Method for enhancing cyanate resin by co-doping europium-terbium complex and phenolphthalein polyethersulfone

Abstract

The invention discloses a method for co-doping and enhancing cyanate ester resin by using a europium-terbium complex and phenolphthalein polyethersulfone. The method comprises the following steps: (1) preparing a cyanate ester monomer solution and a phenolphthalein polyethersulfone resin solution; (2) blending the cyanate ester solution and the phenolphthalein polyethersulfone solution: mixing the cyanate ester solution and the phenolphthalein polyethersulfone solution; (3) adding the Eu < 3 + >-Tb < 3 + >-uCNTs solution into a cyanate ester and phenolphthalein polyethersulfone mixed solution, and stirring in an oil bath at a certain temperature to remove the solvent to obtain a doped cyanate ester resin system; and (4) casting the prepared mixture into a preheating mold, transferring to a vacuum drying oven for degassing treatment, and carrying out gradient heating curing. According to the cyanate ester resin co-doped with the thermoplastic phenolphthalein polyethersulfone resin and the europium-terbium complex loaded unzipped carbon nanotubes, the mechanical property of the obtained composite material is greatly improved, and compared with pure cyanate ester resin, the bending property of the novel composite material is improved by more than two times, and the tensile property is improved by more than one time.

Description

Technical Field

[0001] The invention relates to the technical field of composite material modification, and in particular to a method for co-doping a europium-terbium complex with phenolphthalein polyethersulfone to enhance a cyanate resin. Background Art

[0002] Cyanate ester resin (CER) is an excellent thermosetting resin with a unique triazine ring network structure that allows for long-term use at high temperatures. Therefore, it is widely used in various fields, such as aerospace and microelectronics packaging. However, its cured product exhibits high brittleness, poor flexibility, and high curing temperature, which hinders its application in certain fields. Therefore, it is important to find an additive that can improve its toughness and mechanical properties while reducing the curing temperature and time.

[0003] Multi-walled carbon nanotubes (MWCNTs) have excellent structural properties and are easy to functionalize. They can be used as reinforcing materials to improve the mechanical properties of polymers. At the same time, MWCNTs have a catalytic effect on CER polymerization and can reduce the curing temperature. However, multi-walled carbon nanotubes are easy to agglomerate and difficult to disperse in CER.

[0004] Lanthanide complexes play an important role in fields such as optics, catalysis, biomedicine, and materials science. They can be used as fluorescent probes for molecular labeling and detection. Their long fluorescence lifetime and strong thermal stability enable highly sensitive detection of specific molecules in samples. Europium, terbium, and other materials are important raw materials for the production of tri-color phosphors, used in lighting equipment such as energy-saving lamps and LEDs, as well as in the manufacture of display devices such as fluorescent screens and cathode ray tubes.

[0005] In the prior art, doping carbon nanotubes into cyanate esters can improve the heat resistance and mechanical properties of cyanate esters, but the toughness of the composite material is poor, which limits its application. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the deficiencies of the existing technology and provide a method for co-doping a europium-terbium complex with phenolphthalein polyethersulfone to strengthen a cyanate ester resin. By adding phenolphthalein polyethersulfone, the toughness of the cyanate ester is improved, while carbon nanotubes are modified. The europium-terbium complex is then anchored to the modified carbon nanotubes, thereby improving the carbon nanotubes' tendency to aggregate and bundle, promoting their dispersion in the cyanate ester resin matrix, and enhancing the mechanical and thermal properties of the composite material. Furthermore, the cyanate ester is endowed with luminescent properties, thereby enabling a wider range of applications.

