High and low temperature resistant TPEE material for electric wire and cable and preparation method thereof

Abstract

The application belongs to the field of high polymer materials, and discloses a high and low temperature resistant TPEE material for electric wires and cables and a preparation method thereof.The high and low temperature resistant TPEE material comprises the following raw materials: TPEE resin 90-110 parts, modified nano-silicon dioxide 8-12 parts, composite flame retardant 15-25 parts, low temperature resistant plasticizer 8-12 parts, maleic anhydride grafted POE 3-5 parts, antioxidant 0.5-1 part, light stabilizer 0.3-0.5 part and silicone micro powder 0.5-1 part; the application takes TPEE resin as a matrix, matches the compatibilizer, antioxidant, light stabilizer and lubricant, and through compounding modified nano-silicon dioxide, composite flame retardant and low temperature resistant plasticizer, the comprehensive performance of the TPEE cable material is significantly improved, and the TPEE cable material has super wide temperature range adaptability, efficient halogen-free flame retardation and excellent environmental durability.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a high and low temperature resistant TPEE material for wires and cables and its preparation method. Background Technology

[0002] Thermoplastic polyester elastomer (TPEE) combines the high elasticity of rubber with the toughness of engineering plastics, exhibiting excellent high and low temperature resistance, oil and chemical resistance, and good electrical insulation properties. It is widely used in wire and cable sheathing and insulation layers. However, existing TPEE materials still have significant shortcomings in their service performance under extreme temperature environments. At low temperatures, traditional TPEE is prone to brittle fracture below -40℃, failing to meet the requirements of high-altitude or polar environments. At high temperatures, the long-term operating temperature is typically no more than 120℃, and it easily softens and deforms in high-temperature environments such as engine compartments and heat-generating equipment, shortening cable life. To improve low-temperature resistance, the conventional method is to add small-molecule plasticizers; however, these plasticizers are prone to volatilization and precipitation during high-temperature processing or use, causing the material to gradually harden and become brittle, with limited low-temperature resistance. To improve heat resistance, inorganic fillers are often used for reinforcement; however, unmodified nanofillers have poor dispersion in the TPEE matrix and are prone to agglomeration, which impairs mechanical properties and electrical insulation.

[0003] Flame retardancy is also a significant challenge for TPEE cable materials. TPEE itself is flammable and produces severe dripping during combustion, which can easily cause a fire to spread. While traditional halogenated flame retardants have high flame retardant efficiency, they release large amounts of toxic fumes during combustion, failing to meet environmental protection requirements. Existing halogen-free flame retardant systems (such as phosphorus-nitrogen-based small molecule flame retardants) tend to migrate and precipitate in TPEE, exhibiting poor long-term flame retardant stability and significantly reducing the material's mechanical properties, making it difficult to achieve a balance between flame retardancy and mechanical properties.

[0004] Furthermore, TPEE cable materials exhibit insufficient long-term durability under harsh environments such as humidity, heat, salt spray, and mold. The ester bonds in the TPEE molecular chain are prone to hydrolysis under high temperature and humidity conditions, leading to a sharp decline in mechanical properties. When used in marine or industrially polluted environments, salt spray can corrode the metal shielding layer, affecting signal transmission and security. Cables exposed to underground or humid environments for extended periods are susceptible to mold growth, accelerating material aging. Existing technologies typically address this by adding anti-hydrolysis agents and antibacterial agents, but these methods suffer from problems such as agent migration, limited functionality, and poor compatibility with the matrix, making it difficult to achieve synergistic protection against multiple environmental factors. Summary of the Invention

[0005] To address the shortcomings mentioned in the background art, the present invention aims to provide a high and low temperature resistant TPEE material for wires and cables and its preparation method. Using TPEE resin as the matrix, it is combined with compatibilizers, antioxidants, light stabilizers and lubricants, and by compounding modified nano-silica, composite flame retardants and low temperature resistant plasticizers, the comprehensive performance of TPEE cable materials is significantly improved, exhibiting ultra-wide temperature range adaptability, high efficiency halogen-free flame retardancy and excellent environmental durability.

[0006] The objective of this invention can be achieved through the following technical solutions: A high and low temperature resistant TPEE material for wires and cables comprises the following raw materials in parts by weight: 90-110 parts TPEE resin, 8-12 parts modified nano silica, 15-25 parts composite flame retardant, 8-12 parts low temperature resistant plasticizer, 3-5 parts maleic anhydride grafted POE, 0.5-1 part antioxidant, 0.3-0.5 parts light stabilizer, and 0.5-1 part silicone micro powder; The modified nano-silica is nano-silica grafted with end-carboxyl hyperbranched polyester and then ZIF-8 nanocrystalline layer grown in situ; the composite flame retardant is diisobutyl aluminum hypophosphite and melamine cyanurate grafted onto the epoxy functionalized polystyrene polymer backbone through interfacial polymerization; the low-temperature resistant plasticizer is hydroxyl-terminated polybutadiene grafted with diisononyl oxalate.

[0007] Preferably, the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1.

