CN114369222A

CN114369222A - High-strength room-temperature rapid self-repairing flexible material and preparation method and application thereof

Info

Publication number: CN114369222A
Application number: CN202210062784.5A
Authority: CN
Inventors: 邹华维; 蔡源博
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2022-01-19
Filing date: 2022-01-19
Publication date: 2022-04-19
Anticipated expiration: 2042-01-19
Also published as: CN114369222B

Abstract

The invention provides a high-strength room-temperature rapid self-repairing flexible material, a preparation method and application thereof, belonging to the field of advanced functional materials. The self-repairing flexible material is prepared from oligomer polyol, isocyanate, a chain extender and a cross-linking agent. The self-repairing flexible material has ultrahigh mechanical strength, good room temperature self-repairing performance, good heat resistance, outstanding ablation resistance and excellent comprehensive performance. The self-repairing flexible material has stable use performance, wide use range and long service life, can be applied to systems of various flexible materials, coating materials, encapsulating materials, adhesives and the like, is particularly applied to high-temperature environments or outer protective coatings and flexible workpiece materials with heat-resistant and ablation-resistant requirements, has the advantages of no maintenance, high reliability and the like, and has wide application prospect.

Description

High-strength room-temperature rapid self-repairing flexible material and preparation method and application thereof

Technical Field

The invention belongs to the field of advanced functional materials, and particularly relates to a high-strength room-temperature rapid self-repairing flexible material, and a preparation method and application thereof.

Background

The self-repairing material is a novel material capable of self-repairing when an object is damaged, and has an important application prospect in automobile coatings, wearable equipment, flexible sensors and aerospace protection materials. The self-repairing purpose is to prevent the crack from continuing to expand in the initial stage of crack formation, or automatically close the crack after the material is damaged, and recover the initial structure and performance of the material, so that the application reliability of the material is improved, the application range is expanded, and the service life is prolonged. Currently, two challenging problems mainly exist in the research of self-repairing materials: firstly, the material with high mechanical strength is difficult to realize self-repairing, and the material capable of self-repairing is not high in mechanical strength generally; secondly, the current self-repairing materials lack various functions, so that the application of the self-repairing materials in practical use scenes is limited. The room temperature self-repairing material has convenience and mild type of repairing conditions, so that the room temperature self-repairing material has important value in practical application, especially in the aspects of self-maintenance of thermal protection materials and the like.

The heat-proof material has irreplaceable key effects in the aerospace craft, the aerodynamic thermal environment is more and more severe along with the continuous improvement of the flight speed of the aerospace craft, and the effective outer heat-proof layer can provide enough protection for the aerospace craft when the aerospace craft is subjected to severe aerodynamic heating, so that the flight safety is ensured. However, the mere presence of a thermal protection layer, whose cracking is a significant risk and a fatal threat to the safety of an aerospace vehicle, is still an ineffectively avoidable risk, and therefore maintaining the structural integrity of the thermal protection layer is of paramount importance. At present, the heat-resistant coating with the flexible structure characteristic is more and more important, the flexible material is easier to generate microcracks due to the fact that the flexible material is subjected to mechanical actions such as static or dynamic stretching, extruding, shearing and twisting for a long time, and the existence of defects such as the cracks is a great potential safety hazard of the heat-proof structure, so that the flexible heat-proof material is modified to have the automatic crack healing function, the integrity of the material structure can be maintained before ablation, and the service life is prolonged, and the maintenance cost is reduced, so that the heat-resistant coating has very important significance.

At present, most of mainstream self-repairing polymer matrixes are linear non-crosslinked molecular structures and generally have the defects of low mechanical strength, poor heat resistance and the like. However, the introduction of the cross-linked structure limits the mobility of the molecular chain and tends to reduce the self-repairing efficiency. For example, patent CN110551269A provides a heat-resistant room temperature fast self-repairing elastic material, and the tensile strength of the elastic material is only about 1 MPa. Meanwhile, the ablation reinforcing filler for improving the ablation performance can also greatly limit the movement capacity of a molecular chain, so that the composite material is difficult to repair at room temperature or the tensile strength of the repaired composite material is not high. At present, no self-repairing material with high strength and good room temperature self-repairing performance is searched for, and further research is needed on how to prepare the self-repairing material with high strength and good room temperature self-repairing performance.