[0007] The technical solution provided by the present invention is: A method for co-doping and reinforcing a cyanate ester resin with a europium-terbium complex and phenolphthalein polyethersulfone comprises: blending a cyanate ester resin with a phenolphthalein polyethersulfone resin to obtain a thermoplastic phenolphthalein polyethersulfone resin-toughened cyanate ester resin blend system; then, using unzippered carbon nanotubes loaded with the europium-terbium complex as a synergistic toughening agent to form a doped cyanate ester resin system; and then curing the system by gradient temperature increase to prepare a highly efficient toughened and modified cyanate ester-phenolphthalein polyethersulfone resin hybrid material. The preparation method comprises the following specific steps: (1) Preparation of cyanate monomer solution and phenolphthalein polyethersulfone resin solution: (2) blending the cyanate ester solution and the phenolphthalein polyethersulfone solution: the cyanate ester solution and the phenolphthalein polyethersulfone solution are mixed, ultrasonicated for 2-3 hours, and then mechanically stirred to obtain a blending system of thermoplastic phenolphthalein polyethersulfone resin toughened cyanate ester resin; (3) Electrochemical dezipping of europium-terbium complex-loaded carbon nanotubes (Eu 3+ -Tb 3+ -uCNTs) solution is added to a mixed solution of cyanate ester and phenolphthalein polyethersulfone in a certain proportion, mechanically stirred for 2-3 hours, and then stirred in an oil bath at a certain temperature to remove the solvent to obtain a doped cyanate ester resin system; (4) The prepared mixture is cast into a preheated mold, moved to a vacuum drying oven for degassing, and cured by gradient heating.

[0008] Prepare a cyanate ester monomer solution: add a cyanate ester resin to a solvent and sonicate for 2-3 hours until the cyanate ester solid dissolves; cyanate ester monomers include but are not limited to cyanate ester A, cyanate ester E, cyanate ester M, cyanate ester F, etc.; the solvent used can be a single solvent or a mixture of 2-3 solvents listed below: acetone, DMF, tetrahydrofuran, chloroform, dichloromethane, etc.; Prepare a phenolphthalein polyethersulfone resin solution: add the phenolphthalein polyethersulfone resin to a solvent and sonicate for 2-3 hours until the phenolphthalein polyethersulfone solid dissolves; the phenolphthalein polyethersulfone resin includes but is not limited to phenolphthalein-bisphenol A copolyethersulfone, phenolphthalein-biphenyl diphenol copolyethersulfone, phenolphthalein polyaryl ethersulfone, sulfonated phenolphthalein polyethersulfone, methylated phenolphthalein polyethersulfone, fluorinated phenolphthalein polyethersulfone, quaternized phenolphthalein polyethersulfone, etc.; the solvent used can be a single solvent or a mixture of two to three solvents listed below: acetone, DMF, tetrahydrofuran, chloroform, dichloromethane, etc.; In the method, in step (1), the concentration of the cyanate ester monomer in the solvent is 10 mL of solvent dissolving 1-50 g of cyanate ester monomer.

[0009] In the method, in step (1), the concentration of phenolphthalein polyethersulfone in the solvent is 10 mL of solvent dissolving 1-38 g of phenolphthalein polyethersulfone resin.

[0010] In the method, in step (2), the mass ratio of cyanate ester to phenolphthalein polyethersulfone is (5-15): (1-9), and the oil bath stirring temperature is controlled between 70°C and 170°C.

[0011] The method described in step (3) wherein the europium-terbium complex electrochemically dezips the carbon nanotubes (Eu 3+ -Tb 3+ -uCNTs) are prepared as follows: (1) Prepare Eu(TTA)3phen complex and Tb(BBA)3phen complex respectively, mix the two complex solutions in a volume ratio of 1:1, and stir for 2h to form Eu 3+ -Tb 3+ Complex mixed solution; (2) Disperse uCNTs in ethanol and ultrasonically form a dispersed carbon nanotube suspension. 3+ -Tb 3+ The complex mixture solution was added to the suspension, stirred evenly, and diluted ammonia was added until the pH was 6-7, and the mixture was stirred to obtain a suspension; the suspension was washed by centrifugation with ethanol, and freeze-dried to obtain the final product Eu 3+ -Tb 3+ -uCNTs. The ratio is 0.6wt%.

[0012] In the method described above, in step (2), 60 mL of rare earth europium-terbium complex solution is added for every 10 mg of unzipped carbon nanotubes.