[0008] Preferably, the light stabilizer is a mixture of benzotriazole ultraviolet absorber and hindered amine light stabilizer in a mass ratio of 1:1.

[0009] Preferably, the method for preparing modified nano-silica includes the following steps: (1) Disperse nano-silica in a mixture of anhydrous ethanol and deionized water, sonicate for 20-40 min, add 3-aminopropyltriethoxysilane, adjust the pH to 4-5 with acetic acid, reflux at 80℃ for 4-8 h, centrifuge, wash 3 times with ethanol, and vacuum dry to obtain aminated nano-silica. (2) Aminated nano-silica was dispersed in dimethyl sulfoxide, and carboxyl-terminated hyperbranched polyester and 4-dimethylaminopyridine were added under nitrogen protection. The temperature was raised to 120°C and the reaction was carried out for 20-28 hours. After the reaction was completed, the mixture was centrifuged, washed three times with dimethyl sulfoxide, and then washed three times with ethanol. The mixture was then dried under vacuum to obtain hyperbranched polyester-grafted nano-silica. (3) Disperse hyperbranched polyester-grafted nano-silica in methanol and sonicate for 10-20 min. Dissolve zinc nitrate in methanol to obtain solution A. Dissolve 2-methylimidazole in methanol to obtain solution B. Add solution A dropwise to the hyperbranched polyester-grafted nano-silica dispersion and stir for 5-15 min. Then slowly add solution B. Stir the reaction at room temperature for 1.5-2.5 h. Collect the product by centrifugation, wash it three times with methanol, and dry it under vacuum to obtain modified nano-silica.

[0010] Preferably, the mass ratio of nano-silica to 3-aminopropyltriethoxysilane is 2:1, the mass ratio of aminated nano-silica to carboxyl-terminated hyperbranched polyester is 2:5, and the mass ratio of hyperbranched polyester grafted with nano-silica, zinc nitrate, and 2-methylimidazole is 10:3:6. Preferably, the preparation method of the composite flame retardant includes the following steps: A. Dissolve epoxy-functionalized polystyrene in xylene, heat to 80°C and stir to dissolve, add toluene diisocyanate and dibutyltin dilaurate, and react at 80°C for 1.5~2.5h; B. Add diisobutyl aluminum hypophosphite and melamine cyanurate to the above system, continue the reaction for 3-5 hours, and maintain the temperature at 80℃. After the reaction is completed, remove the solvent by vacuum distillation, wash 3 times with N,N-dimethylformamide, wash 3 times with deionized water, dry under vacuum, and then pulverize at -40℃ through a 200-mesh sieve to obtain the composite flame retardant.

[0011] Preferably, the mass ratio of epoxy-functionalized polystyrene, toluene diisocyanate, aluminum diisobutylphosphite, and melamine cyanurate is 4:1:2:2.

[0012] Preferably, the preparation method of the low-temperature resistant plasticizer includes the following steps: a. Under dry nitrogen protection, hydroxyl-terminated polybutadiene is dissolved in anhydrous toluene, heated to 60°C, toluene diisocyanate and dibutyltin dilaurate are added, and the mixture is reacted at 60°C for 2-4 hours to obtain NCO-terminated polybutadiene prepolymer. b. Add diisononyl oxalate to the prepolymer and continue the reaction for 3-5 hours. When the temperature is raised to 80℃ and the characteristic peak of -NCO disappears in infrared detection, stop the reaction. Remove toluene by vacuum distillation to obtain a viscous liquid. Wash the liquid three times with n-hexane to remove unreacted diisononyl oxalate. Dry the liquid under vacuum to obtain a low-temperature resistant plasticizer.

[0013] Preferably, the mass ratio of hydroxyl-terminated polybutadiene to diisononyl oxalate is 5:4.

[0014] A method for preparing high and low temperature resistant TPEE material for wires and cables includes the following steps: S1. Dry mix modified nano silica, composite flame retardant, and maleic anhydride grafted POE in a high-speed mixer for 3-5 minutes, add TPEE powder accounting for 30% of the total TPEE resin weight, continue mixing for 3-5 minutes, and extrude the above premix in a twin-screw extruder to obtain functional masterbatch. S2. A twin-screw extruder is used for melt blending and granulation. 70% of the total TPEE resin weight of TPEE granules, antioxidants, UV absorbers and lubricants are added from the main feed port. Functional masterbatch and low-temperature resistant plasticizer are added from the side feed port. After extrusion, water cooling and pelletizing are carried out and then air drying is performed to obtain high and low temperature resistant TPEE material for wires and cables.

