High-strength cable tie and preparation method thereof

Abstract

The invention relates to the technical field of cable ties, in particular to a high-strength cable tie and a preparation method thereof. The high-strength cable tie is prepared from the following components in parts by weight: 70 to 85 parts of nylon 66, 12 to 25 parts of rigid-flexible dual-phase nano composite reinforcement, 3 to 8 parts of two-dimensional lamellar nano filler, 0.1 to 0.5 part of nucleating agent, 0.5 to 1.5 parts of lubricating agent, 0.2 to 0.6 part of heat stabilizer and 0.1 to 0.3 part of antioxidant. According to the high-strength cable tie provided by the invention, the strength, heat resistance, fracture toughness and long-term mechanical retentivity of a material are improved, the toughness of the material is improved, and the problems that the material is fractured due to overlarge local stress and the performance is reduced due to interface debonding are prevented.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cable ties, in particular, relates to a high-strength cable tie and a preparation method thereof. BACKGROUND

[0002] Cable ties are usually made of materials with certain strength and toughness, and their basic structure includes a tie body and a locking part. In use, the tie body is wrapped around the cable and other fixed objects, and the locking part is used for self-locking fixation. Common cable tie materials include nylon, polypropylene and other plastic materials, which have certain strength and flexibility and can meet the use requirements in general environments. However, in some special working conditions, such as high temperature, high stress, long-term vibration and other environments, the performance of traditional cable ties will often decrease significantly, resulting in fixation failure and even causing safety accidents.

[0003] Although the existing high-strength cable ties and their preparation methods improve the performance of cable ties to some extent, there are still some deficiencies. In the process of improving the strength of cable ties, the toughness of the material is often sacrificed. For example, adding inorganic fibers such as glass fibers can significantly improve the strength and stiffness of the material, but it will make the material brittle and reduce the toughness. In actual use, the cable tie may be subjected to complex external forces, such as bending, twisting, etc. If the toughness of the material is insufficient, it is easy to break, resulting in fixation failure. Therefore, how to improve the strength of the material while maintaining or improving the toughness of the material is one of the key problems to realize the high performance of cable ties. In some high-temperature environments, such as the engine compartment of a car, the interior of power equipment, etc., the cable tie needs to withstand high temperature. The traditional cable tie material is prone to thermal degradation reaction at high temperature, resulting in a decrease in the strength, toughness and other properties of the material, and even losing the use function. In addition, the cable tie may be subjected to long-term vibration, stress and other effects during use, which requires the material to have good long-term mechanical retention. Based on this, the present application proposes a high-strength cable tie and a preparation method thereof. SUMMARY

[0004] The present application proposes a high-strength cable tie and a preparation method thereof, which improves the strength, heat resistance, fracture toughness and long-term mechanical retention of the material, improves the toughness of the material, and prevents the material from breaking due to excessive local stress and performance degradation due to interface debonding.

[0005] The technical solutions of the present application are as follows: In a first aspect, the present application provides a high-strength cable tie, comprising the following components in parts by weight: nylon 6670-85 parts, rigid-flexible dual-phase nano composite reinforcing agent 12-25 parts, two-dimensional sheet nano filler 3-8 parts, nucleating agent 0.1-0.5 parts, lubricant 0.5-1.5 parts, thermal stabilizer 0.2-0.6 parts, antioxidant 0.1-0.3 parts.

[0006] As a further technical solution, the preparation method of the rigid-flexible dual-phase nano composite reinforcing agent comprises: A1. Disperse the cage-type silsesquioxane with amino functional groups in an N-methyl pyrrolidone solvent to form a suspension, and heat to 75-85℃ under nitrogen protection; A2. Add ε-caprolactam, catalyst and polyether amine to the suspension in sequence, and stir and react at 80-90℃ for 1-2 hours to form a prepolymer system; A3. Reduce the temperature of the prepolymer system to 55-65℃, add a micro-crosslinking agent, and after the dropwise addition is completed, heat to 85-95℃ and react for 1.5-2.5 hours; A4. Pour the reaction product into deionized water for precipitation, crush, wash, and vacuum dry at 95-105℃ for 10-14 hours to obtain the powder-like rigid-flexible dual-phase nano composite reinforcing agent.

