Poly (urethane-urea) elastomer for improving damage resistance by utilizing supramolecular interaction of soft and hard phase interfaces as well as preparation method and application of poly (urethane-urea) elastomer

Abstract

The invention belongs to the technical field of synthesis of high-performance polymer materials, and particularly relates to a method for improving damage resistance by regulating and controlling supramolecular interaction of soft and hard phase interfaces of a poly (urethane-urea) elastomer and application. The invention provides a strategy for enhancing the damage resistance of the elastomer by adjusting the number and strength of hydrogen bonds at a soft and hard interface. The influence of the number of hydrogen bonds on the impact resistance of the elastomer is explored by changing the number of hydrogen bond donors and acceptors, and a high-impact-resistance material with a large number of interface hydrogen bonds is synthesized; the influence of the hydrogen bond strength on the tear resistance of the elastomer is further explored by changing the content of aliphatic rings in the system, and a high-tear-resistance material with moderate interface hydrogen bond strength is synthesized. In addition, the two materials have excellent toughness, good repairability and recoverability, meanwhile, the experiment process is simple and easy to implement, the cost is low, and large-scale preparation can be carried out.

Description

Technical Field

[0001] This invention belongs to the field of high-performance polymer material synthesis technology, specifically relating to a polyurethane material that utilizes supramolecular interactions at the soft-hard phase interface to improve damage resistance. Urea elastomers, their preparation methods, and applications. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Polyurethane-urea elastomers (PUEs) are highly regarded for their excellent elasticity and deformation recovery, thanks to their biphase structure consisting of flexible soft segments and robust hard segments. The soft segments impart flexibility and resilience, while the hard segments provide structural stability and strength. This biphase structure gives PUEs superior mechanical properties, making them indispensable in numerous fields such as biomedical devices, soft robotics, and wearable technologies. Despite their wide range of applications, traditional PUEs are susceptible to damage under extreme mechanical stresses, such as impact and tearing, which shortens their lifespan, increases maintenance costs, and raises safety concerns; these drawbacks limit their application in environments with extremely high durability and safety requirements. Therefore, improving the damage resistance of PUEs is crucial.

[0004] Studies have shown that poly(urethane-urea) elastomers can improve material properties by optimizing supramolecular interactions within their structure. The inventors have found that while considerable progress has been made in modulating supramolecular interactions in the hard or soft phases of elastomers, there is still a pressing need to develop poly(urethane-urea) elastomers with superior damage resistance under extreme mechanical stress. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a polyurethane material that utilizes supramolecular interactions at the soft-hard phase interface to enhance its damage resistance. Urea elastomers, their preparation methods, and applications. This invention obtains an elastomer with a high number of hydrogen bonds at the interface between the soft and hard phases and excellent impact resistance by selecting a combination of soft segments with a specific number of hydrogen bond acceptors and chain extenders with a specific number of hydrogen bond donors; and an elastomer with moderate hydrogen bond strength at the interface between the soft and hard phases and excellent tear resistance by selecting a specific combination of hard segments and chain extenders.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a polyurethane material with improved damage resistance by utilizing supramolecular interactions at the soft-hard phase interface. Methods for preparing urea elastomers include: In the presence of an initiator, a prepolymer is formed by prepolymerizing a soft-segment polyester diol and a hard-segment isocyanate to obtain a prepolymer. The prepolymer was polymerized with a hydrogen bond donor chain extender to obtain a poly(urethane-urea) elastomer. The soft segment polyester diol is a polyester diol containing a hydrogen bond donor carbonyl group. The hydrogen bond donor chain extender is a combination of one of isophorone diamine, 1,6-hexanediamine or 1,7-diaminoheptane and N,N-dihydroxyethyloxalamide.

[0007] This invention reveals that optimizing supramolecular interactions at the soft-hard phase interface is crucial for improving the damage resistance of elastomers under extreme mechanical stress. Therefore, a method has been developed to enhance the damage resistance (such as high impact and tear resistance) of poly(urethane-urea) elastomer materials by utilizing supramolecular interactions between the soft and hard phase interfaces. This method is of great significance for the development of high-performance poly(urethane-urea) elastomers.

