Nitrogen-boron complexing crosslinker and method of making, acrylate elastomer adhesive and method of making
By preparing nitrogen-boron coordination crosslinking agents and acrylate elastomer adhesives, the problem of performance degradation of dynamic covalent polymer networks during chemical recycling and reprocessing has been solved, achieving controllable mechanical and adhesive properties suitable for a variety of applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTH CHINA UNIV OF TECH
- Filing Date
- 2023-12-05
- Publication Date
- 2026-06-30
AI Technical Summary
Existing dynamic covalent polymer networks exhibit performance degradation during chemical recycling and reprocessing, and there is a contradiction between mechanical properties and self-healing capabilities, making it difficult to achieve tunable mechanical and adhesive properties.
A nitrogen-boron coordination crosslinking agent and its preparation method were developed. A nitrogen-boron coordination cyclic intermediate was generated by reacting 4-hydroxymethylphenylboronic acid and triethanolamine, and then reacted with isocyanate methyl methacrylate and a catalyst to prepare the nitrogen-boron coordination crosslinking agent. This agent was used for the random copolymerization of acrylate elastomer adhesives and combined with ultraviolet reaction to form acrylate elastomer adhesives.
Nitrogen-boron coordination crosslinking agents have a dynamic coordination structure that can meet the performance requirements of different applications. Acrylic elastomer adhesives achieve tunable mechanical and adhesive properties, are non-volatile and non-corrosive, and are suitable for sealing components, biomedical tissue engineering, and wearable electronics.
Smart Images
Figure CN117886838B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of functional polymer materials technology, specifically to nitrogen-boron coordination crosslinking agents and their preparation methods, and acrylate elastomer adhesives and their preparation methods. Background Technology
[0002] Polymers, with their lightweight, high performance, cost-effectiveness, and ease of processing, have become one of the most important materials in the global market, and their applications continue to expand. Polymers with dynamic bonds are a class of functional materials with broad application prospects. Their polymer chains can be linked together through reversible covalent (e.g., glass-like structures) or non-covalent (e.g., hydrogen and ionic bonds) interactions. These transient interactions are reversible, which not only helps in developing materials with self-healing, high ductility, shape memory, and controllable stress relaxation functions, but also makes them easy to process and recycle. A common type of interaction is binary interaction, where two complementary groups form a reversible bond. Important parameters of this bond are the binding / dissociation energy and the transient bond lifetime, which can be adjusted according to the chemical properties of the functional groups. On shorter timescales, materials with these dynamic bonds often exhibit glassy behavior. When the timescale is comparable to the timescale of bond dissociation, the material exhibits viscoelastic viscous behavior. When the timescale of interaction is much longer than the timescale of bond dissociation, the material exhibits viscous flow behavior. However, despite the rapid progress made in the research of dynamic covalent polymer networks, challenges remain. For example, the main challenge in achieving chemical recycling through dynamic bonding is the inevitable performance degradation. At the same time, the contradiction between mechanical properties (especially rigidity) and self-healing ability also needs to be resolved.
[0003] Therefore, it is of great significance to develop crosslinking agents with dynamic coordination structures and acrylate elastomer adhesives with tunable mechanical and adhesive properties. Summary of the Invention
[0004] The purpose of this invention is to provide nitrogen-boron coordination crosslinking agents and their preparation methods, as well as acrylate elastomer adhesives and their preparation methods.
[0005] The technical solution adopted in this invention is:
[0006] A nitrogen-boron coordination crosslinking agent, the structural formula of which is:
[0007]
[0008] A method for preparing a nitrogen-boron coordination crosslinking agent as described above includes the following steps:
[0009] 1) 4-hydroxymethylphenylboronic acid and triethanolamine were dispersed in a solvent and reacted to obtain a nitrogen-boron coordinated cyclic intermediate;
[0010] 2) The nitrogen-boron coordination cyclic intermediate, isocyanate methacrylate and catalyst are dispersed in a solvent and reacted to obtain the nitrogen-boron coordination crosslinking agent.
