CN114479011A

CN114479011A - Epoxy glass polymer material based on dynamic reversible covalent bond and preparation method thereof

Info

Publication number: CN114479011A
Application number: CN202210206335.3A
Authority: CN
Inventors: 曾艳宁; 杨伟明
Original assignee: Guilin University of Technology
Current assignee: Guilin University of Technology
Priority date: 2022-03-02
Filing date: 2022-03-02
Publication date: 2022-05-13
Anticipated expiration: 2042-03-02
Also published as: CN114479011B

Abstract

The invention provides an epoxy glass polymer material based on a dynamic reversible covalent bond and a preparation method thereof, belonging to the technical field of glass polymer preparation. The preparation method comprises the following steps: dissolving trimethylolpropane triglycidyl ether, a cross-linking agent and a catalyst in an organic solvent to obtain a mixture; the crosslinking agent comprises 2, 2' - (1, 4-phenylene) -bis [ 4-thiol 1,3, 2-dioxolane and 3, 3-dithiodipropionic acid; and removing the organic solvent in the mixture, and then curing to obtain the epoxy glass polymer material based on the dynamic reversible covalent bond. The epoxy glass polymer material provided by the invention can reduce the repair temperature and improve the repair conditions.

Description

Epoxy glass polymer material based on dynamic reversible covalent bond and preparation method thereof

Technical Field

The invention relates to the technical field of glass-like polymer preparation, in particular to an epoxy glass polymer material based on a dynamic reversible covalent bond and a preparation method thereof.

Background

Epoxy resins are one of the most widely used thermosets. Because the epoxy resin has higher dimensional stability and glass transition temperature (T)_g) And mechanical strength, electrical insulation and resistance to chemical attack, which can be applied as composites, adhesives, coatings, electronic packaging and insulating materials, etc. in everyday goods, buildings, traffic and electronic equipment. As the epoxy resin product is used as the traditional thermosetting polymer material, the product can not be self-repaired, reprocessed and recycled due to the permanent cross-linked network structure of the epoxy resin product, so that the epoxy resin productThe generation of large amounts of epoxy resin waste and environmental problems.

In the last 20 years, in order to obtain self-healing, recyclable and reprocessable epoxy resins, reversible covalent bonds have been introduced into the epoxy network, and such networks containing reversible covalent bonds are referred to as Covalently Adaptable Networks (CANs). Leibler et al (Montarnal D, Capelot M, Tournilhac F, et al, silicon-Like Malleable Materials from Organic Networks [ J ]. Science,2011,334(6058):965-968.DOI:10.1126/science.1212648) first proposed in 2011 a "vitrmer" concept, which uses epoxy resin and fatty acid/anhydride as raw Materials to form a dynamic ester-exchange network upon zinc salt catalysis, which exhibits rheological behavior of glass at high temperature and is therefore called a glass-Like polymer. Due to a bond position exchange mechanism of a reversible covalent bond in the network, the size stability and the crosslinking density of the network can be kept unchanged, so that the epoxy glass network can realize self-repairing and reprocessing under external stimulation (heat, light, PH and the like), and meanwhile, the integrity of the network structure is kept.

However, the existing epoxy glass network can be thermally repaired at high temperature, and the repairing condition is greatly limited. For example, Kessler et al (LiYZ, Zhang YH, Rios O, et al, liquid crystalline epoxide networks with exchangeable ligand bonds [ J ]. Soft Matter,2017,13(29):5021-5027.DOI:10.1039/c7sm00934h) use a disulfide bond-containing aliphatic dibasic acid crosslinking agent to polymerize with biphenyl epoxy monomers to synthesize a reversible dynamic epoxy network with single disulfide bond exchange, and when the hot pressing temperature is more than 150 ℃ and the hot pressing time is more than 2 hours, the material can be reprocessed and reused.