[0007] As a further technical solution, the cage-type silsesquioxane with amino functional groups is octaamino phenyl cage-type silsesquioxane; and the catalyst is caprolactam magnesium bromide.

[0008] As a further technical solution, the micro-crosslinking agent is toluene diisocyanate; and the dropwise addition time of the micro-crosslinking agent is 20-40 minutes.

[0009] As a further technical solution, the weight ratio of the cage-type silsesquioxane with amino functional groups, N-methyl pyrrolidone, ε-caprolactam, catalyst, polyether amine and micro-crosslinking agent is 100:400-600:450-550:4-6:45-55:2.0-3.0.

[0010] As a further technical solution, the two-dimensional sheet nano filler is organically modified montmorillonite.

[0011] As a further technical solution, the nucleating agent is nucleating agent NA-50; and the lubricant is pentaerythritol stearate.

[0012] As a further technical solution, the thermal stabilizer is a composite of potassium iodide and copper stearate in a mass ratio of 1:0.8-1.2.

[0013] The compound heat stabilizer is composed of potassium iodide and copper stearate in a specific mass ratio, and the heat aging resistance of the material is significantly improved through the synergistic effect of the components. In a high temperature environment, the molecular chain of nylon 66 is prone to thermal degradation, resulting in a decrease in material performance. Potassium iodide and copper stearate have different stabilization mechanisms, and the combination of the two can inhibit the thermal degradation process in all directions. Potassium iodide can capture free radicals generated during the thermal degradation of nylon 66, which is a key factor in initiating chain degradation. Potassium iodide reacts with free radicals to convert them into stable molecules, thereby interrupting the chain degradation reaction and slowing down the thermal aging rate of the material. Copper stearate can chemically react with unstable groups in the molecular chain of nylon 66 to form stable chemical bonds, enhancing the stability of the molecular chain and preventing molecular chain breakage. At the same time, copper stearate can also form a protective film on the surface of the material, preventing the entry of oxidizing substances such as oxygen into the material and reducing the occurrence of oxidative degradation reactions. Potassium iodide and copper stearate work together to inhibit the thermal degradation and oxidative degradation of nylon 66 from different angles, greatly improving the heat aging resistance of the material and ensuring the performance stability of the material during long-term use.

[0014] As a further technical solution, the antioxidant is antioxidant 1098.

[0015] In a second aspect, the present application provides a preparation method of a high-strength cable tie, comprising the following steps: S1. Put nylon 66, rigid-flexible dual-phase nano composite reinforcement, two-dimensional sheet nano filler, nucleating agent, lubricant, heat stabilizer and antioxidant into a high-speed mixer, mix at a speed of 800-1200 rpm for 3-8 minutes to obtain a premix; S2. The premix is sent into a co-rotating twin-screw extruder for melt blending and granulation, the temperature of each section of the extruder is set as: zone 1 245-255 DEG C, zone 2 255-265 DEG C, zone 3 260-270 DEG C, zone 4 265-275 DEG C, and the die head 260-270 DEG C, the screw speed is 200-300 rpm, and the composite material master batch is obtained after water cooling and granulation; S3. The composite material master batch is dried at 115-125 DEG C for 3-5 hours to obtain a dried master batch; S4. The dried master batch is put into an injection molding machine, and an injection molding process is carried out by controlling the mold temperature at 100-120 DEG C to obtain the high-strength cable tie.

