Antistatic self-repairing silicone rubber and preparation method thereof

Abstract

The invention provides antistatic self-repairing silicone rubber and a preparation method thereof.The preparation method comprises the following steps that an internal mixer is started, silicone rubber, fumed silica and hydroxyl silicone oil are added, and mixing is conducted for 5-10 min; a self-repairing conductive filler and zinc stearate are added, mixing is conducted for 10-15 min at the temperature of 60 DEG C and the rotating speed of 20-30 rpm, and the rotor gap is 0.3 mm; finally, adding dicumyl peroxide and a boric acid ester cross-linking agent, and mixing for 3-5 minutes to obtain a rubber material; putting the rubber material into a mold, and carrying out first-stage vulcanization in a press vulcanizer; and second-stage vulcanization: treating at 170 DEG C for 1 hour, and treating at 200 DEG C for 1 hour. Triple dynamic bond synergy, hydrogen bonds, ionic bonds and coordinate bonds are adopted to construct a double-conductive network, the double-conductive network comprises electron conduction: an sp2 carbon network of Fe (at) CBC and ion conduction: ion migration of [BMIM] [PF6], and the double-conductive network has a dynamic self-adaptive effect: low temperature (llt; at the temperature of 60 DEG C, hydrogen bond dominated self-repairing is carried out; 180 DEG C): boric acid ester bonds maintain dynamic properties; therefore, the antistatic self-repairing effect is achieved.

Description

TECHNICAL FIELD The present application relates to the field of functional rubber, in particular to an antistatic self-repairing silicone rubber and a preparation method thereof. BACKGROUND With the rapid development of electronic industry, aerospace, medical devices and other fields, the demand for high-performance silicone rubber materials is increasing. Silicone rubber is widely used due to its excellent high and low temperature resistance, weather resistance, electrical insulation and biocompatibility. However, the high insulation of traditional silicone rubber leads to easy accumulation of static electricity, which may cause electrostatic discharge (ESD) risk in precision electronic devices, explosion-proof equipment or antistatic materials, affecting the reliability of the equipment and even causing safety hazards. Traditional antistatic self-repairing silicone rubber usually realizes electrical conductivity by adding fillers such as carbon black, metal powder or conductive polymer, but there are the following problems: poor dispersion of fillers: easy to agglomerate, affecting mechanical properties and processing stability; insufficient dynamic stability: the conductive network is easily damaged after long-term use, leading to degradation of antistatic performance; mechanical properties are sacrificed: high filler content will reduce the flexibility and tensile strength of silicone rubber. Self-repairing materials can repair damage through reversible chemical bonds or physical interactions, extending the service life. The introduction of self-repairing function in conductive fillers can solve the problem of performance degradation caused by micro-cracks or fatigue of the conductive network. Currently, self-repairing systems based on dynamic covalent bonds (such as borate ester bonds, Diels-Alder reactions) or supramolecular interactions (such as hydrogen bonds, ionic interactions) are widely studied, but most of them have problems such as harsh repair conditions (require heating / light) or low mechanical strength. Most self-repairing fillers (such as liquid metal / conductive hydrogel) are difficult to balance high electrical conductivity and stable mechanical properties. Therefore, it is an urgent problem to research and develop an antistatic silicone rubber with self-repairing performance. SUMMARY

[0001] The technical problem to be solved: The present application aims to solve the technical problems of poor antistatic performance of silicone rubber and easy damage of conductive network after long-term use. A triple dynamic bond is used to construct a double conductive network: including: electronic conduction: sp 2 carbon network of Fe@CBC, and ionic conduction: ion migration of [BMIM][PF6], with dynamic adaptive effect: at low temperature (<60℃): hydrogen bond dominates self-repairing, at high temperature (>180℃): borate ester bond maintains dynamicity; thereby realizing the effect of antistatic self-repairing.