Disclosure of Invention

The invention aims to provide a high-strength room-temperature rapid self-repairing flexible material, and a preparation method and application thereof.

The invention provides a high-strength room-temperature rapid self-repairing flexible material which is prepared from raw materials of oligomer polyol, isocyanate, a chain extender and a cross-linking agent; wherein the mass ratio of the oligomer polyol to the isocyanate to the chain extender to the cross-linking agent is (1-100): (1-100): (0.1-20): (0.1 to 20); the chain extender is aliphatic or aromatic diamino disulfide containing reversible disulfide bonds; the cross-linking agent is a tri-functional compound which contains a pyridine or pyrimidine ring structure of a hydrogen bond acceptor and a donor and takes amino or hydroxyl as an active functional group.

Further, the mass ratio of the oligomer polyol to the isocyanate to the chain extender to the cross-linking agent is 15: 6.99: (0.1-5): (0.1-5).

Further, the mass ratio of the oligomer polyol to the isocyanate to the chain extender to the cross-linking agent is 15: 6.99: (0.9-3): (0.3 to 1);

preferably, the mass ratio of the oligomer polyol, the isocyanate, the chain extender and the cross-linking agent is 15: 6.99: (0.9-2): (0.6-1).

Further, the mass ratio of the oligomer polyol to the isocyanate to the chain extender to the cross-linking agent is 15: 6.99: 0.93: 0.945.

further, the oligomer polyol is polytetrahydrofuran, polyoxypropylene polyol or co-polyether polyol;

and/or the isocyanate is a diisocyanate, preferably isophorone diisocyanate, hexamethylene diisocyanate, 4' dicyclohexylmethane diisocyanate, toluene diisocyanate or diphenylmethane diisocyanate;

and/or the chain extender is 4,4' -diaminodiphenyl disulfide, 4' -dihydroxydiphenyl disulfide, 3 ' -dihydroxydiphenyl disulfide or 2-hydroxyethyl disulfide;

and/or the cross-linking agent is 2, 4-diamino-6-hydroxypyrimidine, 2,4, 6-triaminopyrimidine or 2,4, 5-triaminopyridine.

The invention also provides a preparation method of the high-strength room-temperature quick self-repairing flexible material, which comprises the following steps:

(1) synthesis of prepolymer: adding a catalytic amount of catalyst into oligomer polyol and isocyanate, and reacting in a solvent to obtain a prepolymer;

(2) chain extension and crosslinking: adding a cross-linking agent and a chain extender dissolved in a solvent into the prepolymer, and reacting to obtain a reactant;

(3) and (3) curing: and pouring the reactant into a mold, and curing to obtain the catalyst.

Further, the air conditioner is provided with a fan,

in the step (1), the catalyst is dibutyltin dilaurate or stannous octoate;

and/or, in the step (1), the solvent is dimethyl sulfoxide, diethyl sulfoxide or water;

and/or, in the step (2), the solvent is dimethyl sulfoxide, diethyl sulfoxide or water.

Further, the air conditioner is provided with a fan,

in the step (1), the reaction temperature is 60-100 ℃; and/or the environment of the reaction is an inert gas environment; and/or the reaction time is 1-6 h;

and/or in the step (2), the reaction temperature is 60-100 ℃; and/or the reaction time is 0.5-5 h;

and/or in the step (3), the curing condition is that the curing is kept for 20-40 h at 90-150 ℃ in a vacuum environment, and then kept for 10-20h at 120-200 ℃.

The invention also provides the application of the high-strength room-temperature rapid self-repairing flexible material in preparing a room-temperature self-repairing material;

preferably, the room temperature self-repairing material is a flexible material, a coating material, a cladding material, a potting material or an adhesive; or the room temperature self-repairing material is an outer protective coating and a flexible workpiece material which are applied to a high-temperature environment or have heat-resistant and ablation-resistant requirements, and preferably, the room temperature self-repairing material is a flexible heat-proof coating material.

The invention also provides a room temperature self-repairing material which is prepared by taking the high-strength room temperature rapid self-repairing flexible material as a raw material.