[0008] A second aspect of the present invention provides a poly(urethane-urea) elastomer prepared by the above-described method. The poly(urethane) elastomer exhibits superior damage resistance. Urea elastomers are high-impact poly(urethane-urea) elastomers or high-tear-resistance poly(urethane-urea) elastomers.

[0009] A third aspect of the present invention provides the application of the above-mentioned poly(urethane-urea) elastomer in the fields of 3D printing and protective materials, wherein the protective materials include: armor protective materials and bulletproof vest materials.

[0010] Beneficial effects of the present invention (1) This invention proposes a method and application for improving the damage resistance of poly(urethane-urea) elastomers by regulating the supramolecular interactions at the soft and hard phase interfaces. Impact resistance and tear resistance are two aspects of a material's damage resistance. By changing the number of hydrogen bond donors and acceptors, the influence of the number of hydrogen bonds on the impact resistance of the elastomer was explored, and a high-impact-resistant material with a large number of interfacial hydrogen bonds was synthesized. By changing the types of hard segments and chain extenders in the system, the influence of hydrogen bond strength on the tear resistance of the elastomer was explored, and a high-tear-resistant material with moderate interfacial hydrogen bond strength was synthesized. This invention achieves a poly(urethane-urea) elastomer with impact resistance far exceeding that of commercial thermoplastic polyurethanes and Kevlar woven fabrics, as well as a poly(urethane-urea) elastomer with high toughness and fracture energy and high tear resistance.

[0011] (2) This invention discovers the regulation law of damage resistance of poly(urethane-urea) elastomers: the microscopic regulation of the number and strength of interfacial hydrogen bonds to regulate the material's damage resistance is actually regulated by its influence on the material's macroscopic hardness and toughness. Specifically, the hardness of the elastomer is positively correlated with the number and strength of hydrogen bonds, while the toughness increases with the increase of the number of hydrogen bonds (which is not significantly related to the strength), reaching its maximum value at medium bond strength. Elastomers with both high hardness and high toughness exhibit excellent impact resistance, while high tear resistance is achieved at medium hardness and high toughness.

[0012] (3) The method for improving the damage resistance of poly(urethane-urea) elastomer by regulating the supramolecular interaction at the soft and hard phase interface provided by the technical solution of the present invention requires few raw materials, the experimental process is simple and easy to carry out, the cost is low, and it can be prepared on a large scale.

[0013] (4) The preparation method of the present invention is simple, practical and easy to promote. Attached Figure Description

[0014] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0015] Figure 1 This is a comparison diagram of the number of interfacial hydrogen bonds in the elastomers prepared in Example 1 and Comparative Examples 1-3.

[0016] Figure 2 This is a comparison chart of the impact resistance of the elastomers prepared in Example 1 and Comparative Examples 1-3.

[0017] Figure 3 This is a comparison diagram of the hydrogen bond strength of the elastomers prepared in Example 2 and Comparative Examples 4-5.

[0018] Figure 4 This is a comparison chart of the tear resistance properties of the elastomers prepared in Example 2 and Comparative Examples 4-5.

[0019] Figure 5 This is a comparison chart of the toughness properties of the elastomers prepared in Examples 1-2 and Comparative Examples 1-5. Detailed Implementation

[0020] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they are used in accordance with conventional methods in the art or product instructions. Similarly, unless otherwise specified, the test methods of this invention are performed in accordance with conventional methods in the art or industry-standard methods or practices. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0022] Terminology Explanation: PBA 1000: Poly(1,4-butanediol adipate) (molecular weight 1000) PTMEG 1000: Polytetrahydrofuran (molecular weight 1000) IPDI: Isophorone diisocyanate HDI: Hexamethylene diisocyanate HMDI: Dicyclohexylmethane 4,4′-diisocyanate DBTDL: Dibutyltin dilaurate DMF: N,N-dimethylformamide IPDA: Isophorone diamine HMDA: 1,6-Hexanediamine BMHA: 1,7-Diaminoheptane BHO: N,N-dihydroxyethyl oxalamide AHO: 6-Amino-1-hexanol HDO: 1,6-Hexanediol Room temperature: has a meaning known in this technical field, generally referring to 25±5℃; Number of hydrogen bonds: Calculated by infrared peak splitting. Infrared spectroscopy was performed on the synthesized elastomer film, and peak splitting software PeakFit was used to analyze the 1750~1600 cm⁻¹ range. -1 The infrared spectrum is subjected to detailed peak fitting to obtain the positions and areas of free peaks and bonded peaks. The proportion of the area occupied by the bonded peak is the number of hydrogen bonds.