Disclosure of Invention

The invention aims to provide an epoxy glass polymer material based on a dynamic reversible covalent bond and a preparation method thereof.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a preparation method of an epoxy glass polymer material based on a dynamic reversible covalent bond, which comprises the following steps:

dissolving trimethylolpropane triglycidyl ether, a cross-linking agent and a catalyst in an organic solvent to obtain a mixture; the crosslinking agent comprises 2, 2' - (1, 4-phenylene) -bis [ 4-

thiol

1,3, 2-dioxolane and 3, 3-dithiodipropionic acid;

and removing the organic solvent in the mixture, and then curing to obtain the epoxy glass polymer material based on the dynamic reversible covalent bond.

Preferably, the catalyst is an inorganic base catalyst or an organic base catalyst.

Preferably, the inorganic base catalyst comprises lithium hydroxide and/or potassium carbonate; the organic base catalyst comprises one or more of 4-dimethylamino pyridine, imidazole, tetrabutylammonium fluoride, zinc acetylacetonate and 2-methylimidazole.

Preferably, the mass of the catalyst is 1-3% of the mass of the trimethylolpropane triglycidyl ether.

Preferably, the molar ratio of the total molar amount of mercapto groups and carboxyl groups in the crosslinking agent to the epoxy groups in the trimethylolpropane triglycidyl ether is 1.

Preferably, the molar ratio of 2, 2' - (1, 4-phenylene) -bis [ 4-

thiol

1,3, 2-dioxolane to 3, 3-dithiodipropionic acid in the crosslinking agent is (1-3): 1-3.

Preferably, the curing temperature gradient is that the first curing is carried out for 1-3 h at 70-90 ℃ in sequence; second curing at 90-110 ℃ for 1-3 h; thirdly curing for 1-3 h at 110-130 ℃; fourthly curing for 1-3 h at 130-150 ℃; fifth curing at 150-160 ℃ for 1-3 h.

Preferably, removing the organic solvent from the mixture comprises: vacuum drying at 55-65 ℃ for 2-5 h.

Preferably, the trimethylolpropane triglycidyl ether has an epoxy value of 0.70eq/100 g.

The invention provides an epoxy glass polymer material based on a dynamic reversible covalent bond, which is prepared by the preparation method in the scheme.

The invention provides a preparation method of an epoxy glass polymer material based on a dynamic reversible covalent bond, which comprises the following steps: dissolving trimethylolpropane triglycidyl ether, a cross-linking agent and a catalyst in an organic solvent to obtain a mixture; the crosslinking agent comprises 2, 2' - (1, 4-phenylene) -bis [ 4-

thiol

1,3, 2-dioxolane and 3, 3-dithiodipropionic acid; and removing the organic solvent in the mixture, and then curing to obtain the epoxy glass polymer material based on the dynamic reversible covalent bond.

The invention adopts trimethylolpropane triglycidyl ether (TTE for short) as a matrix, 2,2 ' - (1, 4-phenylene) -bis [ 4-

thiol

1,3, 2-dioxolane (BDB for short) and 3, 3-dithiodipropionic acid (DTDPA for short) as cross-linking agents, wherein a mercapto group of BDB and an epoxy group of TTE are subjected to ' click ' reaction to generate a boric acid ester bond and a hydroxyl group, a carboxyl group of DTDPA and an epoxy group of TTE are subjected to esterification reaction to generate an ester bond and a hydroxyl group, and in addition, the DTDPA also contains a disulfide bond. The boric acid ester bonds and the disulfide bonds can be exchanged at a lower temperature, so that the epoxy glass high polymer material provided by the invention has a lower repair temperature, and can realize self-repair at 80 ℃.

Furthermore, the epoxy glass polymer material obtained by controlling the molar ratio of BDB to DTDPA also has excellent mechanical properties. In addition, ester bonds and hydroxyl groups formed by the reaction of the active groups can form hydrogen bonds in a network, and the mechanical property of the epoxy glass polymer material is also improved.

