Deep trap epoxy resin molecule design method, preparation method and verification method with significantly improved dielectric strength

Abstract

The invention provides a design method, a preparation method and a verification method of a deep trap epoxy resin molecule with significantly improved dielectric strength. The method comprises the following steps: establishing different fluorinated epoxy resin monomer molecule models in Material Studio; performing energy optimization on the established fluorinated epoxy resin monomer molecular model by using a Forcite module, and then performing structure optimization; the steps are repeated until the same output result is obtained through two times of continuous optimization; using a Dmol3 module to calculate the molecular state density and Mulliken charge distribution of the fluorinated epoxy resin monomer molecular model; by comparing the molecular state density and Mulliken charge distribution of different fluorinated epoxy resin monomer molecular models, the fluorinated epoxy resin monomer molecular model with the most significant Mulliken charge change and the maximum positive charge value amplification is used as the deep trap epoxy resin molecule.

Description

Technical Field

[0001] The present invention belongs to the field of high voltage and insulation technology, and specifically relates to a design method, a preparation method and a verification method of a deep-trap epoxy resin molecule with significantly improved dielectric strength. Background Art

[0002] Epoxy resin, as an important polymer material, is widely used as an insulating medium in high-voltage electrical equipment due to its excellent electrical, mechanical, and thermal properties. The current development trends of power equipment towards "high voltage," "miniaturization," and "high power" have placed new demands on the performance of epoxy resin. Dielectric strength, as a fundamental property of epoxy resin, is not only the foundation for the development of advanced epoxy-based power equipment, but also the key to ensuring the long-term safe and stable operation of epoxy-based power equipment in ultra-high / ultra-high voltage transmission and transformation systems. The development trends of "high voltage," "miniaturization," and "high power" require epoxy resin to have stronger dielectric strength, so that it can withstand higher voltages with thinner thicknesses. Therefore, how to develop epoxy resin with high dielectric strength has become a research priority that needs to be urgently addressed.

[0003] The macroscopic dielectric strength of epoxy resins is controlled by the charge transport behavior within them. Existing methods for improving the dielectric strength of epoxy resins, in principle, mostly increase the dielectric strength of cured epoxy resins by increasing the dielectric band gap or trap energy levels, thereby affecting the charge transport and spatial charge distribution characteristics within the dielectric. Given the significant gap between the dielectric strength of epoxy resins used in my country's high-voltage power transmission and transformation sector and the insulation design requirements of third-generation electrical equipment, there is an urgent need to improve their dielectric strength. However, the mainstream approach to improving the dielectric strength of epoxy resins, which relies on nano-doping, often focuses on treating symptoms rather than the root cause. While adding a certain mass fraction of nano- or micro-sized fillers to the epoxy matrix can effectively improve the electrical, thermal, and mechanical properties of epoxy composites, this approach does not fundamentally address the insufficient dielectric strength of the epoxy matrix. Furthermore, the trial-and-error approach to polymer development suffers from long development cycles, high costs, and unpredictable results. Efficiently and accurately developing high-dielectric-strength epoxy resins with deep traps remains a challenge. Summary of the Invention

[0004] The purpose of the present invention is to provide a deep-trap epoxy resin molecular design method, preparation method and verification method with significantly improved dielectric strength to overcome the defects of the existing technology. Based on molecular dynamics calculations, the present invention designs a high dielectric strength bisphenol A epoxy resin with deep traps through simulation. Then, using hexafluorobisphenol A (BPAF) and epichlorohydrin as raw materials, a two-step method is adopted to prepare a fluorinated epoxy resin containing CF3 groups. Finally, its effectiveness is verified by experiments.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for designing deep-trap epoxy resin molecules with significantly improved dielectric strength comprises the following steps:

[0007] 1) Create different molecular models of fluorinated epoxy resin monomers in Material Studio;

[0008] 2) Using the Forcite module, the established fluorinated epoxy resin monomer molecular model was energy optimized and then structurally optimized;

[0009] 3) Repeat step 2) until the same output result is obtained after two consecutive optimizations;

[0010] 4) Using the Dmol3 module, calculate the molecular density of states and Mulliken charge distribution of the fluorinated epoxy resin monomer molecular model obtained in step 3);

[0011] 5) By comparing the molecular state density and Mulliken charge distribution of different fluorinated epoxy resin monomer molecular models, the fluorinated epoxy resin monomer molecular model with the most significant Mulliken charge change and the largest increase in the maximum positive charge is selected as the deep trap epoxy resin molecule.

