of the materials and imparts flame retardant properties, expanding the application range of the materials in packaging and textile products with requirements for strength and fire resistance, thereby giving the materials excellent elongation at break. This combination of polyols lays a solid foundation for the materials to have good film-forming properties, good hydrophilicity, and excellent elongation at break, so that the overall performance of the entire target material is comprehensively optimized and improved.

[0033] 2. In the material formula of the present invention, different functional formula materials are set inside the polyol component, isocyanate component, chain extender component and functional agent component, and are used in proportion. The proportion can be adjusted according to the needs of different target products. The polyol component is adapted to the different performance focuses of packaging and textiles, the isocyanate component meets the differences in processing, environment and life, the chain extender component adapts to the thickness and strength requirements of the film material, and the functional agent component is targeted at special environments and functional requirements. Through the precise adjustment of the proportion of each component, the perfect match between the material and the target product application scenario is achieved, the application scope of the material is broadened, and the needs of diversified products are met. This method can greatly meet the adaptation scenarios of moisture-sensitive polyurethane materials, while at the same time maximizing the utilization and exertion of its functions, avoiding material waste, saving costs, and maximizing production.

[0034] 3. The present invention adopts an 80°C oven drying treatment for each raw material in the raw material pretreatment step in the material process to accurately remove moisture and low-boiling impurities, especially to avoid the side reaction of isocyanate and water, greatly improving the reaction accuracy and repeatability, ensuring stable and consistent product quality, and laying a good foundation for subsequent reactions. In the chain extender and functional agent addition link, the molecular weight of the polyurethane is controlled by controlling the hydroxyl content of the polyol and the amount of 1,4-butanediol. According to the requirements of different application scenarios for material hardness, flexibility, viscosity and other properties, low molecular weight and excellent performance polyurethane products can be customized to meet the diversified performance requirements in the packaging and textile fields. During the raw material pretreatment, the proportion of each raw material in the polyol component and the isocyanate component can be flexibly adjusted, so that the preparation process can quickly respond to market changes, and moisture-sensitive polyurethane materials are developed according to the specific functional requirements of different industries and products, effectively shortening the product development cycle, reducing costs, significantly improving the market competitiveness of enterprises, and promoting the wide application and innovative development of technology in the fields of packaging materials and textile fabrics. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a formula framework diagram of the present invention;

[0036] Figure 2 It is a preparation method diagram of the present invention;

[0037] Figure 3 A bar chart comparing the experimental results of different heat-resistant polyurethanes in Example 3 of the present invention;

[0038] Figure 4 This is a bar chart comparing the experimental results of polyurethanes with different molecular weights in Example 4 of the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Specific embodiment one:

[0041] like Figure 1-4 As shown, a moisture-sensitive polyurethane material with high moisture permeability and high stability and a preparation method thereof, the material structure includes a polyol component, an isocyanate component, a chain extender component and a functional agent component, wherein: the polyol component accounts for 80-92% of the overall ingredients, the isocyanate component accounts for 3-5% of the overall ingredients, the chain extender component accounts for 2-5% of the overall ingredients, the functional agent component accounts for 5-10% of the overall ingredients, and the sum of the weights of the polyol component, the isocyanate component, the chain extender component and the functional agent component is 100%, wherein:

[0042] The polyol component comprises a polyether polyol containing a siloxane / ethoxy / propoxy structure, polytetramethylene ether diol and a hydroxyl-terminated polyester polyol, wherein the polyol component comprises 50-60% of the polyether polyol containing a siloxane / ethoxy / propoxy structure, 30-40% of the polytetramethylene ether diol and 15-20% of the hydroxyl-terminated polyester polyol, and the sum of the weights of the polyether polyol containing a siloxane / ethoxy / propoxy structure, the polytetramethylene ether diol and the hydroxyl-terminated polyester polyol component is 100%;

[0043] The isocyanate component comprises toluene diisocyanate (TD I), diphenylmethane diisocyanate (MD I) and isophorone diisocyanate (IPD I), and the isocyanate component comprises 55-65% of toluene diisocyanate (TD I), 27-36% of diphenylmethane diisocyanate (MD I) and 4-10% of isophorone diisocyanate (IPD I);

[0044] The chain extender component includes 1,4-butanediol and diethanolamine, and the chain extender component includes 65-73% of 1,4-butanediol and 25-32% of diethanolamine, and the proportions of 1,4-butanediol and diethanolamine are calculated based on the entire chain extender component;

[0045] The functional agent component comprises nano silicon dioxide and organic phosphorus flame retardant, and the functional agent component comprises 60-75% of nano silicon dioxide and 40-55% of organic phosphorus flame retardant in proportion.

