High-performance room-temperature self-repairing polyurethane elastomer and preparation method thereof

Abstract

The invention relates to a high-performance room-temperature self-repairing polyurethane elastomer and a preparation method thereof.The polyurethane elastomer is synthesized from diisocyanate containing asymmetric aliphatic rings, polyether glycol or polyester glycol and a dynamic hydrogen bond chain extender, linear and non-linear hydrogen bonds exist in a polyurethane molecular chain at the same time, and the linear and non-linear hydrogen bonds are different from each other. The existence of the linear hydrogen bonds endows the material with good mechanical properties, the non-linear hydrogen bonds also enable the polyurethane elastomer to maintain the strength and realize the self-repairing effect at room temperature, and the high steric hindrance of the asymmetric aliphatic ring structure can inhibit the crystallization of the polyurethane chain segment, thereby enhancing the transparency of the polyurethane. Compared with the prior art, the polyurethane elastomer prepared by the invention has excellent tensile property, tensile strength of more than 30MPa, fracture strain of more than 1000%, good self-repairing property, repair efficiency of more than 80% after repairing for 48 hours at room temperature under the assistance of trace water, and good transparency.

Description

Technical Field

[0001] The invention relates to the technical field of self-repairing elastomer materials, and in particular to a high-performance room-temperature self-repairing polyurethane elastomer and a preparation method thereof. Background Art

[0002] Polyurethane refers to a class of polymers containing a large amount of carbamate in its molecular structure, also known as polyurethane, or PU for short. Due to its good elasticity and processability, polyurethane materials are widely used in the fields of construction, automobiles, electronics, packaging, and shoemaking. Polyurethane materials will inevitably be physically damaged during use. In order to extend their service life, a variety of reversible dynamic bonds such as hydrogen bonds, disulfide bonds, imine groups, and metal coordination bonds are introduced into polyurethane elastomers to give them self-healing properties.

[0003] However, the contradiction between mechanical properties and self-healing properties is a major difficulty in the research of self-healing polyurethane elastomers. Introducing compounds containing a large number of hydrogen bond acceptors and donors into polyurethane elastomers is an effective strategy to improve the strength of the material. However, if ordinary linear hydrogen bonds are introduced in large quantities, it will induce crystallization of the elastomer, the molecular chain movement activity will deteriorate, and the repair performance of the elastomer will deteriorate.

[0004] Chinese patent CN109705300A discloses a self-healing polyurethane and its preparation method, which utilizes the synergistic effect of multiple dynamic bonds. First, it includes the dynamic hydrogen bond system inherent in the polyurethane system. Secondly, the oxime urethane bond generated by the reaction of the oxime group and the isocyanate group is also a dynamic covalent bond. Finally, the dynamic metal-coordination bond can be formed by introducing metal ions to coordinate with the oxime. However, the polyurethane material has the technical problem of poor mechanical properties.

[0005] Chinese patent CN118620171A discloses a high-performance self-healing polyurethane and its preparation method. By introducing multiple linear hydrogen bonds into the polyurethane molecular chain, a polyurethane with a strength range of 20 to 40 MPa is obtained. However, it needs to be heated at 50 to 85°C for 12 to 24 hours to restore the mechanical strength to more than 90%.

[0006] At present, the few reported polyurethane materials that can self-repair at room temperature are also based on the compromise of mechanical properties, and are accompanied by problems such as high preparation cost and complex synthesis process. Therefore, it is necessary to design a polyurethane elastomer with self-repair function and excellent mechanical properties at room temperature and its preparation method to solve the above problems. Summary of the invention

[0007] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a high-performance room-temperature self-healing polyurethane elastomer and a preparation method thereof. The prepared polyurethane elastomer has high transparency, self-healing function at room temperature and excellent mechanical properties.

[0008] The conceptual process of the present application is as follows: the present invention synthesizes asymmetric alicyclic diisocyanate-terminated polyether or polyester, and then adopts a chain extender containing dynamic hydrogen bonds to obtain a room temperature self-repairing polyurethane elastomer through a chain extension reaction, while ensuring the good mechanical properties and room temperature self-repairing properties of the polyurethane elastomer.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] In one aspect, the present invention provides a high-performance room temperature self-healing polyurethane elastomer, wherein the raw materials include the following components by molar fraction:

[0011] Diol: 10 parts;

[0012] Diisocyanate: 20-26 parts;

[0013] Catalyst: 0.0002~0.001 parts

[0014] Dynamic hydrogen bond chain extender: 10-16 parts;

[0015] Solvent: 700-1200 parts.