Drawings

FIG. 1 is a schematic diagram of a synthesis route and a network structure of an epoxy glass polymer based on a dynamic reversible covalent bond;

FIG. 2 is an infrared spectrum of each component of an epoxy glass polymer based on a dynamic reversible covalent bond;

FIG. 3 is the mechanical properties of B-S-TTE epoxy glass polymers with different BDB/DTDPA ratios, (a) stress-strain curve; (b) column graphs of tensile strength, strain at break, and modulus of toughness;

FIG. 4 shows the dynamic thermo-mechanical properties of B-S-TTE epoxy glass polymers with different BDB/DTDPA ratios: (a) a storage modulus plot; (b) loss angle plot;

FIG. 5 is a TG curve of B-S-TTE epoxy glass polymer with different BDB/DTDPA ratio;

FIG. 6 is a self-repairing diagram of a B-S-TTE (3:2) epoxy-based glass polymer in example 3;

FIG. 7 shows an epoxy glass polymer of B-S-TTE (3:2) in example 3: (a) welding two broken samples; (b) schematic diagram of dynamic covalent bond (borate bond, disulfide bond, ester bond) exchange reaction; (c) stress-strain curves of the welded samples; (d) column graphs of tensile strength, fracture strain and toughness modulus of the welded sample;

FIG. 8 is a diagram showing a shape memory process of a B-S-TTE (3:2) epoxy based glass polymer in example 3;

FIG. 9 shows an epoxy glass polymer of B-S-TTE (3:2) in example 3: (a) a crushed material reprocessing process diagram; (b) circularly processing a stress-strain curve chart of the sample strip; (c) and (4) circularly processing the bar chart of the tensile strength, the breaking strain and the toughness modulus of the bar chart.

Detailed Description

thiol

1,3, 2-dioxolane and 3, 3-dithiodipropionic acid;

In the present invention, the starting materials used are all commercially available products well known in the art, unless otherwise specified.

According to the invention, trimethylolpropane triglycidyl ether, a cross-linking agent and a catalyst are dissolved in an organic solvent to obtain a mixture.

In the invention, the crosslinking agent comprises 2, 2' - (1, 4-phenylene) -bis [ 4-

thiol

1,3, 2-dioxolane (BDB for short) and 3, 3-dithiodipropionic acid (DTDPA for short), and the molar ratio of BDB to DTDPA is preferably (1-3): 1-3. In embodiments of the invention, specifically 2:1, 3:2, 1:1, 2:3 or 1: 2.

In the invention, the BDB contains a terminal sulfydryl, and the structural formula is shown as formula 1:

in the present invention, the BDB is preferably prepared by a method well known in the art, and the method for preparing the BDB is preferably: dissolving 1.0 g, 4-benzene-diboronic acid and 4.1g 1-thioglycerol in a mixed solution of 80mL tetrahydrofuran and 0.1mL water, adding 5.0g anhydrous magnesium sulfate, stirring at room temperature for 24h, filtering to remove insoluble substances, and carrying out reduced pressure vacuum rotary evaporation on the obtained mixture to obtain a white solid; the white solid was stirred in n-heptane at 50 ℃ for 3h, and the solvent was removed by rotary evaporation to give BDB as a white solid. In the present invention, the water functions to promote the start of the reaction of 1, 4-benzene-diboronic acid and 1-thioglycerol.

In the present invention, the molar ratio of the total molar amount of mercapto groups and carboxyl groups in the crosslinking agent to the epoxy groups in trimethylolpropane triglycidyl ether is preferably 1. In the present invention, the Trimethylolpropane Triglycidyl Ether (TTE) preferably has an epoxy value of 0.70eq/100 g.

In the present invention, the catalyst is preferably an inorganic base catalyst or an organic base catalyst; the inorganic base catalyst preferably comprises lithium hydroxide and/or potassium carbonate; the organic base catalyst preferably comprises one or more of 4-dimethylaminopyridine, imidazole, tetrabutylammonium fluoride, zinc acetylacetonate and 2-methylimidazole, more preferably 4-Dimethylaminopyridine (DMAP) and Imidazole (IM), and in the present invention, the mass ratio of DMAP to IM is preferably 1: 1.

In the invention, the mass of the catalyst is preferably 1-3% of that of TTE, and more preferably 1.5-2.5%.

In the present invention, the organic solvent is preferably tetrahydrofuran, N-dimethylformamide, dimethyl sulfoxide, pyridine or dioxane. The invention has no special requirements on the dosage of the organic solvent, and can completely dissolve all the raw materials.

