A high-performance FEP material and its preparation method

Abstract

This invention discloses a high-performance FEP material and its preparation method, belonging to the field of fluoroplastics technology. The method includes mesoporous silica modification, POSS modification, preparation of composite fillers, pretreatment of perfluoroethylene propylene copolymer, and melt extrusion granulation. By modifying mesoporous silica and POSS, and combining the synergistic effect of composite additives and the FEP matrix, this invention effectively reduces and stabilizes the relative dielectric constant of the material, reducing resistance and interference during high-frequency signal transmission, ensuring the stability and integrity of signal transmission. It can meet the stringent dielectric performance requirements of high-frequency data line insulation layers in 5G communication, radar, and consumer electronics, solving the problem of unstable dielectric constant in ordinary FEP materials.

Description

Technical Field

[0001] This invention relates to the field of fluoroplastics technology, specifically to a novel high-performance FEP material and its preparation method. Background Technology

[0002] With the booming development of 5G communication, radar, medical equipment, industrial control, new energy vehicles and consumer electronics, high-frequency data cables, as the core carrier for connecting digital devices and ensuring signal transmission, have become a key component of modern digital infrastructure construction. High-frequency data cables often face complex operating conditions such as equipment vibration and temperature changes. Moreover, the trend of equipment miniaturization is driving the development of cables to thinner specifications and the insulation layer thickness is constantly decreasing. This requires materials to have sufficient tensile strength, elongation at break and surface hardness to resist tensile damage and deformation, and to avoid affecting use due to insulation layer damage. However, some existing fluoroplastic materials have shortcomings in mechanical properties, such as insufficient tensile strength or weak resistance to deformation. They are prone to cracking and damage during long-term use, which shortens the service life of data cables.

[0003] Currently, fluoroplastics have become the mainstream choice for high-performance high-frequency data cable insulation layers due to their excellent heat resistance, flame retardancy, weather resistance, and processing adaptability. Among them, polytetrafluoroethylene (PTFE) has become a preferred material for high-requirement scenarios because of its extremely low and stable dielectric properties, which can effectively ensure the quality of high-frequency signal transmission. However, the highly stable carbon-fluorine bonds and non-polar symmetric structure in the PTFE molecular structure make its processing significantly more difficult than other fluoroplastics.

[0004] As an important member of the fluoroplastics family, perfluoroethylene propylene copolymer (FEP) has significantly better processing performance than polytetrafluoroethylene (PTFE) and maintains good temperature resistance, weather resistance, and flame retardancy, effectively solving the processing difficulties of PTFE. However, ordinary FEP materials still have obvious shortcomings in high-frequency applications. Their dielectric constant stability is insufficient, and during high-frequency signal transmission, fluctuations in dielectric properties can easily lead to increased signal transmission resistance, resulting in signal interference between cables and affecting the operating accuracy of equipment. The domestic market has long relied on imports for the supply of high-performance FEP materials. Although imported products can meet performance requirements, the high procurement costs and supply chain constraints not only increase the production costs of the domestic high-frequency data cable industry but also restrict the progress of localization in related fields, making it difficult to meet the needs of the rapidly developing downstream industries.

[0005] Based on this, the present invention designs a novel high-performance FEP material and its preparation method to solve the above problems. Summary of the Invention

[0006] To address the aforementioned shortcomings of existing technologies, this invention provides a novel method for preparing high-performance FEP materials, comprising the following steps:

[0007] S1. Mesoporous silica modification;

[0008] Mesoporous silica is calcined at 100-120℃, and the calcined mesoporous silica is added to perfluorohexyl ethyl acrylate. At the same time, a fluorinated dispersant is added and dispersed at high speed and ultrasonically to form a uniform suspension.

[0009] Add dicumyl peroxide to the suspension, heat to 80-100℃, stir for 2-4 hours, after the reaction is complete, cool the product to room temperature, wash with anhydrous ethanol, and dry to obtain modified mesoporous silica.

[0010] S2.POSS modification;

[0011] Octaphenyl-POSS was mixed with perfluoropolyetheramine and then added to anhydrous N,N-dimethylformamide solvent. The mixture was stirred at 60-90°C to obtain a mixed solution.

[0012] After adding a silane coupling agent and reacting at 60-80℃ for 1-2 hours, the mixture was transferred to a rotary evaporator and vacuum distilled to obtain modified POSS.