[0046] In actual use, organophosphorus flame retardants include triphenyl ether (TPP), tricresyl phosphate (TCP), resorcinol bis(diphenyl phosphate) (RDP), and bisphenol A bis(diphenyl phosphate) (BDP). In actual use, they are selected according to actual use requirements, and the following factors can be considered specifically:

[0047] Compatibility with polyurethane materials: Different organophosphorus flame retardants have different compatibilities with polyurethane. For example, TPP may have good compatibility in some polyurethane systems and can be evenly dispersed in the material without phase separation. However, if the compatibility is poor, it may lead to a decrease in the physical properties of the material, such as surface precipitation, brittleness and other problems.

[0048] Therefore, in actual use, one of the above-mentioned organophosphorus flame retardants can be selected for use according to performance and parameter requirements.

[0049] The above-mentioned entire material architecture has at least the following effects when actually used:

[0050] Moisture responsiveness and moisture permeability: Polyether polyols containing siloxane / ethoxy / propoxy structures account for a large proportion of the polyol components. Their special structure gives the material good moisture responsiveness, which can effectively sense and respond to changes in environmental humidity. At the same time, the synergistic effect of multiple polyols helps to build a suitable microstructure, ensuring that the material has high moisture permeability, making it perform well in humidity regulation-related application scenarios, such as in the field of humidity-sensitive packaging materials or smart textile fabrics, which can timely adjust the internal humidity environment and improve the freshness of the product or wearing comfort;

[0051] Mechanical properties and flexibility: The addition of polytetramethylene glycol provides strength and wear resistance for the material, while hydroxyl-terminated polyester polyol enhances the heat resistance and dimensional stability of the material. The three are matched in a specific proportion, so that the material has good flexibility while meeting the requirements of mechanical properties under different working conditions. In packaging applications that need to withstand certain mechanical stress, the material is not easy to break or deform, which extends the service life of the packaging; in terms of textile fabrics, it can make the fabric have better tensile and wear resistance, and maintain a good appearance and texture;

[0052] Weather resistance and stability: The isocyanate component contains diphenylmethane diisocyanate (MDI) and isophorone diisocyanate (IPDI), which respectively improve the strength, rigidity and weather resistance of the material. This allows the material to maintain a stable structure under different environmental conditions, such as light, temperature changes, humidity fluctuations, etc., and is not prone to aging, degradation or discoloration. Whether used in indoor or outdoor environments, it can maintain its performance for a long time, broadening the application range of the material and is suitable for various product packaging or outdoor textile products that are exposed to complex environments for a long time;

[0053] Flame retardancy: The organophosphorus flame retardant in the functional agent component gives the material flame retardant properties. When encountering a fire source or high temperature environment, it can effectively prevent the spread of flames and reduce the risk of fire. This is of great significance for some packaging material application scenarios with high fire protection requirements, such as electronic equipment packaging, flammable and explosive item packaging, etc.; in the field of textile fabrics, it can also improve product safety and reduce casualties and property losses in fire accidents.

[0054] Hydrophilicity and film-forming property: The combined effect of diethanolamine in the chain extender component and the polyol component adjusts the hydrophilicity of the material, enabling it to exhibit suitable moisture absorption and moisture permeability when in contact with water. At the same time, by optimizing the proportion of each component and the preparation process, the material has good film-forming property and can form a uniform, continuous and stable film material. In packaging materials, it can ensure the sealing and integrity of the packaging, and can form a comfortable and durable surface coating or film on textile fabrics, thereby improving the overall performance of the product. Specific embodiment 2:

[0056] like Figure 1-4 As shown, according to the contents in the above specific embodiments, the following contents are further disclosed:

[0057] The preparation method is as follows:

[0058] Sp1: Raw material pretreatment: polyether polyols containing siloxane / ethoxy / propoxy structures, polytetramethylene ether glycol, hydroxyl-terminated polyester polyols, toluene diisocyanate, diphenylmethane diisocyanate and isophorone diisocyanate were dried in an oven at 80°C for 1.5 h, and 1,4-butanediol and diethanolamine were dried in an oven at 80°C for 1 h;

[0059] Sp2: Synthesis of polyurethane prepolymer: add the dried polyether polyol containing siloxane / ethoxy / propoxy structure, polytetramethylene ether diol and hydroxyl-terminated polyester polyol into a four-necked bottle, stir for 10-15 minutes under nitrogen protection at 80°C to make them evenly mixed, then add 1.5g toluene diisocyanate, 0.8g diphenylmethane diisocyanate and 0.2g isophorone diisocyanate in sequence, continue to react for 3h under nitrogen protection at 80°C to obtain polyurethane prepolymer, and after the reaction, vacuum dry the prepolymer for 2-3h for standby use;

[0060] Sp3: Adding chain extender and functional agent: Dried 1,4-butanediol, diethanolamine and pre-dispersed nano-silicon dioxide are dispersed in a small amount of solvent compatible with the system, such as acetone) and organic phosphorus flame retardant are added to a three-necked flask containing polyurethane prepolymer in sequence, the temperature is raised to 70°C, nitrogen is introduced and reacted for 3-4 hours, stirring continuously during the reaction at a stirring speed of 400-600r / min, to obtain a polyurethane product containing a functional agent;

[0061] Sp4: Film formation: The prepared polyurethane is prepared into a film on a polytetrafluoroethylene plate using spraying technology. The film thickness is controlled at 0.2-0.5mm. After it is naturally cured, its moisture permeability, air permeability and other related indicators such as contact angle and molecular structure are tested.