Compared with the prior art, the invention has the beneficial effects that:

the self-repairing flexible material has ultrahigh mechanical strength, good room temperature self-repairing performance, good heat resistance and excellent comprehensive performance. The self-repairing flexible material can overcome the problems of low strength and poor self-repairing effect of the self-repairing material in the prior art, can realize the maintenance-free characteristic of the material, effectively prolongs the service life, and fills the gap in the field. The self-repairing flexible material has stable use performance, wide use range and long service life, can be applied to systems of various flexible materials, coating materials, encapsulating materials, adhesives and the like, is particularly applied to high-temperature environments or outer protective coatings and flexible workpiece materials with heat-resistant and ablation-resistant requirements, such as flexible heat-proof coating materials, and has the advantages of maintenance free, high reliability and the like and good application prospect.

Obviously, many modifications, substitutions, and variations are possible in light of the above teachings of the invention, without departing from the basic technical spirit of the invention, as defined by the following claims.

The present invention will be described in further detail with reference to the following examples. This should not be understood as limiting the scope of the above-described subject matter of the present invention to the following examples. All the technologies realized based on the above contents of the present invention belong to the scope of the present invention.

Drawings

FIG. 1 is an infrared spectrum of self-healing flexible materials with different DAHP contents.

FIG. 2 shows the visible range transmittance of 1mm self-healing flexible material sheets with different DAHP content.

FIG. 3 is TEM photographs of self-repairing flexible materials with different DAHP contents; wherein a is PIDA-2.5, and b is PIDA-5; c is PIDA-7.5; d is PIDA-10.

FIG. 4 is a graph of the size distribution of hard segments of self-healing flexible materials with different DAHP contents; wherein a is PIDA-2.5, and b is PIDA-5; c is PIDA-7.5; d is PIDA-10.

FIG. 5 shows the tensile-shear bonding strength of the self-repairing flexible material PIDA-7.5 to an aluminum sheet.

FIG. 6 is a stress-strain curve before and after self-repair of a self-repaired flexible material; wherein a is PIDA-2.5, b is PIDA-5, c is PIDA-7.5, d is PIDA-10, and e is PIDA-0.

FIG. 7 is a graph showing the effect of a self-repairing flexible material PIDA-7.5 thin sheet self-repairing for 24h at room temperature.

FIG. 8 is a thermal weight loss curve of the self-repairing flexible material of the present invention under nitrogen; wherein a is TG and b is DTG.

FIG. 9 is a graph illustrating the reworking capability of the self-healing flexible material of the present invention; wherein, a is a remodeling schematic diagram, b is tensile strength after two remodeling cycles, and c is a stress-strain curve after two remodeling cycles of PIDA-7.5.

FIG. 10 shows the ablation resistance of the composite material prepared from the self-repairing flexible material PIDA-7.5 of the present invention: wherein, a is a schematic diagram for preparing the composite material, b is an optical image in the ablation process, c is the appearance of a sample before P-5HPM ablation, d is the appearance of the sample after P-5HPM ablation, and e is an SEM image of the sample after P-5HPM ablation; f is the linear ablation rate of each group of composite materials; g is the back plate temperature for each set of composites.

FIG. 11 shows the self-healing properties of a composite material made from the self-healing flexible material PIDA-7.5 of the present invention; wherein a is P-5HPM and b is P-10 HPM.

Detailed Description

The raw materials and equipment used in the embodiment of the present invention are known products and obtained by purchasing commercially available products.

Example 1 preparation of self-healing Flexible Material of the invention

(1) Dehydrating the raw materials: polytetrahydrofuran (PTMEG) with the molecular weight of 1000 as a raw material is poured into a flask, the flask is vacuumized for 2 hours at the temperature of 110 ℃, residual moisture is removed, and isophorone diisocyanate (IPDI) adopts a high-purity analytical reagent without further purification treatment.

(2) Synthesis of prepolymer: PTMEG and IPDI were poured into a flask according to the raw material ratio shown in Table 1, 7.5g of DMSO was added, heated to 60 ℃, 3000ppm of dibutyltin dilaurate (DBTDL) was added, and stirred at 60 ℃ for 3 hours under argon to obtain an isocyanate group-terminated prepolymer.

