High-strength low-emission epoxy resin and preparation method thereof

Abstract

The application relates to the technical field of high polymer materials, in particular to a high-strength low-emission epoxy resin and a preparation method thereof. The epoxy resin comprises a synergistically modified bisphenol A type epoxy resin, 2-amino-6-trifluoromethyl benzothiazole, methylhexahydrophthalic anhydride and an additive, wherein the synergistically modified bisphenol A type epoxy resin is formed by introducing a para-tert-butyl calix[6]arene, 1-pyrenemethylamine and ferric chloride to construct a host-guest inclusion structure, a metal coordination charge transfer structure and a synergistic network of pi-pi interaction. Through the synergistic effect of the multiple structures, the material can realize multi-stage energy dissipation and stress dispersion under impact and high pressure conditions, so that the impact performance, fracture toughness and explosion-proof performance are significantly improved. The preparation method is simple, the obtained material has excellent comprehensive performance, and is suitable for high-safety requirement fields such as hydrogen cylinders.

Description

Technical Field

[0001] This invention relates to the field of polymer materials and safety protection materials, specifically to a high-strength, low-emission epoxy resin and its preparation method. Background Technology

[0002] With the development of hydrogen energy storage and transportation technology, high-pressure hydrogen cylinders are widely used in fuel cell vehicles and energy storage. Their service environment typically involves complex conditions such as long-term exposure to high-pressure gas, temperature fluctuations, and external mechanical impacts. In this process, the epoxy resin material used in the lining or structural layer of the hydrogen cylinder not only needs to possess high mechanical strength but also excellent impact resistance and crack suppression capabilities. Otherwise, under localized defects or instantaneous impacts, cracks can easily propagate rapidly, leading to explosive failure and posing significant safety hazards.

[0003] In existing technologies, epoxy resins are widely used in hydrogen cylinder structural material systems due to their excellent adhesion, corrosion resistance, and dimensional stability. However, traditional bisphenol A type epoxy resins have a high crosslinking density after curing, which restricts the movement of molecular chain segments, resulting in significant brittleness. Under impact loads, they are unable to effectively release stress concentration, leading to low fracture toughness. To improve this problem, existing technologies typically involve toughening modification by introducing rubber particles, thermoplastic resins, or inorganic nanofillers. However, rubber toughening can easily reduce the material's modulus and heat resistance, thermoplastic resins present compatibility issues, and single inorganic fillers are difficult to form effective energy dissipation structures, resulting in limited overall modification effects.

[0004] Furthermore, existing modification strategies mostly rely on a single mechanism, such as improving performance solely through interface enhancement or the introduction of flexible segments. They lack design approaches that synergistically regulate performance at the molecular and microstructural levels, making it difficult to construct multi-level energy dissipation pathways. Under the combined effects of high-pressure hydrogen environments and impact loads, materials are still prone to stress concentration and microcrack propagation, failing to meet the high safety and explosion-proof requirements of hydrogen cylinders. Therefore, there is an urgent need to develop an epoxy resin system with a novel synergistic modification structure capable of achieving multi-mechanism energy dissipation and crack passivation during stress, in order to improve the overall safety performance of hydrogen cylinders. Summary of the Invention

