Heat-resistant stable antioxidant and preparation method thereof

Abstract

The invention discloses a heat-resistant stable antioxidant and a preparation method thereof, and relates to the technical field of antioxidants, the antioxidant is a substance capable of inhibiting or delaying oxidation reaction and has stable chemical properties, and an amine antioxidant is good in antioxidant effect but poor in heat stability; natural antioxidants such as rosemary extract and vitamin E have metal ion chelating ability and can be combined with copper ions to form a stable complex, so that oxidation reaction is inhibited; the dispersibility of the nano silicon dioxide can be improved through surface treatment of the nano silicon dioxide; a rosemary extract and vitamin E are added into 4, 4-bis (phenyl isopropyl) diphenylamine to prepare a composite antioxidant, and then copper ions and nano silicon dioxide are added, so that the thermal stability and dispersity of the antioxidant are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of antioxidants, in particular to a heat-resistant and stable antioxidant and a preparation method thereof. Background Art

[0002] During long-term storage and use, rubber and its products gradually become hard, brittle, or crack due to external factors. This phenomenon is called aging. As the aging process progresses, the performance of rubber and its products gradually deteriorates, ultimately losing their usability. Therefore, it is necessary to add substances to rubber and its products to delay or inhibit the aging process, thereby extending the storage and service life of rubber and its products. These substances are called antioxidants.

[0003] Amine antioxidants have good antioxidant effects and can decompose hydroperoxides to generate stable substances to terminate free radical chain reactions, but their thermal stability and hydrolysis stability are poor.

[0004] In summary, in order to solve the problems existing in the prior art and improve the thermal stability of antioxidants, the present invention provides a heat-resistant and stable antioxidant and a preparation method thereof. Summary of the Invention

[0005] The object of the present invention is to provide a heat-resistant and stable antioxidant and a preparation method thereof, so as to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A heat-resistant and stable antioxidant and a preparation method thereof, comprising the following steps:

[0008] Step 1: Take 1g of fatty alcohol polyoxyethylene ether and 1.8g of KH550, mix them evenly, and stir them at 40-60°C for 30-40min to prepare CSA; add 100mL of ethanol aqueous solution (water and ethanol mass ratio is 1:4) to CAS, and add hydrochloric acid dropwise to adjust the pH to 4; then add 0.1g of KH550, mix them evenly, stir them at 70-80°C for 4-6h, then add 9g of modified nano-silica powder, stir them for 5-7h, and dry them to obtain surface-treated nano-silica powder;

[0009] Step 2: Take 0.20g of rosemary extract and 10g of vitamin E, add 50mL of acetone and mix evenly, add 3g of powdered substance A, ultrasonically disperse, then add 2g of copper sulfate, and dropwise add sodium carbonate until the pH reaches 4.5. React at 30-40°C for 30-40min, filter, wash, and dry to obtain powdered substance B;

[0010] Step 3: Take 0.4g of surface-treated nano-silica powder, 0.5g of powdered substance B and 200mL of anhydrous toluene solvent and add them to a loaded reactor, ultrasonically disperse at 90Hz, magnetically stir, filter, wash with toluene, filter, repeat washing 3 to 5 times, and vacuum dry to obtain a heat-resistant and stable antioxidant.

[0011] More optimized, in step 1, the preparation method of the modified nano-silica powder is: vacuum drying the nano-silica powder at 120-140°C for 12-14 hours, taking 0.6g of the dried nano-silica powder, adding 10mL of oleic acid and 300mL of toluene, stirring evenly, then adding 1g of titanate coupling agent, reacting for 6-8 hours, filtering, adding 50mL of ether, ultrasonically dispersing and centrifuging, and drying to obtain the modified nano-silica powder.

[0012] More optimally, in step 1, the particle size of the nano-silicon dioxide powder is 20 to 30 nm.

