Wear-resistant and aging-resistant cable sheath material and preparation method thereof

Abstract

The invention relates to the technical field of cables, in particular to a wear-resistant and aging-resistant cable sheath material and a preparation method thereof. The sheath material is prepared by mixing hydrogenated nitrile rubber, a plasticizer, a lubricant, a vulcanizing agent, alkenyl metal complex modified silicon dioxide, an ultraviolet light absorber, an antioxidant, a light stabilizer and the like according to a specific proportion. The core technology is that nano silicon dioxide is treated by adopting a multi-stage subsurface modification method, after amination and carboxylation, the nano silicon dioxide reacts with zirconium chloride, unsaturated fatty acid, terephthalic acid and the like, a stable alkenyl metal complex interface layer is constructed, and multiple chemical combination with a rubber matrix is achieved. The composite material is excellent in wear resistance, aging resistance, ultraviolet resistance, fatigue resistance and the like, the service life of a cable sheath can be remarkably prolonged, the interface stability and the overall performance are improved, and the composite material is particularly suitable for a cable sheath system which is high in performance and long in service life and is applied in a severe environment.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a wear-resistant and aging-resistant cable sheath material and a preparation method thereof. Background Art

[0002] Modern power and communications infrastructure places increasingly stringent demands on the long-term reliability of cable systems. As the outermost protective layer of the cable, the cable sheath must maintain long-term stable performance under complex and changing environmental conditions to ensure the safe operation of the cable system. As power networks evolve toward higher voltages and larger capacities, and communications networks toward higher speeds and wider bandwidths, the service environment for cables is becoming increasingly demanding, placing even stricter demands on the durability of sheath materials.

[0003] The durability of cable sheath materials is directly related to the service life and reliability of cable systems. In practical applications, cable sheaths must withstand the long-term effects of various environmental factors, including temperature cycling, mechanical stress, chemical corrosion, UV radiation, and humidity fluctuations. The long-term effects of these factors can cause sheath material aging and degradation, manifesting as decreased mechanical strength, reduced elasticity, and surface cracking, ultimately affecting the overall performance and service life of the cable.

[0004] Traditional cable sheath materials primarily include polyvinyl chloride (PVC), polyethylene (PE), natural rubber, and synthetic rubber. While these materials may meet basic protection requirements during initial use, they often lack durability over long-term service. While PVC offers excellent flame retardancy and mechanical strength, it is susceptible to thermal degradation at high temperatures, releasing corrosive substances such as hydrogen chloride. Furthermore, the material becomes brittle and its impact resistance degrades. Polyethylene (PE) exhibits excellent chemical stability, but its heat and weather resistance are relatively poor. Long-term exposure to sunlight can lead to photooxidation, resulting in material degradation.

[0005] Rubber-based sheathing materials offer relatively superior elasticity and toughness, but their resistance to thermal and oxidative aging remains a key constraint to their long-term use. In high-temperature, aerobic environments, rubber molecular chains undergo oxidation, altering crosslink density, making the material harder and more brittle, and ultimately losing its protective properties. This is particularly true in specialized applications such as submarine cables, mining cables, and petrochemical cables, where sheathing materials must operate in harsher environments for extended periods, posing a significant challenge to their durability.

[0006] To improve the durability of sheath materials, researchers have tried various modification strategies. Adding antioxidants and light stabilizers is one of the most common methods. These additives can slow the aging process to a certain extent, but their effectiveness is limited. Furthermore, over time, the additives themselves are consumed and migrate, gradually reducing their protective effectiveness. Another approach is to modify the material's molecular structure, such as replacing traditional nitrile rubber with hydrogenated nitrile rubber. Hydrogenation can significantly improve the material's resistance to thermal oxidative aging, but simple base material modification still fails to meet the requirements of all applications.

[0007] In recent years, nanocomposite technology has provided a new approach to improving the durability of sheath materials. By adding nanofillers to matrix materials, the mechanical properties, thermal stability, and aging resistance of the materials can be significantly improved. However, issues with the dispersibility and interfacial compatibility of nanofillers have been key factors limiting their effectiveness. Unmodified nanofillers tend to agglomerate in organic matrices, failing to achieve their reinforcing effects and potentially acting as stress concentration points, accelerating material failure.