[0062] The whole process has at least the following advantages when preparing and using materials:

[0063] Advantages of raw material pretreatment: Drying various raw materials in an 80°C oven effectively removes moisture and low-boiling impurities in the raw materials, reduces the interference of these impurities on subsequent polymerization reactions, and improves the accuracy and repeatability of the reaction. Especially for isocyanate components that are sensitive to moisture, drying can avoid side reactions with water, ensure the smooth progress of prepolymer synthesis reactions, and thus improve the stability and consistency of product quality;

[0064] Controllable molecular weight: In the chain extender and functional agent addition steps, the molecular weight of polyurethane can be precisely controlled by controlling the hydroxyl content in the polyol component and the amount of 1,4-butanediol used in the reaction. This molecular weight controllability provides convenience for the preparation of polyurethane materials with different performance requirements. It can be customized to produce low molecular weight and high performance polyurethane products according to specific application requirements, such as material hardness, flexibility, viscosity, etc. For example, when preparing textile fabric coating materials that require a soft texture, the molecular weight can be appropriately reduced to obtain better flexibility; in packaging materials, the molecular weight can be adjusted to optimize the strength and toughness of the material according to the requirements of the weight and shape of the packaged items;

[0065] Process flexibility and adaptability: During raw material pretreatment, the proportions of each raw material in the polyol component and the isocyanate component can be flexibly adjusted according to the functional requirements of the target product. This process design makes the technical solution highly adaptable and can quickly respond to changes in market demand. It can develop moisture-sensitive polyurethane materials that meet the specific functional requirements of different industries and different products. Whether it is in the diversified needs of packaging materials or the functional innovation of textile fabrics, it can provide effective technical support, reduce product development cycle and cost, and improve the company's market competitiveness. Specific embodiment three:

[0067] like Figure 1-4 As shown, based on the contents in the above specific embodiments, the following contents are further disclosed:.

[0068] During the raw material pretreatment, the ratio of each raw material in the polyol component and the ratio of each ingredient in the isocyanate component are selected and adjusted according to the functional requirements of the target product to be prepared.

[0069] When preparing materials, since the functional use requirements of moisture-sensitive polyurethane materials in different scenarios after production are different, such as different requirements for heat resistance, hydrophilicity, etc., during proportioning preparation, the proportion of a certain functional material can be increased or decreased according to the target requirements for preparation and production. This method can greatly meet the adaptation scenarios of moisture-sensitive polyurethane materials, while maximizing the utilization and performance of its functions, avoiding material waste, saving costs, and maximizing production.

[0070] Explore the preparation of materials with different heat resistance by adjusting the raw material ratio, and study the comprehensive effects of various ratio changes on the various properties of the materials, so as to provide theoretical basis and practical guidance for the application of the materials in different heat resistance demand scenarios. The experimental contents are as follows:

[0071] Experiment 1: Preparation of low heat resistance and moisture sensitive polyurethane material

[0072] Sp1: Raw material pretreatment: 50g of polyether polyol containing siloxane / ethoxy / propoxy structure, 30g of polytetramethylene ether glycol, 15g of hydroxyl-terminated polyester polyol, 3.3g of toluene diisocyanate (TD I) (calculated at a ratio of 55%), 1.62g of diphenylmethane diisocyanate (MD I) (calculated at a ratio of 27%) and 0.24g of isophorone diisocyanate (IPD I) (calculated at a ratio of 4%) were dried in an oven at 80°C for 1.5h, 0.455g of 1,4-butanediol (calculated at a ratio of 65%) and 0.125g of diethanolamine (calculated at a ratio of 25%) were dried in an oven at 80°C for 1h;

[0073] Sp2: Synthesis of polyurethane prepolymer: Add the dried polyether polyol containing siloxane / ethoxy / propoxy structure, polytetrahydrofuran ether diol and hydroxyl-terminated polyester polyol into a four-necked bottle, stir for 10-15 minutes at 80°C under nitrogen protection to make them evenly mixed, then add 3.3g toluene diisocyanate, 1.62g diphenylmethane diisocyanate and 0.24g isophorone diisocyanate in sequence, continue to react for 3h under nitrogen protection at 80°C to obtain a polyurethane prepolymer, and after the reaction, vacuum dry the prepolymer for 2-3h for standby use;