After the mixture is obtained, the invention removes the organic solvent in the mixture and then carries out curing to obtain the epoxy glass polymer material based on the dynamic reversible covalent bond.

In the present invention, the removing of the organic solvent in the mixture preferably comprises: vacuum drying at 55-65 ℃ for 2-5 h. According to the invention, the mixture is preferably poured into a mould, and the mould containing the mixture is placed in a vacuum drying oven to remove the organic solvent from the mixture. In the present invention, the mold is preferably a homemade release paper mold.

In the present invention, the temperature gradient of the curing is preferably: sequentially carrying out first curing at 70-90 ℃ for 1-3 h; second curing at 90-110 ℃ for 1-3 h; thirdly curing for 1-3 h at 110-130 ℃; fourthly curing for 1-3 h at 130-150 ℃; fifthly, curing for 1-3 h at 150-160 ℃; more preferably: sequentially carrying out first curing for 2h at 80 ℃; second curing for 2h at 100 ℃; thirdly curing for 2 hours at 120 ℃; fourthly curing for 2h at 140 ℃; and (4) carrying out fifth curing for 1h at 150 ℃.

In the curing process, a crosslinking reaction occurs, specifically, a mercapto group of BDB and an epoxy group of TTE generate a click reaction to generate a borate bond and a hydroxyl group, a carboxyl group of DTDPA and the epoxy group of TTE generate an esterification reaction to generate the ester bond and the hydroxyl group to rapidly form the epoxy glass network polymer. The boric acid ester bonds and the disulfide bonds can be exchanged at a lower temperature, so that the epoxy glass high polymer material provided by the invention has a lower repair temperature, and can realize self-repair at 80 ℃.

In addition, ester bonds and hydroxyl groups formed by the reaction of the active groups can form hydrogen bonds in a network, so that the mechanical property of the epoxy glass polymer material is effectively improved.

The epoxy glass polymer material based on dynamic reversible covalent bond and the preparation method thereof provided by the present invention will be described in detail with reference to the following examples, but they should not be construed as limiting the scope of the present invention.

Comparative example 1

3.0g of 1, 4-benzene-diboronic acid and 4.1g of 1-thioglycerol are dissolved in a mixture of 80mL of tetrahydrofuran and 0.1mL of water, 5.0g of anhydrous magnesium sulfate is added, the mixture is stirred at room temperature for 24h, insoluble substances are removed by filtration, the mixture is subjected to reduced pressure vacuum rotary evaporation to obtain a white solid, and finally, the white solid is stirred in n-heptane at 50 ℃ for 3h, and the white solid obtained by removing the solvent by rotary evaporation is the final product BDB.

Under the premise that the molar ratio of epoxy group/(mercapto group + carboxyl group) is 1, 2g of TTE, a crosslinking agent BDB and DTDPA (the molar ratio is 1:0, namely DTDPA is not added), and catalysts 4-Dimethylaminopyridine (DMAP) and Imidazole (IM) (the addition amounts of DMAP and IM are respectively 1 wt% of TTE) are dissolved in 5mL of tetrahydrofuran together, after the mixture is uniformly mixed, the mixture is poured into a release paper mould, vacuum drying is carried out for 3h in a 60 ℃ oven, the solvent is completely volatilized, the mixture after the complete volatilization is placed in a vacuum drying oven to be heated and cured, a temperature gradient is set, first curing is carried out for 2h at 80 ℃, second curing is carried out for 2h at 100 ℃, third curing is carried out for 2h at 120 ℃, fourth curing is carried out for 2h at 140 ℃, fifth curing is carried out for 1h at 150 ℃, the reaction is fully carried out, the epoxy resin is completely cured, and the yellow film material is the epoxy glass polymer material based on the dynamic covalent bond, denoted B-S-TTE (1: 0).

Example 1

The only difference from comparative example 1 is that the molar ratio of the crosslinking agent BDB to DTDPA is 2:1, and the obtained epoxy glass polymer material based on dynamic reversible covalent bonds is marked as B-S-TTE (2: 1).