[0008] More importantly, the interface between the filler and the matrix is ​​often the weakest link in long-term service. Insufficient interfacial bonding strength can lead to debonding under external forces, forming microcracks. These microcracks gradually expand under cyclic stress, ultimately causing macroscopic damage to the material. Furthermore, the interfacial region is also a preferential permeation path for oxygen and other corrosive media, and the chemical stability of the interface directly affects the long-term durability of the material.

[0009] Therefore, developing a modification technology that can form a stable and lasting interface between the filler and the matrix is ​​of great significance for improving the durability of cable sheath materials. This technology not only needs to solve the problem of filler dispersion, but also needs to build a stable interface structure that can withstand long-term environmental effects, ensuring that the material maintains good performance throughout its service life. Summary of the Invention

[0010] In view of this, the purpose of the present invention is to propose a wear-resistant and aging-resistant cable sheath material and a preparation method thereof, so as to solve the problem that the interface degradation of the cable sheath material during long-term service leads to a decrease in durability, making it difficult to meet the requirements of long-term use in harsh environments.

[0011] Based on the above objectives, the present invention provides a wear-resistant and aging-resistant cable sheath material, which is prepared from the following raw materials, by weight: 80-120 parts of hydrogenated nitrile rubber, 10-20 parts of plasticizer, 0.5-1.5 parts of lubricant, 2-4 parts of vulcanizing agent, 30-50 parts of olefinic metal complex modified silica, 2-4 parts of ultraviolet absorber, 1-3 parts of antioxidant and 1-2 parts of light stabilizer.

[0012] Preferably, the degree of hydrogenation of the hydrogenated nitrile rubber is greater than 98%.

[0013] Preferably, the plasticizer is one of dioctyl adipate, dioctyl sebacate and tricresyl phosphate.

[0014] Preferably, the lubricant is one of zinc stearate, calcium stearate, vinyl bisstearamide and epoxy soybean oil.

[0015] Preferably, the vulcanizing agent is dicumyl peroxide.

[0016] Preferably, the ultraviolet absorber is ultraviolet absorber UV-328 or ultraviolet absorber UV-9.

[0017] Preferably, the antioxidant is one or a mixture of antioxidant DLTDP, antioxidant 1010, antioxidant 168 and antioxidant 264.

[0018] Preferably, the light stabilizer is one or a mixture of light stabilizer HALS-62, light stabilizer 944 and light stabilizer UV-3853.

[0019] Furthermore, the alkenyl metal complex modified silica is obtained by cross-linking terephthalic acid, unsaturated fatty acid and zirconium chloride on the surface of carboxylated silica.

[0020] Preferably, the weight ratio of terephthalic acid, unsaturated fatty acid, zirconium chloride and carboxylated silica is 8-12:6-10:10-20:20-40.

[0021] Preferably, the unsaturated fatty acid is one of arachidonic acid, linoleic acid, eleostearic acid and eicosapentaenoic acid.

[0022] Preferably, the carboxylated silica is obtained by modifying nano-silica with 3-aminopropyltriethoxysilane to obtain amino-silica, which is then reacted with glutaric anhydride.

[0023] Preferably, the weight ratio of the 3-aminopropyltriethoxysilane to the nano-silicon dioxide is 1-5:20-40.

[0024] Preferably, the weight ratio of the amino silica to glutaric anhydride is 20-40:40-80.

[0025] Preferably, the average particle size of the nano-silicon dioxide is 20-100 nm.

[0026] Preferably, the preparation method of the alkenyl metal complex modified silica is as follows: carboxylated silica is added to a mixed solution of deionized water and acetic acid, ultrasonicated for 20-40 minutes, then zirconium chloride, terephthalic acid and unsaturated fatty acid are added, stirred for 20-40 minutes, then transferred to a reactor, hydrothermally reacted at 118-122° C. for 20-28 hours, centrifuged, washed with methanol, and vacuum dried to obtain alkenyl metal complex modified silica.