[0016] The working principle and beneficial effects of the present application are as follows: The rigid-flexible dual-phase nanocomposite reinforcing agent plays a core synergistic role in the present application. The octa-aminophenyl cage silsesquioxane as a rigid nanometer core, its unique cage structure endows the reinforcing agent with high rigidity. In the preparation process, by reacting with ε-caprolactam, catalysts and other reaction systems, a prepolymer system is formed, and then polyether amine is introduced. The flexible segment provided by the polyether amine is ingeniously embedded in the rigid structure to form a rigid-flexible dual-phase structure. When interacting with the nylon 66 matrix, the rigid part can effectively bear external stress, improve the strength and heat resistance of the material; the flexible part can buffer stress concentration, prevent the material from breaking due to excessive local stress, and at the same time improve the toughness of the material. When subjected to external force, the rigid phase and the flexible phase work together to enable the material to withstand a large load, achieving a balance between strength and toughness.

[0017] The two-dimensional sheet nanofiller organic modified montmorillonite also has a synergistic effect with the rigid-flexible dual-phase nanocomposite reinforcing agent and the nylon 66 matrix in the present application. The organic modified montmorillonite has good dispersibility, and its sheet structure can be uniformly distributed in the matrix. On the one hand, the sheet structure can play a physical barrier role. When the material is subjected to external force and cracks, the crack propagation will be hindered when it encounters the sheet structure, thereby changing the crack propagation direction and consuming more energy, improving the strength and fracture toughness of the material; on the other hand, the surface of the sheet structure of the montmorillonite has a large number of functional groups, which can form a strong interfacial interaction between the rigid-flexible dual-phase nanocomposite reinforcing agent and the nylon 66 matrix, and enhance the interfacial bonding force. This good interfacial bonding enables stress to be effectively transmitted between the components, further improving the mechanical properties of the material, and also helps to improve the long-term mechanical retention of the material and prevent performance degradation due to interfacial debonding. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0019] It should be further pointed out that the nylon 66 brand is EPR27; the polyether amine is a product named Jefamine D-2000 and a brand of Huntsman; the organic modified montmorillonite brand is DK4, and the montmorillonite is sodium-based montmorillonite.

[0020] Example 1 The high-strength cable tie provided in the embodiment comprises the following components in parts by weight: nylon 66 80 parts, rigid-flexible dual-phase nano-composite reinforcing agent 18 parts, organically modified montmorillonite 5 parts, nucleating agent NA-50 0.3 parts, pentaerythritol stearate 1.0 part, thermal stabilizer 0.4 part, antioxidant 1098 0.2 part; The thermal stabilizer is a complex of potassium iodide and copper stearate in a mass ratio of 1:1. The preparation method of the rigid-flexible dual-phase nano-composite reinforcing agent comprises the following steps: A1. Disperse 100 parts of octaaminophenyl cage silsesquioxane in 500 parts of N-methylpyrrolidone solvent to form a uniform suspension under magnetic stirring. Transfer the suspension to a three-necked flask with a condensation reflux device and a nitrogen inlet and outlet, protect it by passing nitrogen, and heat it to 80℃ under nitrogen atmosphere; A2. Add 500 parts of ε-caprolactam, 5 parts of caprolactam magnesium bromide and 50 parts of polyether amine to the above suspension in sequence; maintain the system temperature at 85℃, and react for 1.5 hours at a mechanical stirring speed of 300 rpm to form a transparent prepolymer system; A3. Reduce the temperature of the prepolymer system to 60℃; place 2.5 parts of toluene diisocyanate (TDI) in a constant-pressure dropping funnel, and slowly drop it into the reaction system, with the dropping time controlled within 30 minutes; after the dropping is completed, heat the system to 90℃, and continue to stir for 2 hours; A4. Slowly pour the viscous product after the reaction is completed into a large amount of deionized water for precipitation; crush the precipitated solid product by a crusher, and wash it repeatedly with deionized water for 3 times; finally, place the washed product in a vacuum drying oven, and vacuum dry it at 100℃ for 12 hours to obtain a white or light yellow powder product, which is the rigid-flexible dual-phase nano-composite reinforcing agent; The preparation method of the high-strength cable tie in the embodiment comprises the following steps: S1. Accurately weigh the dry nylon 66 resin, rigid-flexible dual-phase nano-composite reinforcing agent, organically modified montmorillonite, nucleating agent, lubricant, thermal stabilizer and antioxidant according to the above proportions; put all the raw materials into a high-speed mixer, mix them for 5 minutes at a speed of 1000 rpm to ensure that the components are uniformly dispersed, and obtain a premix; S2. Send the premix through a loss-in-weight feeder into a co-rotating parallel twin-screw extruder; set the temperatures of each section of the extruder as follows: 250℃ for the first section, 260℃ for the second section, 265℃ for the third section, 270℃ for the fourth section, and 265℃ for the die head; set the screw rotation speed at 250 rpm. The melt-blended material is cooled in a water tank, and then cut into particles by a pelletizer to obtain a uniform composite material master batch; S3. The cut composite master batch is placed in a hot air circulating drying oven, and dried at 120℃ for 4 hours to reduce the water content of the master batch to below 0.1%, to obtain dried master batch; S4. The dried master batch is put into an injection molding machine; a cable tie special mold is used, and the mold temperature is set to 110℃; the injection molding process parameters are: injection pressure 80 MPa, holding pressure 60 MPa, injection speed medium, cooling time 20 seconds; the high-strength cable tie product is obtained after the mold is opened.