[0023] Number of interfacial hydrogen bonds: i.e., the content of interfacial hydrogen bonds, which in the above calculation of the number of hydrogen bonds is between 1750 and 1700 cm⁻¹. –1 The number of hydrogen bonds calculated in part is defined as the number of interfacial hydrogen bonds.

[0024] Hydrogen bond strength: Using the Gauss09 package, the binding energy between hydrogen bond acceptors in the soft segment and hydrogen bond donors in the hard segment of the elastomer was theoretically calculated using density functional theory (DFT). Since hydrogen bonding dominates in the polyurethane elastomer system, the calculated binding energy is defined as the hydrogen bond strength. For ease of discussion, we will use the calculated binding energy between small molecule segments to represent the hydrogen bond strength of the elastomer.

[0025] This invention provides a polyurethane (PU) material with improved damage resistance by utilizing supramolecular interactions at the soft-hard phase interface. Methods for preparing urea elastomers include: In the presence of an initiator, a prepolymer is formed by prepolymerizing a soft-segment polyester diol and a hard-segment isocyanate to obtain a prepolymer. The prepolymer was polymerized with a hydrogen bond donor chain extender to obtain a poly(urethane-urea) elastomer. The soft segment polyester diol is a polyester diol containing a hydrogen bond donor carbonyl group.

[0026] The hydrogen bond donor chain extender is a combination of one of isophorone diamine, 1,6-hexanediamine or 1,7-diaminoheptane and N,N-dihydroxyethyloxalamide.

[0027] According to the present invention, poly(urethane) The damage resistance properties of urea elastomers include impact resistance and tear resistance. When the hard segment isocyanate is isophorone diisocyanate and the hydrogen bond donor chain extender is a combination of 1,6-hexanediamine or 1,7-diaminoheptane and N,N-dihydroxyethyl oxalamide, a poly(urethane-urea) elastomer with abundant interfacial hydrogen bonds and high impact resistance is obtained. When the hard segment isocyanate is hexamethylene diisocyanate and the hydrogen bond donor chain extender is a combination of isophorone diamine and N,N-dihydroxyethyl oxalamide, a poly(urethane-urea) elastomer with moderate interfacial hydrogen bond strength and high tear resistance is obtained.

[0028] The type of soft segment polyester diol affects the properties of the elastomer. Therefore, this invention studies the types of soft segment polyester diols. Preferably, the soft segment polyester diol is selected from at least one of poly(1,4-butanediol adipate), polyethylene adipate diol, polybutylene adipate diol, polypentyl adipate diol, polyhexane adipate diol, or polybutylene succinate diol to obtain better mechanical properties.

[0029] The molecular weight of the soft segment polyester diol affects the properties of the elastomer. Therefore, this invention studies the molecular weight of the soft segment polyester diol. Preferably, the average molecular weight of the soft segment polyester diol is 1000-10000 g / mol to obtain better mechanical properties.

[0030] Preferably, the soft segment polyester diol is dried before use. The specific steps are as follows: vacuum dry at 100-120℃ for 1.5-2 hours, and then cool to room temperature to effectively remove moisture.

[0031] The amount of hard segment isocyanate and soft segment polyester diol affects the properties of the elastomer. Therefore, this invention studies the amount of hard segment isocyanate and soft segment polyester diol. Preferably, the molar ratio of hard segment isocyanate to soft segment polyester diol is 3:1-1.1 to obtain better mechanical properties.

[0032] The type of hard segment isocyanate affects the properties of elastomers. Therefore, this invention studies the types of hard segment isocyanates. Preferably, the hard segment isocyanate is isophorone diisocyanate or hexamethylene diisocyanate to obtain better mechanical properties.

[0033] The present invention does not impose any special limitation on the type of initiator. Preferably, the initiator is one of dimethylaminoethyl ether, dibutyltin dilaurate, and triethylenediamine to improve the initiation efficiency.

[0034] In order to effectively initiate monomer polymerization, the present invention studied the amount of initiator. Preferably, the mass ratio of the initiator to the hard segment isocyanate is 0.003-0.02:1 to effectively initiate the polymerization reaction of the monomer.