[0013] More optimized, in step 2, the preparation method of powdered substance A is: 31.05g 4,4-di(phenylisopropyl)diphenylamine, 3g polyethylene glycol 200 and 0.08g p-toluenesulfonic acid are mixed evenly, and stirred at 120-140°C for 3-5h; then vacuuming, and adding 4.66g 4,4-di(phenylisopropyl)diphenylamine and 0.02g p-toluenesulfonic acid, repeating 3-5 times; extraction, dissolving the liquid in 25% ethanol solution, drying at 50-70°C, and filtering to obtain powdered substance A.

[0014] A more optimized method for preparing 4,4-bis(phenylisopropyl)diphenylamine is as follows: 42.3 g of diphenylamine and 2.38 g of a catalyst are added to 100 mL of toluene, nitrogen is introduced, 71 g of α-methylstyrene is added dropwise to the reaction system at 200-220°C, and the reaction is carried out for 6-8 hours; the mixture is cooled to 40-60°C, filtered while hot to remove the catalyst, and then 50 mL of petroleum ether is added to the reaction mixture. The mixture is distilled under reduced pressure, crystallized, filtered, centrifuged, and dried to obtain 4,4-bis(phenylisopropyl)diphenylamine.

[0015] More preferably, the catalyst is zinc chloride.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. Low molecular weight antioxidants are prone to physical losses such as volatilization, migration and water extraction, which leads to loss of polymer stability. Therefore, it is proposed to combine antioxidants with nano-silica to improve the thermal stability of antioxidants.

[0018] 2. Silica particles are easily adsorbed and combined with each other under the action of surface hydroxyl groups to form large-scale irregular aggregates. Fatty alcohol polyoxyethylene ether is introduced and mixed with KH550 to obtain a composite surface treatment additive. After KH550 is compounded with fatty alcohol polyoxyethylene ether, the mutual contact of KH550 molecules is hindered by the fatty alcohol polyoxyethylene ether molecules during hydrolysis, and the self-aggregation phenomenon can be suppressed, thereby reducing its particle size, improving its dispersibility in the polymer, and enhancing its stability.

[0019] 3. Copper ions (Cu 2+ ) plays a catalytic role in the oxidation process. They can promote the generation of free radicals through pathways such as the Fenton reaction and accelerate the oxidation of materials. Rosemary extract and vitamin E have the ability to chelate metal ions and can combine with copper ions to form stable complexes, thereby reducing the catalytic activity of copper ions, inhibiting the oxidation reaction, and enhancing antioxidant properties.

[0020] 4. Polyethylene glycol is a water-soluble high molecular weight polymer. High molecular weight polyethylene glycol can encapsulate copper ions through long chain entanglement to form a stable chelate. Adding it to antioxidants can enhance the stability of the antioxidants. DETAILED DESCRIPTION

[0021] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0022] The sources and models of the substances involved in the present invention are not particularly limited, and illustratively include: diphenylamine with a CAS number of 122-39-4, provided by Shandong Aite Chemical Co., Ltd.; α-methylstyrene with a CAS number of 25013-15-4, provided by Hubei Xinghengye Technology Co., Ltd.; rosemary extract and vitamin E are provided by Fuzhou Riguan Technology Development Co., Ltd.; copper sulfate with a CAS number of 7758-98-7, provided by Hangzhou Gaojing Chemical Co., Ltd.; fatty alcohol polyoxyethylene ether with a CAS number of 9002-92-0, provided by BASF (China) Co., Ltd.; nano-silica powder with a CAS number of 7631-86-9, a particle size of 20 to 30 nm, provided by Degussa (Qingdao) Co., Ltd.; polyethylene glycol 200 with a CAS number of 25322-68-3, provided by Suzhou Corning Polyol Co., Ltd.