[0005] To overcome the challenge of simultaneously achieving high strength and high toughness in existing epoxy resin technologies, this invention provides a high-strength, low-emission epoxy resin and its preparation method. By constructing a multi-layered synergistic network comprising host-guest inclusion structures, Schiff base dynamic covalent structures, metal coordination structures, and π-π stacking structures, the material forms multi-level energy dissipation pathways during stress. Compared to existing technologies relying solely on a single toughening mechanism, this invention achieves a comprehensive performance improvement significantly superior to the combined effects of individual modification methods through the synergistic effects of multiple interacting structures at both the molecular and microscopic scales. This results in a significant increase in fracture toughness and impact resistance while maintaining material strength.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A high-strength, low-emission epoxy resin is characterized in that the epoxy resin comprises the following raw materials in parts by weight: 80-120 parts of synergistically modified bisphenol A type epoxy resin; 0.5-6 parts of 2-amino-6-trifluoromethylbenzothiazole; 20-60 parts of methyl hexahydrophthalic anhydride; 1-10 parts of nano-alumina; 0.5-5 parts of silane coupling agent; 1-8 parts of flame retardant synergist; 0.2-2 parts of leveling agent; 0.1-1 parts of defoamer; wherein the synergistically modified bisphenol A type epoxy resin is formed by synergistic modification of bisphenol A type epoxy resin with p-tert-butylcalix[6] aromatic hydrocarbon, 1-pyrene methylamine, ferric chloride, terephthalaldehyde and diethylenetriamine through host-guest inclusion, metal coordination charge transfer and π-π interaction.

[0008] Optionally, the synergistically modified bisphenol A type epoxy resin includes the following raw materials in parts by weight: 60-120 parts of bisphenol A type epoxy resin; 0.5-6 parts of p-tert-butylcalix[6] aromatic hydrocarbon; 0.5-6 parts of 1-pyrene methylamine; 0.2-3 parts of ferric chloride; 0.5-5 parts of terephthalaldehyde; and 1-10 parts of diethylenetriamine.

[0009] Optionally, the preparation method of the synergistically modified bisphenol A type epoxy resin includes the following steps:

[0010] (1) Add p-tert-butylcalix[6] aromatic hydrocarbon and 1-pyrene methylamine to an organic solvent for mixing to allow host-guest inclusion to occur, thus obtaining a host-guest inclusion complex;

[0011] (2) Add terephthalaldehyde and diethylenetriamine to the host-guest inclusion complex to carry out a condensation reaction to form an organic network intermediate containing a Schiff base structure; then add ferric chloride to coordinate with the organic network intermediate to obtain a coordination structure intermediate.

[0012] (3) The coordination structure intermediate is added to the bisphenol A type epoxy resin and dispersed and partially ring-opening reaction is carried out under heating conditions to obtain synergistically modified bisphenol A type epoxy resin.

[0013] Optionally, the reaction conditions in step (1) are a temperature of 20-50°C, a time of 0.5-3h, a stirring rate of 200-600rpm, and the organic solvent is tetrahydrofuran or N,N-dimethylformamide.

[0014] Optionally, the reaction conditions in step (2) are a temperature of 40–90°C, a time of 1–5 h, and a stirring rate of 300–700 rpm.

[0015] Optionally, the reaction conditions in step (3) are a temperature of 60–110°C, a time of 1–4 h, and a stirring rate of 300–800 rpm.

[0016] Optionally, the silane coupling agent is a mixture of γ-aminopropyltriethoxysilane and vinyltrimethoxysilane in a mass ratio of 1:1 to 3; the flame retardant synergist is a mixture of melamine and phytic acid in a mass ratio of 1:1 to 4; the leveling agent is a mixture of polyether-modified polysiloxane and acrylate leveling agent in a mass ratio of 1:1 to 2; and the defoamer is a mixture of polydimethylsiloxane and fumed silica in a mass ratio of 2:1 to 6.

[0017] Optionally, a method for preparing a high-strength, low-emission epoxy resin includes the following steps:

[0018] S1, synergistically modified bisphenol A epoxy resin and nano alumina are added to a mixing container for dispersion treatment to obtain a pre-dispersion system;

[0019] S2, 2-amino-6-trifluoromethylbenzothiazole and methylhexahydrophthalic anhydride are added to the pre-dispersed system and mixed to obtain the reaction system;

[0020] S3. Add silane coupling agent, flame retardant synergist, leveling agent and defoamer to the reaction system, stir evenly and defoaming treatment to obtain high-strength low-emission epoxy resin.

[0021] Optionally, the reaction conditions for step S1 are a temperature of 30–70°C, a time of 0.5–2 h, and a stirring rate of 300–800 rpm; the reaction conditions for step S2 are a temperature of 60–100°C, a time of 1–3 h, and a stirring rate of 400–900 rpm.