[0027] Furthermore, the present invention also provides a preparation method of the above-mentioned wear-resistant and aging-resistant cable sheath material, comprising the following steps: adding hydrogenated nitrile rubber, a plasticizer and a lubricant into an internal mixer, heating to 80-90°C, and internal mixing for 4-6 minutes, then adding alkenyl metal complex modified silica, continuing internal mixing for 8-12 minutes, cooling to 73-77°C, adding an ultraviolet absorber, an antioxidant and a light stabilizer, stirring for 5-7 minutes, then heating to 124-126°C, adding a vulcanizing agent, vulcanizing, and finally calendering the vulcanized rubber into shape, curing, and then cooling to room temperature to obtain the wear-resistant and aging-resistant cable sheath material.

[0028] Preferably, the vulcanization temperature is 128-132° C., the pressure is 10-14 MPa, and the time is 13-18 min.

[0029] Preferably, the curing temperature is 145-155° C. and the curing time is 40-50 minutes.

[0030] Beneficial effects of the present invention: This invention utilizes innovative multi-stage surface modification technology to successfully construct an olefinic metal complex-modified silica / hydrogenated nitrile rubber composite system with excellent durability. This technical solution effectively addresses the performance degradation of traditional cable sheathing materials caused by interface degradation during long-term service, providing a strong material guarantee for the long-term reliable operation of cable systems.

[0031] The core technical advantage of the present invention lies in the establishment of a stable and long-lasting multifunctional interface structure. Through sequential surface treatments of amination and carboxylation, a high density of active functional groups is introduced onto the surface of the nanosilica, providing ample reaction sites for the subsequent formation of metal complexes. The alkenyl metal complex formed by zirconium chloride, terephthalic acid, and arachidonic acid not only has excellent thermal stability, but also undergoes multiple chemical interactions with the rubber matrix, forming a composite interface structure combining coordination bonds, covalent bonds, and physical entanglements. This interface structure can effectively resist the effects of environmental stress during long-term service and maintain the stability of the interface bond.

[0032] In terms of durability, the composite material of the present invention exhibits excellent long-term performance stability. The metal complex interface layer has excellent antioxidant properties, effectively blocking the penetration of oxygen and other corrosive media into the interfacial region, thereby slowing the interfacial oxidative degradation process. Furthermore, the aromatic ring structure in the complex provides excellent thermal stability, allowing the interface to maintain a stable chemical structure even in high-temperature environments. The presence of the flexible alkenyl chain segments imparts excellent stress relaxation capabilities to the interface, effectively alleviating interfacial stress concentration caused by temperature changes and mechanical stress, and preventing the generation and expansion of microcracks.

[0033] The multifunctional interface design of this invention also significantly improves the material's fatigue resistance. While traditional physical interfaces are prone to fatigue failure under cyclic loading, the chemically bonded interface constructed in this invention effectively disperses and transfers stress, avoiding stress concentration at the interface and significantly improving the material's fatigue life. This is of great significance for cable applications that must withstand cyclic loading such as vibration and bending.

[0034] The present invention also offers excellent processing stability and product consistency. The modified nanosilica exhibits excellent dispersion stability within the rubber matrix, making it less susceptible to agglomeration and sedimentation, thereby ensuring consistent product quality. Furthermore, the stable interface structure reduces interfacial damage during processing, contributing to the stability of product performance.

[0035] In summary, the olefinic metal complex-modified silica / hydrogenated nitrile rubber composite material constructed by the multi-stage surface modification technology of the present invention shows significant advantages in durability and processing stability, providing important technical support for the development of high-performance and long-life cable sheath materials, and has broad application prospects and important economic value. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0037] In a specific embodiment of the present invention, the average particle size of the nano-silica is 50 nm, the hydrogenated nitrile rubber is Zetpol 2010, the degree of hydrogenation is 99%, and the acrylonitrile content is 36 wt%.

