Preparation method and application of reaction type antioxidant based on sulfydryl-containing benzimidazole micromolecular antioxidant

Abstract

The invention provides a preparation method and application of a reaction type antioxidant based on a sulfydryl-containing benzimidazole micromolecular antioxidant, and the preparation method comprises the following steps: in the presence of a catalyst, carrying out Michael addition reaction on the sulfydryl-containing benzimidazole antioxidant and a bio-based monomer containing double bonds and carboxyl to obtain an intermediate compound; and in the presence of a condensing agent and an activating agent, carrying out esterification reaction on the intermediate compound and cellulose to obtain the reaction type antioxidant based on the sulfydryl-containing benzimidazole micromolecular antioxidant. According to the method, a bio-based monomer containing double bonds and carboxyl and a cellulose chemical grafting micromolecular mercapto-containing benzimidazole antioxidant are adopted to construct a molecular structure with high molecular weight characteristics and multiple antioxidant functions, the bio-based monomer containing double bonds and carboxyl is used as a bridging agent, the micromolecular antioxidant is bonded into a rubber molecular chain, and the molecular structure is formed by compounding the bio-based monomer containing double bonds and carboxyl and the cellulose chemical grafting micromolecular mercapto-containing benzimidazole antioxidant. The problems of migration, volatilization and environmental compatibility of micromolecular antioxidants are fundamentally solved, meanwhile, the anti-oxidation efficiency and the material durability are improved, and the service life of latex gloves is prolonged.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antioxidants, and particularly relates to a preparation method of a reactive antioxidant based on a small-molecule antioxidant containing a mercapto benzimidazole and application thereof. BACKGROUND

[0002] The mercapto benzimidazole antioxidant is a kind of heterocyclic compound with 2-mercapto benzimidazole as a core structure, and has the structural characteristics that a benzene ring is fused with an imidazole ring, and a mercapto group (-SH) is connected to the 2nd position of the imidazole ring. The structure endows the mercapto benzimidazole antioxidant with excellent electron transfer capacity and metal coordination activity, and excellent anti-yellowing capacity, and the mercapto benzimidazole antioxidant is suitable for light-colored rubber products. However, due to the small molecular weight, the mercapto benzimidazole antioxidant is easy to migrate, and in the long-term high-temperature processing or use process, there is a risk of volatilization and decomposition, resulting in a decrease in antioxidant performance. SUMMARY

[0003] Therefore, the purpose of the application is to provide a preparation method of a reactive antioxidant based on a small-molecule antioxidant containing a mercapto benzimidazole and application thereof, and the antioxidant prepared by the method has excellent mechanical properties for a bio-based latex glove.

[0004] The application provides a preparation method of a reactive antioxidant based on a small-molecule antioxidant containing a mercapto benzimidazole, which comprises the following steps:

[0005] In the presence of a catalyst, a mercapto benzimidazole antioxidant and a bio-based monomer containing a double bond and a carboxyl group are subjected to a Michael addition reaction to obtain an intermediate compound;

[0006] In the presence of a condensing agent and an activating agent, the intermediate compound and a cellulose ester are subjected to esterification to obtain a reactive antioxidant based on a small-molecule antioxidant containing a mercapto benzimidazole.

[0007] Preferably, the mercapto benzimidazole antioxidant is selected from one or more of 2-mercapto benzimidazole, 2-mercapto benzimidazole zinc salt, 2-(4-morpholinyl dithio) benzimidazole and 2-mercapto methyl benzimidazole;

[0008] The bio-based monomer containing a double bond and a carboxyl group is selected from one or more of maleic acid, Artepillin C, mycotic acid and sorbic acid.

[0009] Preferably, the catalyst is selected from one or more of triethylamine, triisopropanolamine, 1,8-diazabicycloundec-7-ene, 1,4-diazabicyclo[2.2.2]octane, N,N-diisopropylethylamine, potassium carbonate, cesium carbonate, KOH, tetrabutylammonium bromide, benzyltriethylammonium chloride, AlCl3, ZnCl2 and BF3·Et2O.

[0010] Preferably, the mass ratio of the thiol-containing benzimidazole antioxidant and the double bond and carboxyl-containing bio-based monomer is 1:1-10;

[0011] The catalyst accounts for 1-6% of the total mass of the antioxidant and bio-based monomer.