[0021] Example 2 The high-strength cable tie provided in this example includes the following components by weight: nylon 66 70 parts, rigid-flexible dual-phase nano-composite reinforcing agent 12 parts, organically modified montmorillonite 3 parts, nucleating agent NA-50 0.1 part, pentaerythritol stearate 0.5 part, heat stabilizer 0.2 part, antioxidant 1098 0.1 part; The heat stabilizer is a composite of potassium iodide and copper stearate in a mass ratio of 1:0.8. The preparation method of the rigid-flexible dual-phase nano-composite reinforcing agent includes: A1. Disperse 100 parts of octaaminophenyl cage silsesquioxane in 400 parts of N-methylpyrrolidone solvent to form a uniform suspension under magnetic stirring. Transfer the suspension to a three-necked flask with a condensation reflux device and nitrogen inlet and outlet, protect it with nitrogen, and heat it to 75℃ under nitrogen atmosphere; A2. Add 450 parts of ε-caprolactam, 4 parts of caprolactam magnesium bromide, and 45 parts of polyether amine to the above suspension in sequence; maintain the system temperature at 80℃, and react for 1 hour at a mechanical stirring speed of 300 rpm to form a transparent prepolymer system; A3. Reduce the temperature of the prepolymer system to 55℃; place 2.0 parts of toluene diisocyanate (TDI) in a constant pressure dropping funnel, and slowly add it to the reaction system, with a drop adding time controlled at 20 minutes; after the drop adding is completed, heat the system to 85℃, and continue to stir for 1.5 hours; A4. Slowly pour the viscous product of the completed reaction into a large amount of deionized water for precipitation; coarsely crush the precipitated solid product with a crusher, and wash it repeatedly with deionized water for 3 times; finally, place the washed product in a vacuum drying oven, and vacuum dry it at 95℃ for 10 hours to obtain a white or light yellow powder product, which is the rigid-flexible dual-phase nano-composite reinforcing agent; The preparation method of the high-strength cable tie in this example includes the following steps: S1. Accurately weigh the dry nylon 66 resin, rigid-flexible dual-phase nano-composite reinforcing agent, organically modified montmorillonite, nucleating agent, lubricant, heat stabilizer and antioxidant according to the above ratio. Put all the raw materials into a high-speed mixer and mix at a speed of 800 rpm for 3 minutes to ensure uniform dispersion of each component and obtain a premix; S2. Send the premix through a loss-in-weight feeder into a co-rotating parallel twin-screw extruder. Set the temperature of each section of the extruder as follows: zone 1 245℃, zone 2 255℃, zone 3 260℃, zone 4 265℃, and the die 260℃. Set the screw speed at 200 rpm. The melt-blended material is cooled in a water tank and then granulated by a granulator to obtain a uniform composite masterbatch; S3. Place the cut composite masterbatch in a hot air circulating drying oven and dry it at 115℃ for 3 hours to reduce the water content of the masterbatch to below 0.1% to obtain a dried masterbatch; S4. Put the dried masterbatch into an injection molding machine. Use a cable tie special mold with a mold temperature setting of 100℃. The injection molding process parameters are: injection pressure 80 MPa, holding pressure 60 MPa, injection speed medium, cooling time 20 seconds. The high-strength cable tie product is obtained after the mold is opened.