[0013] S3. Preparation of composite fillers;

[0014] Boron nitride and aluminum oxide were mixed at a mass ratio of 1:1-2 and ball-milled to obtain a composite additive.

[0015] S4. Preprocessing;

[0016] 70-90 parts by weight of perfluoroethylene propylene copolymer, 10-30 parts by weight of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer, and 5-10 parts by weight of perfluoropolyether carboxylic acid are preheated separately, and 0.1-1 parts of silane coupling agent are added and mixed to obtain FEP matrix;

[0017] S5. Melt extrusion granulation;

[0018] The FEP matrix obtained by S4, 3-5 parts of functional filler and 2-10 parts of composite additive are added to a twin-screw extruder. The functional filler is one or two of modified mesoporous silica or modified POSS.

[0019] After extrusion, cooling, pelletizing, drying, and curing, modified FEP masterbatch is obtained, which is the new FEP material.

[0020] Furthermore, S1 specifically involves placing mesoporous silica in a muffle furnace and statically calcining it at 100-120℃ for 2-4 hours, with the heating rate controlled at 5-10℃ / min. During the calcination process, air is continuously introduced to remove moisture, organic impurities, etc. adsorbed on the powder surface, and the powder is then naturally cooled to room temperature.

[0021] The calcined mesoporous silica is added to the perfluorohexyl ethyl acrylate at a mass ratio of 1:3-5, along with 0.5-1% of a fluorinated dispersant by mass of the mesoporous silica. The mixture is dispersed in a high-speed disperser at 800-1200 r / min for 30-60 min, then transferred to an ultrasonic cell disruptor and ultrasonically dispersed at 100-150 W and 20-25 kHz for 20-30 min to form a uniform suspension.

[0022] Add 0.2-0.8% dicumyl peroxide by mass of the suspension to the suspension, stir evenly, and then transfer to a reactor equipped with a nitrogen protection device. First, purge the air in the reactor with nitrogen 3-5 times, then raise the temperature to 80-100℃. During the reaction, stir continuously at a speed of 50-100 r / min for 2-4 h. After the reaction is completed, cool the product to room temperature, wash it with anhydrous ethanol 3-5 times to remove unreacted monomers and free polymers, and vacuum dry it at 80-100℃ for 6-8 h to obtain modified mesoporous silica.

[0023] Furthermore, S2 specifically involves mixing octaphenyl-POSS and perfluoropolyetheramine at a mass ratio of 1:2-4 and adding the mixture to anhydrous N,N-dimethylformamide solvent. The concentration of POSS is controlled at 5-10 wt%. The mixture is stirred at 60-90℃ and 100-200 r / min for 1.5-3 h to obtain a mixed solution.

[0024] Add 0.1-0.3% of silane coupling agent by mass of the mixture, react at 60-80℃ for 1-2 hours, then transfer to a rotary evaporator and distill under reduced pressure at 0.08-0.095 MPa, 50-70℃, and 60-100 r / min for 2-3 hours to obtain a viscous concentrate, i.e., modified POSS.

[0025] Furthermore, S3 specifically involves mixing boron nitride and alumina at a mass ratio of 1:1-2, placing them in a planetary ball mill, using zirconium beads as the grinding medium, and ball milling at a speed of 200-400 r / min for 2-4 hours to obtain the composite additive.

[0026] Furthermore, S4 specifically involves: preheating 70-90 parts by weight of perfluoroethylene propylene copolymer, 10-30 parts by weight of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer, and 5-10 parts by weight of perfluoropolyether carboxylic acid at 140-170°C for 2-3 hours, adding 0.1-1 parts of silane coupling agent, and mixing in a high-speed mixer at a speed of 1500-2000 r / min for 20-30 minutes to obtain the FEP matrix.

[0027] Furthermore, S5 specifically involves adding the FEP matrix obtained in S4, 3-5 parts of functional filler, and 2-10 parts of composite additives to a twin-screw extruder. The functional filler is one or both of modified mesoporous silica or modified POSS. The screw speed is 180-210 r / min, the feeding section temperature is 260-290℃, the compression section temperature is 290-320℃, and the melting section temperature is 320-340℃. The material is kept at the melting section for 4-6 minutes, and after filtering impurities through a 10-20μm pore size filter, it is extruded. The material is then water-cooled at 15-30℃, pelletized, and dried in a hot air drying oven at 120-150℃ for 5-7 hours. Finally, it is cured at a constant temperature of 180-200℃ for 2-3 hours to obtain modified FEP masterbatch, which is the new FEP material.