[0016] Furthermore, the diol is a polyether diol or a polyester diol, the polyether diol includes at least one of polytrimethylene ether diol (PO3G) and polytetramethylene ether diol (PTMG), the polyester diol includes at least one of polycarbonate diol (PCDL) and polycaprolactone diol (PCL), and the number average molecular weight of the diol is 1000 to 5000 g / mol.

[0017] Preferably, the polyether diol is polytetramethylene ether diol (PTMG), and the polyester diol is polycaprolactone diol (PCL).

[0018] Furthermore, the diisocyanate is at least one of dicyclohexylmethane diisocyanate (HMDI) and isophorone diisocyanate (IPDI).

[0019] Furthermore, the catalyst is at least one of stannous octoate, tetramethylbutylene diamine, and dibutyltin dilaurate.

[0020] Preferably, the catalyst is at least one of stannous octoate and dibutyltin dilaurate.

[0021] Furthermore, the dynamic hydrogen bond chain extender is at least one of methylenebis(1-thiosemicarbazide), thiourea, dimethanolthiourea, and thiomethylhydrazine.

[0022] Furthermore, the solvent is at least one of toluene, N,N-dimethylformamide (DMF), acetone, butanone, N,N-dimethylacetamide (DMAC), tetrahydrofuran, and dimethyl sulfoxide.

[0023] Preferably, the solvent is at least one of N,N-dimethylformamide (DMF) and acetone.

[0024] On the other hand, the present invention also provides a method for preparing a high-performance room temperature self-healing polyurethane elastomer, comprising the following steps:

[0025] S1. Before the reaction, 10 parts of diol are dehydrated under vacuum at 110°C for 2-3 hours, then the reaction system is cooled to 60-90°C, 20-26 parts of diisocyanate are added, and the reaction is carried out under the action of 0.0002-0.001 parts of catalyst for 1-3 hours to obtain a prepolymer;

[0026] S2, adjusting the temperature of the reaction system to 25-70° C., adding 200-300 parts of solvent to dilute the prepolymer prepared in S1, then dissolving 10-16 parts of a dynamic hydrogen bond chain extender in 500-900 parts of solvent and adding the solution dropwise to the prepolymer solution, and performing a chain extension reaction for 2-12 hours to obtain a polyurethane;

[0027] S3. Soak the polyurethane prepared in S2 in deionized water for 12 hours, and then vacuum dry it at 80° C. for 48 hours to obtain a room temperature self-healing polyurethane elastomer.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The method for preparing a high-performance room-temperature self-healing polyurethane elastomer provided by the present invention overcomes the defect that excessive linear hydrogen bonds generally cause molecular chains to aggregate and crystallize, thereby affecting the self-healing performance of the polyurethane, by introducing a chain extender containing both linear hydrogen bonds and nonlinear hydrogen bonds into the self-healing polyurethane system.

[0030] (2) The self-healing polyurethane elastomer provided by the present invention has good mechanical properties and exhibits strain hardening during stretching. It not only has high strength (greater than 30 MPa), but also has good transparency and good room temperature self-healing performance. The repair process does not require additional repairing agents or energy input. With the assistance of water, scratches can disappear after being left at room temperature for 4 hours.

[0031] (3) The method of the present invention has mild reaction conditions, simple preparation process, cheap raw materials, high added value of the obtained product, high application value in the fields of coatings, optical equipment, flexible electronic devices, etc., and has strong industrial competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 These are the self-healing photos of the IP-PTMG-TBD prepared in Example 4 of the present invention under a polarizing microscope, (a) 0 h at room temperature after cutting, (b) 4 h water treatment at room temperature after cutting. DETAILED DESCRIPTION

[0033] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Any features such as preparation means, materials, structures or composition ratios not clearly described in this technical solution are regarded as common technical features disclosed in the prior art.

[0034] The raw materials in the following examples are as follows, but are not limited to the raw materials described below. The following raw materials are only used as specific examples to illustrate the effects of the heat-resistant, transparent, self-healing thermoplastic polyurethane elastomer containing dynamic hydrogen bonds.