[0022] Example 3 A high-strength cable tie is provided in this example, which includes the following components by weight: nylon 66 85 parts, rigid-flexible dual-phase nano-composite reinforcing agent 25 parts, organically modified montmorillonite 8 parts, nucleating agent NA-50 0.5 parts, pentaerythritol stearate 1.5 parts, heat stabilizer 0.6 parts, antioxidant 1098 0.3 parts; The heat stabilizer is a composite of potassium iodide and copper stearate in a mass ratio of 1:1.2. The preparation method of the rigid-flexible dual-phase nano-composite reinforcing agent includes: A1. Disperse 100 parts of octaaminophenyl cage silsesquioxane in 600 parts of N-methylpyrrolidone solvent to form a uniform suspension under magnetic stirring. Transfer the suspension to a three-necked flask with a condensation reflux device and nitrogen inlet and outlet, protect it with nitrogen, and heat it to 85℃ under nitrogen atmosphere; A2. Add 550 parts of ε-caprolactam, 6 parts of caprolactam magnesium bromide and 55 parts of polyether amine to the above suspension in sequence. Maintain the system temperature at 90℃ and react for 2 hours at a mechanical stirring speed of 300 rpm to form a transparent prepolymer system; A3. The temperature of the prepolymer system is reduced to 65°C; 3.0 parts of toluene diisocyanate (TDI) is placed in a constant pressure dropping funnel, and slowly added into the reaction system, the dropping time is controlled within 40 minutes; after the dropping is completed, the system is heated to 95°C, and the stirring reaction is continued for 2.5 hours; A4. The viscous product after the reaction is completed is slowly poured into a large amount of deionized water for precipitation; the precipitated solid product is coarsely crushed by a crusher, and then washed repeatedly with deionized water for 3 times, and finally the washed product is placed in a vacuum drying oven, and vacuum dried at 105°C for 14 hours to obtain a white or light yellow powder product, which is a rigid-flexible dual-phase nanocomposite reinforcing body; The preparation method of the high-strength cable tie in the embodiment includes the following steps: S1. According to the above ratio, accurately weigh the dry nylon 66 resin, rigid-flexible dual-phase nanocomposite reinforcing body, organically modified montmorillonite, nucleating agent, lubricant, thermal stabilizer and antioxidant; all the raw materials are put into a high-speed mixer and mixed at a speed of 1200 rpm for 8 minutes to ensure uniform dispersion of each component, and a premix is obtained; S2. The premix is sent into a co-rotating parallel twin-screw extruder through a loss weight feeder; the temperature of each section of the extruder is set as follows: zone 1 255°C, zone 2 265°C, zone 3 270°C, zone 4 275°C, and the die head 270°C; the screw rotation speed is set to 300 rpm. The melt blended material is cooled in a water tank, and then cut into granules by a granulator to obtain uniform composite material masterbatch; S3. The cut composite material masterbatch is placed in a hot air circulating drying oven and dried at 125°C for 5 hours to reduce the water content of the masterbatch to below 0.1%, and a dried masterbatch is obtained; S4. The dried masterbatch is put into an injection molding machine; a cable tie special mold is used, and the mold temperature is set to 120°C; the injection molding process parameters are: injection pressure 80 MPa, holding pressure 60 MPa, injection speed medium, cooling time 20 seconds; the high-strength cable tie product is obtained after the mold is opened.