[0035] Preferably, the soft segment polyester diol, the hard segment isocyanate and the initiator are dissolved in organic solvent A to obtain a mixed solution; the obtained mixed solution is reacted under a nitrogen atmosphere to obtain a prepolymer, so as to ensure that the polymerization system is homogeneous during the reaction process.

[0036] In order to ensure that the soft segment polyester diol, the hard segment isocyanate, and the initiator can be well dissolved in organic solvent A, the present invention has studied the types of organic solvent A. More preferably, the organic solvent A is one or a combination of two or more of N,N-dimethylformamide, tetrahydrofuran, dichloromethane, and butyl acetate; the mass ratio of the hard segment isocyanate to the volume of organic solvent A is 1g:3-10mL to ensure that all substances are fully dissolved.

[0037] Temperature affects the efficiency of the prepolymerization reaction. Therefore, the present invention studies the temperature of the prepolymerization reaction. Preferably, the temperature of the prepolymerization reaction is 70-90°C and the reaction time is 2-3 hours to improve the efficiency of the prepolymerization reaction.

[0038] The amount of hydrogen bond donor chain extender and soft segment polyester diol affects the mechanical properties of elastomers. Therefore, this invention studies the amount of hydrogen bond donor chain extender and soft segment polyester diol. Preferably, the molar ratio of the hydrogen bond donor chain extender to the soft segment polyester diol is 2:1-1.1 to obtain better mechanical properties.

[0039] Preferably, the hydrogen bond donor chain extender is dissolved in organic solvent B, added to the prepolymer, and reacted under a nitrogen atmosphere. After drying, a poly(urethane) compound with improved damage resistance by utilizing supramolecular interactions at the soft and hard phase interfaces is obtained. Urea elastomer.

[0040] More preferably, the organic solvent B is the same as the organic solvent A, and the mass ratio of the hydrogen bond donor chain extender to the volume of the organic solvent B is 1g:20-60mL, so that the hydrogen bond donor chain extender and the prepolymer can be fully dissolved.

[0041] In a further preferred embodiment, before adding the hydrogen bond donor chain extender to the prepolymer, the step of diluting the prepolymer with a diluent, wherein the diluent is the same as organic solvent A; the volume ratio of the diluent to organic solvent A is 0.5-2:1, so as to reduce the viscosity of the elastomer to a suitable range for application through physical dilution.

[0042] Preferably, the polymerization reaction is carried out at a temperature of 20°C-25°C for 3-5 hours. The polymerization reaction of the present invention can be carried out at room temperature, resulting in higher reaction efficiency.

[0043] Preferably, the drying temperature is 60-90℃ and the drying time is 12-24 hours to remove moisture.

[0044] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0045] Toughness testing method: INSTRON 3344 electronic universal testing machine. The specimens are cut into rectangular shapes, measuring 25mm × 5mm × 0.7mm. The test is conducted at room temperature with a tensile rate of 50mm / min. Each specimen is measured at least three times, and the average value is taken. Impact resistance test method: Pendulum impact test was conducted using a JJ TEST XJJD 50 instrument. The sample was cut into a rectangular shape with dimensions of 30mm × 10mm × 0.7mm. The test was conducted at room temperature with a pendulum energy of 50.0J and an impact velocity of 3.8ms. –1 Then, the impact strength value was calculated using the instrument's built-in software; Tear resistance test method: INSTRON 3344 electronic universal testing machine. The sample was cut into dimensions of 40.0mm × 20.0mm × 0.7mm, with an initial cut length of 20mm. The two branches of the sample were tightly clamped by metal plates to prevent slippage during the tear test. The test was conducted at room temperature with a tensile rate of 50 mm / min.

[0046] In the examples, PBA 1000 and PTMEG 1000 were obtained by vacuum dehydration at 120°C for 2 hours and then naturally cooled to room temperature.