[0002] Technical solution: An antistatic self-repairing silicone rubber, comprising the following components by weight: silicone rubber 100 parts, self-repairing conductive filler 10-20 parts, fumed white carbon black 15 parts, 3-5 parts of hydroxyl silicone oil, 2-2.5 parts of dicumyl peroxide, 0.5 parts of zinc stearate and 3-4 parts of borate ester crosslinking agent. The self-repairing conductive filler is a bio-based conductive filler. Further, the preparation method of the self-repairing conductive filler is: Step 1: immerse the bacterial cellulose film into a 0.05-0.1M Fe(NO3)3 solution containing 0.5wt.% citric acid and 0.1wt.% PEG-400, ultrasonic-assisted immersion at 50℃ for 40-60min, then stand for 12h under nitrogen protection, and freeze-dry after taking out; Step 2: carbonize in a tube furnace under N2 protection to obtain Fe 3+ carbonized bacterial cellulose doped with carbon; Step 3: place the Fe 3+ carbonized bacterial cellulose doped with carbon in a plasma treatment instrument for treatment; Step 4: after taking out, soak in a 2.0-3.0wt.% KH-570 ethanol solution, reflux at 60℃ for 8h to obtain modified Fe 3+ carbonized bacterial cellulose doped with carbon; Step 5: immerse the modified Fe 3+ carbonized bacterial cellulose doped with carbon into a 10wt.% [BMIM][PF6] acetone solution for ultrasonic treatment for 30-35min, and vacuum dry at 60℃ until constant weight to obtain modified Fe 3+ carbonized bacterial cellulose doped with carbon loaded with ionic liquid; Step 6: disperse the modified Fe 3+ carbonized bacterial cellulose doped with carbon loaded with ionic liquid in tetrahydrofuran, add polyetheramine ED-900 and 0.1wt.% organotin catalyst, and react at 80℃ for 10-12h; Step 7: wash with ethanol by centrifugation for 3 times to obtain the self-repairing conductive filler. Further, the density of the bacterial cellulose film in step 1 is 0.1-0.5g / cm 3 , the porosity is 80-95%, the pore size is 0.5-5μm, and the thickness is 80-100μm. Further, the carbonization conditions in step 2 are: increase the temperature to 300℃ at 2℃ / min, keep for 1h, continue to increase the temperature to 600℃ at 3℃ / min, keep for 2h, and finally increase the temperature to 900℃ at 5℃ / min, keep for 1h, and the N2 flow rate is 50mL / min. Further, the treatment conditions in the plasma treatment instrument in step 3 are: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60W, chamber pressure 50Pa, and treatment time 10min. Further, the KH-570 ethanol solution in step 4 uses acetic acid as a catalyst, and the pH is adjusted to 5.0. Further, the modified Fe3+ The mass ratio of carbonized bacterial cellulose to polyetheramine ED-900 is 5:(1-2). Furthermore, the organotin catalyst in step 6 includes dibutyltin dilaurate, stannous octoate, di(dodecylthio)dibutyltin, and dibutyltin diacetate. The preparation method of the above-mentioned antistatic self-healing silicone rubber includes the following steps: (1) Start the internal mixer, add silicone rubber, fumed silica and hydroxyl silicone oil, and mix for 5-10 minutes; (2) Add self-healing conductive filler and zinc stearate, mix at 60℃ and 20-30 rpm for 10-15 min, with a rotor gap of 0.3 mm; (3) Finally, add dicumyl peroxide and borate ester crosslinking agent, mix for 3-5 minutes to obtain rubber compound; (4) Place the rubber compound in the mold and vulcanize it in a flat vulcanizing machine; (5) Two-stage vulcanization: Treat at 170℃ for 1 hour, then at 200℃ for 1 hour to obtain the product. Furthermore, in step (4), the vulcanization conditions are 160℃×15min and pressure 10MPa. Beneficial effects: 1. This invention employs a triple dynamic bond synergy, consisting of hydrogen bonds, ionic bonds, and coordination bonds, to construct a dual conductive network, including: electronic conduction: Fe@CBC sp 2 Carbon network and ion conduction: The ion migration of [BMIM][PF6] has a dynamic self-adaptive effect: at low temperature (<60℃): hydrogen bonds dominate self-repair, at high temperature (>180℃): borate ester bonds maintain dynamics; thus achieving the effect of antistatic self-repair. 2. This invention uses bacterial cellulose as a matrix, through Fe... 3+ Doping and carbonization construct a three-dimensional conductive network, Fe 3+ Penetrating into the bacterial cellulose nanofiber network, it acts as a carbonization catalyst, coordinating with cellulose hydroxyl groups to lower the carbonization activation energy. During the carbonization process, Fe... 3+ It is reduced to nano-Fe particles, which promotes the formation of graphitized ordered structures, forms electronic conduction pathways, reduces defect state resistance, and improves the conductivity and catalytic graphitization of carbonized products. 3. This invention employs gradient carbonization and stepwise heating to prevent the fiber structure from collapsing, allowing Fe nanoparticles to be uniformly embedded in the carbon matrix, thereby achieving high conductivity. 4. In this invention, NH3 plasma treatment is first used to introduce surface amino groups (-NH2) to form surface defect sites. Then, KH-570 is grafted to improve the grafting rate of KH-570. At the same time, methacryloyloxy provides sites for subsequent sulfidation reactions. 5. In this invention, [BMIM][PF6] enters the mesopore through capillary action and forms an ion-dipole interaction with the surface -NH2. PF6- provides mobile charge carriers to form hydrogen bonds with the surface -NH2, thus constructing a dynamic ion-conducting channel. 6. This invention employs dynamic crosslinking, where the -NH2 of polyetheramine undergoes hydrogen bonding with the imidazole ring of the ionic liquid, and organotin catalyzes the condensation of silanol groups to form an interpenetrating network of "hard phase (carbon skeleton) - soft phase (ionic liquid)," thereby endowing the material with self-healing capabilities. 