[0038] Example 1: (1) Add 20 g of nano-silica to a mixed solution of 80 g of deionized water and 150 g of anhydrous ethanol, ultrasonicate for 20 min, then add 1 g of 3-aminopropyltriethoxysilane, heat to 55 °C, stir and react for 5 h, centrifuge, wash with anhydrous ethanol three times, and vacuum dry to obtain amino-silica; (2) Add 20 g of amino-silica to 200 g of anhydrous ethanol, sonicate for 20 min, then add 40 g of glutaric anhydride, heat to 35 °C, stir and react for 2 h, centrifuge, wash three times with 0.1 mol / L sodium chloride aqueous solution, and vacuum dry to obtain carboxylated silica; (3) 20 g of carboxylated silica was added to a mixed solution of 1000 g of deionized water and 200 g of acetic acid, and ultrasonicated for 20 min. Then, 10 g of zirconium chloride, 8 g of terephthalic acid, and 6 g of arachidonic acid were added and stirred for 20 min. The mixture was transferred to a reactor and hydrothermally reacted at 118 ° C for 20 h. The mixture was centrifuged, washed with methanol, and vacuum dried to obtain alkenyl metal complex modified silica. (4) 80g hydrogenated nitrile rubber, 10g dioctyl adipate and 0.5g zinc stearate were added to an internal mixer at a speed of 35rpm, heated to 80℃, and internally kneaded for 4min. Subsequently, 30g olefin metal complex modified silica was added and internally kneaded for 8min. The temperature was lowered to 73℃, 2g ultraviolet absorber UV-328, 1g antioxidant DLTDP and 1g light stabilizer HALS-62 were added, and stirred at a speed of 15rpm for 5min. The temperature was then raised to 124℃, 2g diisopropylbenzene peroxide was added, and vulcanized at a speed of 55rpm for 13min. The vulcanization temperature was 128℃ and the pressure was 10MPa. Finally, the vulcanized rubber was calendered and cured at 145℃ for 40min. The mixture was then cooled to room temperature at a gradient of 8℃ / min to obtain a wear-resistant and aging-resistant cable sheath material.

[0039] Example 2: (1) Add 30 g of nano-silica to a mixed solution of 100 g of deionized water and 200 g of anhydrous ethanol, ultrasonicate for 30 min, then add 3 g of 3-aminopropyltriethoxysilane, heat to 60 ° C, stir and react for 6 h, centrifuge, wash with anhydrous ethanol three times, and vacuum dry to obtain amino-silica; (2) Add 30 g of amino-silica to 300 g of anhydrous ethanol, sonicate for 30 min, then add 60 g of glutaric anhydride, heat to 37 °C, stir and react for 3 h, centrifuge, wash three times with 0.1 mol / L sodium chloride aqueous solution, and vacuum dry to obtain carboxylated silica; (3) 30 g of carboxylated silica was added to a mixed solution of 1200 g of deionized water and 300 g of acetic acid, and ultrasonicated for 30 min. Then, 15 g of zirconium chloride, 10 g of terephthalic acid, and 8 g of arachidonic acid were added and stirred for 30 min. The mixture was transferred to a reactor and hydrothermally reacted at 120 ° C for 24 h. The mixture was centrifuged, washed with methanol, and vacuum dried to obtain alkenyl metal complex modified silica. (4) 100 g hydrogenated nitrile rubber, 15 g dioctyl adipate and 1 g zinc stearate were added to an internal mixer at a speed of 40 rpm, heated to 85 °C and mixed for 5 min. Then 40 g olefin metal complex modified silica was added and mixed for 10 min. The mixture was cooled to 75 °C, 3 g ultraviolet absorber UV-328, 2 g antioxidant DLTDP and 1.5 g light stabilizer HALS-62 were added and stirred at a speed of 20 rpm for 6 min. The mixture was heated to 125 °C, 3 g diisopropylbenzene peroxide was added and vulcanized at a speed of 60 rpm for 15 min. The vulcanization temperature was 130 °C and the pressure was 12 MPa. Finally, the vulcanized rubber was calendered and cured at 150 °C for 45 min. The mixture was then cooled to room temperature at a gradient of 10 °C / min to obtain a wear-resistant and aging-resistant cable sheath material.

