Phenyl modified polysiloxane carbon fiber precursor oiling agent and preparation method thereof

Abstract

The invention relates to the technical field of silicone oil production, and discloses a phenyl modified polysiloxane carbon fiber precursor oiling agent and a preparation method thereof, and the phenyl modified polysiloxane carbon fiber precursor oiling agent comprises the following components by weight: 5-20 parts of modified silicone oil, 5-20 parts of a nonionic emulsifier, 1-10 parts of a co-emulsifier, 1-5 parts of a cationic antistatic agent, and 50-80 parts of deionized water. Phenyl, carboxyl and polyether chain are used for modifying silicone oil, so that the oiling agent is endowed with excellent high-temperature resistance, the film-forming tightness is improved, the hydrophilic-hydrophobic balance is adjusted, and the dispersion stability of emulsion is enhanced; the nonionic emulsifier and the co-emulsifier are compounded, so that the interfacial tension between an oil phase and a water phase is reduced, and a stable emulsion system is formed; the cationic antistatic agent effectively eliminates static accumulation generated by fiber friction through the charge conduction effect. According to the invention, the requirements of the carbon fiber precursor oiling agent on thermal stability, lubricity, antistatic property and emulsion stability are met at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of silicone oil production, in particular to a phenyl-modified polysiloxane carbon fiber precursor oil agent and a preparation method thereof. Background Art

[0002] Carbon fiber has been widely used in a variety of fields, including aerospace, automotive, and sporting goods, due to its excellent properties such as high strength, high modulus, low density, high temperature resistance, and chemical corrosion resistance. In the production process of carbon fiber, carbon fiber precursor oil plays a vital role.

[0003] Carbon fiber precursor oil needs to have multiple properties, such as good lubricity to reduce friction between the fiber and equipment components during the production process and prevent fiber damage; appropriate antistatic properties to avoid static electricity accumulation causing fiber adsorption and entanglement, which affects the production process; and during the high-temperature pre-oxidation and carbonization stages, it can protect the fiber surface, reduce thermal damage to the fiber, and improve the quality and performance of the carbon fiber.

[0004] Currently, carbon fiber finishes on the market are primarily categorized as silicone and non-silicone. Silicone finishes are widely used in carbon fiber production due to their superior heat resistance and lubricity. However, existing silicone finishes still have some shortcomings. For example, some finishes lack sufficient heat resistance, making them prone to sticking and roller adhesion during the subsequent carbonization stage, impacting production continuity and product quality. Other finishes also lack ideal antistatic properties, making static electricity more prominent in high-humidity or high-temperature environments, leading to reduced fiber processing performance. Furthermore, some finishes lack fiber compatibility, making it difficult to form a uniform, stable protective film on the fiber surface, thus impacting fiber performance. To meet the demands of high-performance carbon fiber production, developing a carbon fiber finish with excellent heat resistance, antistatic properties, lubricity, and good fiber compatibility is of great practical significance. Summary of the Invention

[0005] (1) Technical problems solved In view of the deficiencies in the prior art, the present invention provides a phenyl-modified polysiloxane carbon fiber precursor oil and a preparation method thereof.

[0006] (2) Technical solution To achieve the above object, the present invention provides the following technical solution: a phenyl-modified polysiloxane carbon fiber precursor oil, comprising the following components by weight: 5-20 parts of modified silicone oil, 5-20 parts of emulsifier, 1-10 parts of co-emulsifier, 1-5 parts of antistatic agent, 50-80 parts of deionized water; The preparation method of modified silicone oil comprises the following steps: A1. Octamethylcyclotetrasiloxane, 1,3,5,7-tetramethyltetraphenylcyclotetrasiloxane, and methylhydrogencyclotrisiloxane were mixed and stirred evenly, and tetramethylammonium hydroxide and hexamethyldisiloxane were added dropwise to react to obtain a silicone oil precursor containing phenyl groups and silicon-hydrogen bonds; A2. A silicone oil precursor, anhydrous methylcyclohexane, and phenothiazine were mixed, nitrogen was introduced, the oil bath was heated, and stirring was performed to form a homogeneous solution. A catalyst platinum-divinyltetramethyldisiloxane complex and triethylamine were added. After heating, 4-pentenoic acid was added dropwise. After the reaction, diatomaceous earth was added as an adsorbent catalyst to obtain a clear filtrate, and vacuum distillation was performed to obtain an intermediate product containing phenyl groups, residual silicon-hydrogen bonds, and carboxyl groups. A3. The above intermediate product and isopropanol were mixed, stirred to dissolve, and then 4Å molecular sieves were added. After filtering, catalyst platinum-divinyltetramethyldisiloxane complex, polyethylene glycol monoallyl ether and 2,6-di-tert-butyl-p-cresol were added. After the reaction, saturated sodium bicarbonate aqueous solution was used for neutralization. The mixture was allowed to stand for separation, and antioxidant 1010 was added to the organic phase. The mixture was distilled under reduced pressure and extracted with supercritical CO2 to obtain a modified silicone oil containing phenyl groups, carboxyl groups and polyether chains.