Example 2

The difference from comparative example 1 is only that the molar ratio of the crosslinking agent BDB to DTDPA is 3:2, and the obtained epoxy glass polymer material based on the dynamic reversible covalent bond is marked as B-S-TTE (3: 2).

To demonstrate the formation of the B-S-TTE epoxy glass crosslinked network, infrared spectroscopic analysis was carried out on TTE as a raw material, BDB and DTDPA as crosslinking agents, and B-S-TTE as an epoxy glass (3:2), respectively, as shown in FIG. 2, wherein 2568cm was observed on the BDB curve in FIG. 2 (a)^-1The position is a-SH stretching vibration absorption peak, which is a characteristic group absorption peak of the synthetic crosslinking agent. On the DTDPA curve, 3100cm^-1Is the absorption peak of OH in carboxyl-COOH, 1695cm^-1Is the absorption peak of C ═ O in the carboxyl group. On the TTE curve, 3500cm^-1The peak is an absorption peak of stretching vibration of-OH, 908cm^-1Is the absorption peak of epoxy group. 3450cm in the B-S-TTE (3:2) curve^-1The peak is a stretching vibration absorption peak of-OH, 2925cm^-1Is the C-H bond stretching vibration absorption peak at 1733cm^-1The position (A) is the stretching vibration absorption peak of carbonyl C ═ O in the ester bond, 1650cm^-1And (b) is an expansion and contraction vibration absorption peak of carbonyl group C ═ O in the carboxyl group. The spectrum of B-S-TTE (3:2) has no absorption peak of-SH when compared with BDB curve, indicating that-SH group in BDB has been completely reacted; compared with DTDPA curve, the absorption peak of OH in carboxyl-COOH is obviously reduced, and the carboxyl reacts with epoxy group to generate ester bond, 1733cm^-1The position is an ester bond stretching vibration absorption peak; compared with TTE curve, 3500cm is due to the effect of hydrogen bond formation (OH- - - -O- - ═ C)^-1Red-shifted to 3450cm^-1Here, the residual-COOH absorption peak was red-shifted to 1650cm^-1Here, the-OH absorption peak of the B-S-TTE (3:2) curve is clearly greater than 2925cm^-1The absorption peak of-C-H shows that a large amount of-OH is generated after the reaction of-SH, -COOH and epoxy, 908cm^-1The absorption peak of the epoxy group disappears. In FIG. 2 (B), the curve B-S-TTE (1:0) is 1518cm on the curve B-S-TTE (1:0) compared with the curve B-S-TTE (0:1)^-1Has a vibration absorption peak of a carbon-carbon double bond on a benzene ring and has no 1733cm^-1The peak of the absorption of the ester bond at (B-S-TTE) (0:1) is exactly opposite and is in line with the theory. At 1733cm^-1Area of absorption peak of ester group (I)₁) And 1650cm^-1Area of carboxyl absorption Peak (I)₀) The ratio of (A) to (B) is the absorption intensity ratio (I)₁/I₀) With increasing proportion of DTDPA in B-S-TTE, I₁/I₀The ratio of (A) gradually increased from 0.80 to 2.60, and a large amount of carboxyl groups reacted with epoxy groups to form ester bonds, in accordance with theory, and 908cm on the curve^-1The absorption peak of the epoxy group at (a) disappears completely. This indicates that-SH, -COOH and epoxy groups react to a large extent to form a crosslinked network of B-S-TTE.

Example 3

The only difference from comparative example 1 is that the molar ratio of the cross-linking agent BDB to DTDPA is 1:1, and the obtained epoxy glass polymer material based on dynamic reversible covalent bonds is marked as B-S-TTE (1: 1).

Example 4

The only difference from comparative example 1 is that the molar ratio of the crosslinking agent BDB to DTDPA is 2:3, and the obtained epoxy glass polymer material based on dynamic reversible covalent bonds is marked as B-S-TTE (2: 3).

Example 5

The only difference from comparative example 1 is that the molar ratio of the cross-linking agent BDB to DTDPA is 1:2, and the obtained epoxy glass polymer material based on dynamic reversible covalent bonds is marked as B-S-TTE (1: 2).

