Preparation process of environment-friendly rubber auxiliary agent NS

Abstract

The application discloses an environment-friendly rubber auxiliary agent NS preparation process and belongs to the technical field of coal. The self-synthesized calcium sulfide / hollow spur-shaped manganese dioxide nanometer balls and interpenetrating polymer polymers are added, the hollow structure of the calcium sulfide / hollow spur-shaped manganese dioxide nanometer balls is provided with a larger specific surface area and porosity, can be used as stress dispersion points in a rubber system, can relieve stress concentration of rubber in a stretching and compression process, can improve tear strength and fatigue resistance of rubber products, the surface spur-shaped morphology can enhance the interface bonding force between the nanometer particles and the rubber matrix, can reduce filler aggregation, can ensure uniform dispersion of the auxiliary agent in the rubber, and further stabilize the mechanical properties of the rubber. The calcium sulfide / hollow spur-shaped manganese dioxide nanometer balls and the interpenetrating polymer polymers interact with each other, and the hollow spur-shaped structure can be embedded into the interpenetrating polymer polymers to play a bridging role.

Description

Technical Field

[0001] This invention belongs to the field of coal technology, specifically a preparation process for an environmentally friendly rubber additive NS. Background Technology

[0002] Rubber is a material with excellent viscoelasticity and is widely used in various aspects of industry and daily life. However, uncured rubber has a narrow operating temperature range and unstable properties. Therefore, in actual processing, it is necessary to add a vulcanization accelerator that promotes crosslinking of rubber, enabling the rubber to vulcanize rapidly and crosslink from a linear chain molecular structure into a three-dimensional network macromolecule, thus transforming the rubber into vulcanized rubber with practical value.

[0003] Rubber vulcanization accelerators are classified into eight categories based on their chemical structure. However, the vulcanization rate of most accelerators is difficult to control during use, and secondary amine accelerators are prone to producing carcinogens. Rubber vulcanization accelerators are generally added to the rubber matrix through compounding, but this process easily generates dust, causing environmental pollution. Furthermore, due to the different polarities of the rubber matrix, migration is likely to occur during use, affecting the appearance and service life of the finished product. Therefore, developing efficient, environmentally friendly, and inexpensive new rubber vulcanization accelerators has become a trend in the current vulcanization accelerator industry.

[0004] Chinese patent CN121160011A discloses a rubber additive and its environmentally friendly new process. In the post-processing of this invention, the addition and modification of chitosan can form an interpenetrating network structure with the components in the additive, resulting in low migration rate of the rubber additive in the rubber matrix, low volatility, small physical loss, and avoidance of environmental pollution. In addition, the amino groups in its structure can play an activating role in the rubber vulcanization process, accelerating the vulcanization of the compound.

[0005] However, the stability of chitosan in this solution is poor. In long-term use, such as in tires under high-temperature environments, chitosan is prone to oxidative degradation, which leads to the destruction of the interpenetrating network structure and a rapid decline in the mechanical properties of the rubber. Summary of the Invention

[0006] The purpose of this invention is to provide an environmentally friendly process for preparing the rubber additive NS. By adding self-synthesized calcium sulfide / hollow burr-shaped manganese dioxide nanospheres and interpenetrating polymers, the hollow structure of the calcium sulfide / hollow burr-shaped manganese dioxide nanospheres provides a large specific surface area and porosity, which can act as stress dispersion points in the rubber system, alleviate stress concentration in the rubber during stretching and compression, and improve the tear resistance and fatigue resistance of rubber products. The burr-like morphology of the surface can enhance the interfacial bonding force between the nanoparticles and the rubber matrix, reduce filler agglomeration, ensure uniform dispersion of the additive in the rubber, and thus stabilize the mechanical properties of the rubber.

[0007] The objective of this invention can be achieved through the following technical solutions: A preparation process for an environmentally friendly rubber additive NS includes the following steps: Step 1: Hollow manganese dioxide nanospheres are formed by redox reaction using sodium thiosulfate pentahydrate as a precursor, polyvinylpyrrolidone as a structure directing agent and stabilizer, and potassium permanganate as a strong oxidant.

[0008] Step 2: Using hexadecyltrimethylammonium bromide as a surfactant and urea as an alkaline regulator, a micelle template is constructed in an aqueous solution. Tetraethyl orthosilicate is used as a silicon source and hydrolyzed to generate silica sol, which is then directionally deposited on the surface of hollow manganese dioxide nanospheres and grows burr-like protrusions to obtain hollow burr-like manganese dioxide nanospheres.