[0023] Example 4 Based on Example 1, the organically modified montmorillonite is replaced with an equal amount of unmodified sodium-based montmorillonite, and the rest is the same as Example 1.

[0024] Example 5 Adjustment is made on the basis of Example 1, and different from Example 1 is that no polyether amine is added in step A2 when preparing the rigid-flexible dual-phase nanocomposite reinforcing agent. The specific preparation method is as follows: first, a comparative reinforcing agent is prepared, steps Al and A2 are the same as those in Example 1, in step A3, 500 parts of ε-caprolactam and 5 parts of catalyst caprolactam magnesium bromide are added into the suspension, and the reaction is carried out at 85°C for 1.5 hours, A4 is the same as that in Example 1, and the rest is the same as that in Example 1.

[0025] Example 6 Adjustment is made on the basis of Example 1, and different from Example 1 is that no micro-crosslinking agent toluene diisocyanate is added in step A3 when preparing the rigid-flexible dual-phase nanocomposite reinforcing agent. The specific preparation method is as follows: first, a comparative reinforcing agent is prepared. Steps Al and A2 are the same as those in Example 1. In step A3, the pre-polymer system is cooled to 60°C, and then TDI is not added dropwise, but is directly heated to 90°C and stirred for 2 hours. A4 is the same as that in Example 1, and the rest is the same as that in Example 1.

[0026] Example 7 Adjustment is made on the basis of Example 1, and different from Example 1 is that no octaaminophenyl cage silsesquioxane is added in step Al when preparing the rigid-flexible dual-phase nanocomposite reinforcing agent. The specific preparation method is as follows: first, a comparative reinforcing agent is prepared. In step Al, 500 parts of N-methylpyrrolidone solvent is heated to 80°C. In step A2, 500 parts of ε-caprolactam, 5 parts of catalyst caprolactam magnesium bromide and 50 parts of polyether amine are directly added, and the reaction is carried out at 85°C for 1.5 hours. Steps A3 and A4 are the same as those in Example 1, and the rest is the same as that in Example 1.

[0027] Comparative Example 1 Adjustment is made on the basis of Example 1, and different from Example 1 is that no rigid-flexible dual-phase nanocomposite reinforcing agent and organically modified montmorillonite are added, and the amount is made up by an equal amount of nylon 66, and the rest is the same as that in Example 1.

[0028] Comparative Example 2 Adjustment is made on the basis of Example 1, and different from Example 1 is that no rigid-flexible dual-phase nanocomposite reinforcing agent is added, and the amount is made up by an equal amount of nylon 66, and the rest is the same as that in Example 1.

[0029] Comparative Example 3 Adjustment is made on the basis of Example 1, and different from Example 1 is that no organically modified montmorillonite is added, and the amount is made up by an equal amount of nylon 66, and the rest is the same as that in Example 1.

[0030] Test Example: The high-strength cable ties prepared in the foregoing Examples 1-7 and Comparative Examples 1-3 are tested as follows: Tensile strength and elongation at break: tested according to ISO 527-1:2019 "Determination of the tensile properties of plastics - Part 1: General principles" using a universal testing machine on dumbbell-shaped (type 1A) specimens at a tensile speed of 50 mm / min, recording the maximum load and the elongation at break of the specimen, and calculating the tensile strength and elongation at break, respectively; Heat resistance (heat deflection temperature): tested according to ISO 75-2:2013 "Determination of the heat distortion temperature of plastics - Part 2: Plastics and ebonite" using a heat deflection temperature tester; method A (flat) was applied, a bending stress of 1.80 MPa was applied, the temperature rate was 120 °C / h, and the temperature at which the specimen deflected to a specified deflection (0.34 mm) was recorded as the heat deflection temperature; Long-term tightening force retention rate: formulated according to ASTM D2990-17 "Tensile, compression, and flexural tests for plastics and its applications" and actual application conditions; a hard, smooth metal round rod with a tightening diameter of 25.0 ± 0.1 mm and a length of not less than 150 mm was tightened by a standard cable tie, and the initial tightening force (F0) was measured; then it was placed in a constant temperature environment of 85 ± 2 °C for 1000 hours, then taken out and cooled to room temperature, and then the remaining tightening force (F1) was measured again; the tightening force retention rate was calculated according to the formula (F1 / F0) x 100%; Heat aging resistance (strength retention rate): the dumbbell-shaped specimen for tensile testing was placed in a blast oven at 120 ± 2 °C for continuous treatment for 168 hours; after taking out, it was adjusted in a standard laboratory environment (23 ± 2 °C, 50 ± 10% RH) for 24 hours; then it was tested according to the above tensile strength test method, the tensile strength after aging was calculated, and compared with the tensile strength of the original specimen without aging, and the strength retention rate was obtained; The results are shown in Table 1 below: Table 1