[0013] The method, in step (4), casts the stirred mixture into a preheated tetrafluoroethylene mold coated with vacuum silicone grease, degassing in a vacuum drying oven at 120°C for 24 hours to remove the solvent, and then curing. The curing process is: 140°C / 2h, 160°C / 2h, 180°C / 2h, 190°C / 1h, 200°C / 1h, 210°C / 1h, 230°C / 2h, 250°C / 2h.

[0014] The method described, in step (3), each 0.02-5g Eu 3+ -Tb 3+ -uCNTs are correspondingly added with 2-30 g of a blending system solution of phenolphthalein polyethersulfone resin and cyanate ester resin, and ultrasonically dispersed.

[0015] The present invention adopts the above technical solution, which has the following beneficial effects: (1) Using Tb complex to enhance the fluorescence properties of Eu complex, and then loading Eu / Tb onto unzipped carbon nanotubes to promote the dispersion of carbon nanotubes in the resin. 3+ Complex to Eu 3+The enhancement effect of the complex luminescence, that is, when Tb 3+ When the f electrons are excited by light energy and undergo energy level transition, they transfer the excitation energy to Eu 3+ , which improves the fluorescence performance of the composite material. When the unzipped carbon nanotubes loaded with europium-terbium complex are co-doped with phenolphthalein polyethersulfone resin, the resulting composite material exhibits a fluorescence of Eu 3+ The luminous intensity of the characteristic luminescence will vary with Tb 3+ The co-doping of Eu 3+ Luminous intensity varies with Tb 3+ The doping ratio increases significantly.

[0016] (2) Rare earth Eu 3+ -Tb 3+ The complex anchors the electrochemically unzipped carbon nanotubes to form luminescent nanoparticles, and the rare earth complex is evenly fixed to the surface wall of the carbon nanotube through physical action and chemical adsorption. At the same time, there are defects on the uCNT tube wall, and the spherical complex crystals just adhere to these defect locations. This combination forms a special groove structure, which not only firmly fixes the rare earth complex on the uCNTs, but also acts as a connector. Compared with CNTs, uCNTs have a larger specific surface area due to nanopore defects, which is conducive to increasing the anchoring amount of rare earth complexes. The larger surface area and increased active sites not only contribute to the uniform distribution and effective attachment of rare earth complexes, but also play a key role in optimizing the fluorescence properties of the material, and may further improve the overall luminescence efficiency of the composite material.

[0017] (3) When phenolphthalein polyethersulfone is added to cyanate ester, a network structure can be formed during curing, which can improve the mechanical properties of the composite material, especially the toughness has been greatly improved. At the same time, the uniform distribution of phenolphthalein polyethersulfone in cyanate ester can be ensured by solution blending.

[0018] (4) The mechanical properties of the composite material obtained by co-doping thermoplastic phenolphthalein polyethersulfone resin and unzippered carbon nanotubes loaded with europium-terbium complex are greatly improved. Compared with pure cyanate ester resin, the bending performance of the new composite material is improved by more than two times, and the tensile performance is improved by more than double. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 CER / Eu of the present invention 3+ -Tb 3+ -Flowchart of the preparation method of uCNTs / PES-C composite material.

[0020] Figure 2 CNT (a, b), uCNTs (c, d), Eu 3+-Tb 3+ -TEM images of uCNTs (e, f).

[0021] Figure 3 Infrared spectra of CNTs and uCNTs.

[0022] Figure 4 Raman spectra of CNTs and uCNTs.

[0023] Figure 5 Tensile strength (a) and flexural strength (b) of CER resins doped with nanoparticles at different concentrations.

[0024] Figure 6 Tensile strength (a) and flexural strength (b) of CER / PES-C composites doped with different concentrations of nanoparticles.

[0025] Figure 7 In order to add 0.6wt% CNTs, uCNTs, Eu into CER composites 3+ -Tb 3+ -Graph of the tensile properties of uCNTs composite materials.