[0040] Example 3: (1) Add 40 g of nano-silica to a mixed solution of 120 g of deionized water and 250 g of anhydrous ethanol, ultrasonicate for 40 min, then add 5 g of 3-aminopropyltriethoxysilane, heat to 65 ° C, stir and react for 7 h, centrifuge, wash with anhydrous ethanol three times, and vacuum dry to obtain amino-silica; (2) Add 40 g of amino-silica to 400 g of anhydrous ethanol, sonicate for 40 min, then add 80 g of glutaric anhydride, heat to 40 °C, stir and react for 4 h, centrifuge, wash three times with 0.1 mol / L sodium chloride aqueous solution, and vacuum dry to obtain carboxylated silica; (3) 40 g of carboxylated silica was added to a mixed solution of 1400 g of deionized water and 400 g of acetic acid, and ultrasonicated for 40 min. Then, 20 g of zirconium chloride, 12 g of terephthalic acid, and 10 g of arachidonic acid were added and stirred for 40 min. The mixture was transferred to a reactor and hydrothermally reacted at 122 °C for 28 h. The mixture was centrifuged, washed with methanol, and vacuum dried to obtain alkenyl metal complex modified silica. (4) 120 g hydrogenated nitrile rubber, 20 g dioctyl adipate and 1.5 g zinc stearate were added to an internal mixer at a speed of 45 rpm, heated to 90 °C and mixed for 6 min, then 50 g olefin metal complex modified silica was added and mixed for 12 min, cooled to 77 °C, 4 g ultraviolet absorber UV-328, 3 g antioxidant DLTDP and 2 g light stabilizer HALS-62 were added, stirred at 25 rpm for 7 min, heated to 126 °C, 4 g diisopropylbenzene peroxide was added, and vulcanized at 65 rpm for 18 min, the vulcanization temperature was 132 °C and the pressure was 14 MPa. Finally, the vulcanized rubber was calendered and cured at 155 °C for 50 min, and then cooled to room temperature at a gradient of 12 °C / min to obtain a wear-resistant and aging-resistant cable sheath material.

[0041] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is that the carboxylated silica in step (3) is replaced by nano-silica; The specific steps are as follows: (1) 30 g of nano-silica was added to a mixed solution of 1200 g of deionized water and 300 g of acetic acid, and ultrasonicated for 30 min. Then, 15 g of zirconium chloride, 10 g of terephthalic acid, and 8 g of arachidonic acid were added and stirred for 30 min. The mixture was transferred to a reactor and hydrothermally reacted at 120 ° C for 24 h. The mixture was centrifuged, washed with methanol, and vacuum dried to obtain alkenyl metal complex modified silica. (2) 100 g of hydrogenated nitrile rubber, 15 g of dioctyl adipate and 1 g of zinc stearate were added to an internal mixer at a speed of 40 rpm, heated to 85 °C and mixed for 5 min. Then 40 g of olefin metal complex modified silica was added and mixed for 10 min. The mixture was cooled to 75 °C, 3 g of ultraviolet absorber UV-328, 2 g of antioxidant DLTDP and 1.5 g of light stabilizer HALS-62 were added and stirred at a speed of 20 rpm for 6 min. The mixture was heated to 125 °C, 3 g of diisopropylbenzene peroxide was added and vulcanized at a speed of 60 rpm for 15 min. The vulcanization temperature was 130 °C and the pressure was 12 MPa. The vulcanized rubber was calendered and cured at 150 °C for 45 min. The mixture was then cooled to room temperature at a gradient of 10 °C / min to obtain a cable sheath material.

[0042] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is that the terephthalic acid in step (3) is replaced by arachidonic acid; The specific steps are as follows: (1) Add 30 g of nano-silica to a mixed solution of 100 g of deionized water and 200 g of anhydrous ethanol, ultrasonicate for 30 min, then add 3 g of 3-aminopropyltriethoxysilane, heat to 60 ° C, stir and react for 6 h, centrifuge, wash with anhydrous ethanol three times, and vacuum dry to obtain amino-silica; (2) Add 30 g of amino-silica to 300 g of anhydrous ethanol, sonicate for 30 min, then add 60 g of glutaric anhydride, heat to 37 °C, stir and react for 3 h, centrifuge, wash three times with 0.1 mol / L sodium chloride aqueous solution, and vacuum dry to obtain carboxylated silica; (3) 30 g of carboxylated silica was added to a mixed solution of 1200 g of deionized water and 300 g of acetic acid, ultrasonicated for 30 min, then 15 g of zirconium chloride and 18 g of arachidonic acid were added, stirred for 30 min, and then transferred to a reactor, hydrothermally reacted at 120 ° C for 24 h, centrifuged, washed with methanol, and vacuum dried to obtain alkenyl metal complex modified silica; (4) Add 100g hydrogenated nitrile rubber, 15g dioctyl adipate and 1g zinc stearate into an internal mixer at a speed of 40rpm, heat to 85℃, and internal mixer for 5min. Then add 40g olefin metal complex modified silica and continue internal mixer for 10min. Cool to 75℃, add 3g ultraviolet absorber UV-328, 2g antioxidant DLTDP and 1.5g light stabilizer HALS-62, stir at 20rpm for 6min, heat to 125℃, add 3g diisopropylbenzene peroxide, and vulcanize at 60rpm for 15min. The vulcanization temperature is 130℃ and the pressure is 12MPa. Finally, the vulcanized rubber is calendered and cured at 150℃ for 45min. Then, it is cooled to room temperature at a gradient of 10℃ / min to obtain a cable sheath material.