[0035] The test methods for tensile strength and elongation at break refer to GB / T 528-2009, the dumbbell-shaped polyurethane specimen has a specification of 75×4×2mm, the tensile rate is 50mm / min, and the toughness is the integral area of ​​the stress-strain curve.

[0036] Repair efficiency: Use a blade to cut the dumbbell-shaped sample in the middle, apply a small amount of water on the cross section, and then splice the cross sections together. After repairing at room temperature for 48 hours, perform a tensile test. Each group of experiments has at least three parallel samples. Self-repair efficiency = tensile strength (fracture strain) of the repaired sample / tensile strength (fracture strain) of the original sample.

[0037] Light transmittance: Refer to GB / T 2410-2008, measured by spectrophotometer, sample thickness is 1mm.

[0038] Example 1

[0039] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0040] S1. Before the reaction, polytetramethylene ether glycol (PTMG) (Mn=2000) (20 g, 10 mmol) was dehydrated in vacuum at 110° C. for 2 h, then the reaction system was cooled to 70° C., isophorone diisocyanate (IPDI) (5 g, 22 mmol) and 0.4 mg of stannous octoate were added, and the mixture was reacted at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0041] S2, adjusting the temperature of the reaction system to 60°C, adding 20 mL of DMF to the prepolymer prepared in S1 to dilute the viscosity, then dissolving methylenebis(1-thiosemicarbazide) (BTO) (2.3 g, 12 mmol) in 60 mL of DMF and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 3 hours to obtain a polyurethane;

[0042] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, denoted as IP-PTMG-BTO. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an IP-PTMG-BTO dumbbell-shaped polyurethane sample.

[0043] The tensile properties of IP-PTMG-BTO dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0044] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the IP-PTMG-BTO polyurethane elastomer prepared in this embodiment is 95.2%.

[0045] Example 2

[0046] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0047] S1. Before the reaction, polytetramethylene ether glycol (PTMG) (Mn=2000) (20 g, 10 mmol) was dehydrated in vacuum at 110° C. for 2 h, then the reaction system was cooled to 70° C., isophorone diisocyanate (IPDI) (5 g, 22 mmol) and 0.4 mg of stannous octoate were added, and the mixture was reacted at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0048] S2, adjusting the temperature of the reaction system to 40°C, adding 20 mL of acetone to the prepolymer prepared in S1 to dilute the viscosity, then dissolving thiourea (THA) (0.9 g, 12 mmol) in 40 mL of acetone and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 2 hours to obtain a polyurethane;

[0049] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, denoted as IP-PTMG-THA. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an IP-PTMG-THA dumbbell-shaped polyurethane specimen.

[0050] The tensile properties of IP-PTMG-THA dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0051] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the IP-PTMG-THA polyurethane elastomer prepared in this embodiment is 93.8%.

[0052] Example 3

[0053] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0054] S1. Before the reaction, polytetramethylene ether glycol (PTMG) (Mn=2000) (20 g, 10 mmol) was dehydrated in vacuum at 110° C. for 2 h, then the reaction system was cooled to 70° C., isophorone diisocyanate (IPDI) (5 g, 22 mmol) and 0.4 mg of stannous octoate were added, and the mixture was reacted at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0055] S2, at 70°C, add 20 mL of DMF to the prepolymer prepared in S1 to dilute the viscosity, then dissolve dimethylthiourea (DTA) (1.6 g, 12 mmol) in 40 mL of DMF and dropwise add it to the diluted prepolymer solution, and carry out chain extension reaction for 12 hours to obtain polyurethane;

[0056] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, recorded as IP-PTMG-DTA. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an IP-PTMG-DTA dumbbell-shaped polyurethane specimen.

[0057] The tensile properties of IP-PTMG-DTA dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0058] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the IP-PTMG-DTA polyurethane elastomer prepared in this embodiment is 90.4%.

[0059] Example 4

[0060] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0061] S1. Before the reaction, polytetramethylene ether glycol (PTMG) (Mn=2000) (20 g, 10 mmol) was dehydrated in vacuum at 110° C. for 2 h, then the reaction system was cooled to 70° C., isophorone diisocyanate (IPDI) (5 g, 22 mmol) and 0.4 mg of stannous octoate were added, and the mixture was reacted at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0062] S2, adjusting the temperature of the reaction system to 40°C, adding 20 mL of acetone to the prepolymer prepared in S1 to dilute the viscosity, then dissolving thiomethylhydrazine (TBD) (1.3 g, 12 mmol) in 60 mL of acetone and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 3 hours to obtain a polyurethane;

[0063] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, denoted as IP-PTMG-TBD. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an IP-PTMG-TBD dumbbell-shaped polyurethane specimen.