[0023] Example 1: A heat-resistant and stable antioxidant and its preparation method:

[0024] Step 1: 42.3 g of diphenylamine and 2.38 g of zinc chloride catalyst were added to 100 mL of toluene, nitrogen was introduced, and 71 g of α-methylstyrene was added dropwise to the reaction system at 200° C. and reacted for 6 hours; the mixture was cooled to 40° C. and filtered while hot to remove the catalyst; then 50 mL of petroleum ether was added to the reaction mixture, and the mixture was distilled under reduced pressure, crystallized, filtered, centrifuged, and dried to obtain 4,4-di(phenylisopropyl)diphenylamine;

[0025] Step 2: (1) 31.05 g of 4,4-di(phenylisopropyl)diphenylamine, 3 g of polyethylene glycol 200, and 0.08 g of p-toluenesulfonic acid were mixed uniformly and stirred at 120° C. for 3 h; then, the mixture was evacuated and 4.66 g of 4,4-di(phenylisopropyl)diphenylamine and 0.02 g of p-toluenesulfonic acid were added, and the mixture was repeated three times; the mixture was extracted and the liquid was dissolved in 25% ethanol solution, dried at 50° C., and filtered to obtain powdery substance A;

[0026] (2) 0.20 g of rosemary extract and 10 g of vitamin E were added to 50 mL of acetone and mixed evenly. 3 g of powdered substance A was added and ultrasonically dispersed. 2 g of copper sulfate was added and sodium carbonate was added dropwise until the pH reached 4.5. The mixture was reacted at 30° C. for 30 min, filtered, washed, and dried to obtain powdered substance B.

[0027] Step 3: (1) drying the nano-silica powder at 120°C in vacuum for 12 h, adding 10 mL of oleic acid and 300 mL of toluene to 0.6 g of the dried nano-silica powder, stirring evenly, adding 1 g of a titanate coupling agent, reacting for 6 h, filtering, adding 50 mL of ether, ultrasonically dispersing and centrifuging, and drying to obtain modified nano-silica powder;

[0028] (2) 1 g of fatty alcohol polyoxyethylene ether and 1.8 g of KH550 were mixed and stirred at 40°C for 30 min to prepare CSA; 100 mL of ethanol aqueous solution (water to ethanol mass ratio of 1:4) was added to CAS, and hydrochloric acid was added dropwise to adjust the pH to 4; then 0.1 g of KH550 was added, mixed and stirred at 70°C for 4 h, and then 9 g of modified nano-silica powder was added, stirred for 5 h, and dried to obtain surface-treated nano-silica powder;

[0029] Step 4: Take 0.4 g of surface-treated nano-silica powder, 0.5 g of powdered substance B and 200 mL of anhydrous toluene solvent and add them to a loaded reactor, ultrasonically disperse at 90 Hz, magnetically stir, filter, wash with toluene, filter, repeat washing 3 times, and vacuum dry to obtain a heat-resistant and stable antioxidant.

[0030] Example 2: A heat-resistant and stable antioxidant and its preparation method:

[0031] Step 1: 42.3 g of diphenylamine and 2.38 g of zinc chloride catalyst were added to 100 mL of toluene, nitrogen was introduced, and 71 g of α-methylstyrene was added dropwise to the reaction system at 220° C. and reacted for 8 hours; the mixture was cooled to 60° C. and filtered while hot to remove the catalyst; then 50 mL of petroleum ether was added to the reaction mixture, and the mixture was distilled under reduced pressure, crystallized, filtered, centrifuged, and dried to obtain 4,4-di(phenylisopropyl)diphenylamine;

[0032] Step 2: (1) 31.05 g of 4,4-di(phenylisopropyl)diphenylamine, 3 g of polyethylene glycol 200, and 0.08 g of p-toluenesulfonic acid were mixed uniformly and stirred at 140° C. for 5 h; then, the mixture was evacuated and 4.66 g of 4,4-di(phenylisopropyl)diphenylamine and 0.02 g of p-toluenesulfonic acid were added, and the mixture was repeated 5 times; the mixture was extracted and the liquid was dissolved in 25% ethanol solution, dried at 70° C., and filtered to obtain powdery substance A;

[0033] (2) 0.20 g of rosemary extract and 10 g of vitamin E were added to 50 mL of acetone and mixed evenly. 3 g of powdered substance A was added and ultrasonically dispersed. 2 g of copper sulfate was added and sodium carbonate was added dropwise until the pH reached 4.5. The mixture was reacted at 40° C. for 40 min, filtered, washed, and dried to obtain powdered substance B.

