A recyclable blue light-activated epoxy resin material and its preparation method

Abstract

The present invention discloses a recyclable blue light-activated epoxy resin material and a preparation method thereof, which belongs to the field of intelligent drive technology. The material is obtained by ring-opening and curing an epoxy monomer containing an azothiazole structure, an epoxy resin monomer, a long-chain diamine, and aminophenylboronic acid at a certain molar ratio at 90°C. The epoxy resin material prepared by the present invention contains a light-responsive azothiazole structure, and through the photoisomerization of the azothiazole structure, the epoxy resin is photoactivated under 450 nm blue light irradiation. In addition, the reversible borate ester bond formed by the dehydration condensation of aminophenylboronic acid gives the epoxy resin recyclability. The epoxy resin material prepared by the present invention has fast blue light actuation capability and recyclable performance, and can be used in the fields of intelligent switches, flexible robots, bionic systems, etc.

Description

Technical Field

[0001] The present invention relates to the field of intelligent drive technology, and in particular to a recyclable blue light-activated epoxy resin material and a preparation method thereof. Background Art

[0002] With the continuous advancement of science and technology, intelligent driving materials have gradually become an important part of promoting the sustainable development of industry, environment and society. Among them, photoactuated materials have become an important technical support for realizing intelligent manufacturing and green and low-carbon transformation due to their advantages such as non-contact driving, fast response speed, and high spatial and temporal resolution. They have broad application prospects in emerging industries such as aerospace, electronic information, new energy, and intelligent manufacturing.

[0003] Epoxy resin has numerous applications in light-driven materials due to its excellent mechanical strength, chemical corrosion resistance and good bonding properties. However, the reported light-driven epoxy resins need to be realized under ultraviolet or infrared light conditions. These light sources have high thermal effects and cause certain damage to the materials. In addition, light-driven epoxy resins form irreversible cross-linked networks after curing, which are difficult to recycle and reprocess, limiting their further application in the context of sustainable development.

[0004] This invention introduces a visible light-responsive azothiazole structure and a reversible borate ester structure into epoxy resin, endowing the epoxy resin material with excellent blue light-activated and recyclable properties. Under 450nm blue light irradiation, the epoxy resin material can be photoactivated and reprocessed by hot pressing at 200°C and 6MPa for 30 minutes. Summary of the Invention

[0005] In order to solve the problems of high thermal effect of the light source required for existing photo-activated epoxy resin materials and the inability to recycle epoxy resin materials, the present invention proposes a recyclable blue light-activated epoxy resin material and a preparation method thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A recyclable blue light-activated epoxy resin material, characterized in that the epoxy resin is obtained by ring-opening curing at 90°C using an epoxy monomer containing an azothiazole structure, an epoxy resin monomer, a long-chain diamine, and aminophenylboronic acid in a molar ratio of 1:0 to 20:3 to 12:1 to 4, wherein the molar content of the epoxy resin monomer is not 0, and the general structural formula of the epoxy monomer containing an azothiazole structure is:

[0008]

[0009] Wherein, the value range of n is 1 to 6;

[0010] Furthermore, the recyclable blue light-activated epoxy resin material is characterized in that the epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, linear aliphatic epoxy resin, and alicyclic epoxy resin;

[0011] Furthermore, the recyclable blue light-activated epoxy resin material is characterized in that the long-chain diamine is one or more of the following structural formulas:

[0012]

[0013] In the formula, the value range of x is 1-30;

[0014] Furthermore, the recyclable blue light-activated epoxy resin material is characterized in that the aminophenylboronic acid is one or more of 2-aminophenylboronic acid, 3-aminophenylboronic acid and 4-aminophenylboronic acid.

[0015] Furthermore, the method for preparing a recyclable blue light-activated epoxy resin material is characterized by comprising the following steps:

[0016] S1. Preparation of an epoxy monomer containing an azothiazole structure: Add a diphenol containing an azothiazole structure, epichlorohydrin, and benzyltributylammonium bromide in a molar ratio of 1:20:0.2 to a round-bottom flask, dissolve with N,N-dimethylformamide, and react with stirring at 105° C. for 4 hours. Then, add 8 equivalents of sodium hydroxide aqueous solution dropwise over 2 hours, and react at 60° C. overnight. After the reaction, extract, wash, and dry to obtain an epoxy monomer containing an azothiazole structure.