[0011] Preferably, a method for preparing a nitrogen-boron coordination crosslinking agent as described above includes the following steps:
[0012] 1) 4-hydroxymethylphenylboronic acid and triethanolamine were stirred and dispersed in a solvent for reaction. After cooling to room temperature, the mixture was precipitated with diethyl ether. The precipitate was then washed and dried to obtain a nitrogen-boron coordinated cyclic intermediate.
[0013] 2) The nitrogen-boron coordination cyclic intermediate, isocyanate methacrylate and catalyst are stirred and dispersed in a solvent for reaction, then precipitated with diethyl ether, and the precipitate is washed and dried to obtain the nitrogen-boron coordination crosslinking agent.
[0014] Preferably, the molar ratio of 4-hydroxymethylphenylboronic acid and triethanolamine in step 1) is 1:1.0 to 1.2.
[0015] Preferably, the solvent in step 1) is at least one of N,N-dimethylformamide (DMF), ethanol, and 1,4-dioxane.
[0016] Preferably, the reaction in step 1) is carried out at a temperature of 40℃ to 45℃ for a reaction time of 4h to 6h.
[0017] Preferably, the molar ratio of the nitrogen-boron coordinated cyclic intermediate and isocyanate methacrylate in step 2) is 1:2.0 to 2.2.
[0018] Preferably, the catalyst in step 2) is an organotin catalyst.
[0019] Preferably, the organotin catalyst is dibutyltin dilaurate (DBTL).
[0020] Preferably, the solvent in step 2) is at least one of N,N-dimethylformamide, ethanol, tetrahydrofuran, and 1,4-dioxane.
[0021] Preferably, the reaction in step 2) is carried out under light-protected conditions at a temperature of 25°C to 30°C for 3 to 5 days.
[0022] An acrylate elastomer adhesive is prepared by random copolymerization of acrylate monomers, 4-vinylphenylboronic acid and the above-mentioned nitrogen-boron coordination crosslinking agent.
[0023] Preferably, the molar ratio of the acrylate monomer, 4-vinylphenylboronic acid, and nitrogen-boron coordination crosslinking agent is 1:0.0025-0.06:0.0025-0.06.
[0024] Preferably, the acrylate monomer is at least one selected from ethyl acrylate, butyl acrylate, hexyl acrylate, and hydroxyethyl acrylate.
[0025] A method for preparing an acrylic elastomer adhesive as described above includes the following steps:
[0026] Acrylic ester monomers, 4-vinylphenylboronic acid and nitrogen-boron coordination crosslinking agent are dispersed in a solvent, an initiator is added and the reaction is carried out in the dark, and then placed in ultraviolet light for ultraviolet reaction to obtain acrylic ester elastomer adhesive.
[0027] Preferably, a method for preparing an acrylic elastomer adhesive as described above includes the following steps:
[0028] Nitrogen-boron coordination crosslinking agent is dispersed in solvent by stirring, then 4-vinylphenylboronic acid is added and stirred evenly, then acrylate monomers are added and stirred evenly, then an initiator is added and carried out in the dark, and then placed in ultraviolet light for ultraviolet reaction to obtain acrylate elastomer adhesive.
[0029] Preferably, the solvent is a mixture of N,N-dimethylformamide and ethanol.
[0030] Preferably, the initiator is at least one of azobisisobutyronitrile (AIBN), benzophenone, and benzoyl peroxide (BPO).
[0031] Preferably, the light-shielding reaction time is 20 min to 40 min.
[0032] Preferably, the ultraviolet reaction time is 6h to 10h.
[0033] The beneficial effects of this invention are: the nitrogen-boron coordination crosslinking agent of this invention has a dynamic coordination structure, which can be used in the polymerization reaction of different monomers. The acrylate elastomer adhesive of this invention has adjustable mechanical and adhesive properties, and is non-volatile and non-corrosive, which can meet the adhesion requirements of different occasions and is suitable for large-scale promotion and application.
