Insulating material for insulating soft sling for extra-high voltage working and preparation method and application of insulating material

Abstract

The invention belongs to the technical field of insulating materials, and particularly discloses an insulating material for an insulating soft sling for extra-high voltage working and a preparation method and application of the insulating material. The insulating material is prepared by mixing ZIF-8 particles and polytetrafluoroethylene powder according to a specific mass ratio and utilizing a dry process. And soaking and coating by using a polydimethylsiloxane (PDMS) solution to obtain a double-layer composite insulating material, and cutting and weaving to obtain the insulating soft sling. The high porosity and excellent gas adsorption performance of ZIF-8 and the insulating performance of PTFE and PDMS are combined, and the comprehensive performance of the insulating material is improved. The introduction of the ZIF-8 particles enhances the mechanical strength and the gas barrier property of the material, the PTFE and the PDMS provide good insulativity and corrosion resistance, and the synergistic effect of the PTFE, the PDMS and the ZIF-8 particles realizes the high-performance application of the insulating sling in a complex environment. Meanwhile, the preparation method and device are easy to operate and low in cost, and large-scale production can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of insulating materials, and in particular to insulating materials for ultra-high voltage electrical working insulating soft slings, and a preparation method and application thereof. Background Art

[0002] In UHV live-line work, traditional insulating tools such as insulating ropes and insulating booms face many challenges. Due to the complexity and particularity of the working environment, these tools have deficiencies in scalability, stability and durability. Especially in high electric field environments, they are easily disturbed by the electric field and fall off due to contact, which seriously threatens the safety of workers.

[0003] As an innovative UHV live working tool, the insulating soft sling is made of a soft material that is lightweight, high-strength and has excellent insulation properties. This material can not only maintain stable insulation properties in high electric field environments, but also greatly improves work efficiency and safety due to its lightness, ease of carrying and operation. In addition, the insulating soft sling also has good torsional and bending resistance, and can maintain high reliability and durability in complex and changing working environments.

[0004] However, the insulation materials currently on the market, such as PET, PC, PVC, PP and other plastic film materials, have limited performance in special environments such as extreme temperature, humidity, corrosion and radiation, and are difficult to meet the high requirements of UHV power systems for insulation materials. Especially with the trend of increasingly miniaturized and integrated electrical equipment, these traditional materials have been unable to meet the stringent requirements of UHV live-line operations for insulation performance, stability and durability.

[0005] Therefore, developing an insulating soft sling suitable for UHV live working and exploring its preparation method and application scenarios are of great significance for ensuring the safe and stable operation of the power system and improving the safety and efficiency of live working. Summary of the invention

[0006] The purpose of the present invention is to address the above-mentioned deficiencies in the existing insulating material technology for ultra-high voltage live working, and to provide an insulating material for ultra-high voltage electric working insulating soft sling, and a preparation method and application thereof. A ZIF-8 / PTFE composite insulating material film is innovatively made through a hot pressing process, and then a polydimethylsiloxane solution is used for immersion coating to form a double-layer composite insulating material, which is finally cut and woven into an insulating soft sling. The introduction of ZIF-8 particles enhances the mechanical strength and gas barrier properties of the material, while polytetrafluoroethylene and polydimethylsiloxane provide good insulation and corrosion resistance. The three work synergistically to achieve high-performance application of the insulating soft sling in complex environments.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The first object of the present invention is to provide a method for preparing an insulating material for ultra-high voltage electrical work insulating soft sling, S1, preparation of modified material ZIF-8:

[0009] Zinc nitrate hexahydrate is added to methanol and stirred to dissolve to form a first solution; dimethyl imidazole is added to methanol and dissolved to form a second solution; the first solution is then quickly poured into the second solution, and stirred at room temperature to form white crystals; and ZIF-8 particles are obtained by centrifugation, washing, and drying;

[0010] S2. Preparation of ZIF-8 / PTFE composite insulating material film:

[0011] The prepared ZIF-8 particles and polytetrafluoroethylene powder are weighed in a certain mass ratio, mixed with a planetary mixer to obtain a mixture, and then the mixture is dried and then ground for 10 to 20 minutes to obtain a powder;

[0012] Place aluminum foil on a flat glass plate, spread the powder on the aluminum foil, and use a hot press to roll the aluminum foil until the surface is smooth to obtain a ZIF-8 / PTFE composite insulating material film.