[0009] Step 3: Using calcium acetate as the calcium source and diphenylthiourea as the sulfur source, and oleic acid, oleylamine, and trioctylamine as dispersants and solvents, a homogeneous reaction system is constructed. Diphenylthiourea undergoes thermal decomposition to generate sulfur ions, which react with calcium ions in situ on the surface of hollow, spiky manganese dioxide to obtain calcium sulfide / hollow, spiky manganese dioxide nanospheres.

[0010] Step 4: Using sodium alginate and epoxy resin as the crosslinking backbone, and castor oil polyether polyol and isocyanate as the polyurethane prepolymer raw materials, an interpenetrating polymer is obtained after crosslinking polymerization.

[0011] Step 5: Mix the styrene-acrylic emulsion, calcium sulfide / hollow spiky manganese dioxide nanospheres and modified accelerator NS evenly at 35-40℃, stir thoroughly, then add the interpenetrating polymer, continue stirring for 20-30 minutes, cool naturally to room temperature, let stand to separate into layers, separate the solid and liquid, and dry at 40-45℃ to obtain an environmentally friendly rubber additive NS.

[0012] Furthermore, the ratio of styrene-acrylic emulsion, calcium sulfide / hollow spiky manganese dioxide nanospheres, modification accelerator NS, and interpenetrating polymer is 30-40g: 14-16g: 3-5g: 1-2g.

[0013] Furthermore, the specific preparation steps of hollow manganese dioxide nanospheres are as follows: Mixed solutions A and B were added to a reaction vessel and stirred for 20 min at 20-25℃ and 500-600 r / min. Then, concentrated hydrochloric acid with a concentration of 6 mol / L was added, and the reaction was continued with stirring for 2-4 h. The mixture was centrifuged at 3000-3200 r / min for 3-5 min. The precipitate was washed once with a polyvinylpyrrolidone solution with a concentration of 0.8 mmol / L by centrifugation. The collected precipitate was redispersed in 1-2 L of a polyvinylpyrrolidone solution with a concentration of 0.8 mmol / L. Then, deionized water and potassium permanganate were added, and the mixture was heated to 60-70℃ and stirred for 5-8 min. The mixture was filtered, and the filter cake was washed 2-4 times with deionized water and ethanol, respectively. The mixture was then vacuum dried at 60-80℃ for 1-2 h to obtain hollow manganese dioxide nanospheres.

[0014] Furthermore, the ratio of the amounts of mixed solution A, mixed solution B, concentrated hydrochloric acid, deionized water, and potassium permanganate is 900-920g: 1000-1100g: 500-520mL: 12-14L: 220-230g.

[0015] Furthermore, mixed solution A is obtained by stirring and mixing 992-1000g of sodium thiosulfate pentahydrate and 5-6L of deionized water.

[0016] Further, mixed solution B is obtained by stirring and mixing 1130-1150g of polyvinylpyrrolidone and 5-6L of deionized water.

[0017] Furthermore, the specific preparation steps for hollow, spiky manganese dioxide nanospheres are as follows: Hexadecyltrimethylammonium bromide, urea, hollow manganese dioxide nanospheres, and deionized water were added to a reaction vessel and stirred for 30-40 min at 20-25 °C and 500-600 r / min. Then, isopropanol and tetraethyl orthosilicate were added, and stirring was continued for another 30-40 min. The mixture was then heated to 70-80 °C and reacted for 16-18 h. After filtration, the filter cake was washed 2-4 times with deionized water and dried under vacuum at 60-70 °C for 1-2 h. The cake was then transferred to a muffle furnace and calcined at 550-600 °C for 6-7 h to obtain hollow, spiky manganese dioxide nanospheres.

[0018] Furthermore, the ratio of hexadecyltrimethylammonium bromide, urea, hollow manganese dioxide nanospheres, deionized water, isopropanol, and tetraethyl orthosilicate is 20-22g: 12-14g: 20-30g: 600-700mL: 600-700mL: 28-30mL.