(3) Chain extension and crosslinking: 2, 4-diamino-6-hydroxypyrimidine (DAHP) and 4,4' -diaminodiphenyl disulfide (APDS) dissolved in 12g DMSO were added to the prepolymer in the raw material ratios shown in Table 1, and stirred at 60 ℃ for 2 hours to obtain a viscous reaction product.

(4) Removing the solvent: and pouring the viscous reactant into a polytetrafluoroethylene mold, putting the polytetrafluoroethylene mold into a 60 ℃ oven, vacuumizing to remove bubbles for 1h, keeping the temperature at 90 ℃ for 36h, keeping the temperature at 120 ℃ for 12h, vacuumizing regularly during the period, and cooling to room temperature to obtain the transparent flexible material, namely the self-repairing flexible material.

According to the raw material proportion shown in Table 1, the prepared self-repairing flexible materials are respectively named as PIDA-10, PIDA-7.5, PIDA-5, PIDA-2.5 and PIDA-0.

TABLE 1 raw material ratio for preparing self-repairing flexible material

The advantageous effects of the present invention are demonstrated by specific test examples below.

Test example 1 structural characterization of self-repairing Flexible Material of the invention

1. Infrared spectroscopy

The self-repairing flexible material solid sheet prepared in the example 1 is subjected to infrared characterization and analysis by adopting ATR. FIG. 1 is an attenuated total reflection infrared spectrum of a flexible material. Peak 2258cm corresponding to-NCO on IPDI^-1Disappearance of the four curves indicates that IPDI has participated in the synthesis and is fully reacted; because the hydroxyl of PTMEG reacts with isocyanate of IPDI to generate a urethane structure, amino groups in DAHP and APDS and isocyanate groups at two ends of prepolymer generate urea bonds during chain extension and crosslinking, and because the PIDA flexible material contains both urethane bonds and urea bonds, 1700cm of flexible material exists^-1The C ═ O stretching vibration peak corresponding to the left and right carbamates also existed 1650cm^-1The C ═ O stretching vibration peak in the polyurea structure is a typical double peak of the polyurethane. At the same time, the depth is 1536cm^-1The peak of N-H in-plane bending vibration corresponding to the two amide bands appears, which is 3350cm^-1The peak is the N-H stretching vibration in-NHCOO-, which indicates that partial hydrogen bonds are generated. 1104cm^-1The peak is the C-O-C vibration peak in PTMEG, the urethane bond, the urea bond and the vibration peak in PTMEG appear in the material at the same time, and the-NCO peak disappears, which indicates that the reaction is finished and the material is successfully prepared.

2. Light transmittance

And (3) performing light transmittance characterization on the self-repairing flexible material sheet (1mm) prepared in the example 1 by using an ultraviolet spectrometer. The results are shown in FIG. 2: with the increase of the content of DAHP and the decrease of the content of APDS containing benzene ring structures, the light transmittance of the PIDA flexible material is improved. The light transmittance of the PIDA-10 in most visible light ranges can reach more than 80%, and an optical photo of the material is closer to colorless transparency. The incorporation of APDS causes the flakes to assume a yellow transparent state, and the absorption of the benzene ring causes a sharp drop in light transmission at wavelengths of 400 to 450 nm.

3、TEM

Ruthenium tetroxide staining is carried out on the self-repairing flexible material prepared in the embodiment 1, TEM characterization is carried out after frozen section, and the microphase separation structure of the self-repairing flexible material is analyzed. As can be seen from fig. 3 and 4, the black part is a part where the hard segment is located, the bright part is a soft segment, the hard segment gradually becomes larger in size with the increase of the crosslinking agent DAHP, and the interface between the hard segment and the soft segment gradually blurs to be in a loose state, and the phase separation is weakened.

Test example 2 mechanical property detection of self-repairing flexible material of the invention

1. Tensile Properties

The tensile property test of the self-repairing flexible material prepared in the example 1 is carried out at the tensile rate of 100 mm/min.