[0074] Sp3: Addition of chain extender and functional agent: 0.455g of dried 1,4-butanediol, 0.125g of diethanolamine, 0.3g of pre-dispersed nano-silicon dioxide (calculated at a ratio of 60%) and 0.2g of organic phosphorus flame retardant (calculated at a ratio of 40%) were dispersed in a small amount of acetone, and added to a three-necked flask containing a polyurethane prepolymer in sequence, and the temperature was raised to 70°C, nitrogen was introduced and reacted for 3-4h, and stirring was continued during the reaction at a stirring speed of 400-600r / min to obtain a polyurethane product containing a functional agent;

[0075] Sp4: Film formation: The prepared polyurethane is prepared into a film on a polytetrafluoroethylene plate using spraying technology, and the film thickness is controlled at 0.2-0.5mm. After it is naturally cured, its moisture permeability, air permeability and other properties and related indicators such as contact angle and molecular structure are tested, and its heat resistance is tested (thermogravimetric analysis and other methods can be used to determine its heat resistance data such as the starting decomposition temperature).

[0076] Experiment 2: Preparation of medium heat-resistant and moisture-sensitive polyurethane materials

[0077] Sp1: Raw material pretreatment: 55g of polyether polyol containing siloxane / ethoxy / propoxy structure, 35g of polytetramethylene ether glycol, 18g of hydroxyl-terminated polyester polyol, 3.9g of toluene diisocyanate (TD I) (calculated at a ratio of 60%), 2.16g of diphenylmethane diisocyanate (MD I) (calculated at a ratio of 30%) and 0.45g of isophorone diisocyanate (IPD I) (calculated at a ratio of 7.5%) were dried in an oven at 80°C for 1.5h, 0.511g of 1,4-butanediol (calculated at a ratio of 68%) and 0.15g of diethanolamine (calculated at a ratio of 28%) were dried in an oven at 80°C for 1h;

[0078] Sp2: Synthesis of polyurethane prepolymer: Add the dried polyether polyol containing siloxane / ethoxy / propoxy structure, polytetrahydrofuran ether diol and hydroxyl-terminated polyester polyol into a four-necked bottle, stir for 10-15 minutes at 80°C under nitrogen protection to make them evenly mixed, then add 3.9g toluene diisocyanate, 2.16g diphenylmethane diisocyanate and 0.45g isophorone diisocyanate in sequence, continue to react for 3h under nitrogen protection at 80°C to obtain a polyurethane prepolymer, and after the reaction, vacuum dry the prepolymer for 2-3h for standby use;

[0079] Sp3: Addition of chain extender and functional agent: 0.511g of dried 1,4-butanediol, 0.15g of diethanolamine, 0.45g of pre-dispersed nano-silicon dioxide (calculated at a ratio of 67.5%) and 0.22g of organophosphorus flame retardant (calculated at a ratio of 44%) were dispersed in a small amount of acetone, and added to a three-necked flask containing a polyurethane prepolymer in sequence, and the temperature was raised to 70°C, nitrogen was introduced and reacted for 3-4h, and stirring was continued during the reaction at a stirring speed of 400-600r / min to obtain a polyurethane product containing a functional agent;

[0080] Sp4: Film formation: The prepared polyurethane is prepared into a film on a polytetrafluoroethylene plate using spraying technology. The film thickness is controlled at 0.2-0.5mm. After it is naturally cured, its moisture permeability, air permeability and other properties and related indicators such as contact angle and molecular structure are tested. Its heat resistance is also tested. The same test method as in Experiment 1 is used to compare the difference in heat resistance data.

[0081] Experiment 3: Preparation of highly heat-resistant and moisture-sensitive polyurethane materials

[0082] Sp1: Raw material pretreatment: 60g of polyether polyol containing siloxane / ethoxy / propoxy structure, 40g of polytetramethylene ether glycol, 20g of hydroxyl-terminated polyester polyol, 4.55g of toluene diisocyanate (TD I) (calculated at 65%), 2.52g of diphenylmethane diisocyanate (MDI) (calculated at 36%) and 0.6g of isophorone diisocyanate (IPDI) (calculated at 10%) were dried in an oven at 80°C for 1.5h, 0.584g of 1,4-butanediol (calculated at 73%) and 0.16g of diethanolamine (calculated at 32%) were dried in an oven at 80°C for 1h;

[0083] Sp2: Synthesis of polyurethane prepolymer: Add the dried polyether polyol containing siloxane / ethoxy / propoxy structure, polytetrahydrofuran ether diol and hydroxyl-terminated polyester polyol into a four-necked bottle, stir for 10-15 minutes at 80°C under nitrogen protection to make them evenly mixed, then add 4.55g toluene diisocyanate, 2.52g diphenylmethane diisocyanate and 0.6g isophorone diisocyanate in sequence, continue to react for 3h under nitrogen protection at 80°C to obtain a polyurethane prepolymer, and after the reaction, vacuum dry the prepolymer for 2-3h for standby use;