[0013] Furthermore, in step S1, the mass ratio of zinc nitrate hexahydrate to dimethylimidazole is 1-3.

[0014] Furthermore, in step S2, the mass ratio of ZIF-8 particles to polytetrafluoroethylene powder is (1-4):(9-6).

[0015] Furthermore, the rotation speed of the planetary mixer is 300-2000 r / min, and the mixing time is 5-6 min; the working temperature of the hot press is 80° C.-85° C., and the linear pressure load is 50-55 N / mm.

[0016] Furthermore, the method further includes step S3, preparation of a ZIF-8 / PTFE / PMDS double-layer composite insulating material, specifically comprising:

[0017] Dissolving polydimethylsiloxane in toluene solvent, and preparing a third solution after the polydimethylsiloxane is completely dissolved;

[0018] By using an immersion coating process, the ZIF-8 / PTFE composite insulating material film prepared in step S2 is immersed in a third solution, taken out, and allowed to stand at room temperature for a preset time to obtain a ZIF-8 / PTFE / PMDS double-layer composite insulating material.

[0019] Furthermore, the third solution is a polydimethylsiloxane solution with a mass concentration of 30% to 35%, the immersion time is 5 to 10 seconds, and the standing time is not less than 48 hours.

[0020] The second object of the present invention is to provide an insulating material for ultra-high voltage electrical working insulating soft sling, which is prepared by the above method.

[0021] The third object of the present invention is to provide the use of the above-mentioned insulating material for ultra-high voltage electrical working insulating soft slings in the preparation of soft slings.

[0022] The fourth object of the present invention is to provide a method for preparing an ultra-high voltage electrical working insulating soft sling, wherein the above-mentioned insulating material is cut into strips according to a predetermined width and length, and is woven using a weaving device according to the required sling size.

[0023] The fifth object of the present invention is to provide the application of the soft sling made by the above preparation method in ultra-high voltage live working.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention successfully synthesizes a novel composite insulating material for insulating soft slings by mixing ZIF-8 particles with polytetrafluoroethylene (PTFE) powder in a specific mass ratio and preparing the mixture using a dry process. This material combines the high porosity and good chemical stability of ZIF-8 with the excellent insulating properties, low friction coefficient and good corrosion resistance of PTFE, thereby greatly improving the comprehensive performance of the insulating soft slings;

[0026] (2) The present invention soaks and coats a ZIF-8 / PTFE composite insulating material film with a polydimethylsiloxane (PDMS) solution to form a double-layer composite insulating material, which is finally cut and woven into an insulating sling. The high porosity and excellent gas adsorption performance of ZIF-8 are combined with the insulating properties of PTFE and PDMS to improve the comprehensive performance of the insulating material. The principle is that the introduction of ZIF-8 particles enhances the mechanical strength and gas barrier properties of the material, while PTFE and PDMS provide good insulation and corrosion resistance. The synergistic effect of the three enables the high-performance application of the insulating sling in complex environments. At the same time, the preparation method and device are simple to operate, low-cost, and can be mass-produced.

[0027] (3) The insulating soft sling prepared by the present invention has significantly improved insulation performance, stability and durability. The introduction of ZIF-8 particles provides an additional barrier layer for the composite insulating material, which helps to block the transfer of current or heat, and further improves the insulation performance of the material. At the same time, PTFE itself is an excellent insulating material, and the combination of the two provides a doubly guaranteed insulation performance. ZIF-8 particles have excellent chemical stability and thermal stability, and can resist the erosion of various chemical substances and the influence of high temperature environment. PTFE also has good aging resistance and is not easily oxidized or degraded. Therefore, this composite insulating material can maintain stable performance during long-term use and extend its service life.

[0028] (4) The present invention adopts a planetary mixer for mixing, which ensures uniform distribution and close combination of the components. At the same time, through the process steps of grinding and rolling, the density and uniformity of the material are further improved. In addition, the entire preparation process is simple and easy to implement, and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a cross-sectional SEM image of the ZIF-8 / PTFE / PMDS double-layer composite insulation material prepared in the present invention;

[0030] Figure 2 The XRD pattern of the ZIF-8 / PTFE / PMDS double-layer composite insulation material prepared by the present invention;

[0031] Figure 3 Thermogravimetric analysis diagram of the ZIF-8 / PTFE / PMDS double-layer composite insulation material prepared by the present invention;

[0032] Figure 4 The tensile strength variation trend diagram of ZIF-8 / PTFE composite insulation material films with different ZIF-8 contents;

[0033] Figure 5 This is a schematic structural diagram of the ZIF-8 / PTFE / PMDS double-layer insulating soft sling for ultra-high voltage live working prepared by the present invention.