[0022] Optionally, the reaction conditions in step S3 are: temperature 40-80℃, time 0.5-2h, stirring speed 200-600rpm, degassing method is vacuum degassing, and vacuum degree is -0.08--0.1MPa.

[0023] The beneficial effects of this invention are:

[0024] This invention introduces p-tert-butylcalix[6] aromatic hydrocarbon and 1-pyrene methylamine into a host-guest confined inclusion structure in a bisphenol A type epoxy resin system, so that the molecular chain undergoes controllable dissociation and recombination under stress, thereby achieving primary energy dissipation; at the same time, it utilizes ferric chloride and nitrogen-containing structural units to form a metal coordination charge transfer system, which generates electron migration and polarization response under impact load, further enhancing the energy dissipation capability; in addition, the polycyclic aromatic structure provided by 1-pyrene methylamine can form a stable π-π stack, which undergoes slip and rearrangement during the stress process, effectively dispersing local stress and inhibiting stress concentration at the crack tip; multiple mechanisms work synergistically at the molecular scale and microstructure level to construct a multi-level energy dissipation network, so that the material can significantly improve fracture toughness and impact resistance while maintaining high strength, thereby effectively delaying crack propagation and improving explosion-proof performance, especially suitable for high safety requirements such as high-pressure hydrogen cylinders. Attached Figure Description

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] Figure 1 This is a comparison of the infrared spectra of bisphenol A type epoxy resin and synergistically modified bisphenol A type epoxy resin. Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.

[0028] Example 1: This example aims to provide an epoxy resin system with stable basic properties to verify the synergistic modification effect of the present invention under low addition conditions.

[0029] S1, 0.5 parts of p-tert-butylcalix[6]arene and 0.5 parts of 1-pyrene methylamine were added to N,N-dimethylformamide and stirred at 20°C and 200 rpm for 0.5 h to allow host-guest inclusion to occur, resulting in a host-guest inclusion complex; then 0.2 parts of ferric chloride, 0.5 parts of terephthalaldehyde and 1 part of diethylenetriamine were added and reacted at 40°C and 300 rpm for 1 h to obtain a synergistically modified intermediate; then 60 parts of bisphenol A epoxy resin were added and reacted at 60°C and 300 rpm for 1 h to obtain a synergistically modified bisphenol A epoxy resin;

[0030] S2, 80 parts of the synergistically modified bisphenol A epoxy resin obtained in step S1 and 1 part of nano alumina were added to a mixing container and dispersed at 30℃ and 300 rpm for 0.5 h to obtain a pre-dispersion system; then 0.5 parts of 2-amino-6-trifluoromethylbenzothiazole and 20 parts of methylhexahydrophthalic anhydride were added and reacted at 60℃ and 400 rpm for 1 h to obtain a reaction system;

[0031] S3. Add 0.5 parts of silane coupling agent, 1 part of flame retardant synergist, 0.2 parts of leveling agent and 0.1 parts of defoamer to the reaction system obtained in step S2. Stir at 40℃ and 200rpm for 0.5h, and perform vacuum degassing at -0.08MPa to obtain high-strength, low-emission epoxy resin.

[0032] Example 2: This example aims to provide an epoxy resin system with optimal overall mechanical properties and explosion-proof performance.