[0043] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is that the arachidonic acid in step (3) is replaced by terephthalic acid; The specific steps are as follows: (1) Add 30 g of nano-silica to a mixed solution of 100 g of deionized water and 200 g of anhydrous ethanol, ultrasonicate for 30 min, then add 3 g of 3-aminopropyltriethoxysilane, heat to 60 ° C, stir and react for 6 h, centrifuge, wash with anhydrous ethanol three times, and vacuum dry to obtain amino-silica; (2) Add 30 g of amino-silica to 300 g of anhydrous ethanol, sonicate for 30 min, then add 60 g of glutaric anhydride, heat to 37 °C, stir and react for 3 h, centrifuge, wash three times with 0.1 mol / L sodium chloride aqueous solution, and vacuum dry to obtain carboxylated silica; (3) 30 g of carboxylated silica was added to a mixed solution of 1200 g of deionized water and 300 g of acetic acid, ultrasonicated for 30 min, then 15 g of zirconium chloride and 18 g of terephthalic acid were added, stirred for 30 min, and then transferred to a reactor, hydrothermally reacted at 120 ° C for 24 h, centrifuged, washed with methanol, and vacuum dried to obtain alkenyl metal complex modified silica; (4) Add 100g hydrogenated nitrile rubber, 15g dioctyl adipate and 1g zinc stearate into an internal mixer at a speed of 40rpm, heat to 85℃, and internal mixer for 5min. Then add 40g olefin metal complex modified silica and continue internal mixer for 10min. Cool to 75℃, add 3g ultraviolet absorber UV-328, 2g antioxidant DLTDP and 1.5g light stabilizer HALS-62, stir at 20rpm for 6min, heat to 125℃, add 3g diisopropylbenzene peroxide, and vulcanize at 60rpm for 15min. The vulcanization temperature is 130℃ and the pressure is 12MPa. Finally, the vulcanized rubber is calendered and cured at 150℃ for 45min. Then, it is cooled to room temperature at a gradient of 10℃ / min to obtain a cable sheath material.

[0044] Comparative Example 4: The difference between Comparative Example 4 and Example 2 is that the alkenyl metal complex-modified silica in step (4) is replaced by nano-silica; The specific steps are as follows: 100g hydrogenated nitrile rubber, 15g dioctyl adipate and 1g zinc stearate were added to an internal mixer at a speed of 40rpm, heated to 85°C, and mixed for 5min. Subsequently, 40g nano-silica was added and mixed for 10min. The mixture was cooled to 75°C, 3g ultraviolet absorber UV-328, 2g antioxidant DLTDP and 1.5g light stabilizer HALS-62 were added, and stirred at a speed of 20rpm for 6min. The mixture was then heated to 125°C, 3g diisopropylbenzene peroxide was added, and vulcanized at a speed of 60rpm for 15min. The vulcanization temperature was 130°C and the pressure was 12MPa. Finally, the vulcanized rubber was calendered and cured at 150°C for 45min. The mixture was then cooled to room temperature at a gradient of 10°C / min to obtain a cable sheath material.

[0045] Performance testing: Wear resistance test: Refer to GB / T 9867-2008 and use a rotating roller abrader to measure volumetric wear. The sample is fixed to a turntable and loaded with a normal force of 10 N. A standard abrasion wheel (type H-18) is used to rub the sample surface at 40 rpm. After a cumulative friction of 1000 revolutions, the sample mass loss is measured using a precision electronic balance (accuracy 0.1 mg) to calculate the volumetric wear.

[0046] Mechanical properties test: Refer to GB / T 528-2009. Use a universal material testing machine with a clamping distance of 50 mm, a preload of 0.1 N, and stretch at a constant speed of 500 mm / min until the specimen breaks. Record the tensile strength and elongation at break.

