Use of a thermoset polymer insulating material containing dynamic covalent bonds in a polymeric dielectric material

Abstract

This invention discloses the application of a thermosetting polymer insulating material containing dynamic covalent bonds in polymer dielectric materials, belonging to the technical field of polymer dielectric materials. By using this thermosetting polymer insulating material containing dynamic covalent bonds as a polymer dielectric material, the internal charge dissipates during the dynamic network reconstruction triggered by high temperature, preventing charge accumulation that could induce electrical treeing damage. The thermosetting polymer insulating material containing dynamic covalent bonds used in this invention not only has a simple preparation method and requires no filler addition, but also exhibits significant charge dissipation at high temperatures.

Description

Technical Field

[0001] This invention belongs to the field of polymer dielectric materials technology, specifically relating to the application of a thermosetting polymer insulating material containing dynamic covalent bonds in polymer dielectric materials. Background Technology

[0002] With the rapid development of electronic devices towards miniaturization, high power density, and extreme environment applications, the risk of breakdown failure and signal interference caused by surface and internal electrostatic accumulation has increased significantly in high-voltage power equipment and even low-voltage electronic devices (such as aerospace systems and new energy battery packs). Traditional antistatic materials rely on conductive fillers, and the preparation process faces problems such as filler agglomeration, rapid conductivity decay after long-term aging, and uncontrolled ion migration due to insufficient thermal stability of the system. Furthermore, the network becomes static after thermosetting resin curing, making it impossible to repair electrical tree damage induced by charge accumulation.

[0003] Chinese invention patent CN101221893A discloses a method for promoting the dissipation of electrostatic charge on a semiconductor wafer. During the process of releasing a semiconductor wafer from a dual-electrode electrostatic chuck, firstly, the polarity of the potentials on the two electrodes of the dual-electrode electrostatic chuck is changed, i.e., a positive potential is changed to a negative potential and a negative potential is changed to a positive potential, and these are maintained for a set time to eliminate induced charges on the semiconductor wafer; then, a negative potential is applied to both electrodes of the dual-electrode electrostatic chuck and maintained for a set time to promote the dissipation of additional charges on the semiconductor wafer.

[0004] Chinese invention patent CN116426086A discloses a method for preparing an epoxy resin-grafted boron nitride composite material with a high surface charge dissipation rate. First, micron-sized boron nitride is exfoliated and hydroxylated with NaOH. Then, BN powder is dispersed and treated with dopamine hydrochloride to obtain grafted BN nanosheets. Finally, raw materials are added in a specific ratio, and the mixture is cured to obtain the composite material. This method improves the surface charge rate and dissipation characteristics of epoxy resin and composite resin at high frequencies by modifying boron nitride with dopamine, providing a basis for the design of the main insulation of high-frequency transformers.

[0005] Existing methods mainly involve passively dissipating charge by introducing external media: (1) adding conductive fillers (such as carbon black and carbon nanotubes) relies on the percolation network conductive path, but the fillers are prone to agglomeration and the insulation resistance decreases, making it difficult to withstand high voltage; (2) surface antistatic agent coatings (such as quaternary ammonium salts and polyethylene glycol derivatives) form ion channels through moisture absorption, but there are problems of humidity dependence, high-temperature decomposition, and easy migration and loss; (3) environmental control (such as humidification and ionizers) requires continuous energy consumption and cannot be applied to closed or extreme working conditions. These static strategies cannot solve the contradiction between the intrinsic insulation of materials and the dynamic dissipation of charge, especially in high-temperature and long-term scenarios, where they face fundamental limitations. Summary of the Invention

[0006] The purpose of this invention is to provide an application of a thermosetting polymer insulating material containing dynamic covalent bonds in polymer dielectric materials. When this material is used as a polymer dielectric material, during the process of dynamic network reconstruction triggered at high temperatures, the internal charge of the material can be effectively dissipated, thereby avoiding electrical treeing damage induced by charge accumulation.

[0007] To achieve the above objectives, the present invention provides the following technical solution: Application of a thermosetting polymer insulating material containing dynamic covalent bonds in polymer dielectric materials.

[0008] Preferably, the dynamic covalent bonds in the thermosetting polymer insulating material containing dynamic covalent bonds include dynamic disulfide bonds or dynamic acetal bonds.