[0031] It can be seen from the above that the comprehensive performance of Examples 1-3 is good, which indicates that the rigid-flexible dual-phase nano-composite reinforcing agent, organically modified montmorillonite, and composite heat stabilizer have good synergistic effect among the components, and high strength, high heat resistance, and excellent long-term mechanical retention are achieved.

[0032] Example 4 is replaced with unmodified montmorillonite, and the dispersibility and interfacial compatibility are poor. Compared with Example 1, the tensile strength is slightly decreased, the elongation at break is greatly reduced, and the long-term tightening force retention rate and heat aging resistance are also significantly reduced. It shows that organic modification of montmorillonite is crucial for its dispersion and interfacial compatibility, and unmodified montmorillonite is easy to agglomerate, resulting in a decrease in toughness and long-term performance.

[0033] Example 5 The absence of polyether amine in the preparation of the reinforcing body, the absence of a flexible phase, affects the long-term mechanical retention. The tensile strength and heat distortion temperature are still relatively high, but the elongation at break and the retention rate of the tightening force decrease significantly. It shows that the introduction of polyether amine provides a flexible segment, which plays an important role in improving the toughness and creep resistance (tightening force retention) of the material.

[0034] Example 6 The absence of a micro-crosslinking agent in the preparation of the reinforcing body, the absence of a crosslinking network, leads to a comprehensive decline in performance. The tensile strength, heat distortion temperature, tightening force retention rate and strength retention rate are significantly lower than those of Example 1. It shows that the micro-crosslinking structure is crucial to the rigidity, heat resistance and creep resistance of the reinforcing body.

[0035] Example 7 The absence of cage-type silsesquioxane in the preparation of the reinforcing body, the absence of rigid nanostructure, the performance decline is most obvious. The tensile strength and heat distortion temperature are the lowest, the tightening force retention rate and the strength retention rate are also poor, but the elongation at break is higher. It shows that octaaminophenyl POSS as a rigid nanocore plays a key role in improving strength, heat resistance and long-term stability, and its absence leads to the loss of the rigid-flexible dual-phase structure advantage of the reinforcing body.

[0036] Comparative Example 1 Without reinforcing body and montmorillonite, the performance of pure nylon 66 is the benchmark. The tensile strength and heat distortion temperature are extremely low, the long-term tightening force retention rate and strength retention rate are poor, but the elongation at break is the highest. It shows that un-reinforced nylon 66 cannot meet the application requirements of high strength and high heat resistance, confirming the necessity of the nano-composite reinforcing system.

[0037] Comparative Example 2 Without rigid-flexible reinforcing body, the reinforcing effect of montmorillonite alone is limited. The tensile strength and heat distortion temperature are slightly improved, but still far lower than those of Example 1, and the tightening force retention rate is also poor. It shows that the use of montmorillonite alone cannot achieve high strength and high heat resistance, and the rigid-flexible dual-phase reinforcing body plays a leading role in reinforcement.