[0034] Specifically:
[0035] 1) The nitrogen-boron coordination crosslinking agent of the present invention has a coordination dynamic structure, which can be used in the polymerization reaction of different monomers and can meet the performance requirements of different occasions.
[0036] 2) The coordination dynamic structure in the nitrogen-boron coordination crosslinking agent of the present invention can be broken when subjected to external force, and can be repeatedly connected after the external load is removed;
[0037] 3) The mechanical and adhesive properties of the acrylate elastomer adhesive of the present invention can be controlled over a wide range, and it is non-biotoxic and non-corrosive, and can be used in sealing components, biomedical tissue engineering, wearable electronic products, flexible devices and other fields.
[0038] 4) The acrylic elastomer adhesive of the present invention can achieve adhesion to different surfaces (e.g., glass surfaces, elastomer surfaces, etc.), and has a wide range of applications.
[0039] 5) The preparation method of the acrylate elastomer adhesive of the present invention is simple, the raw materials are cheap and readily available, and it is easy to carry out large-scale industrial production and application. Attached Figure Description
[0040] Figure 1 The image shows the 1H NMR spectrum of the nitrogen-boron coordinated cyclic intermediate in Example 1.
[0041] Figure 2 The image shows the 1H NMR spectrum of the nitrogen-boron coordination crosslinking agent in Example 1.
[0042] Figure 3 The image shows the carbon NMR spectrum of the nitrogen-boron coordination crosslinking agent in Example 1.
[0043] Figure 4 This is a high-resolution mass spectrum of the nitrogen-boron coordination crosslinking agent in Example 1.
[0044] Figure 5 This is a diagram illustrating the formation mechanism of the acrylate elastomer adhesive in Example 2.
[0045] Figure 6 The graph shows the tensile properties of the acrylate elastomer adhesives in Example 2 and the comparative example.
[0046] Figure 7 The stress-strain curves are those of the acrylate elastomer adhesives in Examples 2-7.
[0047] Figure 8 The curves show the Young's modulus-crosslinking agent dosage relationship of the acrylate elastomer adhesives in Examples 2-7.
[0048] Figure 9 The force-displacement curves are for the acrylate elastomer adhesives in Examples 2, 3, 5, 7 and 8.
[0049] Figure 10The adhesion energy-crosslinking agent dosage relationship curves are shown for the acrylate elastomer adhesives in Examples 2, 3, 5, 7 and 8. Detailed Implementation
[0050] The present invention will be further explained and described below with reference to specific embodiments.
[0051] Example 1:
[0052] A nitrogen-boron coordination crosslinking agent, the preparation method of which is as follows:
[0053] 1) 20g of 4-hydroxymethylphenylboronic acid and 18g of triethanolamine were stirred and dispersed in 200mL of DMF (ultra-dry). The mixture was then placed in an oil bath at 40℃ and stirred for 6h. After naturally cooling to room temperature, the mixture was precipitated with diethyl ether. The precipitation process was repeated 3 times. The precipitate (white solid particles) was washed 3 times with acetone and then vacuum dried at 40℃ for 3 days to obtain the nitrogen-boron coordinated cyclic intermediate (2-(2-(4-(hydroxymethyl)phenyl)-1,3,6,2-dioxaborane-6-yl)ethyl-1-ol).
[0054] 2) Disperse 10g of nitrogen-boron coordinated cyclic intermediate and 12g of isocyanate methacrylate in 90mL of DMF (ultra-dry), then add 20μL of dibutyltin dilaurate (DBTL), and stir the mixture at room temperature for 5 days under light-protected conditions. Then precipitate the mixture with diethyl ether, repeating the precipitation process 3 times. Take the precipitate (pale yellow viscous solid) and freeze-dry it at -55℃ for 3 days to obtain the nitrogen-boron coordinated crosslinking agent (store it in an inert atmosphere at -20℃).