[0015] The beneficial effects of this invention are: This invention uses TPEE resin as the matrix, which exhibits excellent high and low temperature resistance, oil resistance, chemical resistance, and electrical insulation properties. Maleic anhydride-grafted POE is used as a compatibilizer, significantly improving the inorganic-organic interface bonding, preventing nanofiller agglomeration, and ensuring uniform dispersion of all components. This enhances the tensile strength and elongation at break of the material, avoiding the decrease in toughness caused by the addition of fillers. The antioxidant is a combination of hindered phenolic antioxidant 1010 and phosphite antioxidant 168. The hindered phenolic antioxidant can capture free radicals and terminate the thermal oxidation chain reaction, while the phosphite antioxidant can decompose hydrogen peroxide. The combination of these two antioxidants produces a synergistic antioxidant effect, effectively inhibiting the oxidative degradation of TPEE during high-temperature processing and long-term thermal aging, significantly improving the material's thermal stability and service life. A benzotriazole UV absorber is combined with a hindered amine light stabilizer. The benzotriazole UV absorber absorbs ultraviolet light and converts it into heat energy, while the hindered amine light stabilizer (HALS) captures free radicals generated by photo-oxidation. The combination of these two components forms a dual protection against ultraviolet radiation and free radical capture, significantly improving the material's anti-aging ability under outdoor sunlight and preventing surface cracking, pulverization, and mechanical property degradation caused by ultraviolet radiation. Using silicone micropowder as a lubricant reduces friction between the melt and the equipment's metal surface, as well as internal friction between polymer molecules during processing. This effectively prevents increased processing torque and melt fracture caused by high filler content, while also promoting filler dispersion, ensuring extrusion stability and product surface smoothness. By combining modified nano-silica, composite flame retardants, and low-temperature plasticizers, the overall performance of TPEE cable materials is significantly improved. It features ultra-wide temperature range adaptability, high-efficiency halogen-free flame retardancy, and excellent environmental durability. It solves the problems of traditional TPEE materials becoming brittle at extremely low temperatures and softening and deforming at high temperatures. It has high flame retardant efficiency, and the flame retardant does not migrate or precipitate. It is halogen-free and environmentally friendly, and has anti-damp heat aging, antibacterial, anti-mildew, and anti-salt spray corrosion effects, making it suitable for various complex working conditions.

[0016] This invention modifies nano-silica by grafting hyperbranched polyester onto nano-SiO2. Utilizing the three-dimensional branched structure and numerous terminal functional groups of the hyperbranched polyester, ultra-dispersion of nanoparticles within TPEE is achieved. Then, metal-organic framework ZIF-8 nanocrystals are grown in situ on the surface of the hyperbranched polyester shell. The modified nano-silica forms a uniformly dispersed nanonetwork in the matrix, restricting the thermal motion of molecular chains and increasing the Vicat softening temperature. The micropores of ZIF-8 adsorb water vapor, and the hydrophobic shell on its surface delays water molecule diffusion. Simultaneously, the weakly alkaline environment generated by the hydrolysis of ZIF-8 neutralizes the carboxylic acid generated by the hydrolysis of TPEE, inhibiting autocatalytic reactions and improving resistance to damp heat aging. ZIF-8 slowly releases Zn in humid environments. 2+ It disrupts microbial cell membranes and enzyme systems, achieving long-lasting antibacterial effects; uncoordinated nitrogen atoms within the ZIF-8 channels selectively adsorb Cl... - Reduce Cl - The copper corrosion rate decreases as the copper migrates to the metal interface. At high temperatures, ZIF-8 decomposes to generate ZnO, which catalyzes the dehydration of TPEE and phosphorus-nitrogen flame retardants into char, making the char layer denser and achieving a synergistic flame retardant effect.

[0017] This invention's composite flame retardant uses epoxy-functionalized polystyrene as its polymer backbone. Diisobutylaluminum hypophosphite and melamine cyanurate are grafted onto the backbone via isocyanate bridging, forming a macromolecular intumescent flame retardant with a molecular weight ≥8000. At high temperatures, the phosphorus component catalyzes to form char, and the nitrogen component releases non-combustible gases, forming a closed-cell intumescent char layer, resulting in highly efficient intumescent flame retardancy. The macromolecular structure results in an extremely low diffusion coefficient within TPEE, with no precipitation after 85℃×1000h thermal aging, demonstrating long-lasting and stable flame retardant performance. The polystyrene backbone exhibits good compatibility with the hard segments of TPEE, and melamine cyanurate can form hydrogen bonds with the carboxyl groups of TPEE, reducing tensile strength loss compared to traditional small-molecule flame retardants.

[0018] This invention relates to a low-temperature resistant plasticizer made by grafting diisononyl oxalate onto hydroxyl-terminated polybutadiene, resulting in a macromolecular plasticizer with reactive end groups. The polybutadiene backbone itself has an extremely low glass transition temperature, and its terminal hydroxyl groups can react with the terminal carboxyl groups of TPEE to achieve chemical anchoring. The flexible segments of the low-temperature resistant plasticizer increase the free volume of the molecular chain, thereby lowering the Tg and low-temperature embrittlement temperature of TPEE, maintaining flexibility even under extremely cold conditions. The macromolecular structure and chemical anchoring reduce the volatilization loss rate of the low-temperature resistant plasticizer at high temperatures, solving the problem of plasticizer precipitation leading to material embrittlement during high-temperature processing and use. The low-temperature resistant plasticizer maintains a rubbery state at low temperatures, absorbing impact energy at crack tips, thus improving the low-temperature elongation at break of the material. The unsaturated double bonds of the low-temperature resistant plasticizer can undergo addition reactions with the hydroxyl groups of HBPE and with the Zn of ZIF-8. 2+ Coordination bonds are formed, further improving filler dispersion and interfacial bonding.