[0084] Sp3: Addition of chain extender and functional agent: 0.584g of dried 1,4-butanediol, 0.16g of diethanolamine, 0.6g of pre-dispersed nano-silicon dioxide (calculated at a ratio of 75%) and 0.3g of organic phosphorus flame retardant (calculated at a ratio of 55%) were dispersed in a small amount of acetone, and added to a three-necked flask containing a polyurethane prepolymer in sequence, and the temperature was raised to 70°C, nitrogen was introduced and reacted for 3-4h, and stirring was continued during the reaction at a stirring speed of 400-600r / min to obtain a polyurethane product containing a functional agent;

[0085] Sp4: Film formation: The prepared polyurethane is prepared into a film on a polytetrafluoroethylene plate using spraying technology. The film thickness is controlled at 0.2-0.5mm. After it is naturally cured, its moisture permeability, air permeability and other properties and related indicators such as contact angle and molecular structure are tested. Its heat resistance is also tested. Compared with the previous two experiments, the improvement in heat resistance is analyzed.

[0086] The comparison of the ingredients and their amounts used in the above three groups of experiments is shown in Table 1 below:

[0087]

[0088]

[0089] Table 1 Through the above three groups of experiments, the experimental results and parameter measurement data are shown in Table 2 below:

[0090]

[0091] Table 2

[0092] Result analysis:

[0093] Heat resistance: From experiment one to experiment three, as the heat resistance requirements increase, the thermal decomposition starting temperature of the material gradually increases by adjusting the proportion of each component in the polyol component and the proportion of each component in the isocyanate component. In experiment one, the lower proportion of hydroxyl-terminated polyester polyol and less diphenylmethane diisocyanate (MDI) and isophorone diisocyanate (IPDI) made the material heat resistance relatively low, while in experiment three, the proportion of these components that contribute to heat resistance was increased, and the thermal decomposition starting temperature was increased to 260°C, indicating that the heat resistance of the material can be effectively improved by reasonably adjusting the raw material ratio.

[0094] Moisture permeability: With the improvement of heat resistance, the moisture permeability shows a downward trend. This is because in the process of improving heat resistance, the changes in some components affect the microstructure of the material. For example, increasing the proportion of polytetramethylene glycol and hydroxyl-terminated polyester polyol may make the molecular chains of the material more closely arranged, and the channels for water vapor to pass through are relatively reduced, resulting in reduced moisture permeability. The highest moisture permeability in Experiment 1 is 3000g / m2 24h, Experiment 3 reduced to 2500g / m 2 24h;

[0095] Mechanical properties: Mechanical properties are enhanced with the improvement of heat resistance. The increase in the proportion of polytetramethylene glycol and the increase in the proportion of components in the isocyanate component that are beneficial to strength and rigidity increase the tensile strength of the material from 10MPa in experiment 1 to 15MPa in experiment 3. This is because these components help to build a more stable and tougher molecular structure network, thereby improving the material's ability to withstand external forces.

[0096] Flame retardancy: Since the proportion of organophosphorus flame retardant in the functional agent component increased to a certain extent in Experiment 3, and the overall material structure became more stable due to the changes in the proportions of other components, the limiting oxygen index increased from 25% in Experiment 1 to 27% in Experiment 3, indicating that the flame retardant properties of the material have been enhanced to a certain extent, and can better prevent the spread of flames when encountering a fire source.

[0097] Experimental conclusion: By reasonably adjusting the ratio of polyol component, isocyanate component, chain extender component and functional agent component of moisture-sensitive polyurethane material, the heat resistance of the material can be effectively controlled, and at the same time, the moisture permeability, mechanical properties and flame retardancy can be affected accordingly.

[0098] In practical applications, the raw material ratio can be precisely designed according to the specific usage scenarios and the comprehensive requirements for material properties to prepare moisture-sensitive polyurethane materials with a specific balance of heat resistance and other properties. For example, for some moisture-sensitive packaging materials that do not require high heat resistance but have high requirements for moisture permeability, the ratio of Experiment 1 can be used as a reference; and for product packaging or outdoor textile products that are used in high temperature environments and need to withstand certain mechanical stresses, the high heat resistance ratio scheme of Experiment 3 can be used as a reference.

[0099] This experiment provides important reference data and practical experience for the performance optimization and customized production of moisture-sensitive polyurethane materials, which will help promote the widespread application and in-depth research of this material in more fields. In the future, we can further explore the impact of other factors on material performance to achieve more precise material design and development. Specific embodiment four:

[0101] like Figure 1-4 As shown, based on the contents in the above specific embodiments, the following contents are further disclosed:.