[0012] Furthermore, the molecular models of different fluorinated epoxy resin monomers are established in Material Studio, specifically:

[0013] The two CH3 groups in the bisphenol A epoxy molecule were replaced by two CH2F, two CHF2, or two CF3 groups, respectively, to form three fluorinated epoxy resin monomer molecules, recorded as FEP-1, FEP-2, and FEP-3. Then, three fluorinated epoxy resin monomer molecular models were established in Material Studio.

[0014] Furthermore, in step 2), the Forcite module was used, the force field was selected as Compass II, and the calculation accuracy was fine to perform energy optimization on the established fluorinated epoxy resin monomer molecular model, followed by structural optimization;

[0015] In step 4), use the Dmol3 module, use the B3LYP function, set the calculation accuracy to fine, check the density of states option, then check the Population analysis option in the properties option, and set Mulliken Charge to calculate the molecular state density and Mulliken charge distribution of the fluorinated epoxy resin monomer molecular model obtained in step 3).

[0016] A method for preparing the deep trap epoxy resin molecule according to claim 1, comprising the following steps:

[0017] Step 1: Using hexafluorobisphenol A and epichlorohydrin as synthetic raw materials, mixing and stirring to dissolve;

[0018] Step 2: adding a catalyst, benzyltrimethylammonium bromide, to the product obtained in step 1 to carry out an etherification reaction;

[0019] Step 3: Add NaOH solution dropwise to the product obtained in step 2, stir and degas, and perform cyclization reaction;

[0020] Step 4: Stirring and degassing the product obtained in step 3, heat-insulating and dehydrating, and then stirring to evaporate excess epichlorohydrin;

[0021] Step 5: Add methyl isobutyl ketone, deionized water and NaOH solution to the product obtained in step 4, stir and perform a refined reaction;

[0022] Step 6: Add methyl isobutyl ketone and deionized water to the product obtained in step 5 again, and let it stand overnight;

[0023] Step 7: Add deionized water to the product obtained in step 6 for washing, repeat several times, and finally stir to degas, and extract by distillation to obtain deep trap epoxy resin molecules.

[0024] Furthermore, in step 1, the molar ratio of hexafluorobisphenol A to epichlorohydrin is 1:14, and the temperature for stirring and dissolving is 85°C;

[0025] In step 2, the etherification reaction is carried out by stirring at 90° C. for 6 hours, and the mass ratio of benzyltrimethylammonium bromide to epichlorohydrin is 0.51:577.67.

[0026] Furthermore, in step 3, a 50 wt% NaOH solution was added dropwise, stirred and degassed at 55° C., wherein the mass ratio of the NaOH solution to epichlorohydrin was 71.43:577.67;

[0027] In step 4, the mixture is stirred and degassed at 55° C., heat-insulated and dehydrated, and then stirred at 120° C. to evaporate excess epichlorohydrin.

[0028] Furthermore, in step 5, methyl isobutyl ketone, deionized water, and a 50 wt% NaOH solution were added and stirred at 85° C. to perform a refined reaction; wherein the ratio of methyl isobutyl ketone, deionized water, NaOH solution, and epichlorohydrin was 180 mL: 34 mL: 7.14 g: 577.67 g;

[0029] In step 6, methyl isobutyl ketone and deionized water are added to the product obtained in step 5 again, and the mixture is allowed to stand at 70° C. overnight. The ratio of methyl isobutyl ketone, deionized water and epichlorohydrin is 100 mL:200 mL:577.67 g.

[0030] Furthermore, in step seven, 95° C. deionized water was added for washing, and the process was repeated 8 times. Finally, the mixture was stirred and degassed at 140° C., and distilled and extracted to obtain deep trap epoxy resin molecules.

[0031] Wherein, the volume ratio of deionized water in step 5, step 6 and step 7 is 34:200:150.

[0032] A deep trap epoxy resin molecule is prepared by the above preparation method, and the epoxy value of the deep trap epoxy resin molecule is 0.320eq / 100g.