[0026] Figure 8 In order to add 0.6wt% CNTs, uCNTs, Eu into CER composites 3+ -Tb 3+ -Bending performance diagram of uCNTs composite materials.

[0027] Figure 9 In order to add 0.6wt% CNTs, uCNTs, Eu into CER / PES-C composites 3+ -Tb 3+ -Graph of the tensile properties of uCNTs composite materials.

[0028] Figure 10 In order to add 0.6wt% CNTs, uCNTs, Eu into CER / PES-C composites 3+ -Tb 3+ -Bending performance diagram of uCNTs composite materials.

[0029] Figure 11 In order to add 0.6wt% CNTs, uCNTs, Eu into CER / PES-C composites 3+ -Tb 3+ -DSC curves of uCNTs.

[0030] Figure 12 In order to add 0.6wt% CNTs, uCNTs, Eu into CER / PES-C composites 3+ -Tb 3+TG curves of -uCNTs.

[0031] Figure 13 CER / Eu 3+ -Tb 3+ -uCNTs / PES-C composites at different curing temperatures (a) and fluorescence lifetime spectra (b). DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to specific embodiments. Example 1: Preparation of electrochemically unzipped carbon nanotubes (uCNTs):

[0033] Prepare an 80% diluted concentrated sulfuric acid solution using deionized water and concentrated sulfuric acid. Prepare an 80% diluted concentrated nitric acid solution using deionized water and concentrated nitric acid. Mix the concentrated sulfuric acid solution and concentrated nitric acid solution in a 1:1 ratio. Weigh 1g of carbon nanotubes and soak them in the mixed solution for 24 hours. Evenly apply the soaked carbon nanotubes to a custom titanium sheet and wrap it with a polytetrafluoroethylene membrane to serve as the anode. A titanium sheet of the same size is pressed on top of the positive electrode to serve as the cathode. A mixture of sulfuric acid and nitric acid serves as the electrolyte. Connect a power supply and react at 30V DC for 8 hours. After the reaction, wash the carbon nanotubes with deionized water and filter them until the pH of the aqueous solution reaches 7. Collect the resulting sample and freeze-dry it for 24 hours. The dried sample is then ground to obtain unzipped carbon nanotubes (uCNTs). Figure 2 TEM images of CNTs (a, b) and uCNTs (c, d) show that after electrochemical unzipping, the surface of uCNTs becomes very rough, the specific surface area increases, and more defects are generated. Figure 3 The infrared spectra of CNTs and uCNTs are shown in Figure 2. As can be seen, uCNTs incorporate oxygen-containing functional groups (-OH, C=O, CO), which promote their dispersion in resin-based composites. The presence of these oxygen-containing functional groups also facilitates subsequent bonding with rare earth complexes. Figure 4 The Raman spectra of CNTs and uCNTs are shown in Figure 2. The D / G value of uCNTs is larger than that of CNTs, indicating that a large number of defects and functional groups have formed in uCNTs, and the electrochemical unzipping has destroyed the original ordered structure.

[0034] Example 2: Eu 3+ -Tb 3+ Preparation of uCNTs: (1) Weigh EuCl3·6H2O, thenoyltrichloroacetone (TTA), and 1,10-phenanthroline monohydrate (Phen) and prepare a 0.1 mol / L EuCl3, 0.3 mol / L TTA, and 0.1 mol / L Phen solution with anhydrous ethanol for later use. Weigh TbCl3·6H2O, 4-benzoylbenzoic acid (BBA), and 1,10-phenanthroline monohydrate (Phen) and prepare a 0.1 mol / L TbCl3, 0.3 mol / L BBA, and 0.1 mol / L Phen solution with anhydrous ethanol for later use.

[0035] 0.1 mol / L EuCl3, 0.3 mol / L TTA, and 0.1 mol / L Phen solution were gradually added into the beaker in a volume ratio of 1:1:1 and magnetically stirred for 2 h to obtain the Eu(TTA)3phen complex.