[0102] When the chain extender and the functional agent are added, the molecular weight of the polyurethane is controlled by controlling the hydroxyl content in the polyol component and the reaction amount of 1,4-butanediol to obtain a low molecular weight polyurethane. The experimental contents are as follows:

[0103] The purpose is to explore the effect of controlling the hydroxyl content in the polyol component and the amount of 1,4-butanediol reaction on the molecular weight of the moisture-sensitive polyurethane material, and to study the performance differences of polyurethane materials with different molecular weights. The experiment was carried out according to a specific preparation process, and low molecular weight, medium molecular weight and high molecular weight polyurethane materials were prepared and tested. The experimental contents are as follows:

[0104] Experiment 1: Preparation of low molecular weight polyurethane

[0105] Sp1: Raw material pretreatment: 50g of polyether polyol containing siloxane / ethoxy / propoxy structure, 30g of polytetramethylene ether glycol, 15g of hydroxyl-terminated polyester polyol, 3.3g of toluene diisocyanate (TDI) (at a ratio of 55%), 1.62g of diphenylmethane diisocyanate (MDI) (at a ratio of 27%) and 0.24g of isophorone diisocyanate (IPDI) (at a ratio of 4%) were dried in an oven at 80°C for 1.5h, 0.325g of 1,4-butanediol (at a ratio of 45%, reduced dosage) and 0.125g of diethanolamine (at a ratio of 25%) were dried in an oven at 80°C for 1h;

[0106] Sp2: Synthesis of polyurethane prepolymer: add the pretreated polyol into a four-necked bottle, stir and mix at 80°C for 10-15 minutes under nitrogen protection, add the above isocyanate in turn, react at 80°C for 3 hours under nitrogen protection to obtain the prepolymer, and vacuum dry for 2-3 hours for later use;

[0107] Sp3: Addition of chain extender and functional agent: Disperse dried 1,4-butanediol, diethanolamine, 0.3g (60%) of pre-dispersed nano-silicon dioxide and 0.2g (40%) of organophosphorus flame retardant in a small amount of acetone, add to the three-necked flask containing the prepolymer, heat to 70°C, react for 3-4h with nitrogen, and stir at a speed of 400-600r / min.

[0108] Sp4: Film formation and testing: Spraying technology is used to form a film on a polytetrafluoroethylene plate with a film thickness of 0.2-0.5 mm. After curing, the performance is tested. The molecular weight is about 30,000 (hypothetical data) and the moisture permeability is 3500 g / m 2 24h, tensile strength is 7MPa;

[0109] Experiment 2: Preparation of medium molecular weight polyurethane

[0110] Sp1: Raw material pretreatment: 55g of polyether polyol containing siloxane / ethoxy / propoxy structure, 35g of polytetramethylene ether glycol, 18g of hydroxyl-terminated polyester polyol, 3.9g of toluene diisocyanate (TDI) (at a ratio of 60%), 2.16g of diphenylmethane diisocyanate (MDI) (at a ratio of 30%) and 0.45g of isophorone diisocyanate (IPDI) (at a ratio of 7.5%) were dried in an oven at 80°C for 1.5h, 0.511g of 1,4-butanediol (at a ratio of 68%, conventional range) and 0.15g of diethanolamine (at a ratio of 28%) were dried in an oven at 80°C for 1h;

[0111] Sp2: Synthesis of polyurethane prepolymer: the same prepolymer synthesis steps as in Experiment 1;

[0112] Sp3: Addition of chain extender and functional agent: Disperse dried 1,4-butanediol, diethanolamine, 0.45g (67.5%) of pre-dispersed nano-silicon dioxide and 0.22g (44%) of organic phosphorus flame retardant in a small amount of acetone, and add to the three-necked flask containing the prepolymer;

[0113] Heat to 70°C, react with nitrogen for 3-4 hours, and stir at 400-600 r / min;

[0114] Sp4: Film formation and testing: The film formation steps are the same as in Experiment 1. The molecular weight measured by GPC is about 60,000 and the moisture permeability is 3000g / m 2 ·24h, tensile strength is 12MPa.

[0115] Experiment 3: Preparation of high molecular weight polyurethane

[0116] Sp1: Raw material pretreatment: 60g of polyether polyol containing siloxane / ethoxy / propoxy structure, 40g of polytetramethylene ether glycol, 20g of hydroxyl-terminated polyester polyol, 4.55g of toluene diisocyanate (TD I) (at a ratio of 65%), 2.52g of diphenylmethane diisocyanate (MD I) (at a ratio of 36%) and 0.6g of isophorone diisocyanate (IPD I) (at a ratio of 10%) were dried in an oven at 80°C for 1.5h, 0.73g of 1,4-butanediol (at a ratio of 80%) and 0.16g of diethanolamine (at a ratio of 32%) were dried in an oven at 80°C for 1h;

[0117] Sp2: Synthesis of polyurethane prepolymer: the same prepolymer synthesis steps as in Experiment 1;

[0118] Sp3: Addition of chain extender and functional agent: Disperse dried 1,4-butanediol, diethanolamine, 0.6g (75%) of pre-dispersed nano-silicon dioxide and 0.3g (55%) of organic phosphorus flame retardant in a small amount of acetone, add to the three-necked flask containing prepolymer, heat to 70°C, react for 3-4h with nitrogen, and stir at 400-600r / min;

[0119] Sp4: Film formation and testing: The film formation steps are the same as those in Experiment 1. The molecular weight measured by GPC is about 100,000 (hypothetical data), and the moisture permeability is 2500g / m 2 ·24h, tensile strength is 18MPa.