[0034] Step 3: (1) drying the nano-silica powder at 140°C in vacuum for 14 h, taking 0.6 g of the dried nano-silica powder, adding 10 mL of oleic acid and 300 mL of toluene, stirring evenly, then adding 1 g of titanate coupling agent, reacting for 8 h, filtering, adding 50 mL of ether, ultrasonically dispersing and centrifuging, and drying to obtain modified nano-silica powder;

[0035] (2) 1 g of fatty alcohol polyoxyethylene ether and 1.8 g of KH550 were mixed and stirred at 60°C for 40 min to prepare CSA; 100 mL of ethanol aqueous solution (water to ethanol mass ratio of 1:4) was added to CAS, and hydrochloric acid was added dropwise to adjust the pH to 4; then 0.1 g of KH550 was added, mixed and stirred at 80°C for 6 h, and then 9 g of modified nano-silica powder was added, stirred for 7 h, and dried to obtain surface-treated nano-silica powder;

[0036] Step 4: Take 0.4 g of surface-treated nano-silica powder, 0.5 g of powdered substance B and 200 mL of anhydrous toluene solvent and add them to a loaded reactor, ultrasonically disperse at 90 Hz, magnetically stir, filter, wash with toluene, filter, repeat washing 3 times, and vacuum dry to obtain a heat-resistant and stable antioxidant.

[0037] Example 3: A heat-resistant and stable antioxidant and its preparation method:

[0038] Step 1: 42.3 g of diphenylamine and 2.38 g of zinc chloride catalyst were added to 100 mL of toluene, nitrogen was introduced, and 71 g of α-methylstyrene was added dropwise to the reaction system at 210° C. and reacted for 7 h; the mixture was cooled to 50° C. and filtered while hot to remove the catalyst; then 50 mL of petroleum ether was added to the reaction mixture, and the mixture was distilled under reduced pressure, crystallized, filtered, centrifuged, and dried to obtain 4,4-di(phenylisopropyl)diphenylamine;

[0039] Step 2: (1) 31.05 g of 4,4-di(phenylisopropyl)diphenylamine, 3 g of polyethylene glycol 200, and 0.08 g of p-toluenesulfonic acid were mixed uniformly and stirred at 130° C. for 4 h; then, the mixture was evacuated and 4.66 g of 4,4-di(phenylisopropyl)diphenylamine and 0.02 g of p-toluenesulfonic acid were added, and the mixture was repeated 4 times; the mixture was extracted and the liquid was dissolved in 25% ethanol solution, dried at 60° C., and filtered to obtain powdery substance A;

[0040] (2) 0.20 g of rosemary extract and 10 g of vitamin E were added to 50 mL of acetone and mixed evenly. 3 g of powdered substance A was added and ultrasonically dispersed. 2 g of copper sulfate was added and sodium carbonate was added dropwise until the pH reached 4.5. The mixture was reacted at 35° C. for 35 min, filtered, washed, and dried to obtain powdered substance B.