[0034] In the figure, 1. ZIF-8 filling particle layer; 2. PTFE matrix layer; 3. PDMS outer composite layer. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention clearer, embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0036] The present invention provides a method for preparing an insulating material for an ultra-high voltage electrical working insulating soft sling as follows:

[0037] S1. Preparation of modified material ZIF-8

[0038] Zinc nitrate hexahydrate is added to methanol and stirred to dissolve to form a first solution; dimethyl imidazole is added to methanol and dissolved to form a second solution; the first solution is then quickly poured into the second solution, and stirred at room temperature to form white crystals; and ZIF-8 particles are obtained by centrifugation, washing, and drying;

[0039] S2. Preparation of ZIF-8 / PTFE composite insulating material film

[0040] The prepared ZIF-8 particles and polytetrafluoroethylene powder are weighed in a certain mass ratio, mixed with a planetary mixer to obtain a mixture, and then the mixture is dried and then ground for 10 to 20 minutes to obtain a powder;

[0041] Aluminum foil is placed on a flat glass plate, the powder is spread on the aluminum foil, and a hot press is used to roll the aluminum foil until the surface is smooth to obtain a ZIF-8 / PTFE composite insulating material film.

[0042] In some embodiments, in step S1, the mass ratio of zinc nitrate hexahydrate to dimethyl imidazole is 1 to 3; in step S2, the mass ratio of ZIF-8 particles to polytetrafluoroethylene powder is (1 to 4): (9 to 6). When the mass of ZIF-8 particles and polytetrafluoroethylene powder is fixed, the addition amount of ZIF-8 particles can be 10% to 40%, for example, 11%, 11.5%, 12%, 13%, 14%, 17%, 20%, 21%, 22.5%, 25%, 30%, 33.7%, 35%, 38%, 40%, etc.

[0043] It should be noted that the rotation speed of the planetary mixer is 300-2000 r / min, and the mixing time is 5-6 min; the working temperature of the hot press is 80° C.-85° C., and the linear pressure load is 50-55 N / mm.

[0044] The present invention can also prepare a ZIF-8 / PTFE / PMDS double-layer composite insulating material based on the ZIF-8 / PTFE composite insulating material film, specifically:

[0045] Dissolve polydimethylsiloxane in toluene solvent, and prepare a third solution after the polydimethylsiloxane is completely dissolved; adopt an immersion coating process, immerse the ZIF-8 / PTFE composite insulating material film prepared in step S2 in the third solution, take it out, and let it stand at room temperature for a preset time to obtain a ZIF-8 / PTFE / PMDS double-layer composite insulating material.

[0046] In some embodiments, the third solution is a polydimethylsiloxane solution with a mass concentration of 30% to 35%, the immersion time is 5 to 10 seconds, and the standing time is not less than 48 hours.

[0047] The ZIF-8 / PTFE composite insulating material film and the ZIF-8 / PTFE / PMDS double-layer composite insulating material prepared by the above method of the present invention have excellent insulation performance, low friction coefficient and good corrosion resistance, and can be well used in the preparation of ultra-high voltage electrical working insulating soft slings, which are described in detail with specific embodiments below.

[0048] Example 1

[0049] 1. Preparation of modified material ZIF-8

[0050] Weigh zinc nitrate hexahydrate Zn(NO3)2·6H2O (2.933 g, 9.87 mmol) and add it into 200 ml of methanol, stir and dissolve to form solution (Ⅰ); weigh dimethylimidazole Hmim (6.489 g, 79.04 mmol) and add it into 200 ml of methanol to dissolve to form solution (Ⅱ); then quickly pour solution (Ⅰ) into solution (Ⅱ) and stir at room temperature for 1 hour to form white crystals.

[0051] The product was collected by centrifugation (10000 r / min, 15 min), and then washed with methanol three times to obtain a white solid, which was placed in an oven at 150° C. and dried for 24 h to obtain the desired ZIF-8 particles.

[0052] 2. Preparation of composite insulation materials based on dry process

[0053] Based on a total mass of 2 g, the prepared ZIF-8 particles and polytetrafluoroethylene PTFE powder were weighed in a mass ratio of (10-40): (90-60), and a planetary mixer was used to uniformly mix these components at a speed of 300 to 2000 rpm for 6 minutes.