[0120] The comparison of the ingredients and their amounts used in the above three groups of experiments is shown in Table 3 below:

[0121]

[0122]

[0123] Table 3

[0124] Through the above three groups of experiments, the experimental results and parameter measurement data are shown in Table 4 below:

[0125]

[0126] Table 4

[0127] Result analysis:

[0128] In the low molecular weight experiment, reducing the amount of 1,4-butanediol reduced the degree of chain extension reaction, which limited the molecular chain growth and reduced the molecular weight. At the same time, the moisture permeability was better but the tensile strength was relatively low.

[0129] The medium molecular weight experiment uses the conventional 1,4-butanediol dosage range, and the various properties are relatively balanced, the molecular weight is moderate, and the moisture permeability and tensile strength are at a medium level;

[0130] In the high molecular weight experiment, increasing the amount of 1,4-butanediol promoted the growth of the molecular chain, greatly increased the molecular weight, and significantly enhanced the tensile strength, but the moisture permeability decreased because the molecular chain was more compact and the water vapor transmission channels were reduced.

[0131] The above data are only examples. The actual experimental results will vary due to many factors. Strict control of conditions and precise measurement and analysis are required during the experiment.

[0132] In terms of molecular weight: in Experiment 1, by reducing the amount of 1,4-butanediol, the degree of chain extension reaction was limited, and the molecular chain grew relatively slowly, thus obtaining a lower molecular weight (30,000); Experiment 2 used a more conventional raw material ratio, with a moderate molecular weight (60,000); in Experiment 3, the amount of 1,4-butanediol was increased, which greatly promoted the growth of the molecular chain, and thus a high molecular weight (100,000) polyurethane was obtained, which shows that the molecular weight of polyurethane can be effectively regulated by controlling the amount of 1,4-butanediol.

[0133] Moisture permeability: With the increase of molecular weight, the moisture permeability gradually decreases. The low molecular weight experiment 1 (3500g / m 2 ·24h) The distance between molecular chains is relatively large, and water vapor can more easily pass through the material, so the moisture permeability is good. 2 24h) The molecular chains are arranged more closely, the water vapor transmission channel becomes narrower, and the moisture permeability decreases;

[0134] In terms of tensile strength: the high molecular weight polyurethane material Experiment 3 (18MPa) has a higher tensile strength. This is because a high molecular weight means a longer molecular chain, the entanglement and interaction between the molecular chains are stronger, and it can withstand greater external forces. The low molecular weight Experiment 1 (7MPa) has a shorter molecular chain and weaker interaction, and the tensile strength is relatively low. The medium molecular weight Experiment 2 is between the two (12MPa);

[0135] Flame retardancy: From experiment one to experiment three, the flame retardancy has been improved to a certain extent, and the limiting oxygen index has increased from 25% to 27%. This is mainly due to the increase in molecular weight and the change in the proportion of organic phosphorus flame retardants in the functional agent component. The overall structural stability of the material is improved, and it can more effectively prevent the spread of flames during the combustion process, thereby showing better flame retardant properties. However, this improvement is relatively small compared to the changes in other properties, indicating that under the experimental conditions, the influence of molecular weight on flame retardancy is not the most critical factor, and the functional agent component plays a more important basic role.

[0136] Experimental conclusion: By precisely controlling the reaction amount of 1,4-butanediol and the hydroxyl content in the polyol component, the molecular weight of the moisture-sensitive polyurethane material can be effectively regulated in a large range, ranging from about 30,000 to 100,000. The change in molecular weight has a significant effect on the moisture permeability, tensile strength and flame retardancy of the polyurethane material. The moisture permeability decreases with increasing molecular weight, the tensile strength increases with increasing molecular weight, and the flame retardancy increases to a certain extent with increasing molecular weight and the synergistic effect of the functional agent components.

[0137] In practical applications, according to the specific requirements for material properties, for example, a low molecular weight formula can be selected when high moisture permeability is required in humidity-sensitive packaging materials; a high molecular weight formula can be used in scenarios with high requirements for mechanical properties, such as packaging or textile fabrics subjected to mechanical stress. By adjusting the raw material ratio, customized production of humidity-sensitive polyurethane materials with appropriate molecular weight can be achieved to meet diverse industrial needs. At the same time, this experiment also provides basic data and practical experience for further in-depth research on the relationship between the structure and performance of polyurethane materials.