[0007] Furthermore, the emulsifier is a non-ionic emulsifier selected from one of Tween-80, Span-80, and polyoxyethylene castor oil.

[0008] Furthermore, the co-emulsifier is selected from one of n-butanol, ethylene glycol monobutyl ether, and propylene glycol methyl ether.

[0009] Furthermore, the antistatic agent is a cationic antistatic agent, selected from one of dodecyltrimethylammonium chloride, cetylpyridinium bromide, and dioctadecyldimethylammonium chloride.

[0010] Furthermore, in step A1, 100-120 parts of octamethylcyclotetrasiloxane, 60-80 parts of 1,3,5,7-tetramethyltetraphenylcyclotetrasiloxane, 20-30 parts of methylhydrogencyclotrisiloxane, 1-3 parts of tetramethylammonium hydroxide, and 4-8 parts of hexamethyldisiloxane are used.

[0011] Furthermore, in step A2, 100-120 parts of silicone oil precursor, 200-400 parts of anhydrous methylcyclohexane, 0.03-0.08 parts of phenothiazine, 0.1-0.5 parts of platinum-divinyltetramethyldisiloxane complex, 0.04-0.06 parts of triethylamine, 15-20 parts of 4-pentenoic acid, and 5-10 parts of diatomaceous earth are included.

[0012] Furthermore, in step A3, 100-120 parts of the intermediate product, 300-500 parts of isopropyl alcohol, 15-25 parts of 4Å molecular sieves, 0.06-0.12 parts of platinum-divinyltetramethyldisiloxane complex, 10-20 parts of polyethylene glycol monoallyl ether, 0.02-0.05 parts of 2,6-di-tert-butyl-p-cresol, and 0.5-1 parts of antioxidant 1010 are added.

[0013] Furthermore, a method for preparing a phenyl-modified polysiloxane carbon fiber precursor oil comprises the following steps: S1. Preheat the modified silicone oil in a 50°C oven for 30 minutes and set aside. Weigh the emulsifier and co-emulsifier in proportion, add them to a beaker and stir evenly to form a composite emulsification system. Add the antistatic agent to deionized water and stir magnetically until completely dissolved to prepare an antistatic agent aqueous solution with a mass fraction of 10-20%. S2. Add the preheated modified silicone oil and the composite emulsifying system to an emulsifying kettle equipped with a high-speed shearing machine in sequence. Start stirring at a speed of 600-800 r / min and mix for 5-10 minutes. Control the temperature of the emulsifying kettle at 40-45°C and slowly add the antistatic agent aqueous solution dropwise at a rate of 1-2 mL / min. During the addition, increase the speed to 1200-1500 r / min and continue shearing for 10-15 minutes to form colostrum with coarse droplet size. S3. Maintain the temperature at 40-45°C and add deionized water to the emulsifier three times, with an interval of 10 minutes between each addition. After each addition, increase the speed to 2000-2500 r / min and shear for 10-20 minutes. After all the deionized water is added, maintain the speed at 2500 r / min and continue emulsification for 30 minutes. S4. Transfer the emulsion to a high-pressure homogenizer and circulate homogenization three times at a pressure of 20-25 MPa. After homogenization, cool the system to room temperature, adjust the pH to 6.5-7.5, stir for 20-30 min, and vacuum filter the emulsion through a 300-mesh nylon filter to obtain a carbon fiber precursor oil.