[0019] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1 A modified nano-silica, comprising the following steps: nano-silica grafted with end-carboxyl hyperbranched polyester followed by in-situ growth of ZIF-8 nanocrystalline layers; the preparation method of the modified nano-silica includes the following steps: (1) Disperse 10g of nano silica in a mixture of 200mL of anhydrous ethanol and 20mL of deionized water, sonicate for 30min, add 5g of 3-aminopropyltriethoxysilane, adjust the pH to 4-5 with acetic acid, reflux at 80℃ for 6h, centrifuge, wash 3 times with ethanol, and vacuum dry at 60℃ to obtain aminated nano silica. (2) Take 8g of aminated nano silica and disperse it in 150mL of dimethyl sulfoxide. Under nitrogen protection, add 20g of carboxyl-terminated hyperbranched polyester and 0.5g of 4-dimethylaminopyridine. Heat to 120℃ and react for 24h. After the reaction is completed, centrifuge, wash with dimethyl sulfoxide 3 times, then wash with ethanol 3 times, and dry under vacuum at 60℃ to obtain hyperbranched polyester grafted nano silica. (3) Disperse 5g of hyperbranched polyester-grafted nano silica in 100mL of methanol and sonicate for 15min. Dissolve 1.5g of zinc nitrate in 50mL of methanol to obtain solution A. Dissolve 3.0g of 2-methylimidazole in 50mL of methanol to obtain solution B. Add solution A dropwise to the hyperbranched polyester-grafted nano silica dispersion and stir for 10min. Then slowly add solution B. Stir the reaction at room temperature for 2h. Collect the product by centrifugation, wash it three times with methanol, and dry it under vacuum at 60℃ to obtain modified nano silica.

[0022] Example 2 A composite flame retardant, comprising diisobutylaluminum hypophosphite and melamine cyanurate grafted onto an epoxy-functionalized polystyrene polymer backbone via interfacial polymerization, is prepared by the following steps: A. Dissolve 20g of epoxy-functionalized polystyrene in 150mL of xylene, heat to 80℃ and stir to dissolve, add 5g of toluene diisocyanate and 0.1g of dibutyltin dilaurate, and react at 80℃ for 2h; B. Add 10g of diisobutylaluminum hypophosphite and 10g of melamine cyanurate to the above system, continue the reaction for 4h, and maintain the temperature at 80℃. After the reaction is completed, remove the solvent by vacuum distillation, wash 3 times with N,N-dimethylformamide, wash 3 times with deionized water, dry under vacuum at 60℃, and pulverize at -40℃ through a 200-mesh sieve to obtain the composite flame retardant.

[0023] Example 3 A low-temperature resistant plasticizer, wherein the low-temperature resistant plasticizer is hydroxyl-terminated polybutadiene-grafted diisononyl oxalate, and its preparation method includes the following steps: a. Under dry nitrogen protection, 100g of hydroxyl-terminated polybutadiene was dissolved in 200mL of anhydrous toluene, heated to 60℃, and 15g of toluene diisocyanate and 0.2g of dibutyltin dilaurate were added. The mixture was reacted at 60℃ for 3h to obtain NCO-terminated polybutadiene prepolymer. b. Add 80g of diisononyl oxalate (containing a small amount of hydroxyl impurities or pre-hydroxymethylated) to the prepolymer, continue the reaction for 4h, raise the temperature to 80℃, stop the reaction when the infrared detection of the -NCO characteristic peak disappears, remove toluene by vacuum distillation, obtain a viscous liquid, wash three times with n-hexane to remove unreacted diisononyl oxalate, and dry under vacuum at 40℃ to obtain the low-temperature resistant plasticizer.

[0024] Example 4 A high and low temperature resistant TPEE material for wires and cables comprises the following raw materials in parts by weight: 90 parts TPEE resin, 8 parts modified nano silica, 15 parts composite flame retardant, 8 parts low temperature resistant plasticizer, 3 parts maleic anhydride grafted POE, 0.25 parts antioxidant 1010, 0.25 parts antioxidant 168, 0.15 parts benzotriazole ultraviolet absorber, 0.15 parts hindered amine light stabilizer, and 0.5 parts silicone micro powder; wherein the modified nano silica is prepared in Example 1, the composite flame retardant is prepared in Example 2, and the low temperature resistant plasticizer is prepared in Example 3.