[0054] The mixture was transferred to an agate mortar and placed in an oven at 80°C for 20 min.

[0055] Further, the mixture was evenly ground manually using a grinding mortar for 10 to 20 minutes, an aluminum foil was placed on a flat glass plate (glossy side facing up), and a hot press was used to roll the aluminum foil at a temperature of 80°C and a linear pressure load of 50 N / mm until the surface was smooth, thereby obtaining ZIF-8 / PTFE composite insulating material films with different ZIF-8 contents.

[0056] 3. Improvement of insulation material performance

[0057] A certain amount of polydimethylsiloxane (PDMS) was weighed and dissolved in a toluene solvent, and a 30% PDMS solution was prepared by stirring until the PDMS was completely dissolved.

[0058] By using an immersion coating process, the ZIF-8 / PTFE composite insulating material film was immersed in a 30% PDMS solution for 5 seconds, taken out, and allowed to stand at room temperature for 48 hours to obtain a ZIF-8 / PTFE / PMDS double-layer composite insulating material.

[0059] refer to Figure 1 , a cross-sectional SEM image of a double-layer ZIF-8 / PTFE / PMDS composite insulation material prepared by adding 30% ZIF-8 particles, showing the interface structure of the double-layer ZIF-8 / PTFE / PMDS composite insulation material. The interior is dense, ZIF-8 has not agglomerated, and is uniformly doped inside the PTFE. There is no obvious interface layer between the double-layer PTFE / PMDS, indicating that they are tightly combined. In addition, the grayish white tone and rough worn surface of the material indicate that it has excellent mechanical strength and wear resistance.

[0060] refer to Figure 2 The ZIF-8 / PTFE / PMDS double-layer composite insulation material still retains the crystal structure of ZIF-8, and the structure of ZIF-8 is not destroyed. This shows that the ZIF-8 / PTFE / PMDS double-layer composite insulation material fully combines the advantages of ZIF-8 and polymer PTFE and PMDS materials.

[0061] refer to Figure 3 , the thermal stability of ZIF-8 / PTFE / PMDS double-layer composite insulation material is much higher than that of pure PTFE. Pure PTFE begins to decompose after 430K, while the decomposition temperature of ZIF-8 / PTFE / PMDS double-layer composite insulation material is around 650K, and its thermal stability is improved by 200K. This is mainly because, on the one hand, ZIF-8 particles have excellent chemical and thermal stability, and on the other hand, the addition of ZIF-8 improves the density of PTFE.

[0062] refer to Figure 4, for the tensile strength test of ZIF-8 / PTFE / PMDS double-layer composite insulation material at different addition amounts. As can be seen from the figure, with the increase of ZIF-8 content in ZIF-8 / PTFE / PMDS, the tensile strength of ZIF-8 / PTFE / PMDS composite material is also enhanced. This is mainly due to the enhanced interface bonding: the porous structure and metal nodes of ZIF-8 can form a good interface bonding with the PTFE molecular chain, which can prevent the expansion of cracks in the material, thereby improving the tensile strength. Dispersion effect: The uniform dispersion of ZIF-8 particles in the PTFE matrix can form multiple stress concentration points, which can absorb and disperse external stress, thereby slowing down the formation and expansion of cracks. Nano effect: When the particle size of ZIF-8 particles reaches the nanometer level, its surface area will increase significantly, and the contact area with PTFE will also increase accordingly, thereby further enhancing the interface bonding force and tensile strength.

[0063] However, when the ZIF-8 addition reached 40%, its tensile strength decreased. This was mainly because when the ZIF-8 addition reached a certain level, a certain amount of agglomeration would occur, thereby reducing the tensile strength of the ZIF-8 / PTFE / PMDS composite material.

[0064] The electrical properties of the ZIF-8 / PTFE / PMDS double-layer composite insulation material prepared with a ZIF-8 addition of 30% were tested, and the results are shown in Table 1.

[0065] Table 1. Electrical performance test results.

[0066]

[0067]

[0068] From the comparison of electrical properties, we can see that the ZIF-8 / PTFE / PMDS double-layer composite insulation material is superior to pure PTFE in resistivity, dielectric strength and arc resistance. It can ensure the safe and stable operation of the UHV power system under special conditions.

[0069] Example 2

[0070] Preparation of insulating soft slings for UHV power work.