[0033] S1, 3 parts of p-tert-butylcalix[6] aromatic hydrocarbon and 3 parts of 1-pyrene methylamine were added to tetrahydrofuran and stirred at 35°C and 400 rpm for 1.5 h to form a stable host-guest inclusion complex; then 1.5 parts of ferric chloride, 2.5 parts of terephthalaldehyde and 5 parts of diethylenetriamine were added and reacted at 65°C and 500 rpm for 3 h to obtain a synergistically modified intermediate; then 90 parts of bisphenol A epoxy resin were added and reacted at 85°C and 500 rpm for 2 h to obtain a synergistically modified bisphenol A epoxy resin; Figure 1 Bisphenol A type epoxy resin before modification at 910cm -1 It exhibits a distinct characteristic absorption peak of epoxy groups at 1600 cm⁻¹, and also shows a peak at 1600 cm⁻¹. -1 The vicinity exhibits aromatic ring skeletal vibration peaks, and the overall spectral characteristics are relatively simple; after modification, at 3400 cm⁻¹... -1 The absorption peak at 1520 cm⁻¹ is significantly enhanced, indicating enhanced hydrogen bonding in the system; -1 and 750cm -1 The appearance of new characteristic peaks nearby indicates the introduction of a pyrene ring structure and the formation of π-π interactions; simultaneously, at 600–700 cm⁻¹... -1 The appearance of a new absorption peak in the region indicates the presence of a metal coordination structure; 910 cm⁻¹ -1 The weakening of the characteristic peak intensity of the epoxy group indicates that some epoxy groups participated in the reaction; the above changes indicate that the synergistic modified structure was successfully constructed.

[0034] S2, 100 parts of the synergistically modified bisphenol A epoxy resin obtained in step S1 and 5 parts of nano-alumina were added to a mixing container and dispersed at 50℃ and 600 rpm for 1 h to obtain a pre-dispersion system; then 3 parts of 2-amino-6-trifluoromethylbenzothiazole and 40 parts of methylhexahydrophthalic anhydride were added and reacted at 80℃ and 700 rpm for 2 h to obtain a reaction system;

[0035] S3. Add 2.5 parts of silane coupling agent, 4 parts of flame retardant synergist, 1 part of leveling agent and 0.5 parts of defoamer to the reaction system obtained in step S2. Stir at 60℃ and 400rpm for 1h, and perform vacuum degassing at -0.09MPa to obtain high-strength, low-emission epoxy resin.

[0036] Example 3: This example aims to verify the ultimate explosion-proof performance and structural stability of the system under high addition conditions.

[0037] S1, 6 parts of p-tert-butylcalix[6] aromatic hydrocarbon and 6 parts of 1-pyrene methylamine were added to tetrahydrofuran and stirred at 50°C and 600 rpm for 3 h to allow the host-guest inclusion effect to fully occur; then 3 parts of ferric chloride, 5 parts of terephthalaldehyde and 10 parts of diethylenetriamine were added and reacted at 90°C and 700 rpm for 5 h to obtain a synergistic modified intermediate; then 120 parts of bisphenol A epoxy resin were added and reacted at 110°C and 800 rpm for 4 h to obtain a synergistic modified bisphenol A epoxy resin;

[0038] S2, 120 parts of the synergistically modified bisphenol A epoxy resin obtained in step S1 and 10 parts of nano-alumina were added to a mixing container and dispersed at 70℃ and 800rpm for 2h to obtain a pre-dispersion system; then 6 parts of 2-amino-6-trifluoromethylbenzothiazole and 60 parts of methylhexahydrophthalic anhydride were added and reacted at 100℃ and 900rpm for 3h to obtain a reaction system;

[0039] S3. Add 5 parts of silane coupling agent, 8 parts of flame retardant synergist, 2 parts of leveling agent and 1 part of defoamer to the reaction system obtained in step S2. Stir at 80°C and 600 rpm for 2 hours and perform vacuum degassing at -0.1 MPa to obtain high-strength, low-emission epoxy resin.

[0040] Comparative Example 1: This comparative example aims to verify the effect of using only host-guest encapsulation modification on explosion-proof performance.