[0025] The preparation method of the above-mentioned high and low temperature resistant TPEE material for wires and cables includes the following steps: S1. The modified nano-silica, composite flame retardant, and maleic anhydride-grafted POE are dry-mixed in a high-speed mixer for 3 minutes. TPEE powder accounting for 30% of the total TPEE resin weight is added and the mixture is mixed for another 3 minutes. The above premix is ​​then extruded and granulated in a twin-screw extruder to obtain a functional masterbatch. S2. The TPEE granules, comprising 70% of the total TPEE resin weight, antioxidant 1010, antioxidant 168, benzotriazole UV absorber, hindered amine light stabilizer, and silicone micro powder are added from the main feed port. The functional masterbatch and low-temperature resistant plasticizer are added from the side feed port. After extrusion, water cooling, pelletizing, and air drying, the high and low temperature resistant TPEE material for wires and cables is obtained.

[0026] Example 5 A high and low temperature resistant TPEE material for wires and cables comprises the following raw materials in parts by weight: 110 parts TPEE resin, 12 parts modified nano silica, 25 parts composite flame retardant, 12 parts low temperature resistant plasticizer, 5 parts maleic anhydride grafted POE, 0.5 parts antioxidant 1010, 0.5 parts antioxidant 168, 0.25 parts benzotriazole ultraviolet absorber, 0.25 parts hindered amine light stabilizer, and 1 part silicone micro powder; wherein the modified nano silica is prepared in Example 1, the composite flame retardant is prepared in Example 2, and the low temperature resistant plasticizer is prepared in Example 3.

[0027] The preparation method of the above-mentioned high and low temperature resistant TPEE material for wires and cables includes the following steps: S1. Dry mix modified nano silica, composite flame retardant, and maleic anhydride grafted POE in a high-speed mixer for 5 minutes, add TPEE powder accounting for 30% of the total TPEE resin weight, continue mixing for 5 minutes, and extrude the above premix in a twin-screw extruder to obtain functional masterbatch. S2. The TPEE granules, comprising 70% of the total TPEE resin weight, antioxidant 1010, antioxidant 168, benzotriazole UV absorber, hindered amine light stabilizer, and silicone micro powder are added from the main feed port. The functional masterbatch and low-temperature resistant plasticizer are added from the side feed port. After extrusion, water cooling, pelletizing, and air drying, the high and low temperature resistant TPEE material for wires and cables is obtained.

[0028] Example 6 A high and low temperature resistant TPEE material for wires and cables comprises the following raw materials in parts by weight: 100 parts TPEE resin, 10 parts modified nano silica, 20 parts composite flame retardant, 10 parts low temperature resistant plasticizer, 4 parts maleic anhydride grafted POE, 0.35 parts antioxidant 1010, 0.35 parts antioxidant 168, 0.2 parts benzotriazole ultraviolet absorber, 0.2 parts hindered amine light stabilizer, and 0.8 parts silicone micro powder; wherein the modified nano silica is prepared in Example 1, the composite flame retardant is prepared in Example 2, and the low temperature resistant plasticizer is prepared in Example 3.

[0029] The preparation method of the above-mentioned high and low temperature resistant TPEE material for wires and cables includes the following steps: S1. The modified nano-silica, composite flame retardant, and maleic anhydride-grafted POE are dry-mixed in a high-speed mixer for 4 minutes. TPEE powder accounting for 30% of the total TPEE resin weight is added and the mixture is mixed for another 4 minutes. The above premix is ​​then extruded and granulated in a twin-screw extruder to obtain a functional masterbatch. S2. The TPEE granules, comprising 70% of the total TPEE resin weight, antioxidant 1010, antioxidant 168, benzotriazole UV absorber, hindered amine light stabilizer, and silicone micro powder are added from the main feed port. The functional masterbatch and low-temperature resistant plasticizer are added from the side feed port. After extrusion, water cooling, pelletizing, and air drying, the high and low temperature resistant TPEE material for wires and cables is obtained.

[0030] Comparative Example 1 A high and low temperature resistant TPEE material for wires and cables comprises the following raw materials in parts by weight: 100 parts TPEE resin, 20 parts composite flame retardant, 10 parts low temperature resistant plasticizer, 4 parts maleic anhydride grafted POE, 0.35 parts antioxidant 1010, 0.35 parts antioxidant 168, 0.45 parts hindered amine light stabilizer, and 0.8 parts silicone micro powder; the composite flame retardant is prepared in Example 2, and the low temperature resistant plasticizer is prepared in Example 3.

[0031] The preparation method of the high and low temperature resistant TPEE material for wires and cables is the same as in Example 6, except that modified nano-silica is not added in step S1.

[0032] Comparative Example 2 A high and low temperature resistant TPEE material for wires and cables comprises the following raw materials in parts by weight: 100 parts TPEE resin, 10 parts modified nano silica, 10 parts low temperature resistant plasticizer, 4 parts maleic anhydride grafted POE, 0.35 parts antioxidant 1010, 0.35 parts antioxidant 168, 0.45 parts hindered amine light stabilizer, and 0.8 parts silicone micro powder; wherein the modified nano silica is prepared in Example 1, and the low temperature resistant plasticizer is prepared in Example 3.

[0033] The preparation method of the high and low temperature resistant TPEE material for wires and cables is the same as that in Example 6, except that no composite flame retardant is added in step S1.