[0071] Weaving: Cut the prepared insulating material into strips according to the predetermined width and length. Use weaving equipment to weave according to the required sling size. During the weaving process, ensure that the thickness of the strip is uniform and the weaving is tight without gaps. During the weaving process, strong fibers or fiber bundles such as carbon fibers can be added to improve the load-bearing capacity and wear resistance of the sling.

[0072] Seam treatment: Use high-quality sewing thread compatible with insulating materials, such as aramid fiber and carbon fiber for sewing. The seams should be flat and firm, and should not affect the insulation performance of the sling. The end of the seam should be back-sewn to enhance the strength and durability of the seam. The back-seam length should be no less than 25mm.

[0073] Connection ring installation: Install the connection ring at one or both ends of the sling to connect with other equipment or tools. The connection ring should be firmly fixed on the sling without affecting its insulation performance. Install end pieces, such as hooks, buckles, etc. at the ends of the sling. The end pieces should be made of metal or alloy compatible with the sling material and have good strength and durability.

[0074] refer to Figure 5 As shown, the ultra-high voltage electrical work insulating soft sling prepared by the present invention, in which 1 is a ZIF-8 filling particle layer; 2 is a PTFE matrix layer; and 3 is a PDMS outer composite layer.

[0075] For matters not mentioned above, the prior art applies.

[0076] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art to which the present invention belongs may make modifications or supplements to the described specific embodiments or replace them in a similar manner, but they will not deviate from the direction of the present invention or exceed the scope defined by the attached claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc. made to the above implementations based on the technical essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an insulating material for an ultra-high voltage electrical working insulating soft sling, characterized in that: The following steps are involved: S1. Preparation of filling modified material ZIF-8: Zinc nitrate hexahydrate is added to methanol and stirred to dissolve to form a first solution; dimethyl imidazole is added to methanol and dissolved to form a second solution; then the first solution is quickly poured into the second solution and stirred at room temperature to form white crystals; After centrifugation, washing and drying, ZIF-8 particles were obtained; S2. Preparation of ZIF-8 / PTFE composite insulating material film: The prepared ZIF-8 particles and polytetrafluoroethylene powder are weighed in a certain mass ratio, mixed with a planetary mixer to obtain a mixture, and then the mixture is dried and then ground for 10 to 20 minutes to obtain a powder; Aluminum foil is placed on a flat glass plate, the powder is spread on the aluminum foil, and a hot press is used to roll the aluminum foil until the surface is smooth to obtain a ZIF-8 / PTFE composite insulating material film.

2. The preparation method according to claim 1, characterized in that In step S1, the mass ratio of zinc nitrate hexahydrate to dimethylimidazole is 1-3.

3. The preparation method according to claim 1, characterized in that: In step S2, the mass ratio of ZIF-8 particles to polytetrafluoroethylene powder is (1-4):(9-6).

4. The preparation method according to claim 3, characterized in that: The rotation speed of the planetary mixer is 300-2000 r / min, and the mixing time is 5-6 min; the working temperature of the hot press is 80° C.-85° C., and the linear pressure load is 50-55 N / mm.

5. The preparation method according to claims 1-4, characterized in that: The step S3 is also included, preparation of a ZIF-8 / PTFE / PMDS double-layer composite insulating material, specifically comprising: Dissolving polydimethylsiloxane in toluene solvent, and preparing a third solution after the polydimethylsiloxane is completely dissolved; By using an immersion coating process, the ZIF-8 / PTFE composite insulating material film prepared in step S2 is immersed in a third solution, taken out, and allowed to stand at room temperature for a preset time to obtain a ZIF-8 / PTFE / PMDS double-layer composite insulating material.

6. The preparation method according to claim 5, characterized in that: The third solution is a polydimethylsiloxane solution with a mass concentration of 30% to 35%, the immersion time is 5 to 10 seconds, and the standing time is not less than 48 hours.

7. An insulating material for ultra-high voltage electrical work insulating soft sling, characterized in that: The method is prepared according to any one of claims 1 to 6.

8. Use of the insulating material for ultra-high voltage electrical working insulating soft slings as claimed in claim 7 in the preparation of soft slings.

9. A method for preparing a soft insulating sling for ultra-high voltage power work, characterized in that: The insulating material as claimed in claim 8 is cut into strips according to a predetermined width and length, and is woven using a weaving device according to a required sling size.

10. Application of the soft sling made by the preparation method as claimed in claim 9 in ultra-high voltage live working.

Images