The results are shown in table 2: the maximum tensile strength of the PIDA-0 is 0.027MPa, and the elongation at break is more than 1500%; the tensile strength of the PIDA-2.5 is 14.75MPa, and the elongation at break is 501.35%; the tensile strength of the PIDA-5 is 35.37MPa, and the elongation at break is 551.03%; the tensile strength of the PIDA-7.5 is 31.01MPa, and the elongation at break is 662.64%; the tensile strength of PIDA-10 was 71.39MPa, and the elongation at break was 611.17%. It can be seen that the tensile strength of PIDA-0 without addition of DAHP is very low, fluidity is maintained at room temperature for a long time, and therefore elongation at break is very high, and this material is not practical due to its high viscosity characteristics and very low tensile strength. As the content of the DAHP increases, the tensile strength of the self-repairing flexible material shows a trend of increasing, and besides the PIDA-0, the elongation at break of other samples shows a trend of increasing and then decreasing, and reaches a maximum value at the PIDA-7.5. The currently known room temperature self-repairing material is usually low in tensile strength, mostly below 15MPa, and the high tensile strength and the high elongation at break can improve the Toughness (Toughnness) of the material, so that the material can bear higher external force damage, the self-repairing material cannot be easily damaged by the external force, the reliability of the self-repairing material as an external coating material is improved, the protection capability of internal equipment is improved, and the application range of the material in an extreme environment can be expanded.

TABLE 2 tensile strength, elongation at break and toughness of self-healing flexible materials of varying DAHP content

2. Adhesive strength

And (3) testing the tensile shear bonding strength of the aluminum sheet on the PIDA-7.5, wherein the tensile shear rate is 5 mm/min. The method is to coat the PIDA-7.5 on the polished aluminum sheet. The control was pretreated with conventional silane coupling agent KH550 by first coating KH550 on polished aluminum sheets and then coating PIDA-7.5.

The results are shown in FIG. 5: the tensile-shear strength of the PIDA-7.5 flexible material is even higher than that of a mode of carrying out adhesion pretreatment on the surface of an aluminum sheet by using a traditional silane coupling agent KH550, the tensile-shear strength is more than 6MPa, the cross sections of two aluminum sheets subjected to tensile shear are uniformly covered with colloids, cohesive failure is presented, and the bonding failure mode is an ideal bonding failure mode, which shows that the flexible material has excellent bonding performance, and the silane coupling agent is not required to be used for carrying out pretreatment on the surface of the aluminum sheet for bonding the aluminum sheet, so that the bonding strength requirement of a coating can be met.

Test example 3 research on self-repairing performance of self-repairing flexible material

After the samples of the PIDA flexible materials prepared in example 1 and containing different DAHP ratios were cut from the middle of the sample, the samples were spliced and repaired and subjected to tensile testing, and the stress-strain curve of the self-repairing flexible material was obtained as shown in fig. 6. Meanwhile, the self-repairing performance of each group of PIDA flexible materials is shown in tables 3-7.

TABLE 3 PIDA-0 Flexible Material self-healing Performance

TABLE 4 PIDA-2.5 Flexible Material self-healing Performance

TABLE 5 PIDA-5 Flexible Material self-healing Performance

TABLE 6 PIDA-7.5 Flexible Material self-healing Performance

TABLE 7 PIDA-10 Flexible Material self-healing Performance

The PIDA-0 sample shows a viscous state similar to maltose due to no chemical cross-linking bonds, has low mechanical strength, and shows high-efficiency self-repairing performance after being placed at room temperature for a long time, but the material has no feasibility of practical application due to the high viscous characteristic and the extremely low tensile strength of the material. The PIDA-2.5 sample has a high proportion of reversible disulfide bonds and a low crosslinking degree, so that after the sample is repaired at room temperature for 12 hours, the mechanical property is remarkably recovered and even exceeds the initial level, the tensile strength reaches 16.58MPa, the tensile strength repairing efficiency reaches 112.41%, and the breaking elongation repairing efficiency reaches 98.81%. With the increase of the DAHP content, the self-repairing speed and efficiency of the PIDA-5 are reduced, the tensile strength is recovered to 27.52MPa after 168 hours of repairing, the repairing efficiency reaches 77.80%, and the repairing efficiency of the elongation at break reaches 86.72%. The content of DAHP is continuously increased, and the PIDA-7.5 self-repairing efficiency is still at a high level, after 24 hours of repairing, the tensile strength is recovered to 26.99MPa, the repairing efficiency reaches 87.03%, the breaking elongation repairing efficiency reaches 96.31%, after 48 hours of repairing, the tensile strength is recovered to 31.62MPa, the repairing efficiency reaches 101.97%, and the PIDA-2.5 self-repairing effect with a high disulfide bond proportion is equivalent. After DAHP is completely used for chain extension, the self-repairing speed and efficiency of the PIDA-10 are greatly reduced, the PIDA-10 is repaired for 168 hours at room temperature, the tensile strength is only recovered to 8.35MPa, the repairing efficiency is only 11.69%, the repairing efficiency of the elongation at break reaches 22.79%, and heating is needed to achieve higher repairing efficiency.