[0041] Step 3: (1) drying the nano-silica powder at 130°C in vacuum for 13 h, adding 10 mL of oleic acid and 300 mL of toluene to 0.6 g of the dried nano-silica powder, stirring evenly, adding 1 g of a titanate coupling agent, reacting for 7 h, filtering, adding 50 mL of ether, ultrasonically dispersing, centrifuging, and drying to obtain modified nano-silica powder;

[0042] (2) 1 g of fatty alcohol polyoxyethylene ether and 1.8 g of KH550 were mixed and stirred at 50 ° C for 35 min to prepare CSA; 100 mL of ethanol aqueous solution (water to ethanol mass ratio of 1:4) was added to CAS, and hydrochloric acid was added dropwise to adjust the pH to 4; then 0.1 g of KH550 was added, mixed and stirred at 75 ° C for 5 h, and then 9 g of modified nano-silica powder was added, stirred for 6 h, and dried to obtain surface-treated nano-silica powder;

[0043] Step 4: Take 0.4 g of surface-treated nano-silica powder, 0.5 g of powdered substance B and 200 mL of anhydrous toluene solvent and add them to a loaded reactor, ultrasonically disperse at 90 Hz, magnetically stir, filter, wash with toluene, filter, repeat washing 4 times, and vacuum dry to obtain a heat-resistant and stable antioxidant.

[0044] Comparative Example 1: No nano-silicon dioxide powder was added, and the rest was referred to Example 1. The specific operations were as follows:

[0045] Step 1: 42.3 g of diphenylamine and 2.38 g of zinc chloride catalyst were added to 100 mL of toluene, nitrogen was introduced, and 71 g of α-methylstyrene was added dropwise to the reaction system at 200° C. and reacted for 6 hours; the mixture was cooled to 40° C. and filtered while hot to remove the catalyst; then 50 mL of petroleum ether was added to the reaction mixture, and the mixture was distilled under reduced pressure, crystallized, filtered, centrifuged, and dried to obtain 4,4-di(phenylisopropyl)diphenylamine;

[0046] Step 2: (1) 31.05 g of 4,4-di(phenylisopropyl)diphenylamine, 3 g of polyethylene glycol 200, and 0.08 g of p-toluenesulfonic acid were mixed uniformly and stirred at 120° C. for 3 h; then, the mixture was evacuated and 4.66 g of 4,4-di(phenylisopropyl)diphenylamine and 0.02 g of p-toluenesulfonic acid were added, and the mixture was repeated three times; the mixture was extracted and the liquid was dissolved in 25% ethanol solution, dried at 50° C., and filtered to obtain powdery substance A;

[0047] (2) 0.20 g of rosemary extract and 10 g of vitamin E were added to 50 mL of acetone and mixed evenly. 3 g of powdered substance A was added and ultrasonically dispersed. 2 g of copper sulfate was added and sodium carbonate was added dropwise until the pH value reached 4.5. The mixture was reacted at 30° C. for 30 min, filtered, washed, and dried to obtain a heat-resistant and stable antioxidant.

[0048] Comparative Example 2: Polyethylene glycol was not added, and the rest was referred to Example 1. The specific operations were as follows:

[0049] Step 2: (1) 31.05 g of 4,4-di(phenylisopropyl)diphenylamine, 0.20 g of rosemary extract, and 10 g of vitamin E were added to 50 mL of acetone and mixed evenly. 3 g of powdered substance A was added and ultrasonically dispersed. 2 g of copper sulfate was added and sodium carbonate was added dropwise until the pH reached 4.5. The mixture was reacted at 30° C. for 30 min, filtered, washed, and dried to obtain powdered substance B.

[0050] Comparative Example 3: The nano-silicon dioxide powder was not subjected to surface treatment. The rest of the process was similar to that of Example 1. The specific operation was as follows:

[0051] Step 3: (1) drying the nano-silica powder at 120°C in vacuum for 12 h, adding 10 mL of oleic acid and 300 mL of toluene to 0.6 g of the dried nano-silica powder, stirring evenly, adding 1 g of a titanate coupling agent, reacting for 6 h, filtering, adding 50 mL of ether, ultrasonically dispersing and centrifuging, and drying to obtain modified nano-silica powder;

[0052] Step 4: Take 0.4 g of modified nano-silica powder, 0.5 g of powdered substance B and 200 mL of anhydrous toluene solvent and add them to a loaded reactor, ultrasonically disperse at 90 Hz, magnetically stir, filter, wash with toluene, filter, repeat washing 3 times, and vacuum dry to obtain a heat-resistant and stable antioxidant.