[0047] Example 1: Preparation of a high-impact poly(urethane-urea) elastomer with abundant interfacial hydrogen bonds 5g of PBA 1000 was added to a 250mL round-bottom flask, followed by 3.33g of IPDI, 20mL of DMF, and 0.037g of DBTDL. The mixture was prepolymerized for 2 hours under nitrogen atmosphere and oil bath heating at 85℃ with magnetic stirring to obtain the prepolymer. After the reaction was complete, the temperature was lowered to room temperature. 20mL of DMF solution was added to dilute the prepolymer system, and then a mixed solution of 0.93g of HMDA and 0.35g of BHO (molar ratio of HMDA to BHO: 4:1) dissolved in 40mL of DMF was added dropwise. The mixture was reacted for 3 hours under nitrogen atmosphere and magnetic stirring at room temperature. The solution was poured into a silicone mold, and after complete degassing in a vacuum oven, it was dried in an oven at 80℃ for 12 hours to obtain a high-impact poly(urethane-urea) elastomer, denoted as BPM.

[0048] Example 2: Preparation of a high tear resistance poly(urethane-urea) elastomer with moderate interfacial hydrogen bond strength 5g of PBA 1000 was added to a 250mL round-bottom flask, followed by 2.52g of HDI, 20mL of DMF, and 0.037g of DBTDL. The mixture was prepolymerized for 2 hours under nitrogen atmosphere and oil bath heating at 85℃ with magnetic stirring to obtain the prepolymer. After the reaction was complete, the temperature was lowered to room temperature. 20mL of DMF solution was added to dilute the prepolymer system, and then a mixed solution of 1.36g of IPDA and 0.35g of BHO (molar ratio of IPDA to BHO: 4:1) dissolved in 40mL of DMF was added dropwise. The mixture was reacted for 3 hours under nitrogen atmosphere and magnetic stirring at room temperature. The solution was poured into a silicone mold, and after complete degassing in a vacuum oven, it was dried in an oven at 80℃ for 12 hours to obtain a high-tear-resistance poly(urethane-urea) elastomer, denoted as BDP.

[0049] Example 3: Extension to other chain extender systems 5g of PBA 1000 was added to a 250mL round-bottom flask, followed by 3.33g of IPDI, 20mL of DMF, and 0.037g of DBTDL. The mixture was prepolymerized for 2 hours under nitrogen atmosphere and oil bath heating at 85℃ with magnetic stirring to obtain the prepolymer. After the reaction was complete, the temperature was lowered to room temperature. 20mL of DMF solution was added to dilute the prepolymer system, and then a mixed solution of 1.04g of BMHA and 0.35g of BHO dissolved in 40mL of DMF (molar ratio of HMDA to BHO: 4:1) was added dropwise. The mixture was reacted for 3 hours under nitrogen atmosphere and magnetic stirring at room temperature. The solution was poured into a silicone mold, and after complete degassing in a vacuum oven, it was dried in an oven at 80℃ for 12 hours to obtain a high-impact poly(urethane-urea) elastomer.

[0050] Comparative Example 1: Preparation of interfacial hydrogen-bonded poly(urethane-urea) elastomer 5g of PTMEG was added to a 250mL round-bottom flask, followed by 3.33g of IPDI, 20mL of DMF, and 0.037g of DBTDL. The mixture was prepolymerized for 2 hours under nitrogen atmosphere and oil bath heating at 85℃ with magnetic stirring to obtain the prepolymer. After the reaction was complete, the temperature was lowered to room temperature. 20mL of DMF solution was added to dilute the prepolymer system, and then a mixed solution of 0.93g of HMDA and 0.35g of BHO (molar ratio of HMDA to BHO: 4:1) dissolved in 40mL of DMF was added dropwise. The mixture was reacted for 3 hours under nitrogen atmosphere and magnetic stirring at room temperature. The solution was poured into a silicone mold, and after complete degassing in a vacuum oven, it was dried in an oven at 80℃ for 12 hours to obtain a high-impact poly(urethane-urea) elastomer, denoted as TPM.

[0051] Comparative Example 2: Preparation of poly(urethane-urea) elastomers with fewer interfacial hydrogen bonds 5g of PBA 1000 was added to a 250mL round-bottom flask, followed by 3.33g of IPDI, 20mL of DMF, and 0.037g of DBTDL. The mixture was prepolymerized for 2 hours under nitrogen atmosphere and oil bath heating at 85℃ with magnetic stirring to obtain the prepolymer. After the reaction was complete, the temperature was lowered to room temperature. 20mL of DMF solution was added to dilute the prepolymer system, and then 1.17g of AHO solution dissolved in 40mL of DMF was added dropwise. The mixture was reacted for 3 hours under nitrogen atmosphere and magnetic stirring at room temperature. The solution was poured into a silicone mold, and after complete degassing in a vacuum oven, it was dried in an oven at 80℃ for 12 hours to obtain a high-impact poly(urethane-urea) elastomer, denoted as BPH.