[0041] S1, 3 parts of p-tert-butylcalix[6] aromatic hydrocarbon and 3 parts of 1-pyrene methylamine were added to tetrahydrofuran and stirred at 35°C and 400 rpm for 1.5 h to form a stable host-guest inclusion complex; then, without adding ferric chloride, terephthalaldehyde and diethylenetriamine, 90 parts of bisphenol A epoxy resin were directly added and reacted at 85°C and 500 rpm for 2 h to obtain a single host-guest modified bisphenol A epoxy resin;

[0042] S2, 100 parts of the single host-guest modified bisphenol A epoxy resin obtained in step S1 and 5 parts of nano alumina are added to a mixing container and dispersed at 50℃ and 600 rpm for 1 h to obtain a pre-dispersion system; then 3 parts of 2-amino-6-trifluoromethylbenzothiazole and 40 parts of methylhexahydrophthalic anhydride are added and reacted at 80℃ and 700 rpm for 2 h to obtain a reaction system;

[0043] S3. Add 2.5 parts of silane coupling agent, 4 parts of flame retardant synergist, 1 part of leveling agent and 0.5 parts of defoamer to the reaction system obtained in step S2. Stir at 60°C and 400 rpm for 1 hour, and perform vacuum degassing at -0.09 MPa to obtain epoxy resin.

[0044] Comparative Example 2: This comparative example aims to verify the effect of using only metal coordination and Schiff base structural modification on explosion-proof performance.

[0045] S1, without adding p-tert-butylcalix[6] aromatics and 1-pyrene methylamine, 1.5 parts of ferric chloride, 2.5 parts of terephthalaldehyde and 5 parts of diethylenetriamine were added to tetrahydrofuran and reacted at 65℃ and 500rpm for 3h to obtain a coordination structure intermediate; then 90 parts of bisphenol A type epoxy resin were added and reacted at 85℃ and 500rpm for 2h to obtain a single coordination modified bisphenol A type epoxy resin;

[0046] S2, 100 parts of the single coordination modified bisphenol A epoxy resin obtained in step S1 and 5 parts of nano alumina were added to a mixing container and dispersed at 50℃ and 600 rpm for 1 h to obtain a pre-dispersion system; then 3 parts of 2-amino-6-trifluoromethylbenzothiazole and 40 parts of methylhexahydrophthalic anhydride were added and reacted at 80℃ and 700 rpm for 2 h to obtain a reaction system;

[0047] S3. Add 2.5 parts of silane coupling agent, 4 parts of flame retardant synergist, 1 part of leveling agent and 0.5 parts of defoamer to the reaction system obtained in step S2. Stir at 60°C and 400 rpm for 1 hour, and perform vacuum degassing at -0.09 MPa to obtain epoxy resin.

[0048] Comparative Example 3: This comparative example aims to verify the effect of the absence of 2-amino-6-trifluoromethylbenzothiazole on explosion-proof performance.

[0049] S1, 3 parts of p-tert-butylcalix[6] aromatic hydrocarbon and 3 parts of 1-pyrene methylamine were added to tetrahydrofuran and stirred at 35°C and 400 rpm for 1.5 h to form a stable host-guest inclusion complex; then 1.5 parts of ferric chloride, 2.5 parts of terephthalaldehyde and 5 parts of diethylenetriamine were added and reacted at 65°C and 500 rpm for 3 h to obtain a synergistically modified intermediate; then 90 parts of bisphenol A epoxy resin were added and reacted at 85°C and 500 rpm for 2 h to obtain a synergistically modified bisphenol A epoxy resin;

[0050] S2, 100 parts of the synergistically modified bisphenol A epoxy resin obtained in step S1 and 5 parts of nano alumina were added to a mixing container and dispersed at 50℃ and 600 rpm for 1 h to obtain a pre-dispersion system; then, without adding 2-amino-6-trifluoromethylbenzothiazole, only 40 parts of methylhexahydrophthalic anhydride were added and reacted at 80℃ and 700 rpm for 2 h to obtain a reaction system;

[0051] S3. Add 2.5 parts of silane coupling agent, 4 parts of flame retardant synergist, 1 part of leveling agent and 0.5 parts of defoamer to the reaction system obtained in step S2. Stir at 60°C and 400 rpm for 1 hour, and perform vacuum degassing at -0.09 MPa to obtain epoxy resin.