[0064] The tensile properties of IP-PTMG-TBD dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0065] like Figure 1 The self-healing photo of IP-PTMG-TBD prepared in this example under a polarizing microscope is shown. Figure 1 (a) shows the state of the polyurethane elastomer after being cut and left at room temperature for 0 h. Figure 1 (b) After the polyurethane elastomer is cut, the scratch disappears after being placed at room temperature for 4 hours with the assistance of water, indicating that the IP-PTMG-TBD prepared in this example has good room temperature self-healing performance.

[0066] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the IP-PTMG-TBD polyurethane elastomer prepared in this embodiment is 90.2%.

[0067] Example 5

[0068] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0069] S1. Before the reaction, remove water from polytetramethylene ether glycol (PTMG) (Mn=2000) (20 g, 10 mmol) at 110° C. in vacuum for 2 h, then cool the reaction system to 70° C., add dicyclohexylmethane diisocyanate (HMDI) (5.8 g, 22 mmol) and 0.6 mg dibutyltin dilaurate, and react at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0070] S2, adjusting the temperature of the reaction system to 60°C, adding 20 mL of DMF to the prepolymer prepared in S1 to dilute the viscosity, then dissolving methylenebis(1-thiosemicarbazide) (BTO) (2.3 g, 12 mmol) in 60 mL of DMF and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 3 hours to obtain a polyurethane;

[0071] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, denoted as HM-PTMG-BTO. The dried product was then crushed and hot pressed in a flat vulcanizer at 130 °C for 4 min to obtain an HM-PTMG-BTO dumbbell-shaped polyurethane specimen.

[0072] The tensile properties of the HM-PTMG-BTO dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0073] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the HM-PTMG-BTO polyurethane elastomer prepared in this embodiment is 91.9%.

[0074] Example 6

[0075] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0076] S1. Before the reaction, remove water from polytetramethylene ether glycol (PTMG) (Mn=2000) (20 g, 10 mmol) at 110° C. in vacuum for 2 h, then cool the reaction system to 70° C., add dicyclohexylmethane diisocyanate (HMDI) (5.8 g, 22 mmol) and 0.6 mg dibutyltin dilaurate, and react at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0077] S2, adjusting the temperature of the reaction system to 40°C, adding 20 mL of acetone to the prepolymer prepared in S1 to dilute the viscosity, then dissolving thiourea (THA) (0.9 g, 12 mmol) in 40 mL of acetone and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 2 hours to obtain a polyurethane;

[0078] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, recorded as HM-PTMG-THA. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an HM-PTMG-THA dumbbell-shaped polyurethane specimen.

[0079] The tensile properties of the HM-PTMG-THA dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0080] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the HM-PTMG-THA polyurethane elastomer prepared in this embodiment is 91.3%.

[0081] Example 7

[0082] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0083] S1. Before the reaction, remove water from polytetramethylene ether glycol (PTMG) (Mn=2000) (20 g, 10 mmol) at 110° C. in vacuum for 2 h, then cool the reaction system to 70° C., add dicyclohexylmethane diisocyanate (HMDI) (5.8 g, 22 mmol) and 0.6 mg dibutyltin dilaurate, and react at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0084] S2, at 70°C, add 20 mL of DMF to the prepolymer prepared in S1 to dilute the viscosity, then dissolve dimethylthiourea (DTA) (1.6 g, 12 mmol) in 40 mL of DMF and dropwise add it to the diluted prepolymer solution, and carry out chain extension reaction for 12 hours to obtain polyurethane;

[0085] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, recorded as HM-PTMG-DTA. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an HM-PTMG-DTA dumbbell-shaped polyurethane specimen.

[0086] The tensile properties of the HM-PTMG-DTA dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0087] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the HM-PTMG-DTA polyurethane elastomer prepared in this embodiment is 92.2%.