[0014] (3) Beneficial technical effects The present invention uses phenyl, carboxyl, and polyether chain-modified silicone oil. The rigid conjugated structure of the phenyl group gives the oil excellent high-temperature resistance, and can maintain stability in the high-temperature environment of carbon fiber precursor processing, avoiding lubrication failure or pollution caused by thermal decomposition; the carboxyl group enhances the adsorption force with the fiber surface through polarity, improves the film tightness, and reduces friction damage during the spinning process; the polyether chain optimizes the spreadability of the oil on the fiber surface by adjusting the hydrophilic-hydrophobic balance, and at the same time enhances the dispersion stability of the emulsion. The compounding of non-ionic emulsifiers and co-emulsifiers can reduce the interfacial tension between the oil phase and the water phase, forming a stable emulsion system, and ensuring that the oil is evenly attached to the fiber surface; the cationic antistatic agent effectively eliminates the static electricity accumulation caused by fiber friction through charge conduction, avoiding the drifting or breakage of the filament bundle caused by static electricity.

[0015] In summary, the combination of phenyl, carboxyl, and polyether chain modified silicone oils and non-ionic emulsification systems can simultaneously meet the requirements of carbon fiber precursor oils for thermal stability, lubricity, antistatic properties, and emulsion stability. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0017] The carbon fiber precursor oil formulation components of the present invention are commercially available unless otherwise specified. The parts used in the present invention are all parts by weight; In Example 1, the emulsifier is a non-ionic emulsifier selected from Tween-80.

[0018] The co-emulsifier is selected from n-butanol.

[0019] The antistatic agent is a cationic antistatic agent selected from dodecyltrimethylammonium chloride.

[0020] A phenyl-modified polysiloxane carbon fiber precursor oil comprises the following components by weight: 5 parts of modified silicone oil, 5 parts of emulsifier, 1 part of co-emulsifier, 1 part of antistatic agent, 50 parts of deionized water; The preparation method of modified silicone oil comprises the following steps: A1, in a dry four-necked flask, 100 parts of octamethylcyclotetrasiloxane, 60 parts of 1,3,5,7-tetramethyltetraphenylcyclotetrasiloxane, 20 parts of methylhydrogen cyclosiloxane were added in turn, stirred uniformly, nitrogen was introduced, the temperature was raised to 60℃, 1 part of tetramethylammonium hydroxide was added dropwise, the temperature was continuously raised to 100℃, and the reaction was carried out for 4 hours, 4 parts of hexamethyldisiloxane was added, the temperature was raised to 130℃, and maintained for 1 hour, and then distilled under reduced pressure to obtain a silicone oil precursor containing phenyl and silicon-hydrogen bonds; A2, 100 parts of silicone oil precursor, 200 parts of anhydrous methylcyclohexane, and 0.03 parts of phenothiazine were added in turn into a four-necked flask, nitrogen was introduced, the stirring rate was adjusted to 250 r / min, the oil bath was heated to 40℃, the silicone oil precursor was completely dissolved to form a uniform solution, 0.1 parts of platinum-divinyltetramethyldisiloxane complex and 0.04 parts of triethylamine were added, the temperature was continuously raised to 70℃, and maintained for 10 minutes, 15 parts of 4-pentenoic acid was slowly added through a constant pressure dropping funnel, the dropping speed was controlled at 0.8 mL / min, and the temperature was kept unchanged during the dropping process, after the dropping was completed, the temperature was raised to 85℃, and the reaction was carried out for 4 hours, the reaction liquid was cooled to room temperature, 5 parts of diatomite was added to adsorb the catalyst, stirred for 30 minutes, and then filtered under vacuum to obtain a clear filtrate, the filtrate was transferred to a rotary evaporator, distilled at 70℃ and 0.09 MPa for 30 minutes to remove methylcyclohexane and unreacted 4-pentenoic acid, and an intermediate product containing phenyl, residual silicon-hydrogen bonds and carboxyl groups was obtained; A3, 100 parts of the above-mentioned intermediate product and 300 parts of isopropanol were added into a four-necked flask, stirred and dissolved, 15 parts of 4Å molecular sieve was added, stirred for 1 hour, the molecular sieve was removed by filtration, the filtrate was returned to the flask, nitrogen was introduced for protection, the temperature was raised to 60℃, 0.06 parts of platinum-divinyltetramethyldisiloxane complex was added, stirred and activated for 20 minutes, 10 parts of polyethylene glycol monoallyl ether and 0.02 parts of 2,6-di-tert-butyl-p-cresol were added, the temperature was raised to 80℃, and the reaction was carried out for 3 hours, the reaction liquid was cooled, neutralized with saturated sodium bicarbonate aqueous solution, and then separated by standing, the organic phase was washed with 0.1 mol / L hydrochloric acid to adjust the pH to 5.0, and then washed with deionized water until neutral, 0.5 parts of antioxidant 1010 was added to the organic phase, stirred and dissolved, and then transferred to a reduced pressure distillation device, distilled at 90℃ and 0.085 MPa for 1.5 hours, and finally treated by supercritical CO2 extraction for 2 hours at a temperature of 40℃, a pressure of 15 MPa, and a CO2 flow rate of 20 g / h to obtain a modified silicone oil containing phenyl, carboxyl and polyether chains.