[0009] Preferably, the thermosetting polymer material in the thermosetting polymer insulating material containing dynamic covalent bonds includes thermosetting polyurethane, thermosetting phenolic resin, thermosetting polyimide resin, or silicone rubber.

[0010] Preferably, the thermosetting polymer insulating material containing dynamic covalent bonds includes thermosetting polyurethane containing dynamic disulfide bonds, thermosetting phenolic resin containing dynamic acetal bonds, thermosetting polyimide resin containing dynamic disulfide bonds, or silicone rubber containing dynamic acetal bonds.

[0011] Preferably, the dynamic network reconstruction triggering temperature of the thermosetting polymer insulating material containing dynamic covalent bonds is 80~150℃.

[0012] The carrier mobility of the thermosetting polymer insulating material containing dynamic covalent bonds of the present invention is 10 at this temperature. −8 ~10 −4 m 2 ·V -1 ·s -1 Compared to corresponding thermosetting polymer insulating materials without dynamic covalent bonds, this represents an improvement of 1 to 6 orders of magnitude.

[0013] Preferably, the preparation steps of the thermosetting polymer insulating material containing dynamic covalent bonds include: mixing the thermosetting polymer insulating material with a monomer containing dynamic covalent bonds and curing it to obtain the thermosetting polymer insulating material containing dynamic covalent bonds.

[0014] The thermosetting polymer insulating material containing dynamic covalent bonds of the present invention does not require the addition of inorganic fillers during the preparation process.

[0015] Preferably, the polymer dielectric material includes insulating components for high-voltage electrical equipment.

[0016] More preferably, the insulating components of the high-voltage electrical equipment are selected from transformer insulating components, GIS insulators, cable terminals, or motor winding insulating varnish.

[0017] The migration mechanism of charge carriers in polymers is an energy-assisted local state transition process, dominated by hopping conduction: electrons jump between discrete energy states through intramolecular conjugated orbitals or intermolecular tunneling, while ions diffuse based on dynamic free volume generated by chain segment motion; this process is constrained by the deep trapping of trapped states (defects, impurities). In polymers containing dynamic covalent bonds, such as thermosetting resins, high temperature triggers bond exchange, initiating network topology reconstruction—eliminating deep trapped states and forming transient permeation channels, rapidly increasing charge carrier mobility and eliminating residual space charge. This invention utilizes this mechanism to propose a method for controllable charge dissipation in polymer dielectric materials triggered by dynamic network reconstruction (see schematic diagram of charge transfer in polymer dielectric materials triggered by dynamic network reconstruction). Figure 1 Compared to adding conductive fillers to eliminate space charge, thermosetting polymers containing dynamic covalent bonds are not only more environmentally friendly, but also do not require the addition of additional inorganic fillers.

[0018] The beneficial technical effects of the present invention are as follows: This invention employs a thermosetting polymer insulating material containing dynamic covalent bonds as the polymer dielectric material. When dynamic network reconstruction occurs at high temperatures, the carrier mobility of this material is significantly enhanced. This facilitates rapid transport and effective dissipation of space charge, avoiding electrical treeing damage induced by charge accumulation, thereby improving the reliability of the material's high-temperature insulation. Furthermore, this material requires no inorganic fillers, has a simple preparation process, and achieves excellent high-temperature charge dissipation through the structural response of dynamic covalent bonds, demonstrating significant technical advantages and application prospects. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram illustrating charge transfer in polymer dielectric materials triggered by dynamic network reconstruction. Detailed Implementation

[0021] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0022] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0023] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0024] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0025] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0026] Example 1 Polyurethane containing dynamic disulfide bonds was prepared using poly(1,4-butanediol adipate) diol (molecular weight 2000, purity ≥99%, 50.0 g), 4,4'-diphenylmethane diisocyanate (MDI, purity ≥99%, 15.8 g), and 3-mercaptopropionic acid (purity ≥99%, 4.2 g) as raw materials. The three materials were dissolved in N,N-dimethylformamide (DMF, purity ≥99.5%, 25.0 g), and dibutyltin dilaurate (DBTDL, purity ≥97%, 0.6 g) was used as a catalyst. The mixture was stirred at 300 r / min for 35 min, prepolymerized at 75 °C for 1.5 h, and cured at 100 °C for 2.5 h to obtain a polyurethane sample containing dynamic disulfide bonds.