[0017] S2. Preparation of recyclable blue light-activated epoxy resin: After dissolving the epoxy monomer containing azothiazole structure, epoxy resin monomer, and long-chain diamine with N,N-dimethylformamide, add catalyst 1,8-diazabicyclo, react at 90°C for 4 hours, add aminophenylboronic acid and continue to react for 2 hours, pour into a mold and dry to obtain recyclable blue light-activated epoxy resin. The molar ratio of the epoxy monomer containing azothiazole structure, epoxy resin monomer, long-chain diamine, and aminophenylboronic acid is 1:0~20:3~12:1~4.

[0018] Compared with the prior art, the present invention is beneficial in that:

[0019] First, this invention introduces a visible light-responsive azothiazole structure into epoxy resin. Through photoisomerization of the azothiazole structure, the epoxy resin achieves photoactivation under 450nm blue light. This blue light-activated material uses blue light as a stimulus, eliminating the need for ultraviolet and infrared light, which have high thermal effects, to activate existing photoactivated materials, thus avoiding damage to the material caused by heat.

[0020] Secondly, the present invention uses aminophenylboronic acid as a curing agent, and the reversible borate ester bond formed gives the epoxy resin recyclable properties, thereby achieving the existing photoactivated epoxy resin while ensuring photoactivated behavior and having recyclable properties, thereby increasing the service life of the material.

[0021] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the H-NMR spectrum of the epoxy containing azothiazole structure.

[0023] Figure 2 This is the infrared spectrum of the epoxy containing azothiazole structure.

[0024] Figure 3 This is the UV-visible absorption spectrum of the epoxy containing azothiazole structure.

[0025] Figure 4 This is the infrared spectrum of epoxy resin Azops-EP-1.

[0026] Figure 5 This is the differential scanning calorimetry diagram of epoxy resin Azops-EP-1.

[0027] Figure 6 This is the blue light-activated behavior diagram of the epoxy resin Azops-EP-1.

[0028] Figure 7 This is a diagram of the hot pressing recycling process of epoxy resin Azops-EP-1.

[0029] Figure 8 This is the tensile curve of epoxy resin Azops-EP-1 before and after recycling.

[0030] Figure 9 This is the infrared spectrum of epoxy resin Azops-EP-2.

[0031] Figure 10 This is the differential scanning calorimetry diagram of epoxy resin Azops-EP-2.

[0032] Figure 11 This is the tensile curve of epoxy resin Azops-EP-2.

[0033] Figure 12 This is the infrared spectrum of epoxy resin Azops-EP-3.

[0034] Figure 13This is the differential scanning calorimetry diagram of epoxy resin Azops-EP-3.

[0035] Figure 14 This is the tensile curve of epoxy resin Azops-EP-3. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0037] Example 1: (1) Preparation of epoxy monomer containing azothiazole structure:

[0038] 0.2 g (0.711 mmol) of diphenol containing azothiazole structure, 1.315 g (14.21 mmol) of epichlorohydrin, and 0.0568 g (0.159 mmol) of benzyltributylammonium bromide were added to a 50 mL single-necked bottle and dissolved in 2 mL of N, N-dimethylformamide. The mixture was refluxed at 105 ° C for 4 hours at a speed of 350 r / min. Subsequently, 2 mL of 1 mol / L sodium hydroxide solution was added dropwise to the reaction system. The mixture was added after 2 hours of dripping. The mixture was then reacted at 60 ° C overnight. The mixture was then extracted with ethyl acetate, washed three times with water, and washed three times with saturated brine. The organic layer was dried over anhydrous sodium sulfate for 2 hours and then spin-dried to obtain an epoxy monomer containing azothiazole structure. The reaction equation is as follows:

[0039]

[0040] Figure 1 This is the H NMR spectrum of the epoxy containing azothiazole structure 1 H NMR (400 MHz, Chloroform-d) 8.03-6.5 (Ar-H), 4.20, 3.78 (epoxy-CH2), proving its successful preparation.

[0041] Figure 2 The infrared spectrum of epoxy containing azothiazole structure, the infrared absorption peaks are 2966cm -1 、2920cm -1 (-CH2), 1598cm -1 、1486cm -1 (Ar), 1020cm -1 、824cm -1 (COC), proving its successful preparation.

[0042] Figure 3The UV-visible absorption spectrum of the epoxy resin Azos-EP-1 is shown. The absorption peak of the trans azobenzothiazole structure is around 423 nm, while the absorption peak of the cis azobenzothiazole structure is around 493 nm. After irradiation with 450 nm blue light for 60 seconds, the peak at 423 nm decreases and the peak at 493 nm increases due to the conversion of the trans structure to the cis structure. Subsequently, after irradiation with 550 nm green light for 60 seconds, the cis structure converts to the trans structure, causing the peak at 423 nm to increase and the peak at 493 nm to decrease, demonstrating the visible light responsiveness of the epoxy resin Azos-EP-1.