[0038] Comparative Example 3 Without montmorillonite, the absence of sheet barrier and reinforcement leads to a decline in long-term performance. The tensile strength and heat distortion temperature are still relatively high, but the tightening force retention rate and strength retention rate are lower than those of Example 1. It shows that montmorillonite as a two-dimensional sheet filler can improve the barrier property and creep resistance, and has an important contribution to the long-term mechanical retention.

[0039] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A high-strength cable tie, characterized in that, By weight, it includes the following components: 70-85 parts of nylon 66, 12-25 parts of rigid-flexible biphase nanocomposite reinforcement, 3-8 parts of two-dimensional sheet nanofiller, 0.1-0.5 parts of nucleating agent, 0.5-1.5 parts of lubricant, 0.2-0.6 parts of heat stabilizer, and 0.1-0.3 parts of antioxidant.

2. The high-strength cable tie according to claim 1, characterized in that, The method for preparing the rigid-flexible dual-phase nanocomposite reinforcement includes: A1. Disperse a cage-like silsesquioxane with an amino functional group in an N-methylpyrrolidone solvent to form a suspension, and heat it to 75-85℃ under nitrogen protection. A2. Add ε-caprolactam, catalyst and polyetheramine to the suspension in sequence, and stir at 80-90°C for 1-2 hours to form a prepolymer system; A3. Lower the temperature of the prepolymer system to 55-65℃, add the micro-crosslinking agent, and after the addition is complete, raise the temperature to 85-95℃ and react for 1.5-2.5 hours; A4. The reaction product is poured into deionized water for precipitation, then crushed, washed, and vacuum dried at 95-105℃ for 10-14 hours to obtain the powdered rigid-flexible biphase nanocomposite reinforcement.

3. A high-strength cable tie according to claim 2, characterized in that, The cage-like silsesquioxane with amino functional groups is an octaaminophenyl cage-like silsesquioxane; the catalyst is caprolactam magnesium bromide.

4. A high-strength cable tie according to claim 2, characterized in that, The micro-crosslinking agent is toluene diisocyanate; the micro-crosslinking agent is added over a period of 20-40 minutes.

5. A high-strength cable tie according to claim 2, characterized in that, The weight ratio of the amino-functionalized cage-like silsesquioxane, N-methylpyrrolidone, ε-caprolactam, catalyst, polyetheramine, and microcrosslinking agent is 100:400-600:450-550:4-6:45-55:2.0-3.

0.

6. A high-strength cable tie according to claim 1, characterized in that, The two-dimensional sheet-like nanofiller is organically modified montmorillonite.

7. A high-strength cable tie according to claim 1, characterized in that, The nucleating agent is nucleating agent NA-50; the lubricant is pentaerythritol stearate.

8. A high-strength cable tie according to claim 1, characterized in that, The heat stabilizer is a complex composed of potassium iodide and copper stearate in a mass ratio of 1:0.8-1.

2.

9. A high-strength cable tie according to claim 1, characterized in that, The antioxidant is antioxidant 1098.

10. A method for preparing a high-strength cable tie according to any one of claims 1-9, characterized in that the step include: S1. Nylon 66, rigid-flexible biphase nanocomposite reinforcement, two-dimensional sheet nanofiller, nucleating agent, lubricant, heat stabilizer, and antioxidant are put into a high-speed mixer and mixed at 800-1200 rpm for 3-8 minutes to obtain a premix. S2. The premixed material is fed into a co-rotating twin-screw extruder for melt blending and granulation. The temperatures of each section of the extruder are set as follows: Zone 1 245-255℃, Zone 2 255-265℃, Zone 3 260-270℃, Zone 4 265-275℃, and Die Head 260-270℃. The screw speed is 200-300 rpm. After water cooling and pelletizing, composite material masterbatch is obtained. S3. Dry the composite material masterbatch at 115-125℃ for 3-5 hours to obtain the dried masterbatch; S4. The dried masterbatch is fed into an injection molding machine and injection molded using a process where the mold temperature is controlled at 100-120℃ to obtain the high-strength cable tie.

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