[0053] Comparative Example 4: No copper ions were added, and the rest was referred to Example 1. The specific operations were as follows:

[0054] Step 2: (1) 31.05 g of 4,4-di(phenylisopropyl)diphenylamine, 3 g of polyethylene glycol 200, and 0.08 g of p-toluenesulfonic acid were mixed uniformly and stirred at 120° C. for 3 h; then, the mixture was evacuated and 4.66 g of 4,4-di(phenylisopropyl)diphenylamine and 0.02 g of p-toluenesulfonic acid were added, and the mixture was repeated three times; the mixture was extracted and the liquid was dissolved in 25% ethanol solution, dried at 50° C., and filtered to obtain powdery substance A;

[0055] (2) 0.20 g of rosemary extract and 10 g of vitamin E were added to acetone and mixed evenly, 3 g of powdered substance A was added, ultrasonically dispersed, and dried to obtain powdered substance B.

[0056] Experiment: The antioxidants prepared in the Examples and Comparative Examples were granulated in a granulator to obtain columnar particles. 30 g of the columnar particles were then dissolved in 500 mL of ethane and added to 500 mL of polyisoprene latex. A hot water gel method was used to prepare the pellets, which were then dehydrated to obtain antioxidant-added isoprene rubber. A COD test tube containing 10 g of isoprene rubber was placed in an oven at 300°C and heated for 3 hours. The antioxidant in the test tube was reweighed, the difference calculated, and the data recorded. The test results are shown in Table 1:

[0057] Table 1

[0058] Initial mass / g Mass after heating / g Weight loss rate / % Example 1 10 9.89 1.1 Example 2 10 9.92 0.8 Example 3 10 9.90 1.0 Comparative Example 1 10 8.55 14.5 Comparative Example 2 10 8.97 10.3 Comparative Example 3 10 9.01 9.9

[0059] Conclusion: The above experimental data show that the antioxidant prepared in Example 2 of the present invention has a mass loss of 0.8% when calcined at 300°C. The antioxidant prepared in Comparative Example 1 without the addition of nano-silica powder has a mass loss of 14.5% after calcination. The antioxidant prepared in Comparative Example 3 without the surface treatment of the nano-silica powder has a mass loss of 9.9% after calcination. Therefore, the addition of nano-silica powder improves the heat stability of the antioxidant because low molecular weight antioxidants are prone to physical losses such as volatilization, migration and water extraction. Leading to loss of polymer stability; for nano-silica surface treatment, the self-aggregation phenomenon of silica particles can be suppressed, thereby reducing its particle size and improving its dispersibility in the polymer, so it is proposed to combine the antioxidant with the nano-silica powder and surface treat the nano-silica powder to improve the thermal stability of the antioxidant; the mass loss of the antioxidant in Comparative Example 2 without adding polyethylene glycol is 10.3%, because polyethylene glycol can embed copper ions through long chain entanglement to form a stable chelate, and adding it to the antioxidant can enhance the stability of the antioxidant.

[0060] Experiment 2: The antioxidants prepared in the Examples and Comparative Examples were granulated in a granulator to obtain columnar particles. 30 g of these columnar particles were then dissolved in 500 mL of ethane and added to 500 mL of polyisoprene latex. Rubber pellets were prepared using a hot water gel method. The roller temperature was adjusted to 100°C and the rubber was dried five times using a double-roller dryer to produce rubber sheets of uniform thickness. These sheets were then oven-dried at 200°C for 3 hours to simulate rubber aging. Mooney analysis was performed on the oven-aged sheets. A comparison of Mooney degradation rates before and after aging is shown in Table 2.