[0033] A method for verifying deep trap epoxy resin molecules comprises the following steps:

[0034] Step A: Deep trap epoxy resin FEP was used as the target group, and bisphenol A epoxy resin EP1 with a degree of polymerization of 1 was selected as the control group;

[0035] Step B: Characterize the molecular chemical structures of EP1 and FEP using NMR spectroscopy;

[0036] Step C: Using GPC to measure the molecular weight and distribution of EP1 and FEP;

[0037] Step D: The polarization current density of FEP was measured by TSDC experiment and compared with that of the epoxy resin EP1 cured product with bisphenol A structure;

[0038] Step E: Use a ball electrode to measure the dielectric strength of EP1 and FEP in an insulating oil environment.

[0039] Compared with the prior art, the present invention has the following beneficial technical effects:

[0040] The present invention replaces the CH3 group in the bisphenol A epoxy molecule with a fluorine-containing structure, creating fluorinated epoxy resin molecules with different structures. Through simulation, the fluorinated epoxy resin molecular structure with the optimal trap parameters is screened and synthesized using a two-step method. Finally, the performance is verified through experiments. Based on simulation calculations and experimental verification, the present invention screens out the optimal fluorinated bisphenol A epoxy resin structure based on Mulliken charge distribution, provides a feasible synthesis technology route for deep-trap epoxy resins, and verifies the scientific nature of molecular design to control molecular structure and construct deep traps with larger energy levels to enhance the dielectric strength of epoxy resins, which has very important practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Molecular diagrams of designed fluorinated epoxy resin monomers with different molecular structures, among which (a) is BPAF, (b) is FEP-1, (c) is FEP-2, and (d) is FEP-3;

[0042] Figure 2 The Mulliken charge distribution diagrams of three fluorinated epoxy resin monomer molecules, where (a) is the Mulliken charge distribution of the molecule and (b) is the Mulliken charge maximum of the molecule;

[0043] Figure 3 is the NMR spectrum of EP1 and FEP fluorinated epoxy resin monomer molecules, where (a) is 19 F spectrum, (b) is 1 H spectrum;

[0044] Figure 4 GPC curves (molecular weight distribution) of EP1 and FEP fluorinated epoxy resin monomer molecules, where (a) is the GPC curve and (b) is the deformation of the GPC curve;

[0045] Figure 5 This is the polarization current density diagram of EP1 and FEP fluorinated epoxy resin cured products;

[0046] Figure 6 This is the Weibull distribution diagram of EP1 and FEP fluorinated epoxy resin cured product. DETAILED DESCRIPTION

[0047] The embodiments of the present invention will be described in detail below with reference to the examples. The examples are preferred embodiments of the present invention and are not intended to limit the scope of the present invention. In the following examples, the methods and experimental equipment used are conventional methods and instruments unless otherwise specified.

[0048] A method for designing, preparing, and verifying deep-trap epoxy resin molecules with significantly improved dielectric strength was developed. Fluorinated epoxy resin molecules with different structures were constructed by replacing the CH3 group in the bisphenol A epoxy molecule with a fluorinated structure. The molecular structure of the fluorinated epoxy resin with the best trapping parameters was selected through simulation and synthesized using a two-step method. Finally, performance was verified experimentally. The method specifically includes the following steps:

[0049] The molecular structure design process of S1 deep trap epoxy resin is as follows:

[0050] 1) Create three fluorinated epoxy resin monomer molecular models in Material Studio. Specifically, replace the two CH3 groups in the bisphenol A epoxy molecule with two CH2F, two CHF2, or two CF3 groups, respectively, to form three fluorinated epoxy resin monomer molecules, labeled FEP-1, FEP-2, and FEP-3. Then, create three fluorinated epoxy resin monomer molecular models in Material Studio.