[0034] Comparative Example 3 A high and low temperature resistant TPEE material for wires and cables comprises the following raw materials in parts by weight: 100 parts TPEE resin, 10 parts modified nano silica, 20 parts composite flame retardant, 4 parts maleic anhydride grafted POE, 0.35 parts antioxidant 1010, 0.35 parts antioxidant 168, 0.45 parts hindered amine light stabilizer, and 0.8 parts silicone micro powder; wherein the modified nano silica is prepared in Example 1, and the composite flame retardant is prepared in Example 2.

[0035] The preparation method of the high and low temperature resistant TPEE material for wires and cables is the same as in Example 6, except that no low temperature resistant plasticizer is added in step S2.

[0036] Performance testing The high and low temperature resistant TPEE materials for wires and cables prepared in Examples 4-6 and Comparative Examples 1-3 were extruded using a single-screw extruder. The extruder temperatures were: feeding section 160°C, compression section 190°C, metering section 210°C, die head 205°C, and screw speed 30-60 r / min. After segmented water cooling and blow-drying, the materials were cut into corresponding standard samples and subjected to the following performance tests: (1) Mechanical properties Tensile strength and elongation at break were determined according to GB / T 1040.2-2022. The specimens were type I dumbbell specimens with a gauge length of 50 mm and a width of 10.0 mm (neck) to 20.0 mm (end). An electronic universal testing machine was used with a tensile rate of 50 mm / min and a room temperature of 23℃. The low-temperature embrittlement temperature was determined according to GB / T 5470-2008, with a temperature control range of -80℃ to 0℃. The specimen size was 20×2.5×1.6 mm, the impact speed was 2.0 m / s, and the impact blade radius was 1.6 mm. (2) Thermal performance The glass transition temperature was determined according to GB / T19466.2-2004 using differential scanning calorimetry (DSC). The sample consisted of 5-10 mg of high and low temperature resistant TPEE material particles for wires and cables, under a nitrogen atmosphere, with a heating rate of 10℃ / min, sweeping from -100℃ to 200℃. The Vicat softening temperature was determined according to GB / T1633-2000 using a circular disk with a diameter of 10 mm and a thickness of 4 mm, using the B50 method (load 50 N, heating rate 50℃ / h). (3) Flame retardant properties Vertical flammability was determined according to GB / T 2408-2021, with a sample size of 125×13×1.6mm; Limiting oxygen index (LOI) was determined according to GB / T 2406.2-2009, with a sample size of 100×6.5×3mm. (4) Hydrolysis resistance The damp heat aging test was carried out in accordance with GB / T 12000-2017. The Type I dumbbell specimens for tensile testing were placed in a constant temperature and humidity chamber at 85℃ and 90% relative humidity for 1000 h. The tensile strength after aging was tested and the retention rate (%) was calculated. (5) Antibacterial properties According to GB / T 24128-2018, the sample size is 50×50×3mm. A mixed spore suspension of Aspergillus niger, Aspergillus flavus, Penicillium cordiformis, Penicillium wanyi, and Trichoderma viride is used for inoculation. The sample is placed in an incubator at 28℃ and relative humidity ≥85% for 28 days. The anti-mold level is determined based on the proportion of mold patch area. (6) Salt spray resistance The procedure was performed according to GB / T 12000-2017. A copper sheet (simulating a cable shielding layer) was placed on the sample surface, and the sample was sprayed with 5% NaCl salt spray at 35°C for 500 h. After the process, the mass loss due to corrosion of the copper sheet was measured (mg / cm³). 2 ); The results are shown in Table 1 below.

[0037] Table 1. Performance test results of high and low temperature resistant TPEE materials for wires and cables

[0038] As can be seen from the data in Table 1, the tensile strength of Comparative Example 1 is lower than that of Example 6. The modified nano-silica has a rigidity-enhancing effect. The hyperbranched polyester graft layer forms physical cross-linking and chemical anchoring with the TPEE matrix. The nano-silica core acts as a stress transfer center, effectively bearing and dispersing the load, thereby improving the tensile strength. The tensile strength of Comparative Examples 2 and 3 is higher than that of Example 6, indicating that the composite flame retardant and low-temperature plasticizer will reduce the strength to a certain extent. The flame retardant macromolecular chain may destroy the hard segment crystallization of TPEE, while the plasticizer increases the slippage of the molecular chain. Comparative Example 1 has the highest elongation at break because the molecular chain is more easily extended due to the lack of rigid nanoparticle confinement. Comparative Example 3 has the lowest elongation at break, indicating that the low-temperature plasticizer is crucial for improving toughness. The flexible segments of the low-temperature plasticizer insert between the TPEE molecular chains, weakening the hydrogen bonds between hard segments and increasing the mobility of soft segments.