[0043] (2) Preparation of recyclable blue light-activated epoxy resin:

[0044] In a 50 mL single-necked bottle, 0.11 g (0.27 mmol) of epoxy monomer containing an azothiazole structure, 1 g of E51, and 0.447 g (1.1 mmol) of polyetheramine D400 were added, and 5 mL of N,N-dimethylformamide was added to dissolve. 0.1243 g of catalyst 1,8-diazabicyclo was added, and the reaction was carried out at 90 ° C for 4 hours. 0.2297 g (1.6 mmol) of 2-aminophenylboronic acid was added and the reaction was continued for 2 hours. The epoxy resin containing an azothiazole structure was poured into a mold and dried.

[0045] The epoxy resin containing azothiazole structure was cut into a rectangular film of 5 mm × 40 mm and oriented at 100 ° C for 20 min. 2 The blue light is irradiated to realize photo-actuated behavior, the specimen is cut into pieces, and hot pressed at 200℃ and 6MPa pressure for 30min to achieve recycling and reprocessing.

[0046] Figure 4 This is the infrared spectrum of epoxy resin Azos-EP-1. The infrared absorption peaks are 3331cm -1 (-OH-), 2966cm -1 、2925cm -1 (-CH2), 1664cm -1 、1609cm -1 、1509cm -1 、1460cm -1 (Ar), 1376cm -1 (-BO), 1182cm -1 (COC), proving the successful preparation of epoxy resin Azos-EP-1.

[0047] Figure 5 The differential scanning calorimetry (DSC) of epoxy resin Azos-EP-1 shows that the glass transition temperature of epoxy resin Azos-EP-1 is 63.0°C.

[0048] Figure 6 Figure 2 shows the photoactuated behavior of the epoxy resin Azos-EP-1. After 10 seconds of blue light irradiation, Azos-EP-1 begins to actuate, reaching its maximum value after 20 seconds.

[0049] Figure 7 This is the hot pressing recovery diagram of epoxy resin Azos-EP-1. It can be seen that good recovery can be achieved by hot pressing at 6 MPa and 200°C for 30 minutes.

[0050] Figure 8 The figure shows the mechanical property curve of epoxy resin Azos-EP-1 before and after recycling. The initial tensile stress of the spline is 23.7 MPa, and the elongation at break is 11.2%. After hot pressing recycling, the tensile stress of the spline is 8.34 MPa, the elongation at break is 11.8%, the stress repair efficiency is 35.18%, and the strain repair efficiency is almost 100%.

[0051] Example 2: The method for preparing an epoxy monomer containing an azothiazole structure is the same as step (1) in Example 1

[0052] (2) Preparation of recyclable blue light-activated epoxy resin:

[0053] In a 50 mL single-necked bottle, 0.0527 g (0.133 mmol) of epoxy monomer containing an azothiazole structure, 1 g of E51, and 0.2147 g (0.536 mmol) of polyetheramine D400 were added, and 5 mL of N,N-dimethylformamide was added to dissolve the mixture. 0.1243 g of catalyst 1,8-diazabicyclo was added and reacted at 90 ° C for 4 hours. 0.2205 g (1.6 mmol) of 2-aminophenylboronic acid was added and the reaction was continued for 2 hours. The mixture was poured into a mold and dried to obtain an epoxy resin containing an azothiazole structure.

[0054] The epoxy resin containing azothiazole structure was cut into a rectangular film of 5 mm × 40 mm and oriented at 100 ° C for 20 min. 2 The blue light is irradiated to realize photo-actuated behavior, the specimen is cut into pieces, and hot pressed at 200℃ and 6MPa pressure for 30min to achieve recycling and reprocessing.

[0055] Figure 9 This is the infrared spectrum of epoxy resin Azos-EP-2, with infrared absorption peaks at 3339cm -1 (-OH), 2967 cm -1 、2926cm -1 (-CH2), 1665cm -1 、1608cm -1 、1508cm -1、1460cm -1 (Ar), 1383cm -1 (BO), 1183cm -1 (COC), proving the successful preparation of epoxy resin Azos-EP-2.

[0056] Figure 10 This is the differential scanning calorimetry diagram of epoxy resin Azos-EP-2. It can be seen that the glass transition temperature of Azos-EP-2 is 117.4℃.

[0057] Figure 11 This is the tensile curve of epoxy resin Azos-EP-2. It can be seen from the figure that the tensile stress of the spline is 23.6MPa and the elongation at break is 6.28%.