[0051] 2) Using the Forcite module, with Compass II as the force field and fine as the calculation accuracy, the energy optimization of the established fluorinated epoxy resin monomer molecular model was performed, followed by structural optimization;

[0052] 3) Repeat the steps in 2) until the same output result is obtained after two consecutive optimizations;

[0053] 4) Using the Dmol3 module, calculate the molecular density of states and Mulliken charge distribution of the fluorinated epoxy resin monomer molecular model obtained in step 3);

[0054] 5) By comparing the molecular state density and Mulliken charge distribution of different fluorinated epoxy resin monomer molecular models, it was found that the overall trend of the molecular state density did not change significantly. It was considered that the molecule with the most significant Mulliken charge change and the largest increase in the maximum positive charge may have the largest trap energy level. The fluorinated epoxy resin monomer molecular model with the most significant Mulliken charge change and the largest increase in the maximum positive charge (the fluorinated epoxy resin monomer molecular model corresponding to FEP-3 in the present invention) was selected as the deep trap epoxy resin molecule;

[0055] The synthesis method of S2 deep trap epoxy resin is as follows:

[0056] 1) Hexafluorobisphenol A (BPAF) and epichlorohydrin are mixed as synthetic raw materials in a molar ratio of 1:14 and stirred and dissolved at 85°C;

[0057] 2) adding a catalyst, benzyltrimethylammonium bromide, and stirring at 90° C. for 6 h to carry out an etherification reaction;

[0058] 3) adding 50 wt% NaOH solution dropwise, stirring and degassing at 55° C. to carry out cyclization reaction;

[0059] 4) stirring and degassing at 55°C, heat-insulating and dehydrating, and then stirring and evaporating excess epichlorohydrin at 120°C;

[0060] 5) adding methyl isobutyl ketone, deionized water and 50 wt% NaOH solution, stirring at 85° C. to carry out a refined reaction;

[0061] 6) Add methyl isobutyl ketone and deionized water again and let it stand at 70°C overnight;

[0062] 7) Add 95°C deionized water for washing, repeat 8 times, and finally stir and degas at 140°C, and extract by distillation to obtain deep trap epoxy resin molecules;

[0063] The S3 test verification process is as follows:

[0064] 1) The deep-trap epoxy resin molecule FEP (CF3 group replacement, epoxy value 0.320 eq / 100 g, i.e., the epoxy resin corresponding to FEP-3) prepared in S2 was used as the target group. Meanwhile, bisphenol A epoxy resin EP1 (epoxy value 0.532 eq / 100 g) with a degree of polymerization of 1 was selected as the control group.

[0065] 2) characterize the molecular chemical structures of EP1 and FEP using NMR spectroscopy;

[0066] 3) Use GPC to measure the molecular weight and distribution of EP1 and FEP;

[0067] 4) The polarization current density of FEP was measured by TSDC experiment and compared with that of bisphenol A epoxy resin EP1 cured product;

[0068] 5) Using a ball electrode, measure the dielectric strength of two epoxy resins in an insulating oil environment;

[0069] Based on simulation calculations and experimental verification, the present invention screened out the optimal fluorinated bisphenol A epoxy resin structure based on Mulliken charge distribution, provided a feasible synthesis technology route for deep-trap epoxy resins, and guided the design of bisphenol A epoxy resins for high-voltage electrical equipment.

[0070] The present invention replaces the CH3 group in the bisphenol A epoxy molecule with a fluorine-containing structure, creating fluorinated epoxy resin molecules with different structures. Through simulation, the fluorinated epoxy resin molecular structure with the optimal trap parameters is screened and synthesized using a two-step method. Finally, the performance is verified through experiments. Based on simulation calculations and experimental verification, the present invention screens out the optimal fluorinated bisphenol A epoxy resin structure based on Mulliken charge distribution, provides a feasible synthesis technology route for deep-trap epoxy resins, and verifies the scientific nature of molecular design to control molecular structure and construct deep traps with larger energy levels to enhance the dielectric strength of epoxy resins, which has very important practical value.

[0071] In summary, the present invention verifies the scientific nature of regulating molecular structure through molecular design and constructing deep traps with larger energy levels to enhance the dielectric strength of epoxy resin, and has strong practical value.

[0072] Example

[0073] S1. The molecular structure design process of deep trap epoxy resin is as follows:

[0074] 1) Replace the two CH3 groups in the molecule with two CH2F, CHF2, and CF3 groups, respectively, to form three fluorinated epoxy resin molecules, labeled FEP-1, FEP-2, and FEP-3. Subsequently, create molecular models of the three fluorinated epoxy resin monomers in Material Studio.