[0088] Example 8

[0089] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0090] S1. Before the reaction, remove water from polytetramethylene ether glycol (PTMG) (Mn=2000) (20 g, 10 mmol) at 110° C. in vacuum for 2 h, then cool the reaction system to 70° C., add dicyclohexylmethane diisocyanate (HMDI) (5.8 g, 22 mmol) and 0.6 mg dibutyltin dilaurate, and react at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0091] S2, adjusting the temperature of the reaction system to 40°C, adding 20 mL of acetone to the prepolymer prepared in S1 to dilute the viscosity, then dissolving thiomethylhydrazine (TBD) (1.3 g, 12 mmol) in 60 mL of acetone and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 3 hours to obtain a polyurethane;

[0092] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, recorded as HM-PTMG-TBD. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an HM-PTMG-TBD dumbbell-shaped polyurethane specimen.

[0093] The tensile properties of the HM-PTMG-TBD dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0094] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the HM-PTMG-TBD polyurethane elastomer prepared in this embodiment is 92.8%.

[0095] Example 9

[0096] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0097] S1. Polycaprolactone diol (PCL) (Mn=2000) (20 g, 10 mmol) was dehydrated under vacuum at 110° C. for 2 h before the reaction, and then the reaction system was cooled to 70° C., isophorone diisocyanate (IPDI) (5 g, 22 mmol) and 0.4 mg of stannous octoate were added, and the reaction was carried out at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0098] S2, adjusting the temperature of the reaction system to 60°C, adding 20 mL of DMF to the prepolymer prepared in S1 to dilute the viscosity, then dissolving methylenebis(1-thiosemicarbazide) (BTO) (2.3 g, 12 mmol) in 60 mL of DMF and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 3 hours to obtain a polyurethane;

[0099] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, recorded as IP-PCL-BTO. The dried product was then crushed and hot pressed in a flat vulcanizer at 130 °C for 4 min to obtain an IP-PCL-BTO dumbbell-shaped polyurethane sample.

[0100] The tensile properties of IP-PCL-BTO dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0101] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the IP-PCL-BTO polyurethane elastomer prepared in this embodiment is 93.9%.

[0102] Example 10

[0103] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0104] S1. Polycaprolactone diol (PCL) (Mn=2000) (20 g, 10 mmol) was dehydrated under vacuum at 110° C. for 2 h before the reaction, and then the reaction system was cooled to 70° C., isophorone diisocyanate (IPDI) (5 g, 22 mmol) and 0.4 mg of stannous octoate were added, and the reaction was carried out at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0105] S2, adjusting the temperature of the reaction system to 40°C, adding 20 mL of acetone to the prepolymer prepared in S1 to dilute the viscosity, then dissolving thiourea (THA) (0.9 g, 12 mmol) in 40 mL of acetone and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 2 hours to obtain a polyurethane;

[0106] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, recorded as IP-PCL-THA. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an IP-PCL-THA dumbbell-shaped polyurethane specimen.

[0107] The tensile properties of IP-PCL-THA dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0108] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the IP-PCL-THA polyurethane elastomer prepared in this embodiment is 90.1%.

[0109] Embodiment 11

[0110] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0111] S1. Polycaprolactone diol (PCL) (Mn=2000) (20 g, 10 mmol) was dehydrated under vacuum at 110° C. for 2 h before the reaction, and then the reaction system was cooled to 70° C., isophorone diisocyanate (IPDI) (5 g, 22 mmol) and 0.4 mg of stannous octoate were added, and the reaction was carried out at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0112] S2, at 70°C, add 20 mL of DMF to the prepolymer prepared in S1 to dilute the viscosity, then dissolve dimethylthiourea (DTA) (1.6 g, 12 mmol) in 40 mL of DMF and dropwise add it to the diluted prepolymer solution, and carry out chain extension reaction for 12 hours to obtain polyurethane;

[0113] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, recorded as IP-PCL-DTA. The dried product was then crushed and hot pressed at 130 °C for 4 min in a flat vulcanizer to obtain an IP-PCL-DTA dumbbell-shaped polyurethane specimen.

[0114] The tensile properties of IP-PCL-DTA dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0115] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the IP-PCL-DTA polyurethane elastomer prepared in this embodiment is 92.5%.