[0012] Preferably, the temperature of the Michael addition reaction is 40-120°C, and the time is 6-36h.

[0013] Preferably, the condensing agent is selected from one of dicyclohexyl carbodiimide, diisopropyl carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate, O-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, 4-dimethylaminopyridine and 1-hydroxybenzotriazole;

[0014] The condensing agent accounts for 20-80% of the total mass of the cellulose and intermediate compound.

[0015] Preferably, the activating agent is selected from one or more of 4-dimethylaminopyridine, N,N'-dicyclohexyl carbodiimide, N,N'-diisopropyl carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, O-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, O-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, oxalyl chloride, thionyl chloride phosphorus oxychloride, isobutyl chloroformate, N,N'-carbonyldiimidazole, ethoxycarbonyl ethoxydihydroquinoline;

[0016] The activating agent accounts for 2-8% of the total mass of the cellulose and intermediate compound.

[0017] Preferably, the temperature of the esterification reaction is 20-100°C, and the time is 4-36h.

[0018] Preferably, the crude product obtained by esterification is extracted to obtain a reactive antioxidant based on a thiol-containing benzimidazole small molecule antioxidant;

[0019] The extracting agent is selected from diethyl ether.

[0020] The application of the reactive antioxidant based on a thiol-containing benzimidazole small molecule antioxidant prepared by the preparation method described in the above technical solution in latex gloves.

[0021] The application provides a preparation method of a reactive antioxidant based on a small-molecule antioxidant containing a mercapto benzimidazole, comprising the following steps: performing a Michael addition reaction on a small-molecule antioxidant containing a mercapto benzimidazole and a bio-based monomer containing a double bond and a carboxyl group in the presence of a catalyst to obtain an intermediate compound; and performing an esterification reaction on the intermediate compound and cellulose in the presence of a condensing agent and an activating agent to obtain the reactive antioxidant based on the small-molecule antioxidant containing the mercapto benzimidazole. The method uses a bio-based monomer containing a double bond and a carboxyl group and a small-molecule antioxidant containing a mercapto benzimidazole to chemically graft a small-molecule antioxidant to construct a molecular structure with high molecular weight characteristics and multiple antioxidant functions. The bio-based monomer containing a double bond and a carboxyl group is used as a bridging agent to bond the small-molecule antioxidant to a rubber molecular chain, fundamentally solving the problems of migration, volatilization and environmental compatibility of the small-molecule antioxidant, improving the antioxidant efficiency and material durability, and prolonging the service life of a latex glove. DETAILED DESCRIPTION

[0022] The application provides a preparation method of a reactive antioxidant based on a small-molecule antioxidant containing a mercapto benzimidazole, comprising the following steps:

[0023] performing a Michael addition reaction on a small-molecule antioxidant containing a mercapto benzimidazole and a bio-based monomer containing a double bond and a carboxyl group in the presence of a catalyst to obtain an intermediate compound;

[0024] performing an esterification reaction on the intermediate compound and cellulose in the presence of a condensing agent and an activating agent to obtain the reactive antioxidant based on the small-molecule antioxidant containing the mercapto benzimidazole.

[0025] The application performs a Michael addition reaction on a small-molecule antioxidant containing a mercapto benzimidazole and a bio-based monomer containing a double bond and a carboxyl group in the presence of a catalyst to obtain an intermediate compound.

[0026] In the application, the catalyst is selected from one or more of triethylamine, triisopropanolamine, 1,8-diazabicycloundec-7-ene, 1,4-diazabicyclo[2.2.2]octane, N,N-diisopropylethylamine, potassium carbonate, cesium carbonate, KOH, tetrabutylammonium bromide, benzyltriethylammonium chloride, AlCl3, ZnCl2 and BF3·Et2O. The addition amount of the catalyst is 1% to 6% of the total amount of the antioxidant and the bio-based monomer, and can be specifically 1%, 2%, 3%, 4%, 5% or 6%; the dropping time of the catalyst is 1 to 3 hours, and can be specifically 1 hour, 1.5 hours, 2 hours, 2.5 hours or 3 hours. The application preferably drops a predetermined amount of the catalyst at a constant rate; the dropping time is 1 to 3 hours.