[0039] The low-temperature embrittlement temperature of Example 6 reached -80℃, while that of Comparative Example 3 was only -52℃. The hydroxyl-terminated polybutadiene backbone of the low-temperature resistant plasticizer has an extremely low glass transition temperature. After blending with TPEE, the long-chain flexible segments are inserted into the soft segment region, increasing the free volume and reducing the overall Tg of the material, allowing the molecular chains to still move at low temperatures and avoiding brittle fracture. The embrittlement temperature of Comparative Example 2 is even lower, and the rigid benzene ring structure of the composite flame retardant slightly increases the low-temperature embrittlement temperature. Comparative Example 1 is slightly lower than that of Example 6. The modified nano-silica has a slight negative impact on low-temperature toughness, and its rigid particles may act as low-temperature stress concentration points, but this is fully compensated for by the plasticizing effect of the low-temperature resistant plasticizer. The trends of glass transition temperature and embrittlement temperature are consistent, indicating that the addition of the low-temperature resistant plasticizer can significantly reduce Tg.

[0040] The UL94 flame retardancy rating of Comparative Example 1 dropped to V-2, indicating that the modified nano-silica not only acts as a mechanical filler but also possesses a significant synergistic flame retardant effect. ZIF-8 decomposes at high temperatures to release ZnO. ZnO, as a Lewis acid, catalyzes the dehydration of TPEE and the flame retardant system into char, promoting the formation of a dense, continuous expanded char layer. This char layer can more effectively insulate against heat and oxygen while inhibiting dripping. Furthermore, the porous structure of ZIF-8 can adsorb some combustible volatiles, slowing down the combustion process. Comparative Example 2 failed to pass any UL94 rating, indicating that the composite flame retardant is the primary flame retardant. At high temperatures, diisobutyl aluminum hypophosphite decomposes to generate phosphoric acid and polyphosphoric acid, catalyzing the dehydration of ester bonds and hydroxyl groups in TPEE into char. Melamine cyanurate releases non-combustible gases such as NH3 and N2, causing the char layer to expand and thicken. The expanded char layer formed synergistically by both has multiple effects, including heat insulation, oxygen isolation, smoke suppression, and anti-dripping. The flame retardant effect of Comparative Example 3 is similar to that of Example 6, indicating that the low-temperature resistant plasticizer has no effect on flame retardancy, and its macromolecular structure does not produce easily fusible droplets of low molecular weight products during combustion.

[0041] The tensile strength retention rate decreased most significantly after damp heat aging compared to Example 1, demonstrating the anti-hydrolysis effect of modified nano-silica. The hyperbranched polyester shell is hydrophobic, which can slow down the diffusion rate of water vapor in the TPEE matrix. The micropores of ZIF-8 have a strong affinity for water molecules, which can preferentially capture trace amounts of water that have penetrated into the matrix, thereby reducing the probability of water molecules contacting the TPEE ester bonds. The carboxylic acid produced by TPEE hydrolysis will autocatalytically accelerate the hydrolysis. The Zn in ZIF-8 2+ Imidazole ligands are weakly basic and can neutralize some acidic groups, thus inhibiting autocatalytic reactions.

[0042] The groups containing modified nano-silica all had an antibacterial rating of 0, while Comparative Example 1 only had a rating of 2, demonstrating that modified nano-silica plays a key role in improving the antibacterial properties of the material. In humid environments, ZIF-8 in the modified nano-silica slowly releases Zn. 2+ Zn 2+It can disrupt ion channels in microbial cell membranes, interfering with enzyme systems after entering the cell and leading to cell death. Simultaneously, the 2-methylimidazole ligand also possesses weak antibacterial activity. This slow-release mechanism achieves long-term antifungal effects without the need for additional organic biocides, aligning with environmental trends. In Comparative Example 1, the copper sheet showed significant corrosion loss. The microporous structure of ZIF-8 in the modified nano-silica exhibits selective adsorption capacity for chloride ions, and the uncoordinated nitrogen sites on the inner surface of the pores can bind with Cl-. - Forming coordinate bonds, thereby allowing Cl to - Fixed near the filler, reducing the chance of it migrating to the copper surface; in addition, the uniform dispersion of modified nano-silica may also form a physical barrier layer.

[0043] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A high and low temperature resistant TPEE material for wires and cables, characterized in that, The raw materials include the following parts by weight: 90-110 parts TPEE resin, 8-12 parts modified nano silica, 15-25 parts composite flame retardant, 8-12 parts low-temperature resistant plasticizer, 3-5 parts maleic anhydride grafted POE, 0.5-1 part antioxidant, 0.3-0.5 parts light stabilizer, and 0.5-1 part silicone micro powder; The modified nano-silica is nano-silica grafted with end-carboxyl hyperbranched polyester and then ZIF-8 nanocrystalline layer grown in situ; the composite flame retardant is diisobutyl aluminum hypophosphite and melamine cyanurate grafted onto epoxy functionalized polystyrene polymer backbone through interfacial polymerization; the low-temperature resistant plasticizer is hydroxyl-terminated polybutadiene grafted with diisononyl oxalate.

2. The high and low temperature resistant TPEE material for wires and cables according to claim 1, characterized in that, The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:

1.