[0116] Example 12

[0117] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0118] S1. Polycaprolactone diol (PCL) (Mn=2000) (20 g, 10 mmol) was dehydrated under vacuum at 110° C. for 2 h before the reaction, and then the reaction system was cooled to 70° C., isophorone diisocyanate (IPDI) (5 g, 22 mmol) and 0.4 mg of stannous octoate were added, and the reaction was carried out at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0119] S2, adjusting the temperature of the reaction system to 40°C, adding 20 mL of acetone to the prepolymer prepared in S1 to dilute the viscosity, then dissolving thiomethylhydrazine (TBD) (1.3 g, 12 mmol) in 60 mL of acetone and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 3 hours to obtain a polyurethane;

[0120] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, recorded as IP-PCL-TBD. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an IP-PCL-TBD dumbbell-shaped polyurethane specimen.

[0121] The tensile properties of IP-PCL-TBD dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0122] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the IP-PCL-TBD polyurethane elastomer prepared in this embodiment is 91.7%.

[0123] Comparative Example 1

[0124] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0125] S1. Before the reaction, polytetramethylene ether glycol (PTMG) (Mn=2000) (20 g, 10 mmol) was dehydrated in vacuum at 110° C. for 2 h, then the reaction system was cooled to 70° C., isophorone diisocyanate (IPDI) (5 g, 22 mmol) and 0.4 mg of stannous octoate were added, and the mixture was reacted at 70° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0126] S2, adjusting the temperature of the reaction system to 60° C., adding 20 mL of DMF to the prepolymer prepared in S1 to dilute the viscosity, then dissolving adipic acid dihydrazide (ADH) (2.1 g, 12 mmol) in 80 mL of DMF and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 3 h to obtain a polyurethane;

[0127] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, denoted as IP-PTMG-ADH. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an IP-PTMG-ADH dumbbell-shaped polyurethane sample.

[0128] The tensile properties of IP-PTMG-AHD dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0129] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the IP-PTMG-AHD polyurethane elastomer prepared in this embodiment is 95.2%.

[0130] Comparative Example 2

[0131] The present invention provides a method for preparing a high-performance room temperature self-repairing polyurethane elastomer, comprising the following steps:

[0132] S1. Before the reaction, remove water from polytetramethylene ether glycol (PTMG) (Mn=2000) (20 g, 10 mmol) at 110° C. in vacuum for 2 h, then cool the reaction system to 70° C., add diphenylmethane diisocyanate (MDI) (5.5 g, 22 mmol) and 0.6 mg dibutyltin dilaurate, and react at 60° C. for 2 h to obtain a prepolymer with a certain viscosity;

[0133] S2, adjusting the temperature of the reaction system to 40°C, adding 20 mL of acetone to the prepolymer prepared in S1 to dilute the viscosity, then dissolving thiourea (THA) (0.9 g, 12 mmol) in 40 mL of acetone and adding dropwise to the diluted prepolymer solution, and performing a chain extension reaction for 2 hours to obtain a polyurethane;

[0134] S3. The polyurethane prepared in S2 was immersed in deionized water for 12 h, and then vacuum dried at 80 °C for 48 h to obtain a room temperature self-healing polyurethane elastomer, recorded as M-PTMG-THA. The dried product was then crushed and hot-pressed in a flat vulcanizer at 130 °C for 4 min to obtain an M-PTMG-THA dumbbell-shaped polyurethane specimen.

[0135] The tensile properties of the M-PTMG-THA dumbbell-shaped polyurethane specimens were measured according to GB / T 528-2009. The specimens were then cut in the middle and a small amount of water was applied to the cross section. The specimens were repaired at room temperature for 48 hours and then subjected to a tensile test. The test results are shown in Table 1.

[0136] According to GB / T 2410-2008, the light transmittance of a sample with a thickness of 1 mm was measured. The test results are shown in Table 1. The light transmittance (wavelength 600 nm) of the M-PTMG-THA polyurethane elastomer prepared in this embodiment is 43.8%.

[0137] As can be seen from Table 1, the repair efficiencies of the polyurethanes prepared using asymmetric alicyclic isocyanates and chain extenders containing dynamic hydrogen bonds in Examples 1-12 were greater than 80% at room temperature for 48 hours with the assistance of trace amounts of water. However, the polyurethanes prepared using chain extenders without dynamic hydrogen bonds in Comparative Example 1 did not have a good repair effect at room temperature even with the assistance of trace amounts of water. The polyurethanes prepared using symmetrical isocyanates containing benzene ring structures in Comparative Example 2 had poor room temperature repair effects and poor transparency because the symmetrical benzene ring structure induced crystallization of polyurethane molecular segments.