[0052] Comparative Example 3: Preparation of polyurethane elastomers with fewer interfacial hydrogen bonds 5g of PBA 1000 was added to a 250mL round-bottom flask, followed by 3.33g of IPDI, 20mL of DMF, and 0.037g of DBTDL. The mixture was prepolymerized for 2 hours under a nitrogen atmosphere and oil bath at 85℃ with magnetic stirring to obtain the prepolymer. After the reaction was complete, the temperature was lowered to room temperature. 20mL of DMF solution was added to dilute the prepolymer system, followed by 1.18g of HDO solution dissolved in 40mL of DMF. The mixture was then reacted under a nitrogen atmosphere and magnetic stirring at room temperature for 3 hours. The solution was poured into a silicone mold, and after complete degassing in a vacuum oven, it was dried in an oven at 80℃ for 12 hours to obtain a high-impact poly(urethane-urea) elastomer, denoted as BPD.

[0053] Comparative Example 4: Preparation of poly(urethane-urea) elastomers with weak interfacial hydrogen bond strength 5g of PBA 1000 was added to a 250mL round-bottom flask, followed by 2.52g of HDI, 20mL of DMF, and 0.037g of DBTDL. The mixture was prepolymerized for 2 hours under nitrogen atmosphere and oil bath heating at 85℃ with magnetic stirring to obtain the prepolymer. After the reaction was complete, the temperature was lowered to room temperature. 20mL of DMF solution was added to dilute the prepolymer system, and then 1.16g of HMDA solution dissolved in 40mL of DMF was added dropwise. The mixture was reacted for 3 hours under nitrogen atmosphere and magnetic stirring at room temperature. The solution was poured into a silicone mold, and after complete degassing in a vacuum oven, it was dried in an oven at 80℃ for 12 hours to obtain a high-tear-resistance poly(urethane-urea) elastomer, denoted as BDM.

[0054] Comparative Example 5: Preparation of poly(urethane-urea) elastomers with strong interfacial hydrogen bonding strength 5g of PBA 1000 was added to a 250mL round-bottom flask, followed by 3.33g of IPDI, 20mL of DMF, and 0.037g of DBTDL. The mixture was prepolymerized for 2 hours under a nitrogen atmosphere and oil bath at 85℃ with magnetic stirring to obtain the prepolymer. After the reaction was complete, the temperature was lowered to room temperature. 20mL of DMF solution was added to dilute the prepolymer system, and then 1.70g of IPDA solution dissolved in 40mL of DMF was added dropwise. The mixture was reacted for 3 hours under a nitrogen atmosphere and magnetic stirring at room temperature. The solution was poured into a silicone mold, and after complete degassing in a vacuum oven, it was dried in an oven at 80℃ for 12 hours to obtain a high-tear-resistance poly(urethane-urea) elastomer, denoted as BPP.

[0055] Comparative Example 6: Preparation of poly(urethane-urea) elastomers with excessively strong interfacial hydrogen bonds 5g of PBA 1000 was added to a 250 mL round-bottom flask, followed by 3.94g of HMDI, 20mL of DMF, and 0.037g of DBTDL. The mixture was prepolymerized for 2 hours under a nitrogen atmosphere and oil bath at 85°C with magnetic stirring to obtain the prepolymer. After the reaction was complete, the temperature was lowered to room temperature. 20mL of DMF solution was added to dilute the prepolymer system, and then 1.70g of IPDA solution dissolved in 40mL of DMF was added dropwise. The mixture was reacted for 3 hours under a nitrogen atmosphere and magnetic stirring at room temperature. The solution was poured into a silicone mold, and after complete degassing in a vacuum oven, it was dried in an oven at 80°C for 12 hours to obtain the poly(urethane-urea) elastomer.

[0056] Figure 1 This is a comparison chart of the number of interfacial hydrogen bonds in the elastomers prepared in Example 1 and Comparative Examples 1-3. Figure 1 It can be seen that Example 1 has the highest number of interface hydrogen bonds.

