Preparation method of modified silicone rubber elastomer

Abstract

The invention relates to the technical field of silicone rubber, and discloses a preparation method of a modified silicone rubber elastomer, the modified silicone rubber elastomer comprises 100 parts by weight of methyl vinyl silicone rubber, 5-25 parts by weight of organosilicon grafted cellulose microcrystalline, 12-20 parts by weight of white carbon black, 1.7-2.4 parts by weight of a vulcanizing agent, 2.6-4.2 parts by weight of a cross-linking agent, and 1.5-2 parts by weight of an auxiliary agent, 1.2 to 1.6 parts by weight of an anti-aging agent; the organic silicon grafted cellulose microcrystal contains a siloxane structure and has good compatibility with the methyl vinyl silicone rubber, and in the high-temperature vulcanization process, alkenyl of the organic silicon grafted cellulose microcrystal can be subjected to a cross-linking reaction with the methyl vinyl silicone rubber and triallyl isocyanurate, so that the organic silicon grafted cellulose microcrystal can be used for curing the methyl vinyl silicone rubber and the triallyl isocyanurate. The interface bonding strength between the cellulose microcrystal and the methyl vinyl silicone rubber is enhanced, so that the silicone rubber elastomer shows higher tensile property, hardness and tearing strength.

Description

Technical Field

[0001] The invention relates to the technical field of silicone rubber, in particular to a method for preparing a modified silicone rubber elastomer. Background Art

[0002] Silicone rubber elastomers have good elasticity, temperature resistance, aging resistance, and solvent resistance, and are widely used in toughening agents, impact modifiers, electronic appliances, aerospace, and other fields. Improving the mechanical strength of silicone rubber elastomers can expand their practical application areas. Cellulose reserves are abundant, cheap and easy to obtain, green and environmentally friendly, and have high mechanical strength. It is a reinforcing filler with excellent performance. It is widely used in plastics, rubber and other polymer materials. Patent CN113755014B discloses using silicone rubber and butyl rubber as the base rubber and using cellulose as the loading matrix of antibacterial nanoparticles to improve the antibacterial properties of bacterial materials. However, the cellulose does not improve the mechanical properties of the rubber material such as the tensile strength.

[0003] Functional modification of cellulose and expansion of its practical application in rubber and other elastomeric materials are research hotspots. The paper "Preparation and Properties of Nanocellulose-Polypyrrole / Natural Rubber Flexible Conductive Elastomers" discloses that polypyrrole can be polymerized in situ in cellulose nanofibrils and then evenly dispersed in a natural rubber elastic matrix to obtain a highly flexible natural rubber conductive elastomer. The present invention aims to graft cellulose microcrystals to obtain cellulose microcrystals containing siloxane and olefin groups, thereby improving the mechanical properties of silicone rubber elastomers. Summary of the invention

[0004] The technical problem solved by the invention is to provide a modified silicone rubber elastomer with mechanical properties.

[0005] The technical scheme of the present invention is: a method for preparing a modified silicone rubber elastomer, comprising 100 parts by weight of methyl vinyl silicone rubber, 5-25 parts by weight of organosilicon grafted cellulose microcrystals, 12-20 parts by weight of white carbon black, 1.7-2.4 parts by weight of a vulcanizing agent, 2.6-4.2 parts by weight of a crosslinking agent, 1.5-2 parts by weight of an auxiliary agent, and 1.2-1.6 parts by weight of an antioxidant.

[0006] The preparation method of the modified silicone rubber elastomer comprises:

[0007] Step A, add pyridine and cellulose microcrystals to N,N-dimethylformamide, introduce nitrogen after stirring, add bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane, stir and react at 40-65°C for 36-48h, pour the solution into water, filter, wash with water, ethanol and dichloromethane in turn, and dry to obtain organosilicon-grafted cellulose microcrystals.

[0008] Step B, adding methyl vinyl silicone rubber, organosilicon grafted cellulose microcrystals, white carbon black, additives, and antioxidants into an open mill for primary mixing, then adding a vulcanizing agent and a crosslinking agent for secondary mixing, and finally vulcanizing the materials in a flat vulcanizer, discharging the materials, and obtaining a modified silicone rubber elastomer.

[0009] Preferably, the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, the crosslinking agent is triallyl isocyanurate, the auxiliary agent is stearic acid, and the antioxidant is N-phenyl-2-naphthylamine.