[0058] Example 3: The method for preparing an epoxy monomer containing an azothiazole structure is the same as step (1) in Example 1

[0059] (2) Preparation of recyclable blue light-activated epoxy resin:

[0060] In a 50 mL single-necked bottle, 0.25 g (0.63 mmol) of epoxy monomer containing an azothiazole structure, 1 g of E51, and 0.255 g (0.63 mmol) of polyetheramine D400 were added, and 5 mL of N,N-dimethylformamide was added to dissolve. 0.1243 g of catalyst 1,8-diazabicyclo was added, and the reaction was carried out at 90 ° C for 4 hours. 0.2618 g (1.9 mmol) of 2-aminophenylboronic acid was added and the reaction was continued for 2 hours. The epoxy resin containing an azothiazole structure was poured into a mold and dried.

[0061] The epoxy resin containing azothiazole structure was cut into 5mm×40mm rectangular films, stretched and oriented at 100℃ for 20min, and irradiated with 200mW / cm2 blue light to achieve photoactivated behavior. The strips were cut into pieces and hot pressed at 200℃ and 6MPa pressure for 30min to achieve recycling and reprocessing.

[0062] Figure 12 This is the infrared spectrum of epoxy resin Azos-EP-3, with infrared absorption peaks at 3318 cm -1 (-OH), 2966cm -1 、2925cm -1 (-CH2), 1664cm -1 、1605cm -1 、1508cm -1 、1452cm -1 (Ar), 1383cm -1 (BO), 1183cm -1(COC), proving the successful preparation of epoxy resin Azos-EP-3.

[0063] Figure 13 This is the differential scanning calorimetry diagram of epoxy resin Azos-EP-3. It can be seen that the glass transition temperature of Azos-EP-3 is 90.9℃.

[0064] Figure 14 This is the tensile curve of epoxy resin Azos-EP-3. It can be seen from the figure that the tensile stress of the spline is 3.52MPa and the elongation at break is 1.49%.

[0065] Example 4: The method for preparing an epoxy monomer containing an azothiazole structure is the same as step (1) in Example 1

[0066] (2) Preparation of recyclable blue light-activated epoxy resin:

[0067] In a 50 mL single-necked bottle, 0.25 g (0.63 mmol) of epoxy monomer containing an azothiazole structure, 1 g of Flanders F3, and 0.255 g (0.63 mmol) of polysiloxane diamine 400 were added, and 5 mL of N,N-dimethylformamide was added to dissolve. 0.1243 g of catalyst 1,8-diazabicyclo was added and reacted at 90 ° C for 4 hours. 0.2618 g (1.9 mmol) of 3-aminophenylboronic acid was added and the reaction was continued for 2 hours. The mixture was poured into a mold and dried to obtain an epoxy resin containing an azothiazole structure.

[0068] The epoxy resin containing azothiazole structure was cut into 5mm×40mm rectangular films, stretched and oriented at 100℃ for 20min, and irradiated with 200mW / cm2 blue light to achieve photoactivated behavior. The strips were cut into pieces and hot pressed at 200℃ and 6MPa pressure for 30min to achieve recycling and reprocessing.

[0069] Example 5: The method for preparing an epoxy monomer containing an azothiazole structure is the same as step (1) in Example 1

[0070] (2) Preparation of recyclable blue light-activated epoxy resin:

[0071] In a 50 mL single-necked bottle, 0.0527 g (0.133 mmol) of epoxy monomer containing an azothiazole structure, 1 g of E51, and 0.2147 g (0.536 mmol) of polyethylene glycol diamine 400 were added, and 5 mL of N,N-dimethylformamide was added to dissolve it. 0.1243 g of catalyst 1,8-diazabicyclo was added and reacted at 90 ° C for 4 hours. 0.2205 g (1.6 mmol) of 4-aminophenylboronic acid was added and the reaction was continued for 2 hours. The mixture was poured into a mold and dried to obtain an epoxy resin containing an azothiazole structure.

[0072] The epoxy resin containing azothiazole structure was cut into a rectangular film of 5 mm × 40 mm and oriented at 100 ° C for 20 min. 2 The blue light is irradiated to realize photo-actuated behavior, the specimen is cut into pieces, and hot pressed at 200℃ and 6MPa pressure for 30min to achieve recycling and reprocessing.