[0057] Figure 2 To compare the impact resistance of the elastomers prepared in Example 1 and Comparative Examples 1-3, from... Figure 2 As can be seen from the data, Example 1, which has the most hydrogen bonds at the interface, has the highest impact resistance.

[0058] Figure 3 This is a comparison chart of the hydrogen bond strength of the elastomers prepared in Example 2 and Comparative Examples 4-5. Figure 3 It can be seen from the example that the hydrogen bond strength of Example 2 is moderate.

[0059] Figure 4 To compare the tear resistance of the elastomers prepared in Example 2 and Comparative Examples 4-5, from... Figure 4 As can be seen from the data, Example 2, with its moderate interface strength, exhibits the highest tear resistance.

[0060] Figure 5 To compare the toughness properties of the elastomers prepared in Examples 1-2 and Comparative Examples 1-5, from... Figure 5 It can be seen from the examples 1-2 that the toughness is the highest.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A polyurethane material with improved damage resistance by utilizing supramolecular interactions at the soft-hard phase interface. A method for preparing urea elastomers, characterized in that, include: In the presence of an initiator, a prepolymer is formed by prepolymerizing a soft-segment polyester diol and a hard-segment isocyanate to obtain a prepolymer. The prepolymer was polymerized with a hydrogen bond donor chain extender to obtain a poly(urethane-urea) elastomer. The soft segment polyester diol is a polyester diol containing a hydrogen bond donor carbonyl group. The hydrogen bond donor chain extender is a combination of one of isophorone diamine, 1,6-hexanediamine or 1,7-diaminoheptane and N,N-dihydroxyethyloxalamide.

2. The method for preparing poly(urethane-urea) elastomer with improved damage resistance utilizing supramolecular interactions at the soft-hard phase interface as described in claim 1, characterized in that, The soft segment polyester diol is selected from at least one of poly(1,4-butanediol adipate), poly(ethylene adipate diol), poly(butylene adipate diol), poly(neoprene adipate diol), poly(hexanediol adipate diol), or poly(butylene succinate diol). Alternatively, the average molecular weight of the soft segment polyester diol is 1000-10000 g / mol; Alternatively, the soft segment polyester diol may be dried before use, with the following specific steps: vacuum drying at 100-120℃ for 1.5-2 hours, followed by cooling to room temperature.

3. The method for preparing poly(urethane-urea) elastomer with improved damage resistance utilizing supramolecular interactions at the soft-hard phase interface as described in claim 1, characterized in that, The molar ratio of the hard segment isocyanate to the soft segment polyester diol is 3:1-1.

1.

4. The method for preparing poly(urethane-urea) elastomer with improved damage resistance utilizing supramolecular interactions at the soft-hard phase interface as described in claim 1, characterized in that, The hard segment isocyanate is isophorone diisocyanate or hexamethylene diisocyanate.

5. The method for preparing poly(urethane-urea) elastomer with improved damage resistance by utilizing supramolecular interactions at the soft-hard phase interface as described in claim 1, characterized in that, The initiator is one of dimethylaminoethyl ether, dibutyltin dilaurate, and triethylenediamine; Alternatively, the mass ratio of the initiator to the hard segment isocyanate is 0.003-0.02:

1.

6. The method for preparing poly(urethane-urea) elastomer with improved damage resistance by utilizing supramolecular interactions at the soft-hard phase interface as described in claim 1, characterized in that, The prepolymerization reaction is carried out at a temperature of 70-90℃ for 2-3 hours.

7. The method for preparing poly(urethane-urea) elastomer with improved damage resistance by utilizing supramolecular interactions at the soft-hard phase interface as described in claim 1, characterized in that, The molar ratio of the hydrogen bond donor chain extender to the soft segment polyester diol is 2:1-1.

1.

8. The method for preparing poly(urethane-urea) elastomer with improved damage resistance by utilizing supramolecular interactions at the soft-hard phase interface as described in claim 1, characterized in that, The polymerization reaction is carried out at a temperature of 20℃-25℃ for 3-5 hours.

9. The poly(urethane-urea) elastomer prepared by the method according to any one of claims 1-8.

10. The application of the poly(urethane-urea) elastomer according to claim 9 in the fields of 3D printing and protective materials, characterized in that, The protective materials include: armor protection materials and bulletproof vest materials.

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