[0036] 0.1 mol / L TbCl3, 0.3 mol / L BBA, and 0.1 mol / L Phen solution were gradually added into the beaker in a volume ratio of 1:1:1 and magnetically stirred for 2 h to obtain Tb(BBA)3phen complex.

[0037] The two complex solutions were mixed in a volume ratio of 1:1 and stirred for 2 h to form Eu 3+ -Tb 3+ Complex mixed solution.

[0038] (2) Weigh 10 mg of uCNTs and disperse them in ethanol. After ultrasonication for a period of time, stir them continuously for 2 h under a magnetic stirrer to form a dispersed carbon nanotube suspension. 3+ -Tb 3+ The complex mixture solution was added to the suspension and stirred evenly for about 2 h. A small amount of 1 mol / L dilute ammonia solution was then added until the pH was 6-7. The suspension was stirred for about 1 h. The suspension was washed by centrifugation with ethanol and freeze-dried to obtain the final product Eu. 3+ -Tb 3+ -uCNTs. Figure 2 For Eu 3+ -Tb 3+ TEM images of -uCNTs (e, f). Rare earth complexes are spherical crystals that are uniformly anchored to the surface of carbon nanotubes through physical interactions and chemical adsorption, forming a unique "tenon-like" structure without changing the tubular structure of the carbon nanotubes.

[0039] Example 3: CER, CER / PES-C, CER / CNTs / PES-C, CER / uCNTs / PES-C, CER / Eu 3+ -Tb 3+ Preparation of -uCNTs / PES-C hybrid nanocomposites Take 10g of cyanate resin and add 10mL of dichloromethane, ultrasonicate for 2h until the cyanate solid dissolves; take 3g of phenolphthalein polyethersulfone resin and add 30mL of dichloromethane, ultrasonicate for 3h until the solid phenolphthalein polyethersulfone dissolves; mix the cyanate solution and phenolphthalein polyethersulfone solution, ultrasonicate for 2h and then mechanically stir; take 0.2wt%, 0.4wt%, 0.6wt%, 0.8wt%, and 1.0wt% of CNTs, uCNTs, and Eu at room temperature, respectively 3+ -Tb 3+ -uCNTs were dispersed in 10 ml of dichloromethane and ultrasonicated for 2 h to make them uniformly dispersed in the solvent.

[0040] Then, the dispersed nanoparticles were doped into a blend solution of cyanate ester and phenolphthalein polyethersulfone, ultrasonicated for 2 h, and heated with mechanical stirring for 4 h.

[0041] The stirred mixture was cast into a preheated Teflon mold coated with vacuum silicone grease, degassed in a vacuum drying oven at 120°C for 24 hours to remove the solvent, and then cured. The curing process was: 140°C / 2 hours, 160°C / 2 hours, 180°C / 2 hours, 190°C / 1 hour, 200°C / 1 hour, 210°C / 1 hour, 230°C / 2 hours, and 250°C / 2 hours.

[0042] Figure 5 The tensile strength (a) and flexural strength (b) of CER resins doped with nanoparticles at different concentrations are shown in the figure. As can be seen from the figure, the trends in the changes in tensile and flexural properties are basically the same. Compared with pure CER, the mechanical properties of the composite system are improved after the introduction of nanoparticles. Within the concentration range of 0.2-0.6wt%, the mechanical properties gradually increase with the increase in nanoparticle content; however, when the concentration reaches 0.6-1.0 wt%, the mechanical properties begin to show a downward trend. It is worth noting that when the nanoparticle addition amount is 0.6 wt%, the composite material exhibits the best mechanical properties, so this optimal addition amount was used for testing in subsequent experiments.

[0043] Figure 6The tensile strength (a) and flexural strength (b) of CER / PES-C composites doped with nanoparticles at different concentrations are shown. As can be seen from the figure, when different mass fractions of nanoparticles are uniformly dispersed in the composite, the tensile and flexural strengths of the composite show a systematic increase. At low nanoparticle concentrations of 0.2-0.6 wt%, the mechanical properties of the composite show a regular growth trend. However, when the nanoparticle concentration is further increased to 0.6-1.0 wt%, the mechanical properties of the material actually decrease. Therefore, when the nanoparticle addition is 0.6 wt%, the composite exhibits the best mechanical properties.