[0027] In the present application, the thiol-containing benzimidazole antioxidant is selected from one or more of 2-mercaptobenzimidazole, 2-mercaptobenzimidazole zinc salt, 2-(4-morpholinyl dithio) benzimidazole and 2-mercaptomethylbenzimidazole; the double bond and carboxyl-containing bio-based monomer is selected from one or more of maleic acid, Artepillin C, Mycotic Acid and Sorbic Acid.

[0028] In the present application, the mass ratio of the thiol-containing benzimidazole antioxidant and the double bond and carboxyl-containing bio-based monomer is 1:1-10; specifically, it can be 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10.

[0029] In the present application, the Michael addition reaction is carried out in an organic solvent; the organic solvent is selected from one or more of dimethyl sulfoxide, dimethyl formamide and acetonitrile. The added amount of the organic solvent used in the Michael addition reaction is 10-20 times the total mass of the antioxidant and bio-based monomer.

[0030] In the present application, the temperature of the Michael addition reaction is 40-120°C, specifically, it can be 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C; the time is 6-36h, specifically, it can be 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, 24h, 25h, 26h, 27h, 28h, 29h, 30h, 31h, 32h, 33h, 34h, 35h or 36h.

[0031] The present application preferably carries out the Michael addition reaction in a three-necked flask; the three-necked flask is sealed and purged with nitrogen to replace air. After the Michael addition reaction is completed, the present application preferably pours the reaction solution into a beaker, slowly adds excess deionized water and continuously stirs until the precipitate is precipitated. The precipitate is collected by filtration and vacuum dried at 40°C to constant weight to obtain an intermediate compound.

[0032] After obtaining the intermediate compound, the present application carries out esterification reaction of the intermediate compound and cellulose in the presence of a condensing agent and an activating agent to obtain a reactive antioxidant based on a thiol-containing benzimidazole small molecule antioxidant.

[0033] The present application pours the intermediate compound into a three-necked flask, then adds cellulose and a solvent to dissolve the cellulose; then preferably uniformly adds the condensing agent and the activating agent within 1-3h; after sealing, nitrogen is introduced. The present application preferably carries out the esterification reaction under stirring.

[0034] In this invention, the cellulose has a molecular weight of 680,000 to 720,000, a degree of polymerization (DS) of 0.85 to 0.95, and a viscosity of 1,500 to 4,500 mPa·s; in a specific embodiment, the cellulose has a molecular weight of 700,000, a degree of polymerization (DS) of 0.9, and a viscosity of 1,500 to 3,100 mPa·s. The mass ratio of the intermediate compound to cellulose is 4 to 10:1; specifically, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1.

[0035] In this invention, the condensing agent is selected from one of dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, benzotriazole-N,N,N',N'-tetramethylurea hexafluorophosphate, tetrafluoroborate (O-benzotriazole-1-yl)-N,N,N',N'-tetramethylurea, hexafluorophosphate (O-(7-azabenzotriazole-1-yl)-N,N,N',N'-tetramethylurea), 4-dimethylaminopyridine, and 1-hydroxybenzotriazole; the condensing agent accounts for 20-80% of the total mass of the cellulose and intermediate compounds, specifically 20%, 30%, 40%, 50%, 60%, 70%, or 80%.

[0036] In this invention, the activator is selected from one or more of 4-dimethylaminopyridine, N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate, O-benzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate, O-benzotriazol-1-yl)-N,N,N',N'-tetramethylurea tetrafluoroborate, oxaloyl chloride, thionyl chloride phosphorus oxychloride, isobutyl chloroformate, N,N'-carbonyldiimidazole, and ethoxycarbonylethoxydihydroquinoline. The activator in this invention accounts for 2-8% of the total mass of the cellulose and intermediate compounds, specifically 2%, 3%, 4%, 5%, 6%, 7%, or 8%.