[0075] 2) Using the Forcite module, with Compass II as the force field and fine as the calculation accuracy, the established molecular model was energy optimized and then structurally optimized;

[0076] 3) Repeat the steps in 2) until the same output result is obtained for two consecutive geometry optimizations;

[0077] 4) Using the Dmol3 module, use the B3LYP function, set the calculation precision to fine, select the density of states option, then select Population analysis in the properties option and set the Mulliken charge to calculate the molecular density of states and Mulliken charge distribution of the fluorinated epoxy resin monomer molecular model obtained in step 3);

[0078] 5) By comparing the molecular state density and Mulliken charge distribution of different fluorinated epoxy resin monomer molecular models, it was found that the overall trend of the molecular state density did not change significantly. It was considered that the molecule with the most significant Mulliken charge change and the largest increase in the maximum positive charge may have the largest trap energy level. The fluorinated epoxy resin monomer molecular model with the most significant Mulliken charge change and the largest increase in the maximum positive charge (the fluorinated epoxy resin monomer molecular model corresponding to FEP-3 in the present invention) was selected as the deep trap epoxy resin molecule;

[0079] S2. The synthesis method of deep trap epoxy resin is as follows:

[0080] 1) Weigh 150 g of hexafluorobisphenol A (BPAF) and 557.67 g of epichlorohydrin as synthetic raw materials, and stir and dissolve them at 85°C;

[0081] 2) Add 0.51 g of benzyltrimethylammonium bromide as a catalyst and stir at 90° C. for 6 h to carry out etherification reaction;

[0082] 3) adding 71.43 g of 50 wt% NaOH solution dropwise, stirring and degassing at 55° C. to carry out a cyclization reaction;

[0083] 4) stirring and degassing at 55°C, heat-insulating and dehydrating, and then stirring and evaporating excess epichlorohydrin at 120°C;

[0084] 5) Add 180 ml of methyl isobutyl ketone, 34 ml of deionized water, and 7.14 g of 50 wt% NaOH solution, and stir at 85° C. to carry out a refined reaction;

[0085] 6) Add 100 ml of methyl isobutyl ketone and 200 ml of deionized water again, and let it stand at 70°C overnight;

[0086] 7) Add 150 ml of 95° C. deionized water for washing, repeat 8 times, and finally stir and degas at 140° C., and extract by distillation to obtain deep trap epoxy resin molecules.

[0087] S3. The test verification process is as follows:

[0088] 1) The deep-trap epoxy resin molecule FEP (CF3 group replacement, epoxy value 0.320 eq / 100 g) prepared in S2 was selected as the target group. At the same time, bisphenol A epoxy resin EP1 with a degree of polymerization of 1 (epoxy value 0.532 eq / 100 g) was selected as the control group.

[0089] 2) characterize the molecular chemical structures of EP1 and FEP using NMR spectroscopy;

[0090] 3) Use GPC to measure the molecular weight and distribution of EP1 and FEP;

[0091] 4) The polarization current density of FEP was measured by TSDC experiments to extract its trapping parameters and compared with that of bisphenol A epoxy resin EP1 cured product.

[0092] 5) The breakdown test uses a spherical electrode with an electrode diameter of 50 mm. The test is carried out in 55# insulating oil. The power supply is a DC source with a voltage ramp rate of 1 kV / s. At least three samples are measured for each epoxy, and a total of 19 breakdown tests are performed. The breakdown data are characterized by Weibull.

[0093] Simulation calculations found that the Mulliken charge of FEP molecules changed most significantly, with the largest increase in the maximum positive charge, and the greatest possibility of having larger trap energy levels, making it a modified bisphenol A epoxy resin with high dielectric strength. Test results show that compared with bisphenol A epoxy resin EP1, the dielectric strength of FEP cured product under Weibull distribution increased from 366.39 kV·mm -1 Increased to 483.62kV·mm -1 , its breakdown strength increased by 31.99%, achieving a significant improvement in dielectric strength.

[0094] Attachment Figure 1Molecular diagrams of designed fluorinated epoxy resin monomers with different molecular structures;

[0095] Attachment Figure 2 The Mulliken charge distribution diagrams of three fluorinated epoxy resin monomer molecules show that the Mulliken charge change of the epoxy molecule FEP-3 is the most significant, with the largest increase in the maximum positive charge and the largest trap energy level.