[0055] The synthesis reaction of nitrogen-boron coordination crosslinking agents is as follows:
[0056]
[0057] Structural characterization:
[0058] 1) The 1H NMR spectrum of the nitrogen-boron coordinated cyclic intermediate in this embodiment is shown below. Figure 1 As shown, Figure 1 The corresponding spectral data are as follows:
[0059] 1H NMR (500MHz, DMSO-d6, δ, ppm): 7.45-7.42 (m, 1H), 7.17 (d, J = 7.6Hz, 1H), 5.02 (t, J = 5.7Hz, 1H), 4.74 (t, J = 5.2Hz, 1H), 4. 45(d,J=5.7Hz,1H),3.92(dtd,J=13.3,9.8,5.9Hz,2H),3.59(q,J=5.7Hz,1H),3.21-3.06(m,2H),2.27(t,J=5.9Hz,1H).
[0060] Depend on Figure 1 It can be seen that this embodiment did indeed prepare a nitrogen-boron coordinated cyclic intermediate with the expected structure.
[0061] 2) The 1H NMR spectrum of the nitrogen-boron coordination crosslinking agent in this embodiment is shown below. Figure 2 As shown, the carbon NMR spectrum is as follows: Figure 3 As shown, the high-resolution mass spectrum is as follows: Figure 4 As shown, Figures 2-4 The corresponding spectral data are as follows:
[0062] 1 H NMR (500MHz, DMSO-d) 6, δ, ppm): 7.44 (d, J=7.4Hz, 2H), 7.28-7.09 (m, 2H), 6.02 (d, J=12.9Hz, 2H), 5.65 (s, 2H), 4.98 (d, J= 22.8Hz, 2H), 4.15-3.90 (m, 10H), 3.29-3.05 (m, 8H), 2.38 (d, J = 5.9Hz, 2H), 1.84 (d, J = 4.4Hz, 6H).
[0063] 13C NMR (126MHz, DMSO-d6, δ, ppm): 167.08, 167.04, 162.84, 156.98, 156.31, 141.64, 141.47, 136.33, 136.1 0,135.91,134.70,134.52,133.78,133.54,127.08,126.42,125.90,125.84,125.77,66.29,66.24,65.4 7,63.85,63.81,63.77,63.69,63.31,63.19,61.47,60.47,58.37,57.59,57.55,57.50,40.48,40.31,40.14,39.98,39.81,39.64,39.48,36.32,36.28,36.26,36.22,31.30,31.26,31.23,31.19,18.45,15.65.
[0064] HRMS(ESI)m / z: Calcd for C 27 H 38 BN3NaO 10 [M+Na] + 598.2542,Found 598.2553.
[0065] Depend on Figures 2-4 It can be seen that this embodiment has indeed prepared a nitrogen-boron coordination crosslinking agent with the expected structure.
[0066] Note:
[0067] Nuclear Magnetic Resonance (NMR) Measurement: Deuterated dimethyl sulfoxide (DMSO-d6) was used as the solvent on a Bruker AV spectrometer at 500 MHz (H solvent residual signal: 2.50 ppm, water signal: 3.33 ppm; C solvent signal: 39.52 ppm), with a small amount of TMS as an internal standard. 1 H NMR and 13 C NMR spectroscopy was performed at a temperature of 25°C, with 8 and 1024 scans.
[0068] High-resolution mass spectrometry (HRMS) testing: The sample was dissolved in methanol and HRMS was recorded in positive ion mode on a Bruker MaXis Impact and Agilent 1290 Infinity liquid chromatography system. The mass-to-charge ratio test range was 50–800.