[0037] After the esterification reaction is completed, the crude product solution obtained by the esterification reaction is filtered and the filtrate is collected. The present invention adds excess diethyl ether to the filtrate through a separatory funnel, collects the lower layer solution, and slowly adds the collected bottom layer solution to excess deionized water under mechanical stirring to produce a precipitate. The precipitate product is dried to constant weight under vacuum at 40°C to obtain a reactive antioxidant based on a small molecule antioxidant containing mercaptobenzimidazole.

[0038] The present invention preferably applies a reactive antioxidant based on a small molecule antioxidant containing a mercaptobenzimidazole to the preparation of latex gloves; the raw materials for preparing the latex gloves, by weight, include: 3000 parts of bio-based itaconic acid ester latex, 59 parts of KOH, 75 parts of zinc oxide solution, 26 parts of sulfur, 22 parts of ZDB-50, 4 parts of ZDE-50, 37 parts of black paste and 18 parts of a reactive antioxidant based on a small molecule antioxidant containing a mercaptobenzimidazole.

[0039] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, provides a method for preparing a reactive antioxidant based on a small molecule antioxidant containing mercaptobenzimidazole and its application, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0040] Examples 1-9

[0041] 1) A measured amount of antioxidant and bio-based monomer were added to a three-necked flask containing solvent. A predetermined amount of catalyst was added dropwise at a constant rate over 1–3 hours. After sealing the three-necked flask system and purging the air with nitrogen, the mixture was heated and stirred at a constant speed to generate the target intermediate. After the reaction was complete, the resulting solution was poured into a beaker, and excess deionized water was slowly added while stirring continuously until a precipitate formed. The precipitate was collected by filtration and dried under vacuum at 40°C to constant weight to finally obtain the intermediate compound.

[0042] 2) Add a quantitative amount of intermediate compound to a three-necked flask, add a quantitative amount of cellulose, dissolve in a certain amount of solvent, add a quantitative amount of condensing agent and activator dropwise at a uniform rate over 1-3 hours, seal, introduce nitrogen gas, heat and start stirring at a uniform rate to react and obtain a crude product solution of reactive antioxidant based on mercaptobenzimidazole antioxidant.

[0043] 3) Filter the crude product solution of the reactive antioxidant to collect the filtrate. Add excess diethyl ether to the filtrate through a separatory funnel and collect the lower layer solution. Under mechanical stirring, slowly add the collected bottom layer solution to excess deionized water to produce a precipitate. Dry the precipitate to constant weight under vacuum at 40°C to obtain a reactive antioxidant based on a small molecule antioxidant containing mercaptobenzimidazole.

[0044] The types and amounts of raw materials used in Examples 1-9 (respectively #1-#9) are shown in Table 1:

[0045] Table 1

[0046]

[0047] Table 2 shows the product yields of Examples 1-9:

[0048] Table 2

[0049]

[0050] Sample preparation: For sample 1, 3000 g of bio-based itaconic acid latex, 59 g of KOH, 75 g of zinc oxide solution, 26 g of sulfur, 22 g of ZDB-50, 4 g of ZDE-50, 37 g of black paste, and 18 g of antioxidant MB were added to a container and stirred for 5 h. After standing for 12 h, 60 g of casein was added, and after standing for 4 h, the final viscosity was measured. The glove core was placed on a mold and preheated in an oven at 55°C for 4 h. Then, it was immersed in a coagulant containing 98% methanol and 2% calcium nitrate for about 2 s. After standing for 70 s, it was immersed in the latex solution prepared above for 20 s and slowly pulled out, turning the mold to ensure even force distribution. Latex gloves were placed in an oven for drying and vulcanization. The vulcanization time varied with temperature: 15 min at room temperature, 10-15 min at 70℃, 10-15 min at 80℃, 30 min at 90℃, and 70 min at 105℃.

[0051] Sample 2: 3000 g of bio-based itaconic acid latex, 59 g of KOH, 75 g of zinc oxide solution, 26 g of sulfur, 22 g of ZDB-50, 4 g of ZDE-50, 37 g of black paste, and 18 g of antioxidant synthesized in each example were added to a container and stirred for 5 h. After standing for 12 h, 60 g of casein was added, and after standing for 4 h, the final viscosity was measured. The glove core was placed on a mold and preheated in an oven at 55°C for 4 h. Then it was immersed in a coagulant containing 98% methanol and 2% calcium nitrate for about 2 s. After standing for 70 s, it was immersed in the latex solution prepared above for 20 s and slowly pulled out, turning the mold to ensure even force distribution. Latex gloves were placed in an oven for drying and vulcanization. The vulcanization time varied with temperature: 15 min at room temperature, 10-15 min at 70℃, 10-15 min at 80℃, 30 min at 90℃, and 70 min at 105℃.