[0021] A method for preparing a phenyl-modified polysiloxane carbon fiber precursor oil, comprising the following steps: S1. Preheat the modified silicone oil in a 50°C oven for 30 minutes and set aside. Weigh the emulsifier and co-emulsifier in proportion, add them to a beaker and stir evenly to form a composite emulsification system. Add the antistatic agent to deionized water and stir magnetically until completely dissolved to prepare an antistatic agent aqueous solution with a mass fraction of 10%. S2. Add the preheated modified silicone oil and the composite emulsifying system to an emulsifying kettle equipped with a high-speed shearing machine in sequence, start stirring at a speed of 600 r / min, mix for 5 minutes, control the temperature of the emulsifying kettle at 40°C, and slowly add the antistatic agent aqueous solution dropwise at a rate of 1 mL / min. During the addition, increase the speed to 1200 r / min and continue shearing for 10 minutes to form colostrum with coarse droplet size. S3. Maintain the temperature at 40°C and add deionized water to the emulsification kettle three times, with an interval of 10 minutes between each addition. After each addition of water, increase the speed to 2000 r / min and shear for 10 minutes. After all the deionized water is added, maintain the speed at 2500 r / min and continue emulsification for 30 minutes. S4. Transfer the emulsion to a high-pressure homogenizer and circulate homogenization three times at a pressure of 20 MPa. After homogenization, cool the system to room temperature, adjust the pH to 6.5, stir for 20 min, and vacuum filter the emulsion through a 300-mesh nylon filter to obtain a carbon fiber precursor oil.

[0022] In Example 2, the emulsifier is a nonionic emulsifier selected from Span-80.

[0023] The co-emulsifier is selected from ethylene glycol monobutyl ether.

[0024] The antistatic agent is a cationic antistatic agent selected from cetylpyridinium bromide.