[0028] A novel high-performance FEP material prepared according to the preparation method described above.

[0029] Compared with the prior art, the beneficial effects of this invention are as follows:

[0030] 1. This invention, through the modification of mesoporous silica and POSS, combined with the synergistic effect of composite additives and FEP matrix, effectively reduces and stabilizes the relative dielectric constant of the material, reduces resistance and interference in high-frequency signal transmission, and ensures the stability and integrity of signal transmission. It can meet the stringent requirements of dielectric performance for high-frequency data line insulation layers in 5G communication, radar, consumer electronics, etc., and solve the problem of unstable dielectric constant of ordinary FEP materials.

[0031] 2. This invention significantly improves the tensile strength, elongation at break, and hardness of the material by adding modified fillers and composite additives, enhancing the material's resistance to tensile failure, deformation, and surface hardness. Even under complex operating conditions such as equipment vibration and temperature fluctuations, it can reduce material cracking and damage, extend the service life of products such as high-frequency data cables, and is suitable for scenarios with high requirements for material mechanical stability, such as industrial control and new energy vehicles.

[0032] 3. This invention endows the material with excellent and stable flame retardant effect, and can maintain a high flame retardant rating in most usage environments. It effectively reduces the risk of fire in high-frequency data cables under accidental conditions such as high temperature and short circuit, meets the mandatory requirements for fire safety of materials in the fields of electronics, electrical engineering, and new energy, and improves the safety of equipment operation. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0034] Figure 1 The Fourier transform infrared spectra of mesoporous silica before and after modification in Example 3 of this invention are shown below.

[0035] Figure 2 The Fourier transform infrared spectra of octaphenyl-POSS before and after modification in Example 3 of this invention are shown. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0037] Example 1: This example provides a method for preparing a novel high-performance FEP material, including the following steps:

[0038] S1. Mesoporous silica modification;

[0039] Mesoporous silica (Qinghe County Chaotai Metal Materials Co., Ltd., 300nm) was placed in a muffle furnace and statically calcined at 120℃ for 4 hours. The heating rate was controlled at 10℃ / min. Air was continuously introduced during the calcination process to remove moisture, organic impurities, etc. adsorbed on the powder surface. The powder was then naturally cooled to room temperature.

[0040] Mesoporous silica and perfluorohexyl ethyl acrylate (Zhongshan Dixin Chemical Co., Ltd.) were mixed at a mass ratio of 1:5. The calcined mesoporous silica was added to the perfluorohexyl ethyl acrylate, and 1% of the mass of the mesoporous silica was added as a fluorinated dispersant (1H,1H,2H,2H-perfluorooctyltrimethoxysilane). The mixture was dispersed in a high-speed disperser at 1200 r / min for 60 min, and then transferred to an ultrasonic cell disruptor. The mixture was ultrasonically dispersed at 150 W and 25 kHz for 30 min to form a uniform suspension.

[0041] Add 0.8% dicumyl peroxide by mass of the suspension to the suspension, stir evenly, and then transfer to a reaction vessel equipped with a nitrogen protection device. First, purge the air in the vessel with nitrogen five times, then raise the temperature to 100°C. During the reaction, stir continuously at 100 r / min for 4 h. After the reaction is completed, cool the product to room temperature, wash it five times with anhydrous ethanol to remove unreacted monomers and free polymers, and vacuum dry it at 100°C for 8 h to obtain modified mesoporous silica.

[0042] S2. Preparation of composite fillers;

[0043] Boron nitride and alumina were mixed at a mass ratio of 1:2 and placed in a planetary ball mill. Zirconia beads were used as the grinding media, and the mixture was ball-milled at a speed of 400 r / min for 4 h to obtain the composite additive.

[0044] S3. Pretreatment;

[0045] 90 parts by weight of perfluoroethylene propylene copolymer (FEP, Dongguan Zhanyu Plastic Raw Materials Co., Ltd.), 30 parts by weight of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer (PFA, Shanghai Hehongcheng Plastic Technology Co., Ltd.), and 10 parts by weight of perfluoropolyether carboxylic acid (Hubei Shuaiyan Ligao Biomedical Co., Ltd.) were preheated at 170℃ for 3 hours, 1 part of silane coupling agent (KH-550) was added, and the mixture was mixed in a high-speed mixer at 2000 r / min for 30 minutes to obtain the FEP matrix;

[0046] S4. Melt extrusion granulation;

[0047] The FEP matrix prepared by S3, 5 parts of functional filler and 10 parts of composite additives were added to a twin-screw extruder. The functional filler was modified mesoporous silica. The screw speed was 210 r / min, the feeding section temperature was 290℃, the compression section temperature was 320℃ and the melting section temperature was 340℃. The material was kept at the melting section for 6 min, and after filtering impurities through a 20μm pore size filter screen, it was extruded. The material was cooled by water at 30℃, pelletized, and then dried in a 150℃ hot air drying oven for 7 h. It was then cured at a constant temperature of 200℃ for 3 h to obtain the modified FEP masterbatch, which is the new FEP material.