[0052] Test on the resistance to thermo-oxidative aging of latex gloves:

[0053] The antioxidant properties of latex gloves are of paramount importance, directly determining their reliability and lifespan as critical protective equipment. Both the abundant unsaturated double bonds in the molecular chains of natural rubber and the specific chemical groups in synthetic rubbers (such as nitrile and neoprene) are highly sensitive to environmental factors like oxygen and ozone. Irreversible damage to the molecular structure of latex gloves, leading to chain breakage or excessive cross-linking, causes them to rapidly lose their original flexibility and elasticity, resulting in surface embrittlement, stickiness, or cracking. This degradation of physical properties significantly shortens the effective service life of gloves and increases production costs. Adding antioxidants to latex gloves can prevent their thermal and oxidative decomposition during processing and storage. Accelerated thermal and oxidative aging tests can be used to evaluate the thermal and oxidative aging resistance of latex gloves and to assess the antioxidant efficacy of antioxidants.

[0054] To evaluate the thermo-oxidative aging resistance of the antioxidants prepared in Example 1 of this invention and antioxidant MB to latex gloves, the accelerated thermo-oxidative aging test was conducted according to GB / T 3512-2014, with an aging temperature of 100±1℃ and an aging time of 48 hours. After 48 hours of aging, the tensile strength retention rate and elongation at break retention rate of the blank sample, the latex gloves with the antioxidants prepared in Example 1 of this invention, and the latex gloves with antioxidant MB were tested respectively. The tensile properties were determined according to GB / T528-2009, with a tensile rate of 500 mm / min.

[0055] Table 3. Test results of mechanical properties of latex gloves

[0056]

[0057] As shown in Table 3, the tensile strength of the latex gloves without antioxidants is 20.7 MPa. The highest tensile strength (29.1 MPa) is achieved when the antioxidant prepared in Example 1 of this invention is added. When antioxidant MB-A is added, the tensile strength is 25.8 MPa. This indicates that the antioxidant prepared in Example 1 of this invention exhibits superior tensile properties for bio-based latex gloves compared to antioxidant MB-A. Furthermore, the addition of antioxidants resulted in different changes in the elongation at break, 100% modulus of elasticity, and 300% modulus of elasticity. The table shows that the antioxidant prepared in Example 1 of this invention exhibits superior mechanical properties for bio-based latex gloves compared to antioxidant MB-A.

[0058] Table 4 Results of thermo-oxidative aging performance test

[0059]

[0060] As shown in Table 4, compared with bio-based latex gloves without added antioxidants, the latex gloves with added antioxidants prepared in Example 1 of this invention or antioxidant MB-A have significantly higher tensile strength retention and elongation at break retention rates. This indicates that both the antioxidants prepared in Example 1 of this invention and antioxidant MB-A can effectively inhibit the thermo-oxidative aging of bio-based latex gloves. After aging for 48 hours, the bio-based latex gloves with added antioxidants prepared in Example 1 of this invention have higher tensile strength retention and elongation at break retention rates than the latex gloves with added antioxidant MB-A. This indicates that the antioxidants prepared in Example 1 of this invention have better thermo-oxidative aging resistance than antioxidant MB-A without sorbic acid grafting.

[0061] The reactive antioxidants prepared in Examples 2-9, when applied to latex gloves, exhibited similar tensile strength retention and elongation at break retention as the reactive antioxidants prepared in Example 1 in latex gloves.