[0044] Figure 7 and Figure 8 0.6wt% CNTs, uCNTs, and Eu were added into CER. 3+ -Tb 3+ -The tensile performance and bending performance diagrams of uCNTs composite materials. As can be seen from the figure, doping different nanoparticles in CER resin can greatly improve the mechanical properties of the composite material. The tensile and bending properties of CNTs / CER are improved by 16.14% and 59.01% respectively compared with pure CER, and the tensile and bending properties of uCNTs / CER are improved by 47.26% and 82.39% respectively compared with pure CER. 3+ -Tb 3+ When the uCNTs luminescent nanoparticles were added, the tensile and flexural properties of the composite material were improved by 97.55% and 162.78%, respectively. This demonstrates that the electrochemical dezipping of europium-terbium complex-loaded carbon nanotubes toughened cyanate ester resin.

[0045] Figure 9 and Figure 10 0.6wt% CNTs, uCNTs, and Eu were added to CER / PES-C. 3+ -Tb 3+ -uCNTs composite material tensile performance diagram and bending performance diagram. As can be seen from the figure, blending phenolphthalein polyethersulfone and doping different nanoparticles in CER resin can greatly improve the mechanical properties of the composite material. The tensile and bending properties of CER / CNTs / PES-C are improved by 37.5% and 85.92% respectively compared with pure CER, and the tensile and bending properties of CER / uCNTs / PES-C are improved by 60.75% and 126.1% respectively compared with pure CER. 3+ -Tb 3+ When the luminescent nanoparticles of -uCNTs were added, the tensile and flexural properties of the composite material increased by 120.2% and 209.1%, respectively. This demonstrates that phenolphthalein polyethersulfone synergizes with the electrochemical dezipping of europium-terbium complex-loaded carbon nanotubes to toughen cyanate ester resin.

[0046] Figure 11 In order to add 0.6wt% CNTs, uCNTs, Eu into CER / PES-C composites 3+ -Tb 3+ -uCNTs DSC curve, it can be found that there is a downward endothermic peak at about 106 ° C, which is the monomer melting peak; but when Eu is added 3+ -Tb 3+ The melting peak of the uCNTs appears around 90°C, demonstrating that the addition of rare earth nanoparticles lowers the melting point of the composite. Curing peaks of varying volumes appear sequentially between approximately 250°C and 350°C, demonstrating the exothermic polymerization of the monomers. The different peaks demonstrate the catalytic effect of the addition of different nanoparticles on the curing of the resin. The addition of rare earth nanoparticles lowers the curing temperature of the resin by approximately 70°C, creating favorable conditions for its application.

[0047] Figure 12 To dope 0.6 wt% CNTs, uCNTs, Eu into CER / PES-C composites under nitrogen atmosphere 3+ -Tb 3+ -uCNTs TG curve. ,The study shows that under high temperature environment (800℃), the mass wear rate of CER / CNTs / PES-C composite material is reduced by about 5% compared with CER / PES-C, while CER / Eu 3+ -Tb 3+ -uCNTs / PES-C composite material mass wear rate is reduced by about 32%; at the same time, the mass loss starting temperature of CER / PES-C composite material is 348.52℃, and the mass loss starting temperature of CER / Eu 3+ -Tb 3+ -uCNTs / PES-C mass loss starting temperature is 421.54℃, which proves that the addition of Eu 3+ -Tb 3+ -uCNTs nanoparticles exhibit strong heat and high temperature resistance. While retaining the heat resistance of the resin structure, they promote the formation of triazine ring structure, further enhancing the heat resistance.