[0069] Example 2:
[0070] An acrylic elastomer adhesive, the preparation method of which is as follows:
[0071] 0.538 g of nitrogen-boron coordination crosslinking agent (prepared in Example 1) was added to a mixed solvent consisting of 3 mL of DMF (ultra-dry) and 3 mL of anhydrous ethanol. The solution was shaken for 30 min at room temperature until it became homogeneous and transparent. Then, 0.277 g of 4-vinylphenylboronic acid was added and shaken for 15 min. Next, 12 g of butyl acrylate was added and shaken in the dark for 15 min. Then, 0.0154 g of AIBN was added and shaken in the dark for 30 min (ensuring the solution remained clear and transparent). The reaction solution was then poured into a glass mold in an anhydrous and oxygen-free environment and sealed with plastic wrap. The mold was then irradiated with a UV lamp for 8 h. The product was then removed from the glass mold and placed in a vacuum oven at 45 °C for 3 days. The temperature was then increased to 65 °C and dried for 2 days. Finally, the temperature was increased to 70 °C and vacuum dried for 2 days to obtain the acrylate elastomer adhesive (formation mechanism diagram shown in Figure 1). Figure 5 (As shown).
[0072] Example 3:
[0073] An acrylic elastomer adhesive is prepared in the same manner as in Example 2, except that the amount of nitrogen-boron coordination crosslinking agent is adjusted from "0.538g" to "1.076g".
[0074] Example 4:
[0075] An acrylic elastomer adhesive is prepared in the same manner as in Example 2, except that the amount of nitrogen-boron coordination crosslinking agent is adjusted from "0.538g" to "1.614g".
[0076] Example 5:
[0077] An acrylic elastomer adhesive is prepared in the same manner as in Example 2, except that the amount of nitrogen-boron coordinating crosslinking agent is adjusted from "0.538g" to "2.152g".
[0078] Example 6:
[0079] An acrylic elastomer adhesive is prepared in the same manner as in Example 2, except that the amount of nitrogen-boron coordination crosslinking agent is adjusted from "0.538g" to "2.690g".
[0080] Example 7:
[0081] An acrylic elastomer adhesive is prepared in the same manner as in Example 2, except that the amount of nitrogen-boron coordination crosslinking agent is adjusted from "0.538g" to "3.228g".
[0082] Example 8:
[0083] An acrylic elastomer adhesive is prepared in the same manner as in Example 2, except that the amount of nitrogen-boron coordinating crosslinking agent is adjusted from "0.538g" to "0.1345g".
[0084] Comparative example:
[0085] An acrylate elastomer adhesive is prepared in the same manner as in Example 2, except that the "nitrogen-boron coordination crosslinking agent" is replaced with "polyethylene glycol diacrylate (PEGDA 600)".
[0086] Performance testing:
[0087] 1) The acrylic elastomer adhesives from Example 2 and the comparative example were cut into strips (length × width = 20mm × 10mm), and tensile properties were tested using a universal testing machine at a speed of 10mm / min and a sensor of 100N. The tensile property test results are as follows: Figure 6 As shown.
[0088] Depend on Figure 6 It can be seen that: the acrylate elastomer adhesive prepared by nitrogen-boron coordination crosslinking agent in Example 2 has a Young's modulus of only about half that of the acrylate elastomer adhesive prepared by polyethylene glycol diacrylate in the comparative example, but its toughness can be up to 10 times greater.
[0089] 2) The acrylic elastomer adhesives from Examples 2-7 were cut into strips (length × width = 20mm × 10mm), and then tensile properties (uniaxial tensile) were tested using a universal testing machine at a speed of 10mm / min. The stress-strain curves obtained from the tests are shown below. Figure 7 As shown, the Young's modulus-crosslinking agent dosage (molar ratio of monomer dosage) relationship curve is as follows: Figure 8 As shown.
[0090] Depend on Figure 7 and Figure 8 It is known that the mechanical properties of acrylate elastomer adhesives are closely related to the amount of nitrogen-boron coordination crosslinking agent. Increasing the amount of nitrogen-boron coordination crosslinking agent can significantly improve the tensile fracture stress and Young's modulus of acrylate elastomer adhesives and reduce their fracture strain (for example, the fracture strain can be adjusted from 1808% to 662%, the fracture stress can be adjusted from 138 kPa to 327 Pa, and the Young's modulus can be adjusted from 48 kPa to 372 kPa).