[0047] Thermal oxidative aging test: Referring to GB / T 3512-2014, dumbbell-shaped tensile specimens were placed in a hot air aging chamber; the temperature was set at 130°C and the aging time was 168 hours. After aging, the specimens were removed and conditioned in a standard temperature and humidity environment for 16 hours. The tensile strength before and after aging was measured, and the retention rate was calculated. The above test results are shown in Table 1.

[0048] Table 1 Performance test results

[0049] Data Analysis: As can be seen from the data of Examples 1-3 in Table 1, the cable sheath material prepared by the present invention exhibits relatively excellent comprehensive performance across various performance indicators. The data show that its volume wear, tensile strength, elongation at break, and tensile strength retention all reach high levels, which may be related to the unique structure of the alkenyl metal complex-modified silica. During the preparation process, amino groups are first introduced to the silica surface through an amination treatment, followed by a carboxylation treatment to further enhance the surface activity. Ultimately, the alkenyl metal complex structure is formed through the synergistic action of zirconium chloride, terephthalic acid, and arachidonic acid. This multi-level surface modification may form a more stable interface structure in the rubber matrix, where the presence of the metal complex may enhance the interaction between the filler and the matrix through the dual effects of coordination and covalent bonds. The introduction of alkenyl groups may provide additional reaction sites during the vulcanization process, promoting the formation and optimization of the cross-linked network. The rigid aromatic ring structure of terephthalic acid may help to improve the mechanical strength of the material, while the flexible chain segments of arachidonic acid may improve the toughness and processing properties of the material. The synergistic effect of the two may achieve a balance between strength and toughness.

[0050] As can be seen from the data of Example 2 and Comparative Example 1 in Table 1, Example 2 is all superior to Comparative Example 1 in wear resistance, mechanical properties and thermal oxidative aging performance, which may be related to the better surface activity and interfacial compatibility of carboxylated silica compared to unmodified nano silica. The presence of carboxyl groups may provide more reaction sites for subsequent metal complex formation, so that zirconium chloride, terephthalic acid and arachidonic acid can be better anchored on the silica surface, forming a more stable complex structure. The stability of this structure may still maintain good interface bonding under high temperature conditions, thereby improving the thermal oxidative aging performance of the material. Unmodified nano silica may be difficult to form effective interface bonding with the rubber matrix due to lower surface activity, causing the dispersion and compatibility of filler in the matrix to be poor.

[0051] As can be seen from the data of Example 2 and Comparative Example 2 in Table 1, when terephthalic acid is replaced with arachidonic acid, the performance data shows that the thermal stability of the material is significantly reduced. The lack of aromatic ring rigid structural units in the coordination system of Comparative Example 2 may cause the heat deformation temperature of the metal complex to drop. During the thermal oxidative aging process, the oxidative degradation rate of the long-chain fatty structure of arachidonic acid is relatively fast, causing the zirconium ion coordination structure to dissociate, thereby reducing the interfacial bonding strength between the particles and the rubber. In addition, the single fatty chain structure has a weak stabilizing effect on the dispersed state of the particles, which may accelerate the surface damage process of the material during the friction process.

[0052] As can be seen from the data of Example 2 and Comparative Example 3 in Table 1, after the removal of arachidonic acid in Comparative Example 3, the data show that the toughness and wear resistance of the material have both decreased. This is mainly related to the insufficient interfacial crosslinking density: the alkenyl groups provided by arachidonic acid can participate in the construction of the crosslinking network as free radical acceptors during vulcanization, and its multiple double bond structure can enhance the chemical bond strength between the particles and the rubber. Although the use of a single terephthalic acid ensures thermal stability, the excessively rigid interface layer will limit the mobility of the molecular chains. After the synergistic effect of the two is broken, the material is prone to stress concentration when subjected to tensile deformation, while reducing the elastic recovery ability during the friction process.

[0053] As can be seen from the data in Example 2 and Comparative Example 4 in Table 1, the data from Comparative Example 4, which directly uses unmodified silica, shows systematic degradation of all performance indicators, confirming the key role of the olefinic metal complex modification. Experimental results demonstrate that this specialized interface layer simultaneously addresses three core issues: the metal coordination bonds significantly enhance the dispersion stability of the particles in the rubber; the improved compatibility of the organic ligands with the rubber inhibits the propagation of microcracks at the friction interface; and the unsaturated double bonds participate in vulcanization to form a three-dimensional network, enabling more uniform transmission of stress loads along the interface. This multi-level structural design effectively blocks the propagation path of molecular chain breaks caused by thermal oxidative aging, thereby comprehensively improving overall performance.