7. In this invention, silicone rubber and silica form a "shell-core" structure, and hydroxyl silicone oil reduces the Mooney viscosity of the system; 8. The present invention employs a dual crosslinking mechanism: DCP generates free radical crosslinking, and borate esters form BO-Si bonds with Si-OH, thereby improving mechanical properties. Detailed Implementation Raw materials and reagents: Bacterial cellulose film: Density: 0.1–0.5 g / cm³ 3 Porosity: 80–95%, pore size: 0.5–5 μm, thickness: 80–100 μm; Citric acid (C6H8O7): analytical grade (AR, ≥99.5%), anhydrous or monohydrate; PEG-400 (Polyethylene Glycol 400): Average molecular weight 400; Ferric nitrate (Fe(NO3)3·9H2O): purity ≥98%, metal impurity content <0.01%; KH-570: Purity ≥ 98%, Moisture content < 0.5%; Anhydrous ethanol: analytical grade (≥99.7%), water content <0.1%; Acetic acid (CH3COOH): analytical grade (≥99.8%); [BMIM][PF6]: Purity ≥99%, Water content <100ppm, Cl- content <50ppm; Acetone: Analytical grade (≥99.5%), moisture <0.1%; Polyetheramine ED-900: Molecular weight 900±50, primary amine content ≥90%; Dibutyltin dilaurate (DBTL): Tin content ≥18.5%, moisture <0.1%; Tetrahydrofuran (THF): Anhydrous grade (≥99.9%), moisture <50ppm. Example 1 The preparation method of self-healing conductive filler is as follows: Step 1: The bacterial cellulose film was immersed in a 0.05M Fe(NO3)3 solution containing 0.5wt.% citric acid and 0.1wt.% PEG-400, and was ultrasonically assisted for 55min at 50℃, and then was left to stand for 12h under nitrogen protection, and was freeze-dried after being taken out; Step 2: The Fe 3+ doped carbonized bacterial cellulose; Step 3: The Fe 3+ doped carbonized bacterial cellulose was placed in a plasma treatment instrument, and was treated under the following conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60W, chamber pressure 50Pa, and treatment time 10min; Step 4: The modified Fe 3+ doped carbonized bacterial cellulose; Step 5: The modified Fe 3+ doped carbonized bacterial cellulose was immersed in a 10wt.% [BMIM][PF6] acetone solution for ultrasonic treatment for 35min, and was vacuum dried at 60℃ until the weight was constant, to obtain the modified Fe 3+ doped carbonized bacterial cellulose; Step 6: The modified Fe 3+ doped carbonized bacterial cellulose was dispersed in tetrahydrofuran, and polyetheramine ED-900 and 0.1wt.% dibutyltin dilaurate were added, and the modified Fe 3+ doped carbonized bacterial cellulose and the polyetheramine ED-900 were reacted at a mass ratio of 5:1.5 at 80℃ for 11h; Step 7: The self-repairing conductive filler was obtained by centrifugal washing with ethanol for 3 times. Example 2 The preparation method of the self-repairing conductive filler was as follows: Step 1: The bacterial cellulose film was immersed in a 0.08M Fe(NO3)3 solution containing 0.5wt.% citric acid and 0.1wt.% PEG-400, and was ultrasonically assisted for 55min at 50℃, and then was left to stand for 12h under nitrogen protection, and was freeze-dried after being taken out; Step 2: Carbonization in a tube furnace under N2 protection, carbonization conditions: heating to 300℃ at 2℃ / min, holding for 1 h, then heating to 600℃ at 3℃ / min, holding for 2 h, finally heating to 900℃ at 5℃ / min, holding for 1 h, N2 flow rate is 50 mL / min, to obtain Fe 3+ carbonized doped bacterial cellulose; Step 3: Fe 3+ carbonized doped bacterial cellulose is placed in a plasma treatment instrument for treatment, treatment conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60 W, chamber pressure 50 Pa, treatment time 10 min; Step 4: After taking out, soak in 2.5 wt.% KH-570 ethanol solution adjusted to pH 5.0 with acetic acid, reflux at 60℃ for 8 h, to obtain modified Fe 3+ carbonized doped bacterial cellulose; Step 5: The modified Fe 3+ carbonized doped bacterial cellulose is immersed in a 10 wt.% [BMIM][PF6] acetone solution for 35 min of ultrasonic treatment, and vacuum dried at 60℃ to constant weight, to obtain modified Fe 3+ carbonized doped bacterial cellulose; Step 6: The modified Fe 3+ carbonized doped bacterial cellulose is dispersed in tetrahydrofuran, and polyetheramine ED-900 and 0.1 wt.% dibutyltin dilaurate are added, to obtain modified Fe 3+ carbonized doped bacterial cellulose and polyetheramine ED-900 with a mass ratio of 5:1.5, and the reaction is carried out at 80℃ for 11 h; Step 7: Centrifugal washing with ethanol for 3 times, to obtain the self-repairing conductive filler. Example 3 The preparation method of the self-repairing conductive filler is as follows: Step 1: The bacterial cellulose film is immersed in a 0.1M Fe(NO3)3 solution containing 0.5 wt.% citric acid and 0.1 wt.% PEG-400, and ultrasonic-assisted immersion is carried out at 50℃ for 55 min, followed by standing under nitrogen protection for 12 h, and then freeze-drying after taking out; Step 2: Carbonization in a tube furnace under N2 protection, carbonization conditions: heating to 300℃ at 2℃ / min, holding for 1 h, then heating to 600℃ at 3℃ / min, holding for 2 h, finally heating to 900℃ at 5℃ / min, holding for 1 h, N2 flow rate is 50 mL / min, to obtain Fe 3+ carbonized doped bacterial cellulose; Step 3: Fe 3+The carbon-doped bacterial cellulose is placed in a plasma treatment instrument and treated under the following conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60 W, chamber pressure 50 Pa, and treatment time 10 min; Step 4: After taking out, soak in a 2.5wt.% KH-570 ethanol solution with acetic acid to adjust the pH to 5.0, and reflux at 60°C for 8h to obtain modified Fe 3+ The carbon-doped bacterial cellulose is placed in a plasma treatment instrument and treated under the following conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60 W, chamber pressure 50 Pa, and treatment time 10 min; Step 5: The modified Fe 3+ The carbon-doped bacterial cellulose is placed in a plasma treatment instrument and treated under the following conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60 W, chamber pressure 50 Pa, and treatment time 10 min; 3+ The carbon-doped bacterial cellulose is placed in a plasma treatment instrument and treated under the following conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60 W, chamber pressure 50 Pa, and treatment time 10 min; Step 6: The modified Fe 3+ The carbon-doped bacterial cellulose is placed in a plasma treatment instrument and treated under the following conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60 W, chamber pressure 50 Pa, and treatment time 10 min; 3+ The mass ratio of the carbon-doped bacterial cellulose and polyetheramine ED-900 is 5:1.5, and the reaction is carried out at 80°C for 11h; Step 7: Centrifugal washing with ethanol for 3 times to obtain the self-repairing conductive filler. Example 4 The preparation method of the self-repairing conductive filler is as follows: Step 1: The bacterial cellulose film is immersed in a 0.08M Fe(NO3)3 solution containing 0.5wt.