[0010] Preferably, in step A, the mass ratio of cellulose microcrystals to bis(3,3'-carbonyl chloride-5,5'-vinylphenoxy)dimethylsilane is 100:(15-80).

[0011] Preferably, the preparation method of bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane comprises:

[0012] (1) In an ice bath, add methyl 3-bromo-5-hydroxybenzoate, pyridine and dichlorodimethylsilane in a molar ratio of (2-2.2):(2-2.4):1 to toluene, and react at 20-35°C for 4-8 hours. Concentrate the solution under reduced pressure, wash with water and petroleum ether in turn, add the product to methanol, then add sodium hydroxide aqueous solution, heat to 70-85°C, condense and reflux for 3-5 hours, add hydrochloric acid solution to neutralize, add dichloromethane, extract and separate, dry the organic phase with anhydrous sodium sulfate, filter, concentrate the filtrate under reduced pressure, and recrystallize the product with ethanol to obtain intermediate 1.

[0013] (2) Add intermediate 1, vinylboronic acid pinacol ester, 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride, and N,N-diisopropylethylamine in a molar ratio of 1:(2-2.4):(0.08-0.09):(3.4-4) to toluene, heat to 80-90°C in a nitrogen atmosphere, react for 5-8h, concentrate under reduced pressure, wash with petroleum ether and acetone in turn, and recrystallize the product with dichloromethane to obtain intermediate 2.

[0014] (3) Add intermediate 2 to thionyl chloride in a molar ratio of (12-18):1, heat to 60-70°C, condense and reflux for 3-4 hours, concentrate under reduced pressure, wash with petroleum ether, and dry to obtain bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane. The reaction formula is as follows:

[0015]

[0016] Preferably, in step B, during mixing, the roller temperature of the open mixer is 45-55° C., the roller distance is 1-2 mm, the first mixing time is 5-8 min, and the second mixing time is 2-3 min.

[0017] Preferably, in step B, the temperature of the flat vulcanizing press during vulcanization is 165-175° C., the time is 20-30 min, and the pressure is 10-15 MPa.

[0018] The technical effect of the present invention is as follows: the present invention uses 3-bromo-5-hydroxybenzoic acid methyl ester, dichlorodimethylsilane, vinylboronic acid pinacol ester and thionyl chloride as reactants to prepare bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane, which contains an acyl chloride group and reacts with the hydroxyl group of cellulose microcrystals to obtain organosilicon-grafted cellulose microcrystals. Thus, siloxane groups and alkenyl groups are introduced into the molecular chains of the cellulose microcrystals.

[0019] The present invention uses methyl vinyl silicone rubber as the base rubber of the silicone rubber elastomer, and uses organic silicon grafted cellulose microcrystals as a modifier, which contains a siloxane structure and has structural similarity with the methyl vinyl silicone rubber, thereby improving the compatibility between the two and forming a homogeneous compatible system. The two will not have phase separation and interface defects due to interface incompatibility, which is beneficial for the cellulose microcrystals to improve the mechanical properties of the silicone rubber elastomer.

[0020] The present invention uses 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane as a vulcanizing agent. During the high-temperature vulcanization process, the alkenyl groups of the organic silicon grafted cellulose microcrystals can undergo a cross-linking reaction with methyl vinyl silicone rubber and triallyl isocyanurate, thereby enhancing the interfacial bonding strength between the cellulose microcrystals and the methyl vinyl silicone rubber. The cellulose microcrystals form a rigid chemical cross-linking network in the methyl vinyl silicone rubber, thereby increasing the cross-linking density of the silicone rubber elastomer, enhancing the mechanical properties of the silicone rubber, and exhibiting higher tensile properties, hardness, and tear strength. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution in the embodiments of the present invention is clearly and completely described below. Obviously, the described embodiments 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 creative work should fall within the scope of protection of the present invention.

[0022] Example 1

[0023] (1) In an ice bath, add 22 mmol 3-bromo-5-hydroxybenzoic acid methyl ester (CAS No. 192810-12-1), 20 mmol pyridine, and 10 mmol dichlorodimethylsilane (CAS No. 75-78-5) to 20 mL toluene, and react at 20°C for 8 hours. After the reaction, the solution is concentrated under reduced pressure, washed with water and petroleum ether in turn, the product is added to 60 mL methanol, and then 60 mL of a sodium hydroxide aqueous solution with a molar concentration of 4 mol / L is added, heated to 85°C, condensed and refluxed for 3 hours, and neutralized by adding hydrochloric acid solution, and then adding dichloromethane, extracting and separating, the organic phase is dried with anhydrous sodium sulfate, filtered, and the filtrate is concentrated under reduced pressure, and the product is recrystallized from ethanol to obtain Intermediate 1.