[0062] As can be seen from the above embodiments, the present invention provides a method for preparing a reactive antioxidant based on a small molecule antioxidant containing a mercaptobenzimidazole group, comprising the following steps: in the presence of a catalyst, a Michael addition reaction is carried out between a mercaptobenzimidazole-containing antioxidant and a bio-based monomer containing double bonds and carboxyl groups to obtain an intermediate compound; in the presence of a condensing agent and an activator, the intermediate compound is reacted with cellulose via esterification to obtain a reactive antioxidant based on a small molecule antioxidant containing a mercaptobenzimidazole group. This method uses a bio-based monomer containing double bonds and carboxyl groups and cellulose chemically grafted with a small molecule mercaptobenzimidazole-containing antioxidant to construct a molecular structure that combines high molecular weight characteristics with multiple antioxidant functions. Using the bio-based monomer containing double bonds and carboxyl groups as a bridging agent, the small molecule antioxidant is bonded to the rubber molecular chain, fundamentally solving the problems of migration, volatilization, and environmental compatibility of small molecule antioxidants, while simultaneously improving antioxidant efficiency and material durability, and extending the service life of latex gloves. The experimental results show that the tensile strength of the latex gloves is 29.1 MPa, the elongation at break is 589%, the 100% modulus at constant elongation is 2.3%, and the 300% modulus at constant elongation is 6.1%.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a reactive antioxidant based on a small-molecule antioxidant containing a mercapto group of a benzimidazole, comprising the following steps: performing a Michael addition reaction on a small-molecule antioxidant containing a mercapto group of a benzimidazole and a bio-based monomer containing a double bond and a carboxyl group in the presence of a catalyst to obtain an intermediate compound; and performing an esterification reaction on the intermediate compound and cellulose in the presence of a condensing agent and an activating agent to obtain a reactive antioxidant based on a small-molecule antioxidant containing a mercapto group of a benzimidazole. The small-molecule antioxidant containing a mercapto group of a benzimidazole is selected from one or more of 2-mercapto benzimidazole, 2-mercapto benzimidazole zinc salt, 2-(4-morpholinyl disulfide) benzimidazole, and 2-mercapto methyl benzimidazole. The bio-based monomer containing a double bond and a carboxyl group is selected from one or more of maleic acid, Artepillin C, Mycotic acid, and sorbic acid.

2. The production method according to claim 1, characterized by, The catalyst is selected from one or more of triethylamine, triisopropanolamine, 1,8-diazabicycloundec-7-ene, 1,4-diazabicyclo[2.2.2]octane, N,N-diisopropylethylamine, potassium carbonate, cesium carbonate, KOH, tetrabutylammonium bromide, benzyltriethylammonium chloride, AlCl3, ZnCl2, and BF3·Et2O. The mass ratio of the small-molecule antioxidant containing a mercapto group of a benzimidazole to the bio-based monomer containing a double bond and a carboxyl group is 1:1-10.

3. The production method according to claim 1, characterized by, The catalyst accounts for 1-6% of the total mass of the antioxidant and the bio-based monomer.

4. The method of claim 1, wherein, The temperature of the Michael addition reaction is 40-120°C, and the time is 6-36 h. The condensing agent is selected from one of dicyclohexyl carbodiimide, diisopropyl carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate, O-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, 4-dimethylaminopyridine, and 1-hydroxybenzotriazole.

5. The preparation method according to claim 1, characterized in that, The condensing agent accounts for 20-80% of the total mass of the cellulose and the intermediate compound.

6. The method of claim 1, wherein, The activating agent is selected from one or more of 4-dimethylaminopyridine, N,N'-dicyclohexyl carbodiimide, N,N'-diisopropyl carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, O-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, O-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate, oxalyl chloride, thionyl chloride phosphorus oxychloride, isobutyl chloroformate, N,N'-carbonyldiimidazole, and ethoxycarbonyl ethoxydihydroquinoline. The activating agent accounts for 2-8% of the total mass of the cellulose and the intermediate compound.

7. The preparation method according to claim 1, characterized in that, The temperature of the esterification reaction is 20-100°C, and the time is 4-36 h. The crude product obtained by the esterification reaction is extracted to obtain a reactive antioxidant based on a small-molecule antioxidant containing a mercapto group of a benzimidazole.

8. The method of claim 1, wherein, The extractant is selected from diethyl ether.

9. The method of claim 1, wherein, ​ ​ 10. The use of the reactive antioxidant based on small molecule antioxidant containing mercapto benzimidazole prepared by the method according to any one of claims 1 to 9 in latex gloves.

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