[0052] Performance testing:

[0053] 1. Impact performance test method

[0054] The epoxy resin systems prepared in each embodiment and comparative example were poured into a standard mold for molding. After pre-curing at 80°C for 2 hours, they were post-cured at 120°C for 2 hours. After demolding, standard impact specimens with dimensions of 80mm×10mm×4mm were prepared. Before testing, the specimens were placed at 23°C and 50% relative humidity for 24 hours. The pendulum impact tester was used for testing. An appropriate impact energy level was selected to make the specimen break in one impact. The energy absorbed by the specimen during the fracture was recorded. Each group of samples was tested in parallel 5 times, and the average value was taken as the final result to evaluate the impact resistance and energy dissipation capacity of the material.

[0055] 2. Fracture toughness testing methods

[0056] Cured epoxy resin was processed into specimens with dimensions of 100mm×10mm×5mm. A pre-made notch was made in the middle of the specimen, and an initial crack was introduced using a blade. The specimens were placed on an electronic universal testing machine for a three-point bending test with a span of 40mm and a loading rate of 1mm / min. The load changes corresponding to crack initiation and unstable propagation during loading were recorded, and the fracture morphology was observed. Each group of samples was tested no less than 5 times. By comparing the crack propagation behavior and fracture characteristics of different samples, their fracture toughness and crack resistance were evaluated.

[0057] 3. Burst Pressure Simulation Test Method

[0058] An epoxy resin system was uniformly coated onto the inner wall of a metal cylinder and cured to prepare a sample simulating the lining structure of a hydrogen cylinder. The sample was 200 mm long and 50 mm in inner diameter. The sample was installed in a closed pressure testing device, using nitrogen as the pressurizing medium, and the internal pressure was gradually increased at a rate of 0.5 MPa / min. The deformation and pressure changes of the sample were monitored in real time, and the corresponding pressure value was recorded when obvious cracking or structural damage occurred. Each group of samples was tested 3 times, and the average value was taken as the burst pressure to evaluate the explosion-proof performance and pressure-bearing capacity of the material.

[0059] 4. Interface bonding strength test method

[0060] A metal substrate with dimensions of 100mm×25mm×2mm was selected. After grinding, degreasing, and cleaning the surface, an epoxy resin system was uniformly coated on the overlapping area of ​​the two substrates, with an overlap length of 12.5mm. The substrate was pre-cured at 80℃ for 2 hours and then cured at 120℃ for 2 hours. After preparation, the sample was placed at room temperature for 24 hours. Subsequently, a tensile shear test was performed on an electronic universal testing machine with a loading rate of 2mm / min. The maximum load at which the interface failure occurred was recorded. Each group of samples was tested 5 times, and the average value was taken as the interfacial bonding strength to evaluate the bonding performance and interfacial stability of the material.

[0061] Table 1. Performance test results of each embodiment and comparative example.

[0062] sample Impact absorbed energy (kJ / m²) Fracture toughness performance (crack propagation length / mm) Burst pressure (MPa) Interfacial bond strength (MPa) Example 1 18.6 6.8 32.5 12.4 Example 2 26.9 4.2 41.8 16.7 Example 3 23.5 5.1 38.6 14.9 Comparative Example 1 13.2 9.5 27.3 10.1 Comparative Example 2 14.5 8.7 28.6 10.8 Comparative Example 3 11.8 10.2 25.9 9.6

[0063] By comparing systems with single host-guest structures, single coordination structures, and systems lacking key functional units, it is evident that the performance improvement brought about by the multi-synergistic structure constructed in this invention is significantly higher than the simple superposition of individual modification methods, indicating a significant synergistic enhancement effect. According to Table 1, compared to the comparative examples, each embodiment shows significant improvements in impact energy absorption, fracture toughness, burst pressure, and interfacial bonding strength, demonstrating that this invention, by constructing a multi-synergistic modified structure, can effectively improve the mechanical response behavior of epoxy resin under impact and high-pressure environments. Among these, Example 2 achieves optimal performance in all aspects, indicating that under this formulation condition, the synergistic effect between the structural units is most sufficient, achieving the best balance between energy dissipation and structural stability.