[0025] A phenyl-modified polysiloxane carbon fiber precursor oil comprises the following components by weight: 10 parts of modified silicone oil, 10 parts of emulsifier, 5 parts of co-emulsifier, 3 parts of antistatic agent, 60 parts of deionized water; The preparation method of modified silicone oil comprises the following steps: A1. In a dry four-necked flask, 110 parts of octamethylcyclotetrasiloxane, 70 parts of 1,3,5,7-tetramethyltetraphenylcyclotetrasiloxane, and 25 parts of methylhydrogencyclotrisiloxane were added in sequence, stirred evenly, introduced nitrogen, and heated to 70°C. 2 parts of tetramethylammonium hydroxide were added dropwise, and the temperature was continued to rise to 105°C. The reaction was carried out for 5 h, and 6 parts of hexamethyldisiloxane were added. The temperature was raised to 135°C and maintained for 1 h. The mixture was then distilled under reduced pressure to obtain a silicone oil precursor containing phenyl groups and silicon-hydrogen bonds. A2. Add 110 parts of silicone oil precursor, 300 parts of anhydrous methylcyclohexane and 0.06 parts of phenothiazine to a four-necked flask in sequence, introduce nitrogen, adjust the stirring rate to 300 r / min, heat the oil bath to 45°C, dissolve the silicone oil precursor completely to form a uniform solution, add 0.3 parts of catalyst platinum-divinyltetramethyldisiloxane complex and 0.05 parts of triethylamine, continue to heat to 75°C, keep warm for 15 min, slowly add 18 parts of 4-pentenoic acid through a constant pressure dropping funnel, control the dropping rate at 0.9 mL / min, and keep the temperature unchanged during the addition. After the addition is completed, heat to 90°C, keep warm for 5 h, cool the reaction solution to room temperature, add 8 parts of diatomaceous earth adsorption catalyst, stir for 40 min and then vacuum filter to obtain a clear filtrate, transfer the filtrate to a rotary evaporator, and distill at 75°C and 0.09 MPa for 45 min, removing methylcyclohexane and unreacted 4-pentenoic acid to obtain an intermediate product containing phenyl groups, residual silicon-hydrogen bonds and carboxyl groups; A3. Add 110 parts of the above intermediate product and 400 parts of isopropanol into a four-necked flask, stir and dissolve, then add 20 parts of 4Å molecular sieves, stir for 2 hours, filter to remove the molecular sieves, return the filtrate to the flask, purge with nitrogen, heat to 65°C, add 0.09 parts of catalyst platinum-divinyltetramethyldisiloxane complex, stir and activate for 25 minutes, add 15 parts of polyethylene glycol monoallyl ether and 0.04 parts of 2,6-di-tert-butyl-p-cresol, heat to 80°C, keep warm and react for 4 hours, cool the reaction solution, neutralize it with saturated sodium bicarbonate aqueous solution, let it stand and separate the liquids, wash the organic phase with 0.1 mol / L hydrochloric acid, adjust the pH to 5.5, and then wash with deionized water until neutral, add 0.8 parts of antioxidant 1010 to the organic phase, stir and dissolve, transfer to a vacuum distillation apparatus, distill at 95°C and 0.09 MPa for 2 hours, and finally extract it with supercritical CO2 for 2 hours at 40°C and 15 MPa, CO2 flow rate 20 g / h, and modified silicone oil containing phenyl, carboxyl and polyether chains was obtained.

[0026] A method for preparing a phenyl-modified polysiloxane carbon fiber precursor oil comprises the following steps: S1. Preheat the modified silicone oil in a 50°C oven for 30 minutes and set aside. Weigh the emulsifier and co-emulsifier in proportion, add them to a beaker and stir evenly to form a composite emulsification system. Add the antistatic agent to deionized water and stir magnetically until completely dissolved to prepare an antistatic agent aqueous solution with a mass fraction of 15%. S2. Add the preheated modified silicone oil and the composite emulsifying system to an emulsifying kettle equipped with a high-speed shearing machine in sequence, start stirring at a speed of 700 r / min, mix for 10 minutes, control the temperature of the emulsifying kettle at 45°C, and slowly add the antistatic agent aqueous solution dropwise at a rate of 1 mL / min. During the addition, increase the speed to 1300 r / min and continue shearing for 10 minutes to form colostrum with coarse droplet size. S3. Maintain the temperature at 40°C and add deionized water to the emulsifier three times, with an interval of 10 minutes between each addition. After each addition, increase the speed to 2200 r / min and shear for 15 minutes. After all the deionized water is added, maintain the speed at 2500 r / min and continue emulsification for 30 minutes. S4. Transfer the emulsion to a high-pressure homogenizer and circulate homogenization three times at a pressure of 22 MPa. After homogenization, cool the system to room temperature, adjust the pH to 7, stir for 30 min, and vacuum filter the emulsion through a 300-mesh nylon filter to obtain a carbon fiber precursor oil.

[0027] In Example 3, the emulsifier is a nonionic emulsifier selected from polyoxyethylene castor oil.

[0028] The co-emulsifier is selected from propylene glycol methyl ether.

[0029] The antistatic agent is a cationic antistatic agent selected from dioctadecyldimethylammonium chloride.