[0138] Table 1 Performance test results of polyurethane elastomers of Examples 1-12

[0139] Example Tensile strength(MPa) Elongation at break (%) Repair efficiency at room temperature for 48 hours (%) transparency(%) Example 1 43.2 1537.2 92.7 95.2 Example 2 34.0 2118.3 92.1 93.8 Example 3 30.7 3375.1 93.2 90.4 Example 4 36.9 2718.3 91.2 90.2 Example 5 52.3 1560.1 86.9 91.9 Example 6 37.8 2321.1 84.7 91.3 Example 7 32.8 3133.2 88.9 92.2 Example 8 40.1 2143.1 88.2 92.8 Example 9 60.3 1239.1 82.3 93.9 Example 10 41.2 2150.3 88.7 90.1 Embodiment 11 36.7 2159.4 90.4 92.5 Example 12 43.2 2153.8 84.3 91.7 Comparative Example 1 47.1 1630.8 13.1 95.2 Comparative Example 2 41.9 1738.6 5.4 43.8

[0140] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A high-performance room temperature self-healing polyurethane elastomer, characterized in that: In molar parts, the raw materials include the following components: Diol: 10 parts; Diisocyanate: 20-26 parts; Catalyst: 0.0002~0.001 parts Dynamic hydrogen bond chain extender: 10-16 parts; Solvent: 700-1200 parts.

2. A high-performance room temperature self-healing polyurethane elastomer according to claim 1, characterized in that: The diol is a polyether diol or a polyester diol. The polyether diol includes at least one of polytrimethylene ether diol and polytetramethylene ether diol. The polyester diol includes at least one of polycarbonate diol and polycaprolactone diol. The number average molecular weight of the diol is 1000 to 5000 g / mol.

3. A high-performance room temperature self-healing polyurethane elastomer according to claim 1, characterized in that: The diisocyanate is at least one of dicyclohexylmethane diisocyanate and isophorone diisocyanate.

4. The high-performance room temperature self-repairing polyurethane elastomer according to claim 1, characterized in that: The catalyst is at least one of stannous octoate, tetramethylbutylene diamine and dibutyltin dilaurate.

5. The high-performance room temperature self-repairing polyurethane elastomer according to claim 1, characterized in that: The dynamic hydrogen bond chain extender is at least one of methylenebis(1-thiosemicarbazide), thiourea, dimethanolthiourea, and thiomethylhydrazine.

6. The high-performance room temperature self-repairing polyurethane elastomer according to claim 1, characterized in that: The solvent is at least one of toluene, N,N-dimethylformamide, acetone, butanone, N,N-dimethylacetamide, tetrahydrofuran and dimethyl sulfoxide.

7. A method for preparing a high-performance room temperature self-healing polyurethane elastomer according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Dewater 10 parts of diol before reaction, cool the reaction system to 60-90°C, add 20-26 parts of diisocyanate, and react for 1-3 hours under the action of 0.0002-0.001 parts of catalyst to obtain a prepolymer; S2, adjusting the temperature of the reaction system to 25-70° C., adding 200-300 parts of solvent to dilute the prepolymer prepared in S1, then dissolving 10-16 parts of a dynamic hydrogen bond chain extender in 500-900 parts of solvent and adding the solution dropwise to the prepolymer solution, and performing a chain extension reaction for 2-12 hours to obtain a polyurethane; S3. Soak the polyurethane prepared in S2 in deionized water, and then vacuum dry it to obtain a room temperature self-healing polyurethane elastomer.

8. The method for preparing a high-performance room temperature self-repairing polyurethane elastomer according to claim 7, characterized in that: In S1, the diol needs to be dehydrated under vacuum at 110° C. for 2 to 3 hours before the reaction.

9. The method for preparing a high-performance room temperature self-repairing polyurethane elastomer according to claim 7, characterized in that: In S3, the polyurethane is immersed in deionized water for 12 hours.

10. The method for preparing a high-performance room temperature self-repairing polyurethane elastomer according to claim 7, characterized in that: In S3, the vacuum drying temperature is 80° C., and the vacuum drying time is 48 h.

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