Comparative example 2

The only difference from comparative example 1 is that the molar ratio of the crosslinking agent BDB to DTDPA is 0:1, and the obtained epoxy glass polymer material based on dynamic reversible covalent bonds is marked as B-S-TTE (0: 1).

The epoxy glass polymer materials based on the dynamic reversible covalent bonds obtained in the comparative examples 1-2 and examples 1-5 are subjected to mechanical property tests, and the results are shown in FIG. 3 and Table 1; the epoxy glass polymer materials based on the dynamic reversible covalent bond obtained in comparative examples 1-2 and examples 1-5 were subjected to DMA dynamic thermo-mechanical property test, and the result is shown in FIG. 4, in which (a) is a storage modulus curve; (b) is a graph of loss angle; the glass transition temperature can be derived from FIG. 4, as shown in Table 1. The results of measuring the thermogravimetric curves of the epoxy glass polymer materials based on the dynamic reversible covalent bond obtained in comparative examples 1 to 2 and examples 1 to 5 are shown in fig. 5 and table 1.

TABLE 1 comprehensive Properties of B-S-TTE of comparative examples 1 to 2 and examples 1 to 5

As is clear from Table 1 and FIG. 3, B-S-TTE (1:0) shows brittle fracture, and as the DTDPA ratio increases, the tensile strength of B-S-TTE (1:0 to 1:1) starts to decrease but the toughness increases, while B-S-TTE (1:1) shows the strongest toughness but weaker tensile strength, and B-S-TTE (3:2) shows strong and tough properties, and the overall performance is the best. The analysis reason is that BDB is a rigid structure with a benzene ring, the strength of the material is improved, DTDPA is a flexible structure with a short chain, a disulfide bond is a flexible weak bond, the flexibility of the material is improved, and the material is combined with toughness, so that the BDB shows strong and tough characteristics. As the DTDPA ratio continues to increase, the tensile strength of the B-S-TTE type glass body decreases and the toughness thereof also decreases at B-S-TTE (1:1 to 0:1), which is the lowest value at B-S-TTE (0: 1). For analysis reasons, the DTDPA content in the network is increased, and disulfide bonds are weak bonds and are easy to break, so that a soft network structure is formed, and the mechanical property of the network is continuously reduced. The glass transition temperature of B-S-TTE (1: 0-0: 1) is reduced along with the reduction of the rigid structure content of BDB, which is in line with the theoretical trend, and B-S-TTE (3:2) is a relatively better value. As can be seen from Table 1 and FIG. 5, the thermal properties of the components are relatively stable except for the B-S-TTE (0:1) which has the worst mechanical properties. Therefore, the comprehensive performance of the B-S-TTE (3:2) spline is optimal by taking the reserved mechanical property as a main body and the rest properties as extension.

The self-repairing test was performed on B-S-TTE (3:2), a cross-scratch treatment was performed on the B-S-TTE (3:2) material with a blade, the scratch width was about 5.16 μm, and the material surface scratches were substantially healed after 6h in an oven at 80 ℃, as shown in FIG. 6. As shown in (a) and (b) of fig. 7, a welding test is carried out on the sample, the fractures of the two sample strips are aligned and attached tightly, the sample is placed at 80 ℃ for 2-6 h, and reversible movement occurs between the attached fracture surfacesAnd (3) carrying out exchange reaction of the covalent bonds (borate ester bond, disulfide bond and ester bond) to realize network rearrangement, so that the two fractures are repaired, and the sample bands are connected together. As shown in FIGS. 7 (c) and (d), B-S-TTE (3:2) was best recovered by welding at 80 ℃ for 6 hours, and had a tensile strength of 14.0MPa, an elongation at break of 134.54%, and a modulus of toughness of 14.1MJ/m³Therefore, the tensile strength recovery rate was 80.0%, the elongation at break recovery rate was 93.13%, and the toughness modulus recovery rate was 71.68%.