[0048] Example 2: This example provides a method for preparing a novel high-performance FEP material, including the following steps:

[0049] S1.POSS modification;

[0050] The mixture of octaphenyl-POSS (Guangdong Daxiao Chemical Co., Ltd.) and perfluoropolyetheramine (Hubei Xinyuhong Biomedical Technology Co., Ltd.) at a mass ratio of 1:2 was added to anhydrous N,N-dimethylformamide solvent. The concentration of POSS was controlled at 5wt%. The mixture was stirred at 60℃ and 100r / min for 1.5h to obtain a mixed solution.

[0051] Add 0.1% by weight of silane coupling agent (KH-550) to the mixture, react at 60℃ for 1 h, then transfer to a rotary evaporator and distill under reduced pressure at 0.08-0.095 MPa, 50℃, and 60 r / min for 2 h to obtain a viscous concentrate, namely modified POSS;

[0052] S2. Preparation of composite fillers;

[0053] Boron nitride and alumina were mixed at a mass ratio of 1:1 and placed in a planetary ball mill. Zirconia beads were used as the grinding media, and the mixture was ball-milled at a speed of 200 r / min for 2 h to obtain a composite additive.

[0054] S3. Pretreatment;

[0055] 70 parts by weight of perfluoroethylene propylene copolymer (FEP, Dongguan Zhanyu Plastic Raw Materials Co., Ltd.), 10 parts by weight of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer (PFA, Shanghai Hehongcheng Plastic Technology Co., Ltd.), and 5 parts by weight of perfluoropolyether carboxylic acid (Hubei Shuaiyan Ligao Biomedical Co., Ltd.) were preheated at 140℃ for 2 hours, and 0.1 parts of silane coupling agent (KH-560) were added. The mixtures were then mixed in a high-speed mixer at 1500 r / min for 20 minutes to obtain the FEP matrix.

[0056] S4. Melt extrusion granulation;

[0057] The FEP matrix obtained from S3, 3 parts of functional filler, and 2 parts of composite additives were added to a twin-screw extruder. The functional filler was modified POSS. The screw speed was 180 r / min, the feeding section temperature was 260℃, the compression section temperature was 290℃, and the melting section temperature was 320℃. The material was kept at the melting section for 4 min, and after filtering impurities through a 10 μm pore size filter, it was extruded. The material was then water-cooled at 15℃, pelletized, and dried in a 120℃ hot air drying oven for 5 h. After being cured at a constant temperature of 180℃ for 2 h, the modified FEP masterbatch was obtained, which is the new FEP material.

[0058] Example 3: This example provides a method for preparing a novel high-performance FEP material, including the following steps:

[0059] S1. Mesoporous silica modification;

[0060] Mesoporous silica (Qinghe County Chaotai Metal Materials Co., Ltd., 300nm) was placed in a muffle furnace and statically calcined at 100℃ for 2 hours. The heating rate was controlled at 5℃ / min. Air was continuously introduced during the calcination process to remove moisture, organic impurities, etc. adsorbed on the powder surface. The powder was then naturally cooled to room temperature.

[0061] Mesoporous silica and perfluorohexyl ethyl acrylate (Zhongshan Dixin Chemical Co., Ltd.) were mixed at a mass ratio of 1:3. The calcined mesoporous silica was added to the perfluorohexyl ethyl acrylate, along with 0.5% of the mass of the mesoporous silica containing a fluorinated dispersant (1H,1H,2H,2H-perfluorooctyltriethoxysilane). The mixture was dispersed in a high-speed disperser at 800 r / min for 30 min, then transferred to an ultrasonic cell disruptor and ultrasonically dispersed at 100 W and 20 kHz for 20 min to form a uniform suspension.