[0096] Attachment Figure 3 The NMR spectra of EP1 and FEP fluorinated epoxy resin monomer molecules show that the introduction of the highly electronegative fluorine element causes some chemical peaks in FEP to disappear or shift. Furthermore, a chain extension side reaction occurs during the synthesis process, generating long-chain molecules.

[0097] Attachment Figure 4 The GPC curves (molecular weight distribution) of EP1 and FEP fluorinated epoxy resin monomer molecules show that although impurity molecules with a degree of polymerization of 1 were introduced during the synthesis process, the difference between the FEP molecular composition and the expected value can be ignored from the perspective of improved electrical performance. It is believed that the molecular structure of FEP approximately meets the molecular design expectations.

[0098] Attachment Figure 5 Polarization current density diagrams of two epoxy material cured products show that the relaxation activation energy increases from 2.10eV to 3.90eV, verifying that FEP cured products have deeper trap energy levels.

[0099] Attachment Figure 6 The Weibull distribution diagram of the two epoxy resins shows that the breakdown field strength of FEP is 31.99% higher than that of EP1.

[0100] Figure 2 Indicates that access to CF n The Mulliken charge of some molecules after the group changed significantly, among which the Mulliken charge of FEP-3 molecule changed most significantly, with the largest increase in the maximum positive charge, which may have the largest trap energy level. Figure 3 and Figure 4 It can be found that although an impurity molecule with a degree of polymerization of 1 is introduced into FEP, this molecule is similar to the target molecular structure and contains more CF3 groups, which also helps to improve the trap energy level of the epoxy resin. Therefore, from the perspective of improving electrical performance, the difference between the molecular composition of FEP and the expected one can be ignored, and it is believed that the molecular structure of FEP approximately meets the molecular design expectations. Figure 5 It shows that from the fitting results, it can be seen that the relaxation activation energy of FEP cured material increases from 2.10eV to 3.90eV, which further verifies that the trap energy level of FEP cured material is deep. Figure 6It shows that compared with EP1 cured product, the dielectric strength of FEP cured product under Weibull distribution is 366.39kV·mm -1 Increased to 483.62kV·mm -1 , the improvement reached 31.99%, verifying the feasibility and effectiveness of constructing an epoxy resin molecular structure with a larger trap energy level in improving dielectric strength. At the same time, based on simulation calculations and experimental verification, the present invention screened out the optimal fluorinated bisphenol A epoxy resin structure based on Mulliken charge distribution, provided a practical and feasible synthesis technology route for deep trap epoxy resins, and verified the scientific nature of improving the dielectric strength of epoxy resins by regulating molecular structure through molecular design and constructing deep traps with larger energy levels. Therefore, the present invention's method for designing and constructing deep trap epoxy resin molecules with significantly improved dielectric strength has very important practical value and can provide reliable insulating media and packaging materials for high-voltage electrical equipment.

[0101] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for designing deep-trap epoxy resin molecules with significantly improved dielectric strength, characterized in that: The following steps are involved: 1) Create different molecular models of fluorinated epoxy resin monomers in Material Studio; 2) Using the Forcite module, the established fluorinated epoxy resin monomer molecular model was energy optimized and then structurally optimized; 3) Repeat step 2) until the same output result is obtained after two consecutive optimizations; 4) Using the Dmol3 module, calculate the molecular density of states and Mulliken charge distribution of the fluorinated epoxy resin monomer molecular model obtained in step 3); 5) By comparing the molecular state density and Mulliken charge distribution of different fluorinated epoxy resin monomer molecular models, the fluorinated epoxy resin monomer molecular model with the most significant Mulliken charge change and the largest increase in the maximum positive charge is selected as the deep trap epoxy resin molecule.

2. The method for designing deep-trap epoxy resin molecules with significantly improved dielectric strength according to claim 1, characterized in that: The different fluorinated epoxy resin monomer molecular models are established in Material Studio, specifically: The two CH3 groups in the bisphenol A epoxy molecule were replaced by two CH2F, two CHF2, or two CF3 groups, respectively, to form three fluorinated epoxy resin monomer molecules, recorded as FEP-1, FEP-2, and FEP-3. Then, three fluorinated epoxy resin monomer molecular models were established in Material Studio.