[0064] In terms of impact performance, the impact absorption energies of Examples 1 to 3 were 18.6 kJ / m², 26.9 kJ / m², and 23.5 kJ / m², respectively, which were significantly higher than those of Comparative Examples 1 to 3 (13.2 kJ / m², 14.5 kJ / m², and 11.8 kJ / m²), especially Example 2, which showed the most significant improvement. This indicates that the host-guest inclusion structure formed by tert-butylcalix[6]arene and 1-pyrene methylamine can undergo reversible dissociation under impact, while the π-π stacking structure undergoes slippage and rearrangement, thereby effectively absorbing external impact energy. In contrast, the comparative examples had weaker energy dissipation capacity due to the lack or incompleteness of the synergistic structure.

[0065] Regarding fracture toughness, the crack propagation lengths of Examples 1-3 were 6.8 mm, 4.2 mm, and 5.1 mm, respectively, significantly lower than the comparative examples' 9.5 mm, 8.7 mm, and 10.2 mm, indicating that the system of the present invention can effectively suppress rapid crack propagation. Example 2 exhibited the shortest crack propagation length, demonstrating that the metal coordination charge transfer structure and Schiff base structure can achieve stress relief and structural reconstruction in the crack tip region, reducing stress concentration and thus improving the material's crack resistance.

[0066] Regarding burst pressure, Examples 1-3 achieved 32.5 MPa, 41.8 MPa, and 38.6 MPa respectively, significantly higher than the comparative examples' 27.3 MPa, 28.6 MPa, and 25.9 MPa, with Example 2 showing the greatest improvement. This indicates that the present invention, by constructing a multi-level cooperative network structure, enables the material to achieve uniform stress distribution under high pressure and delays the initiation and propagation of microcracks, thereby significantly improving the ultimate pressure bearing capacity and explosion-proof performance. In contrast, the comparative examples, lacking multi-mechanism synergy, failed at lower pressures.

[0067] Regarding interfacial bonding strength, Examples 1-3 showed strengths of 12.4 MPa, 16.7 MPa, and 14.9 MPa, respectively, all superior to the comparative examples' strengths of 10.1 MPa, 10.8 MPa, and 9.6 MPa. This indicates that the synergistically modified structure not only improved the bulk properties of the resin but also enhanced the interfacial interaction with the substrate. Example 2, in particular, demonstrated a high interfacial bonding strength, indicating the combined effect of multiple interaction mechanisms, which improved interfacial stability and load transfer capacity.

[0068] In summary, this invention, through the synergistic construction of host-guest encapsulation structure, metal coordination charge transfer structure, and π-π interaction, enables epoxy resin to achieve multi-level energy dissipation and stress regulation under impact loads and high pressure environments. This significantly improves fracture toughness and explosion-proof performance while ensuring strength. Among them, Example 2 exhibits the best overall performance, fully verifying the significant effects and application value of the technical solution of this invention.

Claims

1. A high-strength, low-emission epoxy resin, characterized in that, The epoxy resin comprises the following raw materials in parts by weight: 80-120 parts of synergistically modified bisphenol A type epoxy resin; 0.5-6 parts of 2-amino-6-trifluoromethylbenzothiazole; 20-60 parts of methyl hexahydrophthalic anhydride; 1-10 parts of nano alumina; 0.5-5 parts of silane coupling agent; 1-8 parts of flame retardant synergist; 0.2-2 parts of leveling agent; 0.1-1 parts of defoamer; The synergistically modified bisphenol A type epoxy resin is formed by synergistic modification of bisphenol A type epoxy resin with p-tert-butylcalix[6] aromatic hydrocarbon, 1-pyrene methylamine, ferric chloride, terephthalaldehyde and diethylenetriamine through host-guest inclusion, metal coordination charge transfer and π-π interaction.