[0030] A phenyl-modified polysiloxane carbon fiber precursor oil comprises the following components by weight: 20 parts of modified silicone oil, 20 parts of emulsifier, 10 parts of co-emulsifier, 5 parts of antistatic agent, 80 parts of deionized water; The preparation method of modified silicone oil comprises the following steps: A1. In a dry four-necked flask, 120 parts of octamethylcyclotetrasiloxane, 80 parts of 1,3,5,7-tetramethyltetraphenylcyclotetrasiloxane, and 30 parts of methylhydrogencyclotrisiloxane were added in sequence, stirred evenly, introduced nitrogen, and heated to 80°C. 3 parts of tetramethylammonium hydroxide were added dropwise, and the temperature was continued to rise to 110°C. The reaction was carried out for 6 h, and 8 parts of hexamethyldisiloxane were added. The temperature was raised to 140°C and maintained for 1 h. The mixture was then distilled under reduced pressure to obtain a silicone oil precursor containing phenyl groups and silicon-hydrogen bonds. A2. Add 120 parts of silicone oil precursor, 400 parts of anhydrous methylcyclohexane and 0.08 parts of phenothiazine to a four-necked flask in sequence, introduce nitrogen, adjust the stirring rate to 350 r / min, heat the oil bath to 50°C, dissolve the silicone oil precursor completely to form a uniform solution, add 0.5 parts of catalyst platinum-divinyltetramethyldisiloxane complex and 0.06 parts of triethylamine, continue to heat to 80°C, keep warm for 20 min, slowly add 20 parts of 4-pentenoic acid through a constant pressure dropping funnel, control the dropping rate at 1 mL / min, and keep the temperature unchanged during the addition. After the addition is completed, heat to 90°C, keep warm for 6 h, cool the reaction solution to room temperature, add 10 parts of diatomaceous earth adsorption catalyst, stir for 40 min and then vacuum filter to obtain a clear filtrate, transfer the filtrate to a rotary evaporator, and distill at 80°C and 0.1 MPa for 45 min, removing methylcyclohexane and unreacted 4-pentenoic acid to obtain an intermediate product containing phenyl groups, residual silicon-hydrogen bonds and carboxyl groups; A3. Add 120 parts of the above intermediate product and 500 parts of isopropanol into a four-necked flask, stir and dissolve, then add 25 parts of 4Å molecular sieves, stir for 2 hours, filter to remove the molecular sieves, return the filtrate to the flask, purge with nitrogen, heat to 65°C, add 0.12 parts of catalyst platinum-divinyltetramethyldisiloxane complex, stir and activate for 30 minutes, add 20 parts of polyethylene glycol monoallyl ether and 0.05 parts of 2,6-di-tert-butyl-p-cresol, heat to 85°C, keep warm and react for 5 hours, cool the reaction solution, neutralize it with saturated sodium bicarbonate aqueous solution, let it stand and separate the liquids, wash the organic phase with 0.1 mol / L hydrochloric acid, adjust the pH to 6.0, and then wash with deionized water until neutral, add 1 part of antioxidant 1010 to the organic phase, stir and dissolve, transfer to a vacuum distillation apparatus, distill at 100°C and 0.095 MPa for 2 hours, and finally extract it with supercritical CO2 for 2 hours at 40°C and 15 MPa, CO2 flow rate 20 g / h, and modified silicone oil containing phenyl, carboxyl and polyether chains was obtained.

[0031] A method for preparing a phenyl-modified polysiloxane carbon fiber precursor oil comprises the following steps: S1. Preheat the modified silicone oil in a 50°C oven for 30 minutes and set aside. Weigh the emulsifier and co-emulsifier in proportion, add them to a beaker and stir evenly to form a composite emulsification system. Add the antistatic agent to deionized water and stir magnetically until completely dissolved to prepare an antistatic agent aqueous solution with a mass fraction of 20%. S2. Add the preheated modified silicone oil and the composite emulsifying system to an emulsifying kettle equipped with a high-speed shearing machine in sequence, start stirring at a speed of 800 r / min, mix for 10 minutes, control the temperature of the emulsifying kettle at 45°C, and slowly add the antistatic agent aqueous solution dropwise at a rate of 2 mL / min. During the addition, increase the speed to 1500 r / min and continue shearing for 15 minutes to form colostrum with coarse droplet size. S3. Maintain the temperature at 45°C and add deionized water to the emulsifier three times, with an interval of 10 minutes between each addition. After each addition, increase the speed to 2500 r / min and shear for 20 minutes. After all the deionized water is added, maintain the speed at 2500 r / min and continue emulsification for 30 minutes. S4. Transfer the emulsion to a high-pressure homogenizer and circulate homogenization three times at a pressure of 25 MPa. After homogenization, cool the system to room temperature, adjust the pH to 7.5, stir for 30 min, and vacuum filter the emulsion through a 300-mesh nylon filter to obtain a carbon fiber precursor oil.