[0027] The carrier mobility of polyurethane samples containing dynamic disulfide bonds was measured using the space charge-confined current method (SCLC). The sample thickness was 50 μm, the test temperature was 100 °C, and an application rate of 0–5 × 10⁻⁵ μm was applied. 5A gradient DC electric field of V / m (corresponding to a voltage range of 0~25V) was established, and the steady-state current density at different voltages was recorded. Within the space charge confinement region (15~25V), the Mott-Gurney equation was used for fitting calculations, where the dielectric constant ε of polyurethane was taken as 3.2, and the calculated carrier mobility was 7.2 × 10⁻⁶. -6 m 2 ·V -1 ·s -1 Compared to the pure polyurethane sample under the same conditions, the carrier mobility (2.6 × 10⁻⁶) was significantly higher. -7 m 2 ·V -1 ·s -1 It increased by 30 times.

[0028] Example 2 A resin containing dynamic acetal bonds was prepared using phenolic resin (linear phenolic resin, purity ≥98%, 50.0 g) and 2,2-dimethylolpropionaldehyde (purity ≥99%, 10.8 g) as raw materials. Using p-toluenesulfonic acid (purity ≥98.5%, 0.8 g) as catalyst and ethylene glycol dimethyl ether (purity ≥99%, 22.0 g) as solvent, the mixture was stirred at 320 r / min for 35 min, prepolymerized at 85℃ for 2 h, cured at 125℃ for 3 h, and post-cured at 155℃ for 1 h to obtain a phenolic resin sample containing dynamic acetal bonds.

[0029] The carrier mobility of the prepared phenolic resin containing dynamic acetal bonds was tested using the space charge-limited current method. The sample thickness was 50 μm, the test temperature was 120℃, and the applied current range was 0~5×10⁻⁶. 5 A gradient DC electric field of V / m (corresponding to a voltage range of 0~25 V) was used to record steady-state current data under different electric field intensities. Within the space charge confinement region (15~25 V), the carrier mobility was calculated to be 5.7 × 10⁻⁶ based on the equation fitting, where the dielectric constant ε of the phenolic resin was taken as 3.5. -5 m 2 ·V -1 ·s -1 Compared to the carrier mobility of the pure phenolic resin sample under the same conditions (6.9 × 10⁻⁶), the carrier mobility of the pure phenolic resin sample was significantly lower. -11 m 2 ·V -1 ·s -1 This represents an increase of nearly six orders of magnitude.

[0030] Example 3 Using pyromellitic dianhydride (PMDA, purity ≥99%, 21.8 g) and 4,4'-diaminodiphenyl ether (ODA, purity ≥99%, 20.0 g) as polyimide matrix raw materials, 4,4'-diaminodiphenyl disulfide (DDS, purity ≥98%, 5.2 g) containing dynamic disulfide bonds was introduced as a dynamic bond modifying monomer, and N,N-dimethylacetamide (DMAc, purity ≥99.5%, 150.0 g) was used as solvent. Under nitrogen protection, the mixture was stirred at 280 r / min for 4 h at room temperature (25 °C) to obtain a polyamic acid precursor. Subsequently, the precursor was gradually imidized by holding at 120 °C for 1 h, 200 °C for 1 h, and 300 °C for 1 h to obtain a polyimide resin sample containing dynamic disulfide bonds.

[0031] The carrier mobility of the polyimide resin sample containing dynamic disulfide bonds was tested using the space charge-confined current method. The sample thickness was 50 μm, the test temperature was 110 °C, and the applied current was 0–5 × 10⁻⁶. 5 A gradient DC electric field of V / m (corresponding to a voltage range of 0~25V) was applied, and the current-voltage characteristic curve was recorded. Within the space charge confinement region (15~25V), the equation was fitted, and the dielectric constant ε of the polyimide resin was taken as 3.0, resulting in a calculated carrier mobility of 8.9 × 10⁻⁶. -8 m 2 ·V -1 ·s -1 Compared to the carrier mobility of the pure polyimide resin sample under the same conditions (1.0 × 10⁻⁶), -10 m 2 ·V -1 ·s -1 It increased by 890 times.