% citric acid and 0.1wt.% PEG-400, and ultrasonic-assisted immersion is carried out at 50°C for 40min, followed by standing under nitrogen protection for 12h, and then freeze-drying after taking out; Step 2: Carbonization in a tube furnace under N2 protection, and the carbonization conditions are as follows: heating to 300°C at a rate of 2°C / min, holding for 1h, then heating to 600°C at a rate of 3°C / min, holding for 2h, and finally heating to 900°C at a rate of 5°C / min, holding for 1h, and the N2 flow rate is 50mL / min, to obtain Fe 3+ The carbon-doped bacterial cellulose is placed in a plasma treatment instrument and treated under the following conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60 W, chamber pressure 50 Pa, and treatment time 10 min; Step 3: The Fe 3+ The carbon-doped bacterial cellulose is placed in a plasma treatment instrument and treated under the following conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60 W, chamber pressure 50 Pa, and treatment time 10 min; Step 4: After taking out, soak in a 2.5wt.% KH-570 ethanol solution with acetic acid to adjust the pH to 5.0, and reflux at 60°C for 8h to obtain modified Fe 3+ The carbon-doped bacterial cellulose is placed in a plasma treatment instrument and treated under the following conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60 W, chamber pressure 50 Pa, and treatment time 10 min; Step 5: The modified Fe3+ The carbonized and doped bacterial cellulose was immersed in 10 wt.% [BMIM][PF6] acetone solution for 35 min under ultrasonic, and dried to constant weight under vacuum at 60℃ to obtain modified Fe 3+ The carbonized and doped bacterial cellulose was immersed in 10 wt.% [BMIM][PF6] acetone solution for 35 min under ultrasonic, and dried to constant weight under vacuum at 60℃ to obtain modified Fe Step 6: The modified Fe 3+ The carbonized and doped bacterial cellulose was immersed in 10 wt.% [BMIM][PF6] acetone solution for 35 min under ultrasonic, and dried to constant weight under vacuum at 60℃ to obtain modified Fe 3+ The carbonized and doped bacterial cellulose was immersed in 10 wt.% [BMIM][PF6] acetone solution for 35 min under ultrasonic, and dried to constant weight under vacuum at 60℃ to obtain modified Fe Step 7: The self-healing conductive filler was obtained by washing with ethanol for 3 times by centrifugation. Example 5 The preparation method of the self-healing conductive filler is as follows: Step 1: The bacterial cellulose film was immersed in 0.08M Fe(NO3)3 solution containing 0.5 wt.% citric acid and 0.1 wt.% PEG-400, and ultrasonic-assisted immersion was carried out at 50℃ for 60 min, followed by standing for 12 h under nitrogen protection, and then freeze-drying after taking out; Step 2: Carbonization was carried out in a tube furnace under N2 protection, and the carbonization conditions were as follows: heating to 300℃ at 2℃ / min, holding for 1 h, continuing to heat to 600℃ at 3℃ / min, holding for 2 h, and finally heating to 900℃ at 5℃ / min, holding for 1 h, and the N2 flow rate was 50 mL / min, to obtain Fe 3+ The carbonized and doped bacterial cellulose was immersed in 10 wt.% [BMIM][PF6] acetone solution for 35 min under ultrasonic, and dried to constant weight under vacuum at 60℃ to obtain modified Fe Step 3: The Fe 3+ The carbonized and doped bacterial cellulose was immersed in 10 wt.% [BMIM][PF6] acetone solution for 35 min under ultrasonic, and dried to constant weight under vacuum at 60℃ to obtain modified Fe Step 4: The modified Fe 3+ The carbonized and doped bacterial cellulose was immersed in 10 wt.% [BMIM][PF6] acetone solution for 35 min under ultrasonic, and dried to constant weight under vacuum at 60℃ to obtain modified Fe Step 5: The modified Fe 3+ The carbonized and doped bacterial cellulose was immersed in 10 wt.% [BMIM][PF6] acetone solution for 35 min under ultrasonic, and dried to constant weight under vacuum at 60℃ to obtain modified Fe 3+ The carbonized and doped bacterial cellulose was immersed in 10 wt.% [BMIM][PF6] acetone solution for 35 min under ultrasonic, and dried to constant weight under vacuum at 60℃ to obtain modified Fe Step 6: The modified Fe 3+Doped carbonized bacterial cellulose was dispersed in tetrahydrofuran, and polyetheramine ED-900 and 0.1 wt.% dibutyltin dilaurate were added to obtain modified Fe 3+ The mass ratio of doped carbonized bacterial cellulose and polyetheramine ED-900 was 5:1.5, and the reaction was carried out at 80°C for 11h; Step 7: The self-repairing conductive filler was obtained by centrifugal washing with ethanol for 3 times. Example 6 The preparation method of the self-repairing conductive filler was as follows: Step 1: The bacterial cellulose film was immersed in a 0.08M Fe(NO3)3 solution containing 0.5wt.% citric acid and 0.1wt.% PEG-400, and ultrasonic-assisted immersion was carried out at 50°C for 55min, followed by standing under nitrogen protection for 12h, and then freeze-drying after taking out; Step 2: Carbonization was carried out in a tube furnace under N2 protection, and the carbonization conditions were as follows: heating to 300°C at 2°C / min, holding for 1h, continuing to heat to 600°C at 3°C / min, holding for 2h, and finally heating to 900°C at 5°C / min, holding for 1h, and the N2 flow rate was 50mL / min, to obtain Fe 3+ Doped carbonized bacterial cellulose; Step 3: The Fe 3+ The doped carbonized bacterial cellulose was placed in a plasma treatment instrument for treatment, and the treatment conditions were as follows: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60W, chamber pressure 50Pa, and treatment time 10min; Step 4: After taking out, it was soaked in a 2.5wt.% KH-570 ethanol solution with acetic acid to adjust the pH to 5.0, and refluxed at 60°C for 8h to obtain modified Fe 3+ Doped carbonized bacterial cellulose; Step 5: The modified Fe 3+ The doped carbonized bacterial cellulose was immersed in a 10wt.% [BMIM][PF6] acetone solution for ultrasonic treatment for 30min, and vacuum dried at 60°C to constant weight to obtain modified Fe 3+ Doped carbonized bacterial cellulose; Step 6: The modified Fe 3+ Doped carbonized bacterial cellulose was dispersed in tetrahydrofuran, and polyetheramine ED-900 and 0.1 wt.% dibutyltin dilaurate were added to obtain modified Fe 3+ The mass ratio of doped carbonized bacterial cellulose and polyetheramine ED-900 was 5:1.5, and the reaction was carried out at 80°C for 11h; Step 7: The self-repairing conductive filler was obtained by centrifugal washing with ethanol for 3 times. Example 7 The preparation method of the self-repairing conductive filler was as follows: Step 1: immerse the bacterial cellulose film into 0.08M Fe(NO3)3 solution containing 0.5wt.% citric acid and 0.1wt.% PEG-400, ultrasonic-assisted immersion at 50℃ for 55min, then stand for 12h under nitrogen protection, and freeze-dry after taking out; Step 2: carbonize in a tube furnace under N2 protection, carbonization conditions: heat to 300℃ at 2℃ / min, keep for 1h, continue to heat to 600℃ at 3℃ / min, keep for 2h, finally heat to 900℃ at 5℃ / min, keep for 1h, N2 flow rate is 50mL / min, to obtain Fe 3+ doped carbonized bacterial cellulose; Step 3: immerse the Fe 3+ doped carbonized bacterial cellulose into a plasma treatment instrument, treatment conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60W, chamber pressure 50Pa, treatment time 10min; Step 4: soak in 2.5wt.% KH-570 ethanol solution with acetic acid to adjust pH to 5.0 after taking out, reflux at 60℃ for 8h, to obtain modified Fe 3+ doped carbonized bacterial cellulose; Step 5: immerse the modified Fe 3+ doped carbonized bacterial cellulose into 10wt.% [BMIM][PF6] acetone solution, ultrasonic for 35min, vacuum dry at 60℃ to constant weight, to obtain modified Fe 3+ doped carbonized bacterial cellulose; Step 6: immerse the modified Fe 3+ doped carbonized bacterial cellulose into tetrahydrofuran, add polyetheramine ED-900 and 0.1wt.% dibutyltin dilaurate, the modified Fe 3+ doped carbonized bacterial cellulose and polyetheramine ED-900 with a mass ratio of 5:1, react at 80℃ for 11h; Step 7: wash with ethanol by centrifugation for 3 times, to obtain the self-repairing conductive filler. Example 8 The preparation method of the self-repairing conductive filler is as follows: Step 1: immerse the bacterial cellulose film into 0.08M Fe(NO3)3 solution containing 0.5wt.% citric acid and 0.1wt.% PEG-400, ultrasonic-assisted immersion at 50℃ for 55min, then stand for 12h under nitrogen protection, and freeze-dry after taking out; Step 2: Carbonization in a tube furnace under N2 protection, carbonization conditions: heating to 300℃ at 2℃ / min, holding for 1 h, then heating to 600℃ at 3℃ / min, holding for 2 h, finally heating to 900℃ at 5℃ / min, holding for 1 h, N2 flow rate is 50 mL / min, to obtain Fe 3+ carbonized doped bacterial cellulose; Step 3: Fe 3+ carbonized doped bacterial cellulose is placed in a plasma treatment instrument for treatment, treatment conditions: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60 W, chamber pressure 50 Pa, treatment time 10 min; Step 4: After taking out, soaking in a 2.5wt.% KH-570 ethanol solution adjusted to pH 5.0 with acetic acid, refluxing at 60℃ for 8 h, to obtain modified Fe 3+ carbonized doped bacterial cellulose; Step 5: The modified Fe 3+ carbonized doped bacterial cellulose is immersed in a 10wt.% [BMIM][PF6] acetone solution for ultrasonic treatment for 35 min, and vacuum dried at 60℃ to constant weight, to obtain modified Fe 3+ carbonized doped bacterial cellulose; Step 6: The modified Fe 3+ carbonized doped bacterial cellulose is dispersed in tetrahydrofuran, and polyetheramine ED-900 and 0.1wt.% dibutyltin dilaurate are added, and the modified Fe 3+ carbonized doped bacterial cellulose and polyetheramine ED-900 are reacted at a mass ratio of 5:2 at 80℃ for 11 h; Step 7: Washing with ethanol by centrifugation for 3 times, to obtain the self-repairing conductive filler. Comparative Example 1 The difference between this comparative example and Example 8 is that there is no Fe 3+ doping, Step 1 replaces Fe(NO3)3 solution with pure water. Comparative Example 2 The difference between this comparative example and Example 8 is that there is no carbonization treatment, Step 2 omits the carbonization step, and directly uses the dried bacterial cellulose film. Comparative Example 3 The difference between this comparative example and Example 8 is that there is no plasma treatment, Step 3 skips the plasma treatment, and directly performs KH-570 modification. Comparative Example 4 The difference between this comparative example and Example 8 is that there is no ion liquid loading, Step 5 omits the ion liquid soaking step, and directly performs polyetheramine crosslinking. Comparative Example 5 The difference between this comparative example and Example 8 is that a traditional conductive filler is used to replace the whole process: directly using commercial carbon nanotubes (CNT) mixed with polyetheramine ED-900 at 5:1.5 without any modification. Performance test: Conductivity (S / cm): four-probe method; Self-repairing efficiency (%): resistance recovery rate after 24h healing at room temperature after breaking; Tensile strength (MPa): universal material testing machine (ASTM D638); Ionic liquid loading rate (wt.%): thermogravimetric analysis (TGA); Cycling stability AR: resistance change rate after 1000 bending cycles; the results are shown in Table 1 below: Table 1 As can be seen from the above table, the conductivity of Examples 1-8 (1.85-2.52 S / cm) is significantly higher than that of Comparative Examples 1-5 (0.01-1.75 S / cm), indicating that Fe 3+ Doping, carbonization and ionic liquid loading synergistically improve the conductivity. The conductivity of Example 8 is the highest (2.52 S / cm), mainly because the ratio of polyetheramine (5:2) optimizes the density of the conductive network. The self-repairing efficiency of Examples 1-8 reaches 89.7-95.3%, mainly because of the dynamic bond repair mechanism of ionic liquid ([BMIM][PF6]); the self-repairing efficiency of Comparative Example 3 (without plasma treatment) decreases to 75.2%, mainly because insufficient nitrogen doping leads to a decrease in interfacial bonding force. The carbonization step (Examples 1-8 strength 16.5-20.1 MPa) is significantly better than Comparative Example 2 (5.3 MPa) without carbonization, because carbonization enhances the mechanical stability of the cellulose skeleton; Comparative Example 5 (CNT) has the highest strength (19.8 MPa), but lacks self-repairing function. The ionic liquid loading rate of Examples 1-8 (9.8-10.8%) is higher than that of Comparative Example 3 (8.0%), mainly because plasma activation improves the surface grafting sites. The AR of Examples 1-8 is less than 9.5%, thanks to the stable conductive network of carbonized cellulose and the self-repairing ability of ionic liquid. Comparative Examples 1-2 have poor stability (AR>29.6%) because they lack conductive or repairing components. 3+ - the stable conductive network of carbonized cellulose and the self-repairing ability of ionic liquid. Comparative Examples 1-2 have poor stability (AR>29.6%) because they lack conductive or repairing components. Example 8 has the best comprehensive performance, with a conductivity of 2.52 S / cm, a self-repairing efficiency of 95.3%, a tensile strength of 20.1 MPa, and an AR of less than 6.5%. Subsequent experiments all use the self-repairing conductive filler prepared in Example 8. Example 9 A method for preparing an antistatic self-repairing silicone rubber, comprising the following steps: (1) Start the mixer, add 100 parts of methyl vinyl silicone rubber, 15 parts of fumed white carbon black and 4 parts of hydroxyl silicone oil, mix for 10 min; (2) Add 10 parts of self-repairing conductive filler and 0.5 parts of zinc stearate, mix at 60°C, 25 rpm for 13 min, rotor gap 0.3 mm; (3) Finally add 2.5 parts of dicumyl peroxide and 3.5 parts of triisopropanolamine cyclic borate, mix for 5 min to obtain the rubber compound; (4) Put the rubber compound into the mold, and perform one-stage vulcanization in the flat vulcanization machine, the vulcanization condition is 160°C x 15 min, pressure 10 MPa; (5) Two-stage vulcanization: 170°C for 1 h, 200°C for 1 h, and it is obtained. Example 10 A method for preparing an antistatic self-repairing silicone rubber, comprising the following steps: (1) Start the mixer, add 100 parts of methyl vinyl silicone rubber, 15 parts of fumed white carbon black and 4 parts of hydroxyl silicone oil, mix for 10 min; (2) Add 15 parts of self-repairing conductive filler and 0.5 parts of zinc stearate, mix at 60°C, 25 rpm for 13 min, rotor gap 0.3 mm; (3) Finally add 2.5 parts of dicumyl peroxide and 3.5 parts of triisopropanolamine cyclic borate, mix for 5 min to obtain the rubber compound; (4) Put the rubber compound into the mold, and perform one-stage vulcanization in the flat vulcanization machine, the vulcanization condition is 160°C x 15 min, pressure 10 MPa; (5) Two-stage vulcanization: 170°C for 1 h, 200°C for 1 h, and it is obtained. Example 11 A method for preparing an antistatic self-repairing silicone rubber, comprising the following steps: (1) Start the mixer, add 100 parts of methyl vinyl silicone rubber, 15 parts of fumed white carbon black and 4 parts of hydroxyl silicone oil, mix for 10 min; (2) Add 18 parts of self-repairing conductive filler and 0.5 parts of zinc stearate, mix at 60°C, 25 rpm for 13 min, rotor gap 0.3 mm; (3) Finally add 2.5 parts of dicumyl peroxide and 3.5 parts of triisopropanolamine cyclic borate, mix for 5 min to obtain the rubber compound; (4) Put the rubber compound into the mold, and perform one-stage vulcanization in the flat vulcanization machine, the vulcanization condition is 160°C x 15 min, pressure 10 MPa; (5) Two-stage vulcanization: 170°C for 1 h, 200°C for 1 h, and it is obtained. Example 12 A preparation method of an antistatic self-repairing silicone rubber, comprising the following steps: (1) Start the internal mixer, add 100 parts of methyl vinyl silicone rubber, 15 parts of fumed white carbon black and 4 parts of hydroxyl silicone oil, and mix for 10 min; (2) Add 20 parts of self-repairing conductive filler and 0.5 parts of zinc stearate, and mix at 60°C and a rotation speed of 25 rpm for 13 min, with a rotor gap of 0.3 mm; (3) Finally, add 2.5 parts of dicumyl peroxide and 3.5 parts of triisopropanolamine cyclic borate, mix for 5 min, and obtain a rubber compound; (4) Put the rubber compound into a mold, and perform one-stage vulcanization in a flat vulcanization machine, with a vulcanization condition of 160°C x 15 min and a pressure of 10 MPa; (5) Two-stage vulcanization: treat at 170°C for 1 h and at 200°C for 1 h. Example 13 A preparation method of an antistatic self-repairing silicone rubber, comprising the following steps: (1) Start the internal mixer, add 100 parts of methyl vinyl silicone rubber, 15 parts of fumed white carbon black and 4 parts of hydroxyl silicone oil, and mix for 10 min; (2) Add 18 parts of self-repairing conductive filler and 0.5 parts of zinc stearate, and mix at 60°C and a rotation speed of 30 rpm for 10 min, with a rotor gap of 0.3 mm; (3) Finally, add 2.5 parts of dicumyl peroxide and 3.5 parts of triisopropanolamine cyclic borate, mix for 5 min, and obtain a rubber compound; (4) Put the rubber compound into a mold, and perform one-stage vulcanization in a flat vulcanization machine, with a vulcanization condition of 160°C x 15 min and a pressure of 10 MPa; (5) Two-stage vulcanization: treat at 170°C for 1 h and at 200°C for 1 h. Comparative Example 6 The difference between this example and Example 12 is that there is no self-repairing conductive filler, and the specific process is as follows: A preparation method of a silicone rubber, comprising the following steps: (1) Start the internal mixer, add 100 parts of methyl vinyl silicone rubber, 15 parts of fumed white carbon black and 4 parts of hydroxyl silicone oil, and mix for 10 min; (2) Add 0.5 parts of zinc stearate, and mix at 60°C and a rotation speed of 25 rpm for 13 min, with a rotor gap of 0.3 mm; (3) Finally, add 2.5 parts of dicumyl peroxide and 3.5 parts of triisopropanolamine cyclic borate, mix for 5 min, and obtain a rubber compound; (4) The rubber compound is placed in a mold, and one-stage vulcanization is carried out in a flat vulcanization machine, with a vulcanization condition of 160°C x 15 min, and a pressure of 10 MPa; (5) Two-stage vulcanization: 1 h at 170°C, and 1 h at 200°C, to obtain the product. Comparative Example 7 The difference between this example and Example 12 is that a conventional conductive filler is used, and the specific process is as follows: A preparation method of a silicone rubber, comprising the following steps: (1) Start the internal mixer, and add 100 parts of methyl vinyl silicone rubber, 15 parts of fumed white carbon black, and 4 parts of hydroxyl silicone oil, and mix for 10 min; (2) Add 18 parts of carbon nanotubes and 0.5 parts of zinc stearate, and mix at 60°C and a rotation speed of 25 rpm for 13 min, with a rotor gap of 0.3 mm; (3) Finally, add 2.5 parts of dicumyl peroxide and 3.5 parts of triisopropanolamine borate, and mix for 5 min to obtain the rubber compound; (4) The rubber compound is placed in a mold, and one-stage vulcanization is carried out in a flat vulcanization machine, with a vulcanization condition of 160°C x 15 min, and a pressure of 10 MPa; (5) Two-stage vulcanization: 1 h at 170°C, and 1 h at 200°C, to obtain the product. Comparative Example 8 The difference between this example and Example 12 is that no borate ester crosslinking agent is used, and the specific process is as follows: A preparation method of a silicone rubber, comprising the following steps: (1) Start the internal mixer, and add 100 parts of methyl vinyl silicone rubber, 15 parts of fumed white carbon black, and 4 parts of hydroxyl silicone oil, and mix for 10 min; (2) Add 18 parts of self-repairing conductive filler and 0.5 parts of zinc stearate, and mix at 60°C and a rotation speed of 25 rpm for 13 min, with a rotor gap of 0.3 mm; (3) Finally, add 2.5 parts of dicumyl peroxide, and mix for 5 min to obtain the rubber compound; (4) The rubber compound is placed in a mold, and one-stage vulcanization is carried out in a flat vulcanization machine, with a vulcanization condition of 160°C x 15 min, and a pressure of 10 MPa; (5) Two-stage vulcanization: 1 h at 170°C, and 1 h at 200°C, to obtain the product. Comparative Example 9 The difference between this example and Example 12 is that low-temperature mixing is used, and the specific process is as follows: A preparation method of a silicone rubber, comprising the following steps: (1) Start the internal mixer, and add 100 parts of methyl vinyl silicone rubber, 15 parts of fumed white carbon black, and 4 parts of hydroxyl silicone oil, and mix for 10 min; (2) Add 18 parts of self-repairing conductive filler and 0.5 parts of zinc stearate, and mix at 40°C, 25 rpm for 13 min, with rotor gap of 0.3 mm; (3) Finally add 2.5 parts of dicumyl peroxide and 3.5 parts of triisopropanolamine cyclic borate, and mix for 5 min to obtain the rubber compound; (4) Put the rubber compound into a mold, and perform one-stage vulcanization in a flat vulcanization machine, with vulcanization conditions of 160°C x 15 min, and pressure of 10 MPa; (5) Two-stage vulcanization: 170°C for 1 h, and 200°C for 1 h, to obtain the product. Comparative Example 10 The difference between this example and Example 12 is that low-speed mixing is used, as follows: A method for preparing a silicone rubber, comprising the following steps: (1) Start the internal mixer, and add 100 parts of methyl vinyl silicone rubber, 15 parts of fumed white carbon black, and 4 parts of hydroxyl silicone oil, and mix for 10 min; (2) Add 18 parts of self-repairing conductive filler and 0.5 parts of zinc stearate, and mix at 60°C, 15 rpm for 13 min, with rotor gap of 0.3 mm; (3) Finally add 2.5 parts of dicumyl peroxide and 3.5 parts of triisopropanolamine cyclic borate, and mix for 5 min to obtain the rubber compound; (4) Put the rubber compound into a mold, and perform one-stage vulcanization in a flat vulcanization machine, with vulcanization conditions of 160°C x 15 min, and pressure of 10 MPa; (5) Two-stage vulcanization: 170°C for 1 h, and 200°C for 1 h, to obtain the product. Performance test: Volume resistivity (Ω·cm) test standard: ASTM D257 / IEC 60093; Surface resistivity (Ω / sq) test standard: GB / T 1410-2006; Self-repairing efficiency (%) test method: resistance recovery method: use a four-probe resistance tester, and manually make a standard notch (length of 10 mm, depth of 1 mm), and the repair conditions are 25°C / 24 h; Self-repairing efficiency (%) = conductive rate after repair / original conductive rate x 100%; Tensile strength (MPa) and elongation at break (%) test standard: GB / T 528-2009; Permanent compression set rate (%) test standard: GB / T 7759-2015; The results are shown in Tables 2 and 3 as follows: Table 2 From Table 2 above, as the amount of self-repairing conductive filler increases (Examples 9-12), the volume / surface resistivity decreases significantly (10 5 → 10 4 Ω·cm), the resistivity of Comparative Example 6 (without filler) is the highest (>10 14 ), the conductivity of Comparative Example 7 (carbon nanotubes) is better than that of Comparative Example 6 but not as good as each of the Examples. The self-repairing efficiency of each of the Examples of the present application is >90%, with Example 13 being the highest (95.3%), Comparative Example 7 (carbon nanotubes) has no self-repairing ability at all, and Comparative Examples 8-10 have a 5-10% decrease in self-repairing efficiency due to process defects. Table 3 Mechanical properties of different Examples Tensile strength (MPa) Elongation at break (%) Permanent compression set (%) Example 9 9.8±0.5 420±11 12.5±1.2 Example 10 10.2±0.6 450±6 11.8±1.0 Example 11 10.5±0.3 480±15 10.3±0.9 Example 12 9.5±0.6 430±20 13.2±1.1 Example 13 11.1±0.3 510±16 9.8±0.8 Comparative Example 6 8.2±0.4 380±21 18.6±1.5 Comparative Example 7 9.1±0.5 400±13 15.7±1.3 Comparative Example 8 7.8±0.6 350±17 21.3±1.8 Comparative Example 9 8.5±0.5 390±15 17.2±1.4 Comparative Example 10 8.9±0.6 410±10 16.5±1.3 From Table 3 above, the best tensile strength of the present application appears in Example 13 (11.1 MPa), which is due to the optimized mixing speed (30 rpm), and Comparative Example 8 (without borate crosslinking agent) has the worst mechanical properties, thus showing the key role of the crosslinking agent in the strength of the material; low temperature mixing (Comparative Example 9) and low speed mixing (Comparative Example 10) both result in uneven dispersion of the filler and a decrease in each of the properties. The permanent compression set is closely related to the mixing quality.