[0032] Comparative Example 1: The modified silicone oil was replaced by octamethylcyclotetrasiloxane and methylhydrogencyclotrisiloxane, and the remaining components and preparation method were the same as in Example 1.

[0033] Comparative Example 2: The silicone oil precursor containing phenyl groups and silicon-hydrogen bonds prepared in step A1 was used, and steps A2 and A3 were omitted. The remaining components and preparation method were the same as in Example 1.

[0034] Comparative Example 3: The emulsifier was replaced with sodium lauryl sulfate, and the remaining components and preparation method were the same as in Example 1.

[0035] Performance testing: Thermal stability: Thermogravimetric analysis (TGA) was used to measure the weight loss at 300°C by heating the sample at a rate of 10°C / min to 500°C in a nitrogen atmosphere. Lubricity: The dynamic friction coefficient of the oiled carbon fiber precursor was measured using a fiber friction coefficient tester (test speed 10 m / min, tension 5 cN); Antistatic property: Use a surface resistivity meter to measure the surface resistance of the fiber after oil coating (ambient humidity 50%, temperature 25°C); Emulsion stability: Place the oil in a 50°C oven for 72 hours and observe whether it separates into layers. Centrifuge at 3000 rpm for 30 minutes and record the volume ratio of the separated layers. Film-forming properties: The oil was applied on a glass slide and dried at room temperature for 24 h. The surface smoothness (Ra value) of the film was observed using an atomic force microscope (AFM). Table 1 .

[0036] Table 2 .

[0037] As shown in the table above, phenyl-free silicone oils exhibit significantly reduced thermal stability and poorer lubricity due to the lack of rigid groups, demonstrating that phenyl groups are key to improving the oil's high-temperature resistance and lubricity. Pure phenyl silicone oils, lacking carboxyl groups and polyether chains, exhibit poor emulsion stability, rough film formation, and reduced antistatic properties, demonstrating that carboxyl groups and polyether chains ensure oil dispersibility and functional synergy. Charge conflicts between anionic emulsifiers and cationic antistatic agents lead to decreased emulsion stability and film smoothness, demonstrating the superior compatibility of nonionic emulsifiers with cationic antistatic agents.

[0038] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A phenyl-modified polysiloxane carbon fiber precursor oil, characterized in that: It contains the following components by weight: 5-20 parts of modified silicone oil, 5-20 parts of emulsifier, 1-10 parts of co-emulsifier, 1-5 parts of antistatic agent, 50-80 parts of deionized water; The preparation method of modified silicone oil comprises the following steps: A1. Octamethylcyclotetrasiloxane, 1,3,5,7-tetramethyltetraphenylcyclotetrasiloxane, and methylhydrogencyclotrisiloxane were mixed and stirred evenly, and tetramethylammonium hydroxide and hexamethyldisiloxane were added dropwise to react to obtain a silicone oil precursor containing phenyl groups and silicon-hydrogen bonds; A2. A silicone oil precursor, anhydrous methylcyclohexane, and phenothiazine were mixed, nitrogen was introduced, the oil bath was heated, and stirring was performed to form a homogeneous solution. A catalyst platinum-divinyltetramethyldisiloxane complex and triethylamine were added. After heating, 4-pentenoic acid was added dropwise. After the reaction, diatomaceous earth was added as an adsorbent catalyst to obtain a clear filtrate, and vacuum distillation was performed to obtain an intermediate product containing phenyl groups, residual silicon-hydrogen bonds, and carboxyl groups. A3. The above intermediate product and isopropanol were mixed, stirred to dissolve, and then 4Å molecular sieves were added. After filtering, catalyst platinum-divinyltetramethyldisiloxane complex, polyethylene glycol monoallyl ether, and 2,6-di-tert-butyl-p-cresol were added. After the reaction, saturated sodium bicarbonate aqueous solution was used for neutralization. The mixture was allowed to stand for separation, and antioxidant 1010 was added to the organic phase. The mixture was distilled under reduced pressure and extracted with supercritical CO2 to obtain a modified silicone oil containing phenyl groups, carboxyl groups, and polyether chains.