[0032] Example 4 Using hydroxyl-terminated methyl vinyl silicone rubber (molecular weight 80,000, vinyl content 0.15%, purity ≥99%, 50.0 g) as the matrix, 3-(trimethoxysilyl)propionaldehyde (purity ≥98%, 12.5 g) as the monomer for introducing dynamic acetal bonds, dibutyltin dimethoxylate (purity ≥97%, 0.6 g) as the condensation catalyst, and xylene (purity ≥99.5%, 28.0 g) as the solvent, the mixture was stirred at 280 r / min for 40 min until the system was homogeneous. After prepolymerization at 90℃ for 1.5 h to achieve the acetalization reaction of silanol and silanaldehyde groups, the mixture was cured at 120℃ for 2.5 h and then cured at 150℃ for 1 h to obtain a silicone rubber sample containing dynamic acetal bonds.

[0033] The carrier mobility of silicone rubber samples containing dynamic acetal bonds was tested using the space charge-limited current method. The sample thickness was 50 μm, the test temperature was 150 °C, and the applied current range was 0–6 × 10⁻⁶ μm. 5A gradient DC electric field of V / m (corresponding to a voltage range of 0~30V) was used to collect current-time response curves under different electric field intensities. Within the space charge confinement region (20~30V), the equation was fitted, with the dielectric constant ε of silicone rubber taken as 2.8, and the calculated carrier mobility was 3.6×10⁻⁶. -4 m 2 ·V -1 ·s -1 Compared to the pure silicone rubber sample under the same conditions, the carrier mobility (1.0 × 10⁻⁶) was significantly lower. -10 m 2 ·V -1 ·s -1 This represents an increase of 6 orders of magnitude.

[0034] As can be seen from Examples 1 to 4, thermosetting materials polyurethane, phenolic resin, polyimide resin, and silicone rubber are successively modified and optimized by dynamic covalent bonds (dynamic disulfide bonds or dynamic acetal bonds) to become thermosetting polymer insulating materials containing dynamic covalent bonds (thermosetting polyurethane containing dynamic disulfide bonds, thermosetting phenolic resin containing dynamic acetal bonds, thermosetting polyimide resin containing dynamic disulfide bonds, or silicone rubber containing dynamic acetal bonds). Through performance testing, the carrier mobility of the thermosetting polymer insulating material containing dynamic covalent bonds is significantly improved compared with the pure thermosetting material. This indicates that dynamic covalent bonds undergo dynamic network reconstruction at high temperatures, reducing the potential barrier of chain segment movement, accelerating the rapid transport and effective dissipation of space charge in the material, thereby effectively avoiding electrical tree damage induced by charge accumulation.

[0035] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. Application of a thermosetting polymer insulating material containing dynamic covalent bonds in polymer dielectric materials.

2. Use according to claim 1, characterized in that, The dynamic covalent bonds in the thermosetting polymer insulating material containing dynamic covalent bonds include dynamic disulfide bonds or dynamic acetal bonds.

3. Use according to claim 1, characterized in that, The thermosetting polymer insulating material containing dynamic covalent bonds includes one or more of thermosetting polyurethane, thermosetting phenolic resin, thermosetting polyimide resin, or silicone rubber.

4. Use according to claim 1, characterized in that, The thermosetting polymer insulating material containing dynamic covalent bonds includes one or more of the following: thermosetting polyurethane containing dynamic disulfide bonds, thermosetting phenolic resin containing dynamic acetal bonds, thermosetting polyimide resin containing dynamic disulfide bonds, or silicone rubber containing dynamic acetal bonds.

5. The use according to claim 1, characterized in that, The dynamic network reconstruction triggering temperature of the thermosetting polymer insulating material containing dynamic covalent bonds is 80~150℃.

6. Use according to claim 1, characterized in that, The preparation steps of the thermosetting polymer insulating material containing dynamic covalent bonds include: mixing the thermosetting polymer insulating material with a monomer containing dynamic covalent bonds and curing it to obtain the thermosetting polymer insulating material containing dynamic covalent bonds.

7. Use according to claim 1, characterized in that, The polymer dielectric material includes insulating components for high-voltage electrical equipment.

8. Use according to claim 7, characterized in that, The insulating components of the high-voltage electrical equipment are selected from transformer insulating components, GIS insulators, cable terminals, or motor winding insulating varnish.

Images