FIG. 7 is an effect diagram of the PIDA-7.5 self-repairing flexible material sheet for 24 hours at room temperature, a rectangular sample strip with the length of 30.5mm, the width of 9.7mm and the thickness of 1.5mm and the mass of only 0.46g can be hoisted to a bucket with the weight of 8kg after being repaired at room temperature, and the bearing can reach more than 17000 times, which shows that the flexible material sheet has a good self-repairing effect.

Test example 4 thermo-gravimetric study of self-repairing flexible material of the invention

Thermal decomposition stability of the PIDA self-repairing flexible material is determined by thermal weight loss analysis, fig. 8 is TG and DTG curves of the PIDA self-repairing flexible material under nitrogen, table 8 is a thermal stability parameter table of the self-repairing flexible material under nitrogen, wherein various characteristic decomposition temperatures, T and T of the PIDA flexible material are listed_5％Representing a weight loss of 5% on the thermogravimetric plot is the corresponding temperature, T_maxRepresents the peak temperature corresponding to the maximum thermal decomposition rate of each thermal decomposition stage on the differential thermogravimetric curve. As can be seen from the data in the table, T increases with the DAHP content_5％The temperature shows a gradually rising trend, and the maximum weight loss temperature also shows an increasing trend. The introduction of DAHP is shown to be beneficial in improving the thermal stability of the PIDA compliant material. As can be seen from the DTG graph, the weight loss process of the PIH flexible material mainly has two stages: the first stage is the decomposition of carbamate in the hard segment, the thermal decomposition temperature and rate of the first stage are mainly influenced by the hard segment and the content of the hard segment, and the first maximum weight loss rate temperature is gradually increased along with the increase of the content of APDS; the second stage is thermal degradation of the soft segment PTMEG.

TABLE 8 PIDA self-repairing flexible material thermal stability parameter table under nitrogen

Test example 5 remolding reworkability of self-repairing Flexible Material of the present invention

The four PIDA flexible materials are cut into small particles and filled into a dumbbell type die, and hot-pressed for 30min under the conditions of 10MPa and 120 ℃, so that a series of performances shown in the figure 9 are obtained. It can be seen that, in addition to the relatively severe granular feel of the PIDA-10 after being remolded, the other three reworking properties are all very excellent, and the surface of the reworked sample is smooth. Besides the PIDA-10, the repair efficiency of the reshaped sample strips is over 85 percent, and the one-time reshaping efficiency of the PIDA-7.5 can reach 95 percent.

Test example 6, composite material prepared from self-repairing flexible material and performance research

The self-healing ablative polymer composite material has good application prospect in the fields of aerospace and aviation. The composite material prepared by the self-repairing flexible material of the invention utilizes the excellent plasticity of PIDA-7.5 to prepare PIDA-7.5 composite materials containing 5phr and 10phr of Hollow Phenolic Microspheres (HPM) respectively by a hot pressing method, and the composite materials are named as P-5HPM and P-10HPM respectively, as shown in figure 10 (a).

1. Ablation resistance

The above composite was used for ablation testing. All samples were ablated in a butane flame (about 1300 c) for 30 seconds, and optical images of the ablation process and sample appearance before and after the P-5HPM ablation test are shown in fig. 10b, 10c (before ablation) and 10d (after ablation), respectively.

The linear ablation rate of P-5HPM was reduced by nearly 26% and that of P-10HPM by 39.1% in comparison to pure PIDA-7.5 (FIG. 10f), indicating a significant improvement in ablation resistance of the composite containing HPM.