2. A phenyl-modified polysiloxane carbon fiber precursor oil according to claim 1, characterized in that: The emulsifier is a nonionic emulsifier, which is selected from Tween-80, Span-80 and polyoxyethylene castor oil.

3. The phenyl-modified polysiloxane carbon fiber precursor oil according to claim 1, characterized in that: The auxiliary emulsifier is selected from one of n-butanol, ethylene glycol monobutyl ether and propylene glycol methyl ether.

4. The phenyl-modified polysiloxane carbon fiber precursor oil according to claim 1, characterized in that: The antistatic agent is a cationic antistatic agent, and is selected from one of dodecyltrimethylammonium chloride, cetylpyridinium bromide, and dioctadecyldimethylammonium chloride.

5. The phenyl-modified polysiloxane carbon fiber precursor oil according to claim 1, characterized in that: In step A1, 100-120 parts of octamethylcyclotetrasiloxane, 60-80 parts of 1,3,5,7-tetramethyltetraphenylcyclotetrasiloxane, 20-30 parts of methylhydrogencyclotrisiloxane, 1-3 parts of tetramethylammonium hydroxide, and 4-8 parts of hexamethyldisiloxane are used.

6. The phenyl-modified polysiloxane carbon fiber precursor oil according to claim 1, characterized in that: In step A2, 100-120 parts of silicone oil precursor, 200-400 parts of anhydrous methylcyclohexane, 0.03-0.08 parts of phenothiazine, 0.1-0.5 parts of platinum-divinyltetramethyldisiloxane complex, 0.04-0.06 parts of triethylamine, 15-20 parts of 4-pentenoic acid, and 5-10 parts of diatomaceous earth.

7. The phenyl-modified polysiloxane carbon fiber precursor oil according to claim 1, characterized in that: In step A3, 100-120 parts of the intermediate product, 300-500 parts of isopropyl alcohol, 15-25 parts of 4Å molecular sieves, 0.06-0.12 parts of platinum-divinyltetramethyldisiloxane complex, 10-20 parts of polyethylene glycol monoallyl ether, 0.02-0.05 parts of 2,6-di-tert-butyl-p-cresol, and 0.5-1 parts of antioxidant 1010 are added.

8. The method for preparing a phenyl-modified polysiloxane carbon fiber precursor oil according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Preheat the modified silicone oil in a 50°C oven for 30 minutes and set aside. Weigh the emulsifier and co-emulsifier in proportion, add them to a beaker and stir evenly to form a composite emulsification system. Add the antistatic agent to deionized water and stir magnetically until completely dissolved to prepare an antistatic agent aqueous solution with a mass fraction of 10-20%. S2. Add the preheated modified silicone oil and the composite emulsifying system to an emulsifying kettle equipped with a high-speed shearing machine in sequence. Start stirring at a speed of 600-800 r / min and mix for 5-10 minutes. Control the temperature of the emulsifying kettle at 40-45°C and slowly add the antistatic agent aqueous solution dropwise at a rate of 1-2 mL / min. During the addition, increase the speed to 1200-1500 r / min and continue shearing for 10-15 minutes to form colostrum with coarse droplet size. S3. Maintain the temperature at 40-45°C and add deionized water to the emulsifier three times, with an interval of 10 minutes between each addition. After each addition, increase the speed to 2000-2500 r / min and shear for 10-20 minutes. After all the deionized water is added, maintain the speed at 2500 r / min and continue emulsification for 30 minutes. S4. Transfer the emulsion to a high-pressure homogenizer and circulate homogenization three times at a pressure of 20-25 MPa. After homogenization, cool the system to room temperature, adjust the pH to 6.5-7.5, stir for 20-30 min, and vacuum filter the emulsion through a 300-mesh nylon filter to obtain a carbon fiber precursor oil.