[0024] (2) Add 5 mmol of intermediate 1, 10 mmol of vinylboronic acid pinacol ester (CAS No. 75927-49-0), 0.4 mmol of 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride (CAS No. 72287-26-4), and 20 mmol of N,N-diisopropylethylamine to 70 mL of toluene, heat to 90°C in a nitrogen atmosphere, react for 5 h, concentrate under reduced pressure, wash with petroleum ether and acetone in turn, and recrystallize the product with dichloromethane to obtain intermediate 2.

[0025] (3) Add 5 mmol of intermediate 2 to 90 mmol of thionyl chloride, heat to 70°C, condense and reflux for 4 h, concentrate under reduced pressure, wash with petroleum ether, and dry to obtain bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane.

[0026] Example 2

[0027] (1) In an ice bath, add 20 mmol 3-bromo-5-hydroxybenzoic acid methyl ester, 20 mmol pyridine, and 10 mmol dichlorodimethylsilane to 15 mL toluene, and react at 35°C for 4 hours. After the reaction, the solution was concentrated under reduced pressure, washed with water and petroleum ether in turn, the product was added to 80 mL methanol, and then 80 mL of a sodium hydroxide aqueous solution with a molar concentration of 4 mol / L was added, heated to 70°C, condensed and refluxed for 5 hours, and neutralized by adding hydrochloric acid solution, and dichloromethane was added, extracted and separated, the organic phase was dried with anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure, and the product was recrystallized from ethanol to obtain Intermediate 1.

[0028] (2) Add 5 mmol of intermediate 1, 12 mmol of vinylboronic acid pinacol ester, 0.45 mmol of 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride, and 17 mmol of N,N-diisopropylethylamine to 80 mL of toluene, heat to 80°C in a nitrogen atmosphere, react for 8 h, concentrate under reduced pressure, wash with petroleum ether and acetone in turn, and recrystallize the product with dichloromethane to obtain intermediate 2.

[0029] (3) Add 5 mmol of intermediate 2 to 90 mmol of thionyl chloride, heat to 60°C, condense and reflux for 3 h, concentrate under reduced pressure, wash with petroleum ether, and dry to obtain bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane.

[0030] Example 3

[0031] (1) Add 120 mL of pyridine and 20 g of cellulose microcrystals to 200 mL of N,N-dimethylformamide, stir and introduce nitrogen, add 3 g of bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane (prepared according to the method of Example 1), stir and react at 45° C. for 36 h, pour the solution into water, filter, wash with water, ethanol, and dichloromethane in turn, and dry to obtain organosilicon-grafted cellulose microcrystals.

[0032] (2) Add 100 g of methyl vinyl silicone rubber, 5 g of organosilicon grafted cellulose microcrystals, 12 g of white carbon black, 1.8 g of auxiliary agent stearic acid, and 1.6 g of antioxidant N-phenyl-2-naphthylamine into an open mill, with the roller temperature at 45°C and the roller distance at 2 mm, and mix once for 5 min. Then add 2.4 g of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 4.2 g of cross-linking agent triallyl isocyanurate, and mix twice for 3 min. Finally, vulcanize the material in a flat vulcanizer for 30 min at a temperature of 165°C and a pressure of 10 MPa, and discharge the material to obtain a modified silicone rubber elastomer.

[0033] Example 4

[0034] (1) Add 120 mL of pyridine and 20 g of cellulose microcrystals to 200 mL of N,N-dimethylformamide, stir and introduce nitrogen, add 8 g of bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane (prepared according to the method of Example 1), stir and react at 65° C. for 36 h, pour the solution into water, filter, wash with water, ethanol, and dichloromethane in turn, and dry to obtain organosilicon-grafted cellulose microcrystals.

[0035] (2) Add 100 g of methyl vinyl silicone rubber, 12 g of organosilicon grafted cellulose microcrystals, 20 g of white carbon black, 1.5 g of auxiliary agent stearic acid, and 1.2 g of antioxidant N-phenyl-2-naphthylamine into an open mill, with the roller temperature at 55°C and the roller distance at 2 mm, and mix once for 6 min. Then add 2.4 g of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 3.3 g of cross-linking agent triallyl isocyanurate, and mix twice for 3 min. Finally, vulcanize the material in a flat vulcanizer for 30 min at a temperature of 170°C and a pressure of 15 MPa, and discharge the material to obtain a modified silicone rubber elastomer.