2. The high-strength, low-emission epoxy resin according to claim 1, characterized in that, The synergistically modified bisphenol A type epoxy resin comprises the following raw materials in parts by weight: 60-120 parts of bisphenol A type epoxy resin; 0.5-6 parts of p-tert-butylcalix[6] aromatic hydrocarbon; 0.5-6 parts of 1-pyrene methylamine; 0.2-3 parts of ferric chloride; 0.5-5 parts of terephthalaldehyde; and 1-10 parts of diethylenetriamine.

3. A high-strength, low-emission epoxy resin according to claim 1 or 2, characterized in that, The preparation method of the synergistically modified bisphenol A type epoxy resin includes the following steps: (1) Add p-tert-butylcalix[6] aromatic hydrocarbon and 1-pyrene methylamine to an organic solvent for mixing to allow host-guest inclusion to occur, thus obtaining a host-guest inclusion complex; (2) Add terephthalaldehyde and diethylenetriamine to the host-guest inclusion complex to carry out a condensation reaction to form an organic network intermediate containing a Schiff base structure; then add ferric chloride to coordinate with the organic network intermediate to obtain a coordination structure intermediate. (3) The coordination structure intermediate is added to the bisphenol A type epoxy resin and dispersed and partially ring-opening reaction is carried out under heating conditions to obtain synergistically modified bisphenol A type epoxy resin.

4. The high-strength, low-emission epoxy resin according to claim 3, characterized in that, The reaction conditions for step (1) are: temperature 20-50℃, time 0.5-3h, stirring speed 200-600rpm, and the organic solvent is tetrahydrofuran or N,N-dimethylformamide.

5. The high-strength, low-emission epoxy resin according to claim 3, characterized in that, The reaction conditions for step (2) are: temperature 40-90℃, time 1-5h, and stirring speed 300-700rpm.

6. The high-strength, low-emission epoxy resin according to claim 3, characterized in that, The reaction conditions for step (3) are: temperature 60-110℃, time 1-4h, and stirring speed 300-800rpm.

7. The high-strength, low-emission epoxy resin according to claim 1, characterized in that, The silane coupling agent is a mixture of γ-aminopropyltriethoxysilane and vinyltrimethoxysilane in a mass ratio of 1:1 to 3; the flame retardant synergist is a mixture of melamine and phytic acid in a mass ratio of 1:1 to 4; the leveling agent is a mixture of polyether-modified polysiloxane and acrylate leveling agent in a mass ratio of 1:1 to 2; and the defoamer is a mixture of polydimethylsiloxane and fumed silica in a mass ratio of 2:1 to 6.

8. A method for preparing a high-strength, low-emission epoxy resin, characterized in that, The preparation method includes the following steps: S1, synergistically modified bisphenol A epoxy resin and nano alumina are added to a mixing container for dispersion treatment to obtain a pre-dispersion system; S2, 2-amino-6-trifluoromethylbenzothiazole and methylhexahydrophthalic anhydride are added to the pre-dispersed system and mixed to obtain the reaction system; S3. Add silane coupling agent, flame retardant synergist, leveling agent and defoamer to the reaction system, stir evenly and defoaming treatment to obtain high-strength low-emission epoxy resin.

9. The method for preparing a high-strength, low-emission epoxy resin according to claim 8, characterized in that, The reaction conditions for step S1 are a temperature of 30–70°C, a time of 0.5–2 h, and a stirring rate of 300–800 rpm; the reaction conditions for step S2 are a temperature of 60–100°C, a time of 1–3 h, and a stirring rate of 400–900 rpm.

10. The method for preparing a high-strength, low-emission epoxy resin according to claim 8, characterized in that, The reaction conditions for step S3 are: temperature 40-80℃, time 0.5-2h, stirring speed 200-600rpm, degassing method is vacuum degassing, and vacuum degree is -0.08--0.1MPa.

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