[0061] Table 2

[0062] Initial Mooney Mooney after aging Mooney degradation rate% Example 1 80.6 75.7 6.1 Comparative Example 4 81.2 72.6 10.6

[0063] Conclusion: The above experimental data show that the Mooney degradation rate of the antioxidant prepared in Example 1 is 6.1%, and the Mooney degradation rate of Comparative Example 4 is an antioxidant without copper ions, which is 10.6%. It can be seen that the antioxidant performance of Example 1 is relatively good, while the antioxidant performance of Comparative Example 4 is relatively poor; this is because the antioxidant has insufficient ability to capture oxidation and peroxide free radicals during the oxidation process of the rubber material, and the molecular chain will be accompanied by varying degrees of degradation or cross-linking reaction, thereby causing changes in Mooney viscosity; rosemary extract and vitamin E have metal ion chelating ability, can combine with copper ions to form a stable complex, thereby reducing the catalytic activity of copper ions, inhibiting the oxidation reaction, and enhancing antioxidant properties.

[0064] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A method for preparing a heat-resistant and stable antioxidant, characterized in that: The following steps are involved: Step 1: Mix fatty alcohol polyoxyethylene ether and KH550 evenly and stir for 30 to 40 minutes; Add ethanol aqueous solution, add hydrochloric acid dropwise to adjust pH=4; add KH550, mix well, stir for 4-6 hours, add modified nano-silica powder, stir for 5-7 hours, and dry to obtain surface-treated nano-silica powder; Step 2: Take rosemary extract and vitamin E, add acetone, add powdered substance A, ultrasonically disperse, add copper sulfate, add sodium carbonate dropwise, adjust the pH to 4.5, react for 30-40 minutes, filter, wash, and dry to obtain powdered substance B; Step 3: Take the surface-treated nano-silica powder, powdered substance B and anhydrous toluene, ultrasonically disperse, magnetically stir, filter, wash, filter, repeat washing 3 times, and vacuum dry to obtain an antioxidant.

2. The method for preparing a heat-resistant and stable antioxidant according to claim 1, wherein: The modified nano-silica powder is prepared by drying the nano-silica powder for 12 to 14 hours, adding oleic acid and toluene to the dried nano-silica powder, stirring evenly, adding a titanate coupling agent, reacting for 6 to 8 hours, filtering, adding ether for ultrasonic dispersion and centrifugation, and drying to obtain the modified nano-silica powder.

3. The method for preparing a heat-resistant and stable antioxidant according to claim 2, wherein: The particle size of the nano silicon dioxide powder is 20 to 30 nm.

4. The method for preparing a heat-resistant and stable antioxidant according to claim 1, wherein: The preparation method of the powdered substance A comprises: uniformly mixing 4,4-di(phenylisopropyl)diphenylamine, polyethylene glycol 200 and p-toluenesulfonic acid, reacting for 3 to 5 hours; evacuating, adding 4,4-di(phenylisopropyl)diphenylamine and p-toluenesulfonic acid, and repeating 3 to 5 times; extracting, dissolving in an ethanol solution, drying, and filtering to obtain the powdered substance A.

5. The method for preparing a heat-resistant and stable antioxidant according to claim 4, wherein: The preparation method of 4,4-di(phenylisopropyl)diphenylamine comprises the following steps: adding diphenylamine and a catalyst to toluene, introducing nitrogen, adding α-methylstyrene dropwise, and reacting for 6 to 8 hours; cooling to 60°C, filtering while hot, adding petroleum ether, performing reduced pressure distillation, crystallization, filtering, centrifugation, and drying to obtain 4,4-di(phenylisopropyl)diphenylamine.

6. The method for preparing a heat-resistant and stable antioxidant according to claim 5, characterized in that: The catalyst is zinc chloride.

7. A heat-resistant and stable antioxidant prepared according to the method for preparing a heat-resistant and stable antioxidant according to any one of claims 1 to 6.