3. The high and low temperature resistant TPEE material for wires and cables according to claim 1, characterized in that, The light stabilizer is a mixture of benzotriazole ultraviolet absorber and hindered amine light stabilizer in a mass ratio of 1:

1.

4. The high and low temperature resistant TPEE material for wires and cables according to claim 1, characterized in that, The method for preparing the modified nano-silica includes the following steps: (1) Disperse nano-silica in a mixture of anhydrous ethanol and deionized water, sonicate for 20-40 min, add 3-aminopropyltriethoxysilane, adjust the pH to 4-5 with acetic acid, reflux at 80℃ for 4-8 h, centrifuge, wash 3 times with ethanol, and vacuum dry to obtain aminated nano-silica. (2) Aminated nano-silica was dispersed in dimethyl sulfoxide, and carboxyl-terminated hyperbranched polyester and 4-dimethylaminopyridine were added under nitrogen protection. The temperature was raised to 120°C and the reaction was carried out for 20-28 hours. After the reaction was completed, the mixture was centrifuged, washed three times with dimethyl sulfoxide, and then washed three times with ethanol. The mixture was then dried under vacuum to obtain hyperbranched polyester-grafted nano-silica. (3) Disperse hyperbranched polyester-grafted nano-silica in methanol and sonicate for 10-20 min. Dissolve zinc nitrate in methanol to obtain solution A. Dissolve 2-methylimidazole in methanol to obtain solution B. Add solution A dropwise to the hyperbranched polyester-grafted nano-silica dispersion and stir for 5-15 min. Then slowly add solution B. Stir the reaction at room temperature for 1.5-2.5 h. Collect the product by centrifugation, wash it three times with methanol, and dry it under vacuum to obtain modified nano-silica.

5. The high and low temperature resistant TPEE material for wires and cables according to claim 1, characterized in that, The mass ratio of the nano-silica to 3-aminopropyltriethoxysilane is 2:1, the mass ratio of the aminated nano-silica to the carboxyl-terminated hyperbranched polyester is 2:5, and the mass ratio of the hyperbranched polyester grafted with nano-silica, zinc nitrate, and 2-methylimidazole is 10:3:

6.

6. The high and low temperature resistant TPEE material for wires and cables according to claim 1, characterized in that, The preparation method of the composite flame retardant includes the following steps: A. Dissolve epoxy-functionalized polystyrene in xylene, heat to 80°C and stir to dissolve, add toluene diisocyanate and dibutyltin dilaurate, and react at 80°C for 1.5~2.5h; B. Add diisobutyl aluminum hypophosphite and melamine cyanurate to the above system, continue the reaction for 3-5 hours, and maintain the temperature at 80℃. After the reaction is completed, remove the solvent by vacuum distillation, wash 3 times with N,N-dimethylformamide, wash 3 times with deionized water, dry under vacuum, and then pulverize at -40℃ through a 200-mesh sieve to obtain the composite flame retardant.

7. The high and low temperature resistant TPEE material for wires and cables according to claim 1, characterized in that, The mass ratio of epoxy-functionalized polystyrene, toluene diisocyanate, aluminum diisobutylphosphite, and melamine cyanurate is 4:1:2:

2.

8. The high and low temperature resistant TPEE material for wires and cables according to claim 1, characterized in that, The preparation method of the low-temperature resistant plasticizer includes the following steps: a. Under dry nitrogen protection, hydroxyl-terminated polybutadiene is dissolved in anhydrous toluene, heated to 60°C, toluene diisocyanate and dibutyltin dilaurate are added, and the mixture is reacted at 60°C for 2-4 hours to obtain NCO-terminated polybutadiene prepolymer. b. Add diisononyl oxalate to the prepolymer and continue the reaction for 3-5 hours. When the temperature is raised to 80°C and the infrared detection of the -NCO characteristic peak disappears, stop the reaction. Remove toluene by vacuum distillation to obtain a viscous liquid. Wash the liquid three times with n-hexane to remove unreacted diisononyl oxalate. Dry the liquid under vacuum to obtain the low-temperature resistant plasticizer.

9. The high and low temperature resistant TPEE material for wires and cables according to claim 1, characterized in that, The mass ratio of the hydroxyl-terminated polybutadiene to diisononyl oxalate is 5:

4.

10. The method for preparing high and low temperature resistant TPEE material for wires and cables according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Dry mix modified nano silica, composite flame retardant, and maleic anhydride grafted POE in a high-speed mixer for 3-5 minutes, add TPEE powder accounting for 30% of the total TPEE resin weight, continue mixing for 3-5 minutes, and extrude the above premix in a twin-screw extruder to obtain functional masterbatch. S2. A twin-screw extruder is used for melt blending and granulation. 70% of the total TPEE resin weight of TPEE granules, antioxidants, UV absorbers and lubricants are added from the main feed port. Functional masterbatch and low-temperature resistant plasticizer are added from the side feed port. After extrusion, water cooling and pelletizing are carried out and then dried by air blowing to obtain the high and low temperature resistant TPEE material for wires and cables.

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