3. The method for designing deep-trap epoxy resin molecules with significantly improved dielectric strength according to claim 1, wherein: In step 2), the Forcite module was used, the force field was selected as Compass II, and the calculation accuracy was fine to perform energy optimization on the established fluorinated epoxy resin monomer molecular model, followed by structural optimization; In step 4), use the Dmol3 module, use the B3LYP function, set the calculation accuracy to fine, check the density of states option, then check the Population analysis option in the properties option, and set Mulliken Charge to calculate the molecular state density and Mulliken charge distribution of the fluorinated epoxy resin monomer molecular model obtained in step 3).

4. A method for preparing the deep trap epoxy resin molecule according to claim 1, characterized in that: The following steps are involved: Step 1: Using hexafluorobisphenol A and epichlorohydrin as synthetic raw materials, mixing and stirring to dissolve; Step 2: adding a catalyst, benzyltrimethylammonium bromide, to the product obtained in step 1 to carry out an etherification reaction; Step 3: Add NaOH solution dropwise to the product obtained in step 2, stir and degas, and perform cyclization reaction; Step 4: Stirring and degassing the product obtained in step 3, heat-insulating and dehydrating, and then stirring to evaporate excess epichlorohydrin; Step 5: Add methyl isobutyl ketone, deionized water and NaOH solution to the product obtained in step 4, stir and perform a refined reaction; Step 6: Add methyl isobutyl ketone and deionized water to the product obtained in step 5 again, and let it stand overnight; Step 7: Add deionized water to the product obtained in step 6 for washing, repeat several times, and finally stir to degas, and extract by distillation to obtain deep trap epoxy resin molecules.

5. The method for preparing deep trap epoxy resin molecules according to claim 4, characterized in that: In step 1, the molar ratio of hexafluorobisphenol A to epichlorohydrin is 1:14, and the temperature for stirring and dissolving is 85°C; In step 2, the etherification reaction is carried out by stirring at 90° C. for 6 hours, and the mass ratio of benzyltrimethylammonium bromide to epichlorohydrin is 0.51:577.

67.

6. The method for preparing a deep trap epoxy resin molecule according to claim 4, characterized in that: In step 3, a 50 wt% NaOH solution was added dropwise, stirred and degassed at 55° C., wherein the mass ratio of the NaOH solution to epichlorohydrin was 71.43:577.67; In step 4, the mixture is stirred and degassed at 55° C., heat-insulated and dehydrated, and then stirred at 120° C. to evaporate excess epichlorohydrin.

7. The method for preparing deep trap epoxy resin molecules according to claim 4, characterized in that: In step 5, methyl isobutyl ketone, deionized water, and a 50 wt% NaOH solution were added and stirred at 85° C. to perform a refined reaction; wherein the ratio of methyl isobutyl ketone, deionized water, NaOH solution, and epichlorohydrin was 180 mL:34 mL:7.14 g:577.67 g; In step 6, methyl isobutyl ketone and deionized water are added to the product obtained in step 5 again, and the mixture is allowed to stand at 70° C. overnight. The ratio of methyl isobutyl ketone, deionized water and epichlorohydrin is 100 mL:200 mL:577.67 g.

8. The method for preparing deep trap epoxy resin molecules according to claim 4, characterized in that: In step 7, 95°C deionized water was added for washing, and the process was repeated 8 times. Finally, the mixture was stirred and degassed at 140°C, and distilled to obtain deep trap epoxy resin molecules. Wherein, the volume ratio of deionized water in step 5, step 6 and step 7 is 34:200:

150.

9. A deep trap epoxy resin molecule, characterized in that The deep trap epoxy resin is prepared by the preparation method according to claim 4, and the epoxy value of the deep trap epoxy resin molecule is 0.320eq / 100g.

10. The method for verifying deep trap epoxy resin molecules according to claim 9, characterized in that: The following steps are involved: Step A: Deep trap epoxy resin FEP was used as the target group, and bisphenol A epoxy resin EP1 with a degree of polymerization of 1 was selected as the control group; Step B: Characterize the molecular chemical structures of EP1 and FEP using NMR spectroscopy; Step C: Using GPC to measure the molecular weight and distribution of EP1 and FEP; Step D: The polarization current density of FEP was measured by TSDC experiment and compared with that of the epoxy resin EP1 cured product with bisphenol A structure; Step E: Use a ball electrode to measure the dielectric strength of EP1 and FEP in an insulating oil environment.

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