[0048] Figure 13 CER / Eu 3+ -Tb 3+ -uCNTs / PES-C composites at different curing temperatures (a) and fluorescence lifetime spectra (b). Figure 13 As can be seen in a, CER / Eu 3+ -Tb 3+-uCNTs / PES-C composite materials have different fluorescence properties at different curing temperatures. When the curing temperature reaches 250℃, the composite materials still have strong fluorescence properties. Figure 13 As can be seen in b, when the curing temperature reaches 250°C, the composite material still maintains a relatively high fluorescence lifetime, which makes it possible to be used in the field of luminescent high-temperature resistant devices.

[0049] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A method for co-doping a europium-terbium complex with phenolphthalein polyethersulfone to enhance a cyanate ester resin, characterized in that: The specific steps include: (1) Preparation of cyanate monomer solution and phenolphthalein polyethersulfone resin solution: (2) blending the cyanate ester solution and the phenolphthalein polyethersulfone solution: the cyanate ester solution and the phenolphthalein polyethersulfone solution are mixed, ultrasonicated for 2-3 hours, and then mechanically stirred to obtain a blending system of thermoplastic phenolphthalein polyethersulfone resin toughened cyanate ester resin; (3) Electrochemical dezipping of europium-terbium complex-loaded carbon nanotubes (Eu 3+ -Tb 3+ -uCNTs) solution is added to a mixed solution of cyanate ester and phenolphthalein polyethersulfone in a certain proportion, mechanically stirred for 2-3 hours, and then stirred in an oil bath at a certain temperature to remove the solvent to obtain a doped cyanate ester resin system; (4) The prepared mixture is cast into a preheated mold, moved to a vacuum drying oven for degassing, and cured by gradient heating.

2. The method according to claim 1, characterized in that In step (1), the concentration of the cyanate ester monomer in the solvent is 10 mL of solvent dissolving 1-50 g of the cyanate ester monomer.

3. The method according to claim 1, characterized in that In step (1), the concentration of phenolphthalein polyethersulfone in the solvent is 10 mL of solvent to dissolve 1-38 g of phenolphthalein polyethersulfone resin.

4. The method according to claim 1, wherein In step (2), the mass ratio of cyanate ester to phenolphthalein polyethersulfone is (5-15): (1-9), and the oil bath stirring temperature is controlled between 70°C and 170°C.

5. The method according to claim 1, wherein In step (3), the electrochemical dezipping of the europium-terbium complex-loaded carbon nanotubes (Eu 3+ -Tb 3+ -uCNTs) are prepared as follows: (1) Prepare Eu(TTA)3phen complex and Tb(BBA)3phen complex respectively, mix the two complex solutions in a volume ratio of 1:1, and stir for 2h to form Eu 3+ -Tb 3+ Complex mixed solution; (2) Disperse uCNTs in ethanol and ultrasonically form a dispersed carbon nanotube suspension. 3+ -Tb 3+ The complex mixture solution was added to the suspension, stirred evenly, and diluted ammonia was added until the pH was 6-7, and the mixture was stirred to obtain a suspension; the suspension was washed by centrifugation with ethanol, and freeze-dried to obtain the final product Eu 3+ -Tb 3+ -uCNTs. The ratio is 0.6wt%.

6. The method according to claim 5, characterized in that In step (2), 60 mL of rare earth europium-terbium complex solution is added for every 10 mg of unzipped carbon nanotubes.

7. The method according to claim 1, characterized in that In step (4), the stirred mixture is cast into a preheated polytetrafluoroethylene mold coated with vacuum silicone grease, degassed in a vacuum drying oven at 120°C for 24 hours to remove the solvent, and then cured. The curing process is: 140°C / 2 hours, 160°C / 2 hours, 180°C / 2 hours, 190°C / 1 hour, 200°C / 1 hour, 210°C / 1 hour, 230°C / 2 hours, and 250°C / 2 hours.

8. The method according to claim 1, characterized in that In step (3), every 0.02-5g Eu 3+ -Tb 3+ -uCNTs are correspondingly added with 2-30 g of a blending system solution of phenolphthalein polyethersulfone resin and cyanate ester resin, and ultrasonically dispersed.

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