During the ablation test, the back plate temperature of the samples was recorded simultaneously with the thermocouples, and the results showed that the back plate temperature was below 35 ℃ for all samples after 30s of ablation (fig. 10 g). In addition, the temperature of the backing plate continued to rise after the ablation process was stopped, but was below 50 ℃. The PIDA composite material containing HGM shows better ablation resistance.

2. Self-repairing performance

The self-repairing performance of the composite material is tested, and the self-repairing performance is shown in table 9, table 10 and fig. 11: the mechanical properties of the P-5HPM and the P-10HPM after self-repairing for 24 hours at room temperature can reach about 5MPa, and the requirement of the heat-resistant coating on the tensile strength can be met. Such as: the self-healing efficiency of the P-10HPM reaches 55.4% in 24 hours at room temperature and 97.9% in 60 hours at 60 ℃, although the self-healing efficiency of the composite material at room temperature does not reach a high value, the base strength of the material is high, and the repaired strength can meet the use requirement of the coating. This indicates that timely repair of a PIDA-based composite crack can enhance the resistance of the material to heat flux erosion, thus showing potential application as a room temperature self-healing ablative material.

TABLE 9 self-repairing Performance Table for P-5HPM ablation resistant composite materials

TABLE 10 self-repair Performance Table for P-10HPM ablation resistant composite materials

In conclusion, the self-repairing flexible material has ultrahigh mechanical strength, good room temperature self-repairing performance, good heat resistance and excellent comprehensive performance. The self-repairing flexible material can overcome the problems of low strength and poor self-repairing effect of the self-repairing material in the prior art, can realize the maintenance-free characteristic of the material, effectively prolongs the service life, and fills the gap in the field. The self-repairing flexible material has stable use performance, wide use range and long service life, can be applied to systems of various flexible materials, coating materials, encapsulating materials, adhesives and the like, is particularly applied to high-temperature environments or outer protective coatings and flexible workpiece materials with heat-resistant and ablation-resistant requirements, such as flexible heat-proof coating materials, and has the advantages of maintenance free, high reliability and the like, and has wide application prospect.

Claims

1. A high-strength room-temperature rapid self-repairing flexible material is characterized in that: the polyurethane material is prepared from oligomer polyol, isocyanate, a chain extender and a cross-linking agent as raw materials; wherein the mass ratio of the oligomer polyol to the isocyanate to the chain extender to the cross-linking agent is (1-100): (1-100): (0.1-20): (0.1 to 20); the chain extender is aliphatic or aromatic diamino disulfide containing reversible disulfide bonds; the cross-linking agent is a tri-functional compound which contains a pyridine or pyrimidine ring structure of a hydrogen bond acceptor and a donor and takes amino or hydroxyl as an active functional group.

2. The self-healing flexible material of claim 1, wherein: the mass ratio of the oligomer polyol to the isocyanate to the chain extender to the cross-linking agent is 15: 6.99: (0.1-5): (0.1-5).

3. The self-healing flexible material of claim 2, wherein: the mass ratio of the oligomer polyol to the isocyanate to the chain extender to the cross-linking agent is 15: 6.99: (0.9-3): (0.3 to 1);

4. The self-healing flexible material of claim 3, wherein: the mass ratio of the oligomer polyol to the isocyanate to the chain extender to the cross-linking agent is 15: 6.99: 0.93: 0.945.

5. the self-repairing flexible material as claimed in any one of claims 1 to 4, wherein: the oligomer polyol is polytetrahydrofuran, polyoxypropylene polyol or copolymerized polyether polyol;

6. A preparation method of the high-strength room-temperature rapid self-repairing flexible material as claimed in any one of claims 1 to 5, characterized by comprising the following steps: it comprises the following steps:

7. The method of claim 6, wherein:

in the step (1), the catalyst is dibutyltin dilaurate or stannous octoate;

8. The method of claim 6, wherein:

9. Use of the high-strength room-temperature rapid self-repairing flexible material as claimed in any one of claims 1 to 5 in preparation of a room-temperature self-repairing material;

10. The room temperature self-repairing material is characterized in that: the high-strength room-temperature rapid self-repairing flexible material is prepared from the high-strength room-temperature rapid self-repairing flexible material as claimed in any one of claims 1-5.