[0073] Example 6: The method for preparing an epoxy monomer containing an azothiazole structure is the same as step (1) in Example 1

[0074] (2) Preparation of recyclable blue light-activated epoxy resin:

[0075] In a 50 mL single-necked bottle, 0.25 g (0.63 mmol) of epoxy monomer containing an azothiazole structure, 1 g of ethylene glycol diglycidyl ether, and 0.169 g (0.63 mmol) of hexadecyldiamine were added, and 5 mL of N,N-dimethylformamide was added to dissolve. 0.1243 g of catalyst 1,8-diazabicyclo was added and reacted at 90 ° C for 4 hours. 0.2618 g (1.9 mmol) of 2-aminophenylboronic acid was added and the reaction was continued for 2 hours. The mixture was poured into a mold and dried to obtain an epoxy resin containing an azothiazole structure.

[0076] The epoxy resin containing azothiazole structure was cut into 5mm×40mm rectangular films, stretched and oriented at 100℃ for 20min, and irradiated with 200mW / cm2 blue light to achieve photoactivated behavior. The strips were cut into pieces and hot pressed at 200℃ and 6MPa pressure for 30min to achieve recycling and reprocessing.

[0077] Example 7: The method for preparing an epoxy monomer containing an azothiazole structure is the same as step (1) in Example 1

[0078] (2) Preparation of recyclable blue light-activated epoxy resin:

[0079] In a 50 mL single-necked bottle, 0.25 g (0.63 mmol) of epoxy monomer containing an azothiazole structure, 1 g of E51, and 1.26 g (0.63 mmol) of polyetheramine D2000 were added, and 5 mL of N,N-dimethylformamide was added to dissolve. 0.1243 g of catalyst 1,8-diazabicyclo was added, and the reaction was carried out at 90 ° C for 4 hours. 0.2618 g (1.9 mmol) of 2-aminophenylboronic acid was added and the reaction was continued for 2 hours. The epoxy resin containing an azothiazole structure was poured into a mold and dried.

[0080] The epoxy resin containing azothiazole structure was cut into 5mm×40mm rectangular films, stretched and oriented at 100℃ for 20min, and irradiated with 200mW / cm2 blue light to achieve photoactivated behavior. The strips were cut into pieces and hot pressed at 200℃ and 6MPa pressure for 30min to achieve recycling and reprocessing.

[0081] In summary, the present invention introduces a photoactive azobenzothiazole structure into polyurethane, and through a reversible metal coordination bond that responds to sunlight, achieves the solar-responsive self-repairing of high-strength polyurethane materials, solving the problem that existing photoresponsive self-repairing materials require irradiation with light of a specific wavelength.

[0082] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of the present invention using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A recyclable blue light-activated epoxy resin material, characterized in that: The epoxy resin is obtained by ring-opening and curing at 90° C. at a molar ratio of 1:0 to 20:3 to 12:1 to 4 of an epoxy monomer containing an azothiazole structure, an epoxy resin monomer, a long-chain diamine, and aminophenylboronic acid, wherein the molar content of the epoxy resin monomer is not 0, and the general structural formula of the epoxy monomer containing an azothiazole structure is: Wherein, the value range of n is 1 to 6.

2. The recyclable blue light-activated epoxy resin material according to claim 1, wherein: The epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, linear aliphatic epoxy resin, and alicyclic epoxy resin.

3. The recyclable blue light-activated epoxy resin material according to claim 1, wherein: The long-chain diamine is one or more of the following structural formulas: Wherein, the value range of x is 1-30.

4. The recyclable blue light-activated epoxy resin material according to claim 1, wherein: The aminophenylboronic acid is one or more of 2-aminophenylboronic acid, 3-aminophenylboronic acid and 4-aminophenylboronic acid.

5. The method for preparing a recyclable blue light-activated epoxy resin material according to any one of claims 1 to 4, wherein: The following steps are involved: S1. Preparation of an epoxy monomer containing an azothiazole structure: Add a diphenol containing an azothiazole structure, epichlorohydrin, and benzyltributylammonium bromide in a molar ratio of 1:20:0.2 to a round-bottom flask, dissolve with N,N-dimethylformamide, and react with stirring at 105° C. for 4 hours. Then, add 8 equivalents of sodium hydroxide aqueous solution dropwise over 2 hours, and react at 60° C. overnight. After the reaction, extract, wash, and dry to obtain an epoxy monomer containing an azothiazole structure. S2. Preparation of recyclable blue light-activated epoxy resin: After dissolving the epoxy monomer containing azothiazole structure, epoxy resin monomer, and long-chain diamine with N,N-dimethylformamide, add catalyst 1,8-diazabicyclo, react at 90°C for 4 hours, add aminophenylboronic acid and continue to react for 2 hours, pour into a mold and dry to obtain recyclable blue light-activated epoxy resin. The molar ratio of the epoxy monomer containing azothiazole structure, epoxy resin monomer, long-chain diamine, and aminophenylboronic acid is 1:0~20:3~12:1~4.

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