[0062] Add 0.2% dicumyl peroxide by mass of the suspension to the suspension, stir evenly, and then transfer to a reactor equipped with a nitrogen protection device. First, purge the air in the reactor with nitrogen three times, then raise the temperature to 80°C. During the reaction, stir continuously at 50 r / min for 2 h. After the reaction is completed, cool the product to room temperature, wash it three times with anhydrous ethanol to remove unreacted monomers and free polymers, and vacuum dry it at 80°C for 6 h to obtain modified mesoporous silica.

[0063] S2.POSS modification;

[0064] The mixture of octaphenyl-POSS (Guangdong Daxiao Chemical Co., Ltd.) and perfluoropolyetheramine (Hubei Xinyuhong Biomedical Technology Co., Ltd.) at a mass ratio of 1:4 was added to anhydrous N,N-dimethylformamide solvent. The concentration of POSS was controlled at 10wt%. The mixture was stirred at 90℃ and 200r / min for 3h to obtain a mixed solution.

[0065] Add 0.3% by weight of silane coupling agent (KH-570) to the mixture, react at 80℃ for 2 hours, then transfer to a rotary evaporator and distill under reduced pressure at 0.08-0.095 MPa, 70℃, and 100 r / min for 3 hours to obtain a viscous concentrate, namely modified POSS.

[0066] S3. Preparation of composite fillers;

[0067] Boron nitride and alumina were mixed at a mass ratio of 1:1.4 and placed in a planetary ball mill. Zirconium beads were used as the grinding media and the mixture was ball-milled at a speed of 320 r / min for 3 h to obtain the composite additive.

[0068] S4. Preprocessing;

[0069] 77 parts by weight of perfluoroethylene propylene copolymer (FEP, Dongguan Zhanyu Plastic Raw Materials Co., Ltd.), 12 parts by weight of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer (PFA, Shanghai Hehongcheng Plastic Technology Co., Ltd.), and 8 parts by weight of perfluoropolyether carboxylic acid (Hubei Shuaiyan Ligao Biomedical Co., Ltd.) were preheated at 162, 145, and 148℃ for 2.5 h respectively. 0.8 parts of silane coupling agent (KH-560) were added, and the mixture was mixed in a high-speed mixer at 1800 r / min for 22 min to obtain the FEP matrix.

[0070] S5. Melt extrusion granulation;

[0071] The FEP matrix prepared by S4, 3.7 parts of functional filler and 5 parts of composite additives were added to a twin-screw extruder. The functional filler was a mixture of modified mesoporous silica and modified POSS in a mass ratio of 1:1. The screw speed was 207 r / min, the feeding section temperature was 270-280℃, the compression section temperature was 300-305℃, and the melting section temperature was 320-325℃. The material was kept at the melting section for 5 min, filtered for impurities through a 20μm pore size filter, and then extruded. After being water-cooled at 20℃ and pelletized, the material was dried in a 130℃ hot air drying oven for 5 h and then cured at a constant temperature of 186℃ for 3 h to obtain the modified FEP masterbatch, which is the new FEP material.

[0072] Comparative Example 1: The difference between this comparative example and Example 3 is that the mesoporous silica was not modified.

[0073] Comparative Example 2: The difference between this comparative example and Example 3 is that POSS was not modified.

[0074] Comparative Example 3: The difference between this comparative example and Example 3 is that no composite additive was added in S5.

[0075] Comparative Example 4: This comparative example differs from Example 3 in that the mesoporous silica was not modified, the POSS was not modified, and no composite additive was added in S5.

[0076] Characterization Experiment Example 1: Infrared characterization was performed on the mesoporous silica before and after modification in Example 3. The results are as follows: Figure 1 As shown, the infrared absorption of unmodified mesoporous silica is mainly dominated by the silicon-oxygen framework and surface hydroxyl groups, at 1085 cm⁻¹. -1 The strong absorption peak at 800 cm⁻¹ is due to the asymmetric stretching vibration of the Si-O-Si bond. -1 The moderate intensity peak at 455 cm⁻¹ is due to the symmetric stretching vibration of the Si-O-Si bond. -1 The weak peaks are due to the bending vibrations of Si-O-Si bonds. These three factors together constitute the characteristic absorption of the mesoporous silica silicon-oxygen framework, proving that its basic structure is complete.