[0019] Furthermore, the specific preparation steps for calcium sulfide / hollow spiky manganese dioxide nanospheres are as follows: Deionized water, calcium acetate, oleic acid, hollow spiky manganese dioxide nanospheres, oleylamine, and trioctylamine were added to a reaction vessel and stirred at 120-130℃ and 200-220 r / min for 10-12 min to remove deionized water and unreacted organic solvents. Then, diphenylthiourea and anhydrous ethanol were added, and stirring was continued for 10-12 min to remove ethanol. The mixture was then transferred to a muffle furnace and calcined at 340-360℃ for 1-2 h under nitrogen protection. The product was dispersed in ethanol to precipitate it and centrifuged at 8000-9000 r / min for 3-5 min. The product was washed 2-4 times with ethanol and deionized water, respectively, and then vacuum dried at 60-80℃ for 1-2 h to obtain calcium sulfide / hollow spiky manganese dioxide nanospheres.

[0020] Furthermore, the ratio of deionized water, calcium acetate, oleic acid, hollow spiky manganese dioxide nanospheres, oleylamine, trioctylamine, diphenylthiourea, anhydrous ethanol, and ethanol is 40-50 mL: 1.58-1.62 g: 20-22 mL: 30-32 g: 120-130 mL: 60-70 mL: 6.85-6.95 g: 100-120 mL: 200-300 mL.

[0021] Furthermore, the specific preparation steps for the interpenetrating polymer are as follows: Sodium alginate, epoxy resin, and deionized water were added to a reaction vessel and stirred for 20-30 minutes at 20-25°C and 500-600 r / min. Then, castor oil polyether polyol, isocyanate, and acetone were added and ultrasonically dispersed for 40-60 minutes. Next, a 0.3-0.4% (w / w) dibutyltin dilaurate solution was added, and the mixture was heated to 50-60°C and stirred for 2-4 hours. The mixture was then filtered, and the filter cake was washed 2-4 times with deionized water and dried at 40-45°C to obtain an interpenetrating polymer.

[0022] Furthermore, the ratio of sodium alginate, epoxy resin, deionized water, sesame oil polyether polyol, isocyanate, acetone and dibutyltin dilaurate solution is 12-15g: 5-7g: 50-60mL: 70-80mL: 90-100mL: 500-600mL: 4-5mL.

[0023] The beneficial effects of this invention are: 1. The environmentally friendly rubber additive NS of the present invention, by adding self-synthesized calcium sulfide / hollow burr-shaped manganese dioxide nanospheres and interpenetrating polymer, provides a large specific surface area and porosity for the hollow structure of the calcium sulfide / hollow burr-shaped manganese dioxide nanospheres. It can serve as a stress dispersion point in the rubber system, alleviate stress concentration in the rubber during stretching and compression, improve the tear resistance and fatigue resistance of rubber products, and enhance the interfacial bonding force between the nanoparticles and the rubber matrix by the burr-like morphology of the surface, reduce filler agglomeration, ensure uniform dispersion of the additive in the rubber, and thus stabilize the mechanical properties of the rubber.

[0024] 2. The calcium sulfide / hollow spiky manganese dioxide nanospheres of the present invention contain a composite structure of calcium sulfide and manganese dioxide, which plays a synergistic promoting role in the rubber vulcanization process. Manganese dioxide, as a mild oxidant, can accelerate the vulcanization crosslinking reaction, while calcium sulfide can adjust the pH of the vulcanization system, optimize the crosslinking network structure, make the crosslinking density of the rubber more uniform, and improve the elasticity and wear resistance of the product.

[0025] 3. The interpenetrating polymer of the present invention is obtained by crosslinking and polymerization of sodium alginate and epoxy resin as the crosslinking backbone and castor oil polyether polyol and isocyanate as polyurethane prepolymer raw materials. This gives it both hydrophilic and hydrophobic groups, which can be used as an interface compatibilizer. On the one hand, it combines with the polar nanofiller calcium sulfide / hollow spiky manganese dioxide nanospheres through hydrogen bonds and electrostatic interactions. On the other hand, it is compatible with the non-polar rubber matrix through van der Waals forces, which greatly improves the interfacial compatibility between the filler and the rubber and reduces interfacial defects.