As shown in FIG. 8, under thermal stimulation, the B-S-TTE (3:2) straight sample strip is firstly heated at 80 ℃ for 2-4 min to deform, and then cooled and shaped; then the mixture is placed in an environment with the temperature of 80 ℃ to recover the straight shape within 1-2 min. The key position exchange is carried out through multiple dynamic covalent bonds, the network topology rearrangement is facilitated, and the B-S-TTE (3:2) network can reversibly and repeatedly carry out the shape memory process.

As shown in FIG. 9 (a), B-S-TTE (3:2) sample bars were cut up, passed through a hot press, subjected to cyclic reprocessing at 80 ℃ under 6MPa to reform the sample bars, and tested for mechanical properties. Then cutting again, repeating the hot pressing under the same temperature and pressure conditions to obtain a sample bar, testing the mechanical properties, and repeating the operation. As shown in FIGS. 9 (b) and (c), under the temperature and pressure conditions, the first cycle (1st) is better, the tensile strength is 10.60MPa, the elongation at break is 106.91%, and the toughness modulus is 10.20MJ/m³. The tensile strength recovery rate is 60.0%, the elongation at break recovery rate is 74.01%, and the toughness modulus recovery rate is 51.86%. The effect of the second cycle (2nd) is reduced, the tensile strength is 10.40MPa, the elongation at break is 90.71%, and the toughness modulus is 7.49MJ/m³(ii) a The tensile strength recovery was 58.86%, the elongation at break recovery was 62.79%, and the modulus of toughness recovery was 38.08%. The effect of the third cycle (3rd) is poor, the tensile strength is 10.40MPa, the elongation at break is 81.76 percent, and the toughness modulus is 6.75MJ/m³(ii) a The recovery rate of tensile strength is 58.85 percent, the recovery rate of elongation at break is 56.60 percent, and the recovery rate of toughness modulus is 34.32 percent.

According to the embodiment, the epoxy glass polymer material based on the dynamic reversible covalent bond and the preparation method thereof are provided, the repair temperature can be reduced, and the repair can be completed after heat treatment at 80 ℃ for 6 hours.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of an epoxy glass polymer material based on a dynamic reversible covalent bond comprises the following steps:

dissolving trimethylolpropane triglycidyl ether, a cross-linking agent and a catalyst in an organic solvent to obtain a mixture; the crosslinking agent comprises 2, 2' - (1, 4-phenylene) -bis [ 4-thiol 1,3, 2-dioxolane and 3, 3-dithiodipropionic acid;

2. The method according to claim 1, wherein the catalyst is an inorganic base catalyst or an organic base catalyst.

3. The method of claim 2, wherein the inorganic base catalyst comprises lithium hydroxide and/or potassium carbonate; the organic base catalyst comprises one or more of 4-dimethylamino pyridine, imidazole, tetrabutylammonium fluoride, zinc acetylacetonate and 2-methylimidazole.

4. The method according to claim 2 or 3, wherein the mass of the catalyst is 1 to 3% of the mass of trimethylolpropane triglycidyl ether.

5. The method according to claim 1, wherein the molar ratio of the total molar amount of the mercapto group and the carboxyl group in the crosslinking agent to the epoxy group in the trimethylolpropane triglycidyl ether is 1.

6. The method according to claim 5, wherein the molar ratio of 2, 2' - (1, 4-phenylene) -bis [ 4-thiol 1,3, 2-dioxolane to 3, 3-dithiodipropionic acid in the crosslinking agent is (1-3): (1-3).

7. The method of claim 1, wherein the curing temperature gradient is: sequentially carrying out first curing at 70-90 ℃ for 1-3 h; second curing at 90-110 ℃ for 1-3 h; thirdly curing for 1-3 h at 110-130 ℃; fourthly curing for 1-3 h at 130-150 ℃; fifth curing at 150-160 ℃ for 1-3 h.

8. The method of claim 1, wherein removing the organic solvent from the mixture comprises: vacuum drying at 55-65 ℃ for 2-5 h.

9. The production method according to claim 1, wherein the trimethylolpropane triglycidyl ether has an epoxy value of 0.70eq/100 g.

10. The epoxy glass polymer material based on the dynamic reversible covalent bond prepared by the preparation method of any one of claims 1 to 9.