[0077] 3450cm -1 The broad, strong absorption peak at 950 cm⁻¹ is due to the stretching vibration of surface OH bonds. -1 The moderate intensity peaks at 1630 cm⁻¹ represent the bending vibrations of Si-OH bonds. These two sets of peaks directly reflect the abundance of hydroxyl groups on the surface of mesoporous silica, and are also key active sites for subsequent modification reactions. Additionally, the peak at 1630 cm⁻¹... -1 The extremely weak peak is the HOH bending vibration of trace amounts of residual adsorbed water. The peak intensity is weak and does not interfere with the core characteristics.

[0078] After modification, the original height was 3450cm. -1The intensity of the Si-OH stretching vibration peak decreased significantly, and the peak width narrowed markedly, with a peak width of 950 cm⁻¹. -1 The near disappearance of the Si-OH bending vibration peak indicates that the hydroxyl groups on the surface of mesoporous silica underwent an effective condensation reaction with the ethoxy groups in the modifier molecules. The surface hydroxyl groups were largely consumed or covered, proving that the modifier formed a chemical bond with the mesoporous silica surface, rather than a simple physical adsorption. In the modified spectrum, the peak at 1190 cm⁻¹... -1 A strong absorption peak appears at 2855 cm⁻¹, corresponding to the stretching vibration of the CF bond in the 1H,1H,2H,2H-perfluorooctyltriethoxysilane molecule; simultaneously at 2855 cm⁻¹. -1 With 2925cm -1 Two new weak absorption peaks were observed, representing the symmetric and asymmetric stretching vibrations of the methylene group in the modifier molecule. These new peaks are characteristic absorptions of the fluorine-containing modifier molecule, and their clear peak shapes and stable positions prove that the modifier has been successfully grafted onto the surface of mesoporous silica, rather than being in a free state. The modified peaks are 1085 cm⁻¹. -1 800cm -1 455cm -1 The intensity and position of the Si-O-Si bond vibration peaks remained basically unchanged, with only the peak shape becoming slightly sharper. This phenomenon indicates that the modification reaction only occurred on the surface of mesoporous silica and did not destroy the basic structure of its silicon-oxygen framework, ensuring that the framework stability of mesoporous silica was not affected.

[0079] Characterization Experiment Example 2: Infrared characterization was performed on octaphenyl-POSS before and after modification in Example 3, and the results are as follows: Figure 2 As shown, the infrared absorption of unmodified octaphenyl-POSS is determined by its molecular structure of a cage-like silicon-oxygen core and an octaphenyl ring side chain, with the benzene ring-related vibrational peak at 3060 cm⁻¹ being the most prominent feature. -1 The moderately intense sharp peak corresponds to the stretching vibration of the CH bond in the benzene ring, at 1595 cm⁻¹. -1 The strong absorption peak at 705 cm⁻¹ is due to the stretching vibration of the C=C bond in the benzene ring skeleton. -1 With 755cm -1 The two sets of medium-intensity peaks are the CH bond bending vibrations of the monosubstituted benzene ring. These four sets of peaks together confirm that the benzene ring is stably attached to the POSS molecule as a side chain.

[0080] The characteristic peaks of the cage-like silicon-oxygen core are clear, at 1040 cm⁻¹. -1 The moderately intense broad peak at 475 cm⁻¹ represents the stretching vibration of the Si-O-Si bonds in the POSS cage structure. -1 The weak peaks are due to the bending vibrations of Si-O-Si bonds, and both reflect the integrity of the POSS cage-like core structure.

[0081] After modification, three distinct characteristic absorption peaks of the modifier were added to the spectrum, at 1170 cm⁻¹. -1 The strong absorption peak corresponds to the stretching vibration of the CF bond in the perfluoropolyetheramine molecule, at 1725 cm⁻¹. -1 The moderately intense sharp peak at 2850 cm⁻¹ represents the stretching vibration of the C=O bond in the ester group of the KH-570 molecule. -1 With 2925cm -1 The two sets of weak peaks correspond to the symmetric stretching and asymmetric stretching vibrations of the alkyl group in the modifier molecule, respectively. These newly added peaks have clear peak shapes, stable peak positions, and no interference from free modifiers, directly proving that perfluoropolyetheramine and KH-570 have been successfully bound to the octaphenyl-POSS molecule.

[0082] Modified 3060cm -1 Benzene ring CH stretching peak, 1595 cm⁻¹ -1 The C=C skeleton peak of the benzene ring and the 705 cm⁻¹ peak -1 755cm -1 The intensity of the CH bending peak of monosubstituted benzene decreased significantly, but the peak position did not shift. This change is due to the interaction between the modifier molecule and the benzene ring side chain of octaphenyl-POSS (such as van der Waals forces or local chemical interactions), which weakens the infrared absorption intensity of the benzene ring vibration. This indirectly confirms the binding effect of the modifier with octaphenyl-POSS without destroying the basic structure of the benzene ring.