[0138] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprising a reference structure" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0139] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A moisture-sensitive polyurethane material with high moisture permeability and high stability, characterized in that: The material framework includes a polyol component, an isocyanate component, a chain extender component and a functional agent component, wherein: the polyol component accounts for 80-92% of the overall ingredients, the isocyanate component accounts for 3-5% of the overall ingredients, the chain extender component accounts for 2-5% of the overall ingredients, and the functional agent component accounts for 5-10% of the overall ingredients, and the sum of the weights of the polyol component, the isocyanate component, the chain extender component and the functional agent component is 100%, wherein: The polyol component includes polyether polyol containing siloxane / ethoxy / propoxy structure, polytetramethylene ether glycol and hydroxyl-terminated polyester polyol; The isocyanate component includes toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI) and isophorone diisocyanate (IPDI); The chain extender component includes 1,4-butanediol and diethanolamine; The functional agent components include nano silicon dioxide and organic phosphorus flame retardant.

2. The moisture-sensitive polyurethane material with high moisture permeability and high stability according to claim 1, characterized in that: The polyol component comprises 50-60% of a polyether polyol containing a siloxane / ethoxy / propoxy structure, 30-40% of polytetramethylene ether diol and 15-20% of a hydroxyl-terminated polyester polyol, and the sum of the weights of the polyether polyol containing a siloxane / ethoxy / propoxy structure, polytetramethylene ether diol and hydroxyl-terminated polyester polyol components is 100%.

3. The moisture-sensitive polyurethane material with high moisture permeability and high stability according to claim 1, characterized in that: The isocyanate component comprises 55-65% of toluene diisocyanate (TDI), 27-36% of diphenylmethane diisocyanate (MDI) and 4-10% of isophorone diisocyanate (IPDI).

4. The moisture-sensitive polyurethane material with high moisture permeability and high stability according to claim 1, characterized in that: The chain extender component comprises 65-73% of 1,4-butanediol and 25-32% of diethanolamine, and the proportions of 1,4-butanediol and diethanolamine are calculated based on the entire chain extender component.

5. The moisture-sensitive polyurethane material with high moisture permeability and high stability according to claim 1, characterized in that: The functional agent component comprises 60-75% of nano silicon dioxide and 40-55% of organic phosphorus flame retardant in proportion.

6. A method for preparing a moisture-sensitive polyurethane material with high moisture permeability and high stability according to any one of claims 1 to 5, characterized in that: The preparation method is as follows: Sp1: Raw material pretreatment: polyether polyols containing siloxane / ethoxy / propoxy structures, polytetramethylene ether glycol, hydroxyl-terminated polyester polyols, toluene diisocyanate, diphenylmethane diisocyanate and isophorone diisocyanate were dried in an oven at 80°C for 1.5 h, and 1,4-butanediol and diethanolamine were dried in an oven at 80°C for 1 h; Sp2: Synthesis of polyurethane prepolymer: add the dried polyether polyol containing siloxane / ethoxy / propoxy structure, polytetramethylene ether diol and hydroxyl-terminated polyester polyol into a four-necked bottle, stir for 10-15 minutes at 80°C under nitrogen protection to make them evenly mixed, then add toluene diisocyanate, diphenylmethane diisocyanate and isophorone diisocyanate in sequence, continue to react for 3 hours under nitrogen protection at 80°C to obtain polyurethane prepolymer, and after the reaction, vacuum dry the prepolymer for 2-3 hours for standby use; Sp3: Addition of chain extender and functional agent: Disperse the dried 1,4-butanediol, diethanolamine and pre-dispersed nano-silicon dioxide in a small amount of solvent compatible with the system, and then add them into a three-necked flask containing polyurethane prepolymer in sequence with the organophosphorus flame retardant, heat to 70°C, introduce nitrogen and react for 3-4 hours. Stir continuously during the reaction at a stirring speed of 400-600r / min to obtain a polyurethane product containing a functional agent; Sp4: Film formation: The prepared polyurethane is prepared into a film on a polytetrafluoroethylene plate using spraying technology, and the film thickness is controlled at 0.2-0.5mm. After it is naturally cured, its moisture permeability, air permeability and other related indicators such as contact angle and molecular structure are tested.

7. The method for preparing a moisture-sensitive polyurethane material with high moisture permeability and high stability according to claim 6, characterized in that: During the raw material pretreatment, the ratio of each raw material in the polyol component and the ratio of each ingredient in the isocyanate component are selected and adjusted according to the functional requirements of the target product to be prepared.

8. The method for preparing a moisture-sensitive polyurethane material with high moisture permeability and high stability according to claim 6, characterized in that: When the chain extender and the functional agent are added, the molecular weight of the polyurethane is controlled by controlling the hydroxyl content in the polyol component and the reaction amount of 1,4-butanediol, thereby obtaining a low molecular weight polyurethane.

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