[0036] Example 5

[0037] (1) Add 140 mL of pyridine and 20 g of cellulose microcrystals to 200 mL of N,N-dimethylformamide, stir and introduce nitrogen, add 12 g of bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane (prepared according to the method of Example 1), stir and react at 40° C. for 48 h, pour the solution into water, filter, wash with water, ethanol, and dichloromethane in turn, and dry to obtain organosilicon-grafted cellulose microcrystals.

[0038] (2) Add 100 g of methyl vinyl silicone rubber, 18 g of organosilicon grafted cellulose microcrystals, 15 g of white carbon black, 1.8 g of auxiliary agent stearic acid, and 1.3 g of antioxidant N-phenyl-2-naphthylamine into an open mill, with the roller temperature at 45°C and the roller distance at 2 mm, and perform a first mixing for 8 min. Then, add 1.7 g of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 3.8 g of cross-linking agent triallyl isocyanurate, and perform a second mixing for 2 min. Finally, the material is vulcanized in a flat vulcanizer for 20 min at a temperature of 175°C and a pressure of 10 MPa, and the material is discharged to obtain a modified silicone rubber elastomer.

[0039] Example 6

[0040] (1) Add 140 mL of pyridine and 20 g of cellulose microcrystals to 200 mL of N,N-dimethylformamide, introduce nitrogen after stirring, add 16 g of bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane (prepared according to the method of Example 1), stir and react at 60° C. for 48 h, pour the solution into water, filter, wash with water, ethanol, and dichloromethane in turn, and dry to obtain organosilicon-grafted cellulose microcrystals.

[0041] (2) Add 100 g of methyl vinyl silicone rubber, 25 g of organosilicon grafted cellulose microcrystals, 12 g of white carbon black, 1.5 g of auxiliary agent stearic acid, and 1.2 g of antioxidant N-phenyl-2-naphthylamine into an open mill, with the roller temperature at 45°C and the roller distance at 2 mm, and mix once for 5 min. Then add 2 g of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 2.6 g of cross-linking agent triallyl isocyanurate, and mix twice for 3 min. Finally, vulcanize the material in a flat vulcanizer for 30 min at a temperature of 175°C and a pressure of 10 MPa, and discharge the material to obtain a modified silicone rubber elastomer.

[0042] Comparative Example 1

[0043] (1) 100 g of methyl vinyl silicone rubber, 12 g of white carbon black, 1.8 g of auxiliary agent stearic acid, and 1.6 g of antioxidant N-phenyl-2-naphthylamine were added to an open mill with a roller temperature of 45°C and a roller distance of 2 mm. The mixture was mixed for 5 min. Then, 2.4 g of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 4.2 g of cross-linking agent triallyl isocyanurate were added and mixed for 3 min. Finally, the material was vulcanized in a flat vulcanizer for 30 min at a temperature of 165°C and a pressure of 10 MPa. The material was discharged to obtain a modified silicone rubber elastomer.

[0044] Comparative Example 2

[0045] (2) Add 100 g of methyl vinyl silicone rubber, 5 g of cellulose microcrystals, 12 g of white carbon black, 1.8 g of auxiliary agent stearic acid, and 1.6 g of antioxidant N-phenyl-2-naphthylamine into an open mill, with the roller temperature at 45°C and the roller distance at 2 mm, and mix once for 5 min. Then add 2.4 g of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 4.2 g of cross-linking agent triallyl isocyanurate, and mix twice for 3 min. Finally, vulcanize the material in a flat vulcanizer for 30 min at a temperature of 165°C and a pressure of 10 MPa, and discharge the material to obtain a modified silicone rubber elastomer.

[0046] Comparative Example 3

[0047] (1) Add 5 mmol of intermediate 1 (prepared according to the method of Example 1) to 90 mmol of thionyl chloride, heat to 70°C, condense and reflux for 4 hours, concentrate under reduced pressure, wash with petroleum ether, and dry to obtain bis(3,3'-formyl chloride-5,5'-bromo)dimethylsilane. The structural formula is

[0048] (2) Add 120 mL of pyridine and 20 g of cellulose microcrystals to 200 mL of N,N-dimethylformamide, introduce nitrogen after stirring, add 3 g of bis(3,3'-formyl chloride-5,5'-bromo)dimethylsilane, stir and react at 45°C for 36 hours, pour the solution into water, filter, wash with water, ethanol, and dichloromethane in turn, and dry to obtain organosilicon-grafted cellulose microcrystals.

[0049] (3) Add 100 g of methyl vinyl silicone rubber, 5 g of organosilicon grafted cellulose microcrystals, 12 g of white carbon black, 1.8 g of auxiliary agent stearic acid, and 1.6 g of antioxidant N-phenyl-2-naphthylamine into an open mill, with the roller temperature at 45°C and the roller distance at 2 mm, and mix once for 5 min. Then add 2.4 g of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 4.2 g of cross-linking agent triallyl isocyanurate, and mix twice for 3 min. Finally, vulcanize the material in a flat vulcanizer for 30 min at a temperature of 165°C and a pressure of 10 MPa, and discharge the material to obtain a modified silicone rubber elastomer.

[0050] Comparative Example 4

[0051] (1) Add 120 mL of pyridine and 20 g of cellulose microcrystals to 200 mL of N,N-dimethylformamide, introduce nitrogen after stirring, add 3 g of acryloyl chloride, stir and react at 45°C for 36 h, pour the solution into water, filter, wash with water, ethanol, and dichloromethane in turn, and dry to obtain acrylate-based cellulose microcrystals.

[0052] (2) Add 100 g of methyl vinyl silicone rubber, 5 g of acrylate-based cellulose microcrystals, 12 g of white carbon black, 1.8 g of auxiliary agent stearic acid, and 1.6 g of antioxidant N-phenyl-2-naphthylamine into an open mill, with the roller temperature at 45°C and the roller distance at 2 mm, and mix once for 5 min. Then add 2.4 g of vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 4.2 g of cross-linking agent triallyl isocyanurate, and mix twice for 3 min. Finally, vulcanize the material in a flat vulcanizer for 30 min at a temperature of 165°C and a pressure of 10 MPa, and discharge the material to obtain a modified silicone rubber elastomer.

[0053] The tensile properties were tested according to GB / T 528-2009. The tear strength was tested according to GB / T 529-2008. The hardness was tested according to GB / T 531.1-2008. The results are shown in Table 1.

[0054]

[0055] After testing, compared with comparative example 1, silicone grafted cellulose microcrystals are added to the silicone rubber elastomers of Examples 3-6. After the grafting reaction, the cellulose microcrystals introduce a siloxane structure into the molecular chain, which has structural similarity with the methyl vinyl silicone rubber, thereby improving the compatibility between the cellulose microcrystals and the methyl vinyl silicone rubber, and forming a homogeneous compatible system. The two will not have phase separation and interface defects due to interface incompatibility. In addition, the silicone grafted cellulose microcrystals contain alkenyl groups. Under the action of the vulcanizing agent 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, its alkenyl groups can cross-link with methyl vinyl silicone rubber and triallyl isocyanurate, further enhancing the interface bonding strength between the cellulose microcrystals and the methyl vinyl silicone rubber. The cellulose microcrystals form a rigid chemical cross-linking network in the methyl vinyl silicone rubber, which improves the cross-linking density of the silicone rubber elastomer, can enhance the mechanical properties of the silicone rubber, and show higher tensile properties, hardness and tear strength.

[0056] Ordinary cellulose microcrystals are added to the silicone rubber elastomer of Comparative Example 2, and the compatibility between the cellulose microcrystals and the methyl vinyl silicone rubber is poor. The interface between the two is incompatible, and phase separation is likely to occur to form interface defects, which will affect the mechanical properties of the silicone rubber elastomer.

[0057] Comparison 3: Bis(3,3'-formyl chloride-5,5'-bromo)dimethylsilane reacts with cellulose microcrystals. The obtained organosilicon grafted cellulose microcrystals contain siloxane structures and have good compatibility with methyl vinyl silicone rubber. The cellulose microcrystals can play a reinforcing role and improve the mechanical properties of the silicone rubber elastomer. However, the organosilicon grafted cellulose microcrystals do not contain alkenyl groups and cannot undergo cross-linking reaction with methyl vinyl silicone rubber. No rigid chemical cross-linking network is formed in the silicone rubber, and the effect of improving the mechanical properties of the silicone rubber elastomer is lower than that of the embodiments.

[0058] In Comparative Example 4, acryloyl chloride and cellulose microcrystals are reacted to obtain acrylate-based cellulose microcrystals containing olefinic groups, which can undergo cross-linking reaction with methyl vinyl silicone rubber to form a rigid chemical cross-linking network, which is beneficial to improving the mechanical properties of the silicone rubber elastomer. However, the acrylate-based cellulose microcrystals do not contain a siloxane structure and have poor compatibility with methyl vinyl silicone rubber, and the reinforcing effect on the silicone rubber elastomer is lower than that of the various embodiments.

[0059] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a modified silicone rubber elastomer, characterized in that: The modified silicone rubber elastomer comprises 100 parts by weight of methyl vinyl silicone rubber, 5-25 parts by weight of organosilicon grafted cellulose microcrystals, 12-20 parts by weight of white carbon black, 1.7-2.4 parts by weight of a vulcanizing agent, 2.6-4.2 parts by weight of a crosslinking agent, 1.5-2 parts by weight of an auxiliary agent, and 1.2-1.6 parts by weight of an antioxidant; The preparation method of the modified silicone rubber elastomer comprises: Step A, adding pyridine and cellulose microcrystals to N,N-dimethylformamide, introducing nitrogen after stirring, adding bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane, stirring and reacting at 40-65° C. for 36-48 hours, pouring the solution into water, filtering, washing, and drying to obtain organosilicon-grafted cellulose microcrystals; Step B, adding methyl vinyl silicone rubber, organosilicon grafted cellulose microcrystals, white carbon black, additives, and antioxidants into an open mill for primary mixing, then adding a vulcanizing agent and a crosslinking agent for secondary mixing, and finally vulcanizing the materials in a flat vulcanizer, discharging the materials, and obtaining a modified silicone rubber elastomer.

2. The method for preparing the modified silicone rubber elastomer according to claim 1, characterized in that: The vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, the crosslinking agent is triallyl isocyanurate, the auxiliary agent is stearic acid, and the antioxidant is N-phenyl-2-naphthylamine.

3. The method for preparing the modified silicone rubber elastomer according to claim 1, characterized in that: In the step A, the mass ratio of cellulose microcrystals to bis(3,3'-carbonyl chloride-5,5'-vinylphenoxy)dimethylsilane is 100:(15-80).

4. The method for preparing the modified silicone rubber elastomer according to claim 1, characterized in that: The preparation method of the bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane comprises: (1) In an ice bath, add methyl 3-bromo-5-hydroxybenzoate, pyridine, and dichlorodimethylsilane to toluene, and react at 20-35° C. for 4-8 hours. After the reaction, concentrate the solution under reduced pressure, wash, add the product to methanol, then add sodium hydroxide aqueous solution, heat to 70-85° C., condense and reflux for 3-5 hours, add hydrochloric acid solution to neutralize, add dichloromethane, extract and separate, and recrystallize to obtain intermediate 1; (2) Add intermediate 1, vinylboronic acid pinacol ester, 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride, and N,N-diisopropylethylamine to toluene, heat to 80-90° C. in a nitrogen atmosphere, react for 5-8 hours, concentrate under reduced pressure, wash, and recrystallize to obtain intermediate 2; (3) Add intermediate 2 to thionyl chloride, heat to 60-70° C., condense and reflux for 3-4 hours, concentrate under reduced pressure, wash, and dry to obtain bis(3,3'-formyl chloride-5,5'-vinylphenoxy)dimethylsilane.

5. The method for preparing the modified silicone rubber elastomer according to claim 4, characterized in that: In the above (1), the molar ratio of methyl 3-bromo-5-hydroxybenzoate, pyridine and dichlorodimethylsilane is (2-2.2):(2-2.4):

1.

6. The method for preparing the modified silicone rubber elastomer according to claim 4, characterized in that: In the method (2), the molar ratio of intermediate 1, vinylboronic acid pinacol ester, 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride, and N,N-diisopropylethylamine is 1:(2-2.4):(0.08-0.09):(3.4-4).

7. The method for preparing a modified silicone rubber elastomer according to claim 4, characterized in that: In the above (3), the molar ratio of the intermediate 2 in the thionyl chloride is (12-18):

1.

8. The method for preparing a modified silicone rubber elastomer according to claim 1, characterized in that: In the step B, during mixing, the roller temperature of the open mixer is 45-55° C., the roller distance is 1-2 mm, the first mixing time is 5-8 min, and the second mixing time is 2-3 min.

9. The method for preparing a modified silicone rubber elastomer according to claim 1, characterized in that: In the step B, the temperature of the flat vulcanizing press during vulcanization is 165-175° C., the time is 20-30 min, and the pressure is 10-15 MPa.

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