[0083] Experimental Example 1: The relative density (g / cm³) of the novel FEP material prepared according to this invention was tested according to ASTM D792. 3 ).

[0084] Experimental Example 2: The melting point (°C) of the novel FEP material prepared by this invention was determined according to GB / T 16582.

[0085] Experimental Example 3: The melt flow rate (g / 10min) of the novel FEP material prepared according to the present invention was tested according to ASTM D1238.

[0086] Experimental Example 4: The tensile strength (MPa) of the novel FEP material prepared according to the present invention was tested according to ASTM D638.

[0087] Experimental Example 5: The elongation at break (%) of the novel FEP material prepared according to the present invention was tested according to ASTM D638.

[0088] Experimental Example 6: The Shore hardness (HD) of the novel FEP material prepared according to the present invention was tested according to ASTM D2240.

[0089] Experimental Example 7: The flame retardant properties of the novel FEP material prepared by this invention were tested according to GB / T 2408-2021.

[0090] Experimental Example 8: The relative permittivity (10⁻¹⁰) of the novel FEP material prepared according to ASTM D150 was tested. 6 Hz).

[0091] The results are shown in the table below:

[0092] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 <![CDATA[Relative density g / cm 3 > 2.12-2.18 2.12-2.18 2.12-2.18 2.12-2.18 2.12-2.18 2.12-2.18 2.12-2.18 Melting point ℃ 270±5 270±5 270±5 270±5 270±5 270±5 270±5 Melt flow rate g / 10min 30 30 30 30 30 30 30 Tensile strength (MPa) 27 27 27 25 25 26 20 Elongation at break % 411 410 412 375 366 402 307 Shore Hardness HD 64 64 64 63 62 63 59 Flame retardant properties V0 V0 V0 V0 V0 V0 V1 <![CDATA[Relative dielectric constant 10 6 Hz]]> 1.739 1.776 1.775 1.738 1.792 1.911 2.116

[0093] As shown in the table above, when mesoporous silica or POSS is not modified or no composite additives are added, the material’s resistance to tensile failure, deformation and surface hardness all decrease to varying degrees. In particular, when multiple modifications are missing and no composite additives are added, the mechanical properties are more significantly degraded, which fully demonstrates that the combination of each modification step and composite additives is the key to maintaining the mechanical reliability of the material.

[0094] The combination of modified mesoporous silica, POSS, and composite additives effectively reduces the relative permittivity of the material. When the mesoporous silica and POSS are not modified, or when the key components are missing, the relative permittivity of the material increases significantly. In particular, when multiple modifications and additives are missing, the permittivity increases dramatically. A lower permittivity indicates that the material is less polarized under the action of an electric field, with less charge movement and energy dissipation, thereby improving the energy efficiency and stability of the material in high-frequency insulation and high-frequency device applications.

[0095] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a high-performance FEP material, characterized in that, Includes the following steps: S1. Mesoporous silica modification; Mesoporous silica is calcined at 100-120℃, and the calcined mesoporous silica is added to perfluorohexyl ethyl acrylate. At the same time, a fluorinated dispersant is added and dispersed at high speed and ultrasonically to form a uniform suspension. Add dicumyl peroxide to the suspension, heat to 80-100℃, stir for 2-4 hours, after the reaction is complete, cool the product to room temperature, wash with anhydrous ethanol, and dry to obtain modified mesoporous silica. S2.POSS modification; Octaphenyl-POSS was mixed with perfluoropolyetheramine and then added to anhydrous N,N-dimethylformamide solvent. The mixture was stirred at 60-90°C to obtain a mixed solution. After adding a silane coupling agent and reacting at 60-80℃ for 1-2 hours, the mixture was transferred to a rotary evaporator and vacuum distilled to obtain modified POSS. S3. Preparation of composite fillers; Boron nitride and aluminum oxide were mixed at a mass ratio of 1:1-2 and ball-milled to obtain a composite additive. S4. Preprocessing; 70-90 parts by weight of perfluoroethylene propylene copolymer, 10-30 parts by weight of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer, and 5-10 parts by weight of perfluoropolyether carboxylic acid are preheated separately, and 0.1-1 parts of silane coupling agent are added and mixed to obtain FEP matrix; S5. Melt extrusion granulation; The FEP matrix obtained by S4, 3-5 parts of functional filler and 2-10 parts of composite additive are added to a twin-screw extruder. The functional filler is one or two of modified mesoporous silica or modified POSS. After extrusion, cooling, pelletizing, drying, and curing, modified FEP masterbatch is obtained, which is the FEP material.