[0026] 4. The calcium sulfide / hollow spiky manganese dioxide nanospheres of the present invention interact with the interpenetrating polymer. The hollow spiky structure can be embedded into the interpenetrating polymer to act as a bridge, thereby improving the mechanical strength of the rubber. The sodium alginate contained in the interpenetrating polymer can be used as a crosslinking agent by the calcium ions contained in the calcium sulfide / hollow spiky manganese dioxide nanospheres during the rubber vulcanization process, thereby improving the polymerization strength of the interpenetrating polymer. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1: A preparation process for an environmentally friendly rubber additive NS, comprising the following steps: S1: 992g of sodium thiosulfate pentahydrate and 5L of deionized water were stirred and mixed to obtain mixed solution A. 1130g of polyvinylpyrrolidone and 5L of deionized water were stirred and mixed to obtain mixed solution B. 900g of mixed solution A and 1000g of mixed solution B were added to a reaction vessel and stirred for 20min at 20℃ and 500r / min. Then, 500mL of 6mol / L concentrated hydrochloric acid was added, and the reaction was continued to be stirred for 2h. The mixture was centrifuged at 3000r / min for 3min, and the precipitate was washed once with 0.8mmol / L polyvinylpyrrolidone solution. The collected precipitate was redispersed in 1L of 0.8mmol / L polyvinylpyrrolidone solution, and then 12L of deionized water and 220g of potassium permanganate were added. The mixture was heated to 60℃ and stirred for 5min. The mixture was filtered, and the filter cake was washed twice with deionized water and ethanol, respectively. The mixture was then vacuum dried at 60℃ for 1h to obtain hollow manganese dioxide nanospheres.

[0029] S2: Add 20g hexadecyltrimethylammonium bromide, 12g urea, 20g hollow manganese dioxide nanospheres and 600mL deionized water to a reaction vessel, stir for 30min at 20℃ and 500r / min, then add 600mL isopropanol and 28mL tetraethyl orthosilicate, continue stirring for 30min, heat to 70℃, continue the reaction for 16h, filter, wash the filter cake twice with deionized water, vacuum dry at 60℃ for 1h, transfer to a muffle furnace, heat to 550℃ and calcine for 6h to obtain hollow burr-like manganese dioxide nanospheres.

[0030] S3: 40 mL of deionized water, 1.58 g of calcium acetate, 20 mL of oleic acid, 30 g of hollow, spiky manganese dioxide nanospheres, 120 mL of oleylamine, and 60 mL of trioctylamine were added to a reaction vessel and stirred at 120 °C and 200 r / min for 10 min to remove deionized water and unreacted organic solvent. Then, 6.85 g of diphenylthiourea and 100 mL of anhydrous ethanol were added, and stirring was continued for 10 min to remove ethanol. The mixture was then transferred to a muffle furnace and calcined at 340 °C for 1 h under nitrogen protection. The product was dispersed in 200 mL of ethanol to precipitate it and centrifuged at 8000 r / min for 3 min. The product was washed twice with ethanol and deionized water, respectively, and dried under vacuum at 60 °C for 1 h to obtain calcium sulfide / hollow, spiky manganese dioxide nanospheres.

[0031] S4: Add 12g sodium alginate, 5g epoxy resin and 50mL deionized water to the reactor and stir for 20min at 20℃ and 500r / min. Then add 70mL castor oil polyether polyol, 90mL isocyanate and 500mL acetone and sonicate for 40min. Then add 4mL of 0.3% dibutyltin dilaurate solution, heat to 50℃ and continue stirring for 2h. Filter, wash the filter cake twice with deionized water and dry at 40℃ to obtain interpenetrating polymer.

[0032] S5: Mix 30g of styrene-acrylic emulsion, 14g of calcium sulfide / hollow burr-shaped manganese dioxide nanospheres and 3g of modified accelerator NS at 35℃ until homogeneous, stir thoroughly, then add 1g of interpenetrating polymer, continue stirring for 20min, cool naturally to room temperature, allow to stand and separate into layers, separate solid and liquid, and dry at 40℃ to obtain an environmentally friendly rubber additive NS.

[0033] Example 2: A preparation process for an environmentally friendly rubber additive NS, comprising the following steps: S1: Mix 996g of sodium thiosulfate pentahydrate with 5.5L of deionized water to obtain mixed solution A. Mix 1140g of polyvinylpyrrolidone with 5.5L of deionized water to obtain mixed solution B. Add 910g of mixed solution A and 1050g of mixed solution B to a reaction vessel and stir for 20min at 22.5℃ and 550r / min. Then add 510mL of concentrated hydrochloric acid with a concentration of 6mol / L and continue stirring for 3h. Centrifuge at 0.5°C for 4 min, wash the precipitate once with a 0.8 mmol / L polyvinylpyrrolidone solution, redisperse the collected precipitate in 1.5 L of a 0.8 mmol / L polyvinylpyrrolidone solution, add 13 L of deionized water and 225 g of potassium permanganate, heat to 65°C, stir for 6.5 min, filter, wash the filter cake three times with deionized water and ethanol respectively, and dry under vacuum at 70°C for 1.5 h to obtain hollow manganese dioxide nanospheres.