[0054] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. A wear-resistant and aging-resistant cable sheath material, characterized in that: The composition is prepared from the following raw materials, in parts by weight: 80-120 parts of hydrogenated nitrile rubber, 10-20 parts of a plasticizer, 0.5-1.5 parts of a lubricant, 2-4 parts of a vulcanizing agent, 30-50 parts of alkenyl metal complex modified silica, 2-4 parts of an ultraviolet absorber, 1-3 parts of an antioxidant, and 1-2 parts of a light stabilizer. The alkenyl metal complex modified silica is obtained by cross-linking terephthalic acid, unsaturated fatty acid and zirconium chloride on the surface of carboxylated silica; The weight ratio of the terephthalic acid, the unsaturated fatty acid, the zirconium chloride and the carboxylated silicon dioxide is 8-12:6-10:10-20:20-40.

2. The wear-resistant and aging-resistant cable sheath material according to claim 1, characterized in that: The degree of hydrogenation of the hydrogenated nitrile rubber is greater than 98%.

3. The wear-resistant and aging-resistant cable sheath material according to claim 1, characterized in that: The plasticizer is one of dioctyl adipate, dioctyl sebacate and tricresyl phosphate; the lubricant is one of zinc stearate, calcium stearate, vinyl bisstearamide and epoxy soybean oil.

4. The wear-resistant and aging-resistant cable sheath material according to claim 1, characterized in that: The vulcanizing agent is dicumyl peroxide.

5. The wear-resistant and aging-resistant cable sheath material according to claim 1, characterized in that: The ultraviolet absorber is ultraviolet absorber UV-328 or ultraviolet absorber UV-9; the antioxidant is one or a mixture of antioxidant DLTDP, antioxidant 1010, antioxidant 168 and antioxidant 264; the light stabilizer is one or a mixture of light stabilizer HALS-62, light stabilizer 944 and light stabilizer UV-3853.

6. The wear-resistant and aging-resistant cable sheath material according to claim 1, characterized in that: The unsaturated fatty acid is one of arachidonic acid, linoleic acid, eleostearic acid and eicosapentaenoic acid.

7. The wear-resistant and aging-resistant cable sheath material according to claim 1, characterized in that: The carboxylated silica is obtained by modifying nano-silica with 3-aminopropyltriethoxysilane to obtain amino-silica, which is then reacted with glutaric anhydride.

8. The wear-resistant and aging-resistant cable sheath material according to claim 7, characterized in that: The weight ratio of the 3-aminopropyltriethoxysilane to the nano-silica is 1-5:20-40; the weight ratio of the amino-silica to glutaric anhydride is 20-40:40-80; and the average particle size of the nano-silica is 20-100 nm.

9. The wear-resistant and aging-resistant cable sheath material according to claim 1, characterized in that: The preparation method of the alkenyl metal complex modified silica is as follows: carboxylated silica is added to a mixed solution of deionized water and acetic acid, ultrasonicated for 20-40 minutes, then zirconium chloride, terephthalic acid and unsaturated fatty acid are added, stirred for 20-40 minutes, then transferred to a reactor, hydrothermally reacted at 118-122° C. for 20-28 hours, centrifuged, washed with methanol, and vacuum dried to obtain the alkenyl metal complex modified silica.

10. A wear-resistant and aging-resistant cable sheath material according to any one of claims 1 to 9, characterized in that: The following steps are involved: Add hydrogenated nitrile rubber, plasticizer and lubricant into an internal mixer, heat to 80-90°C, and internally mix for 4-6 minutes. Then add olefin metal complex modified silica and continue internally mixing for 8-12 minutes. Cool to 73-77°C, add ultraviolet absorber, antioxidant and light stabilizer, stir for 5-7 minutes, heat to 124-126°C, add vulcanizing agent, vulcanize, and finally calender the vulcanized rubber into shape, solidify, and then cool to room temperature to obtain wear-resistant and aging-resistant cable sheath material.

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