2. The method for preparing high-performance FEP material according to claim 1, characterized in that, S1 specifically involves placing mesoporous silica in a muffle furnace and statically calcining it at 100-120℃ for 2-4 hours, with the heating rate controlled at 5-10℃ / min. During the calcination process, air is continuously introduced to remove moisture and organic impurities adsorbed on the powder surface, and the powder is then naturally cooled to room temperature. Mesoporous silica and perfluorohexyl ethyl acrylate were added to perfluorohexyl ethyl acrylate at a mass ratio of 1:3-5. Simultaneously, 0.5-1% (by weight of silica) of a fluorinated dispersant was added. The mixture was dispersed in a high-speed disperser at 800-1200 r / min for 30-60 min, then transferred to an ultrasonic cell disruptor and ultrasonically dispersed at 100-150 W and 20-25 kHz for 20-30 min to form a uniform suspension. The fluorinated dispersant was 1H,1H,2H,2H-perfluorooctyltrimethoxysilane or 1H,1H,2H,2H-perfluorooctyltriethoxysilane. Add 0.2-0.8% dicumyl peroxide by mass of the suspension to the suspension, stir evenly, and then transfer to a reactor equipped with a nitrogen protection device. First, purge the air in the reactor with nitrogen 3-5 times, then raise the temperature to 80-100℃. During the reaction, stir continuously at a speed of 50-100 r / min for 2-4 h. After the reaction is completed, cool the product to room temperature, wash it with anhydrous ethanol 3-5 times to remove unreacted monomers and free polymers, and vacuum dry it at 80-100℃ for 6-8 h to obtain modified mesoporous silica.

3. The method for preparing high-performance FEP material according to claim 1, characterized in that, S2 is specifically as follows: Mix octaphenyl-POSS and perfluoropolyetheramine at a mass ratio of 1:2-4, add the mixture to anhydrous N,N-dimethylformamide solvent, control the concentration of POSS to 5-10 wt%, and stir the mixture at 60-90℃ and 100-200 r / min for 1.5-3 h to obtain a mixed solution. Add 0.1-0.3% of silane coupling agent by mass of the mixture, react at 60-80℃ for 1-2 hours, then transfer to a rotary evaporator and distill under reduced pressure at 0.08-0.095 MPa, 50-70℃, and 60-100 r / min for 2-3 hours to obtain a viscous concentrate, i.e., modified POSS.

4. The method for preparing high-performance FEP material according to claim 1, characterized in that, S3 specifically involves mixing boron nitride and aluminum oxide at a mass ratio of 1:1-2, placing them in a planetary ball mill, using zirconium beads as the grinding medium, and ball milling at a speed of 200-400 r / min for 2-4 hours to obtain the composite additive.

5. The method for preparing high-performance FEP material according to claim 1, characterized in that, S4 is specifically prepared by preheating 70-90 parts by weight of perfluoroethylene propylene copolymer, 10-30 parts by weight of tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer, and 5-10 parts by weight of perfluoropolyether carboxylic acid at 140-170℃ for 2-3 hours, adding 0.1-1 parts of silane coupling agent, and mixing in a high-speed mixer at a speed of 1500-2000 r / min for 20-30 minutes to obtain the FEP matrix.

6. The method for preparing high-performance FEP material according to claim 1, characterized in that, S5 specifically involves adding the FEP matrix obtained in S4, 3-5 parts of functional filler, and 2-10 parts of composite additives to a twin-screw extruder. The functional filler is one or both of modified mesoporous silica or modified POSS. The screw speed is 180-210 r / min, the feeding section temperature is 260-290℃, the compression section temperature is 290-320℃, and the melting section temperature is 320-340℃. The material is kept at the melting section for 4-6 minutes, and after filtering impurities through a 10-20μm pore size filter, it is extruded. The material is then water-cooled at 15-30℃, pelletized, and dried in a hot air drying oven at 120-150℃ for 5-7 hours. Finally, it is cured at a constant temperature of 180-200℃ for 2-3 hours to obtain modified FEP masterbatch, which is the FEP material.

7. A high-performance FEP material prepared by the preparation method according to any one of claims 1-6.

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