[0034] S2: 21g hexadecyltrimethylammonium bromide, 13g urea, 25g hollow manganese dioxide nanospheres and 650mL deionized water were added to a reaction vessel and stirred for 35min at 22.5℃ and 550r / min. Then 650mL isopropanol and 29mL tetraethyl orthosilicate were added and stirred for another 35min. The mixture was heated to 75℃ and reacted for 17h. The mixture was filtered, and the filter cake was washed three times with deionized water and dried under vacuum at 65℃ for 1.5h. The cake was then transferred to a muffle furnace and calcined at 575℃ for 6.5h to obtain hollow, spiky manganese dioxide nanospheres.

[0035] S3: 45 mL of deionized water, 1.60 g of calcium acetate, 21 mL of oleic acid, 31 g of hollow, spiky manganese dioxide nanospheres, 125 mL of oleylamine, and 65 mL of trioctylamine were added to a reaction vessel and stirred at 125 °C and 210 r / min for 11 min to remove deionized water and unreacted organic solvent. Then, 6.90 g of diphenylthiourea and 110 mL of anhydrous ethanol were added, and stirring was continued for 11 min to remove ethanol. The mixture was then transferred to a muffle furnace and calcined at 350 °C for 1.5 h under nitrogen protection. The product was dispersed in 250 mL of ethanol to precipitate it and centrifuged at 8500 r / min for 4 min. The product was washed three times with ethanol and three times with deionized water, and then vacuum dried at 70 °C for 1.5 h to obtain calcium sulfide / hollow, spiky manganese dioxide nanospheres.

[0036] S4: Add 13.5g sodium alginate, 6g epoxy resin and 55mL deionized water to a reaction vessel and stir for 25min at 22.5℃ and 550r / min. Then add 75mL castor oil polyether polyol, 95mL isocyanate and 550mL acetone and sonicate for 50min. Then add 4.5mL of 0.35% dibutyltin dilaurate solution, heat to 55℃ and continue stirring for 3h. Filter, wash the filter cake three times with deionized water and dry at 42.5℃ to obtain interpenetrating polymer.

[0037] S5: Mix 35g of styrene-acrylic emulsion, 15g of calcium sulfide / hollow burr-shaped manganese dioxide nanospheres and 4g of modified accelerator NS at 37.5℃ until homogeneous, stir thoroughly, then add 1.5g of interpenetrating polymer, continue stirring for 25min, cool naturally to room temperature, allow to stand and separate into layers, separate solid and liquid, and dry at 42.5℃ to obtain an environmentally friendly rubber additive NS.

[0038] Example 3: A preparation process for an environmentally friendly rubber additive NS, comprising the following steps: S1: Mix 1000g sodium thiosulfate pentahydrate with 6L deionized water to obtain mixed solution A. Mix 1150g polyvinylpyrrolidone with 6L deionized water to obtain mixed solution B. Add 920g mixed solution A and 1100g mixed solution B to a reaction vessel and stir for 20min at 25℃ and 600r / min. Then add 520mL of 6mol / L concentrated hydrochloric acid and continue stirring for 4h. Centrifuge at 3200r / min for 5min. Wash the precipitate once with 0.8mmol / L polyvinylpyrrolidone solution. Redisperse the collected precipitate in 2L of 0.8mmol / L polyvinylpyrrolidone solution. Then add 14L of deionized water and 230g of potassium permanganate. Heat to 70℃ and continue stirring for 8min. Filter and wash the filter cake four times with deionized water and ethanol respectively. Dry under vacuum at 80℃ for 2h to obtain hollow manganese dioxide nanospheres.

[0039] S2: 22g of hexadecyltrimethylammonium bromide, 14g of urea, 30g of hollow manganese dioxide nanospheres and 700mL of deionized water were added to a reaction vessel and stirred for 40min at 25℃ and 600r / min. Then, 700mL of isopropanol and 30mL of tetraethyl orthosilicate were added and stirred for another 40min. The mixture was then heated to 80℃ and reacted for another 18h. After filtration, the filter cake was washed four times with deionized water, dried under vacuum at 70℃ for 2h, transferred to a muffle furnace, and calcined at 600℃ for 7h to obtain hollow, spiky manganese dioxide nanospheres.