Claims

1. An antistatic self-repairing silicone rubber, characterized by, By weight parts, including the following ingredients: silicone rubber 100 parts, self-repairing conductive filler 10-20 parts, fumed white carbon black 15 parts, 3-5 parts of hydroxyl silicone oil, dicumyl peroxide 2-2.5 parts, zinc stearate 0.5 parts and borate ester crosslinking agent 3-4 parts; The self-repairing conductive filler is a bio-based conductive filler.

2. The antistatic self-repairing silicone rubber according to claim 1, characterized in that, The preparation method of the self-repairing conductive filler is: Step 1: immerse the bacterial cellulose film in a 0.05-0.1M Fe(NO3)3 solution containing 0.5wt.% citric acid and 0.1wt.% PEG-400, ultrasonic-assisted immersion at 50℃ for 40-60min, then stand for 12h under nitrogen protection, and freeze-dry after taking out; Step 2: Carbonization in a tube furnace under N2protection to obtain Fe 3+ Carbon-doped carbonized bacterial cellulose; Step 3: Fe 3+ The doped bacterial cellulose carbonization is placed in a plasma treatment instrument for treatment; Step 4: After removal, soak in 2.0-3.0 wt.% KH-570 ethanol solution, reflux at 60°C for 8h to obtain modified Fe 3+ Carbon-doped bacterial cellulose; Step 5: The modified Fe 3+ The carbonized and doped bacterial cellulose was immersed in 10 wt.% [BMIM][PF6] acetone solution for 30-35 min under ultrasonic, and dried to constant weight under vacuum at 60 °C to obtain the modified Fe 3+ carbonized and doped bacterial cellulose; Step 6: Modification of Fe 3+ The doped carbonized bacterial cellulose was dispersed in tetrahydrofuran, polyetheramine ED-900 and 0.1 wt.% organotin catalyst were added and the reaction was carried out at 80°C for 10-12 h. Step 7: wash with ethanol by centrifugation for 3 times, to obtain the self-repairing conductive filler.

3. The antistatic self-repairing silicone rubber according to claim 2, characterized in that, The bacterial cellulose film density in step 1 is 0.1-0.5 g / cm 3 , porosity is 80-95%, pore size is 0.5-5 μm, and thickness is 80-100 μm.

4. The antistatic self-repairing silicone rubber according to claim 2, characterized in that, The carbonization condition in step 2 is: heating to 300℃ at 2℃ / min, holding for 1h, continuing to heat to 600℃ at 3℃ / min, holding for 2h, and finally heating to 900℃ at 5℃ / min, holding for 1h, with N2 flow rate of 50mL / min.

5. The antistatic self-repairing silicone rubber according to claim 2, wherein The treatment condition in the plasma treatment instrument in step 3 is: Ar / NH3 mixed gas with a volume ratio of 7:3, power 60W, chamber pressure 50Pa, and treatment time 10min.

6. The antistatic self-repairing silicone rubber according to claim 2, wherein The KH-570 ethanol solution in step 4 uses acetic acid as catalyst, and adjusts pH to 5.

0.

7. The antistatic self-repairing silicone rubber according to claim 2, wherein The modified Fe in step 6 loaded with ionic liquid 3+ The mass ratio of carbonized bacteria cellulose and polyetheramine ED-900 doped is 5:(1-2).

8. The antistatic self-repairing silicone rubber according to claim 2, wherein The organotin catalyst in step 6 includes dibutyltin dilaurate, stannous octoate, bis(dodecylthio)dibutyltin and dibutyltin diacetate.

9. A process for the preparation of an antistatic self-repairing silicone rubber according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: (1) start the internal mixer, add silicone rubber, fumed white carbon black and hydroxyl silicone oil, and mix for 5-10min; (2) add self-repairing conductive filler and zinc stearate, and mix at 60℃, rotation speed 20-30rpm, mixing time 10-15min, and rotor gap 0.3mm; (3) finally add dicumyl peroxide and borate ester crosslinking agent, and mix for 3-5min to obtain the rubber compound; (4) place the rubber compound in the mold, and perform one-stage vulcanization in the flat vulcanizing machine; (5) two-stage vulcanization: 170℃ for 1h, and 200℃ for 1h, to obtain the product.

10. The method for preparing an antistatic self-healing silicone rubber according to claim 9, characterized in that, The one-stage vulcanization condition in step (4) is 160℃×15min, with pressure 10MPa.

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