[0091] 3) Cut the acrylic elastomer adhesives from Examples 2, 3, 5, 7, and 8 into squares (20mm side length), then sandwich them between two glass slides and compact them. Perform tensile property testing using a universal testing machine at a speed of 10mm / min and a sensor size of 100N. The force-displacement curves obtained are shown below. Figure 9 As shown, the adhesion energy-crosslinking agent dosage relationship curve (adhesion energy G) C It can be expressed by the following formula: G C =(F / w) 2 / 4Eh, where E, h, and w represent the Young's modulus, thickness, and width of the substrate elastomer, respectively. The test results are as follows: Figure 10 As shown.
[0092] Depend on Figure 9 and Figure 10 It is known that the adhesion properties of acrylate elastomer adhesives are closely related to the amount of nitrogen-boron coordination crosslinking agent. Increasing the amount of nitrogen-boron coordination crosslinking agent can significantly improve the adhesion strength and adhesion energy of acrylate elastomer adhesives (for example, the adhesion strength and adhesion energy can be adjusted from 13.9 kPa to 109.2 kPa and 0.35 kJ / m, respectively). 2 Adjusted to 1.54 kJ / m 2 ).
[0093] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. An acrylic elastomer adhesive, characterized in that, It is prepared by random copolymerization of acrylate monomers, 4-vinylphenylboronic acid, and a nitrogen-boron coordination crosslinking agent; the structural formula of the nitrogen-boron coordination crosslinking agent is: 。 2. The acrylate elastomer adhesive according to claim 1, characterized in that: The nitrogen-boron coordination crosslinking agent is prepared by a method comprising the following steps: 1) 4-Hydroxymethylphenylboronic acid and triethanolamine were dispersed in a solvent and reacted to obtain a nitrogen-boron coordinated cyclic intermediate; 2) The nitrogen-boron coordination cyclic intermediate, isocyanate methacrylate and catalyst are dispersed in a solvent and reacted to obtain the nitrogen-boron coordination crosslinking agent.
3. The acrylate elastomer adhesive according to claim 2, characterized in that: In step 1), the molar ratio of 4-hydroxymethylphenylboronic acid and triethanolamine is 1:1.0 to 1.
2.
4. The acrylate elastomer adhesive according to claim 2 or 3, characterized in that: The reaction in step 1) is carried out at a temperature of 40℃~45℃ for a time of 4h~6h.
5. The acrylate elastomer adhesive according to claim 2, characterized in that: In step 2), the molar ratio of the nitrogen-boron coordinated cyclic intermediate to isocyanate methacrylate is 1:2.0 to 2.
2.
6. The acrylate elastomer adhesive according to claim 2 or 5, characterized in that: Step 2) The reaction is carried out under light-protected conditions at a temperature of 25℃~30℃ for 3 to 5 days.
7. The acrylate elastomer adhesive according to claim 1, characterized in that: The molar ratio of the acrylate monomer, 4-vinylphenylboronic acid, and nitrogen-boron coordination crosslinking agent is 1:0.0025-0.06:0.0025-0.
06.
8. The acrylate elastomer adhesive according to claim 1 or 7, characterized in that: The acrylate monomer is at least one of ethyl acrylate, butyl acrylate, hexyl acrylate, and hydroxyethyl acrylate.
9. A method for preparing an acrylic elastomer adhesive as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Acrylic ester monomers, 4-vinylphenylboronic acid and nitrogen-boron coordination crosslinking agent are dispersed in a solvent, an initiator is added and the reaction is carried out in the dark, and then placed in ultraviolet light for ultraviolet reaction to obtain acrylic ester elastomer adhesive.