[0040] S3: 50 mL of deionized water, 1.62 g of calcium acetate, 22 mL of oleic acid, 32 g of hollow spiky manganese dioxide nanospheres, 130 mL of oleylamine, and 70 mL of trioctylamine were added to a reaction vessel and stirred at 130 °C and 220 r / min for 12 min to remove deionized water and unreacted organic solvent. Then, 6.95 g of diphenylthiourea and 120 mL of anhydrous ethanol were added, and stirring was continued for 12 min to remove ethanol. The mixture was then transferred to a muffle furnace and calcined at 360 °C for 2 h under nitrogen protection. The product was dispersed in 300 mL of ethanol to precipitate it and centrifuged at 9000 r / min for 5 min. The product was washed four times with ethanol and four times with deionized water, and then vacuum dried at 80 °C for 2 h to obtain calcium sulfide / hollow spiky manganese dioxide nanospheres.

[0041] S4: Add 15g sodium alginate, 7g epoxy resin and 60mL deionized water to the reactor and stir for 30min at 25℃ and 600r / min. Then add 80mL castor oil polyether polyol, 100mL isocyanate and 600mL acetone and sonicate for 60min. Then add 5mL of 0.4% dibutyltin dilaurate solution, heat to 60℃ and continue stirring for 4h. Filter, wash the filter cake 4 times with deionized water and dry at 45℃ to obtain interpenetrating polymer.

[0042] S5: Mix 40g of styrene-acrylic emulsion, 16g of calcium sulfide / hollow burr-shaped manganese dioxide nanospheres and 5g of modified accelerator NS at 40℃ until homogeneous, stir thoroughly, then add 2g of interpenetrating polymer, continue stirring for 30min, cool naturally to room temperature, allow to stand and separate into layers, separate solid and liquid, and dry at 45℃ to obtain an environmentally friendly rubber additive NS.

[0043] Comparative Example 1: Based on Example 3, the hollow burr-like manganese dioxide nanospheres in step S3 were replaced with the hollow manganese dioxide nanospheres in step S1.

[0044] Comparative Example 2: Based on Example 3, the calcium sulfide / hollow burr-shaped manganese dioxide nanospheres in step S5 were replaced with the hollow burr-shaped manganese dioxide nanospheres prepared in step S2.

[0045] Comparative Example 3: Based on Example 3, the interpenetrating polymer in step S5 was replaced with castor oil polyether polyol.

[0046] Fluorosilicone rubber was prepared under the same conditions using the environmentally friendly rubber additive NS prepared in Examples 1-3 and Comparative Examples 1-3. The obtained fluorosilicone rubber and commercially available fluorosilicone rubber from Anhui Lixin Rubber Technology Co., Ltd. were tested according to GB / T528-2009, GB / T529-2008, GB / T1681-2009, and GB / T7759.1-2015. The results are shown in Table 1. Table 1 ; As can be seen from Table 1, the disappearance of the burr-like morphology in Comparative Example 1 significantly reduced the interfacial bonding area between the nanofiller and the rubber matrix and interpenetrating polymer, making it impossible to effectively anchor the matrix molecular chains, weakening the stress dispersion effect, and resulting in a significant decrease in tensile strength and tear strength.

[0047] The burr-like structure retained in Comparative Example 2 can still play a certain role in interfacial anchoring. Without the participation of calcium sulfide, the pH of the vulcanization system cannot be precisely controlled, the uniformity of the crosslinking network decreases, and at the same time, the interpenetrating polymer loses the reinforcing effect of calcium ions as crosslinking agents, resulting in insufficient polymerization strength, which leads to a decrease in the resilience of the rubber and an increase in the compression set.

[0048] In Comparative Example 3, the castor oil polyether polyol is only a single lipophilic molecule and lacks the interfacial compatibility characteristics of interpenetrating polymers with both hydrophilic and hydrophobic groups. It cannot simultaneously form a stable bond with the polar calcium sulfide / hollow burr-shaped manganese dioxide nanosphere filler and the non-polar rubber matrix, resulting in severe filler agglomeration, increased interfacial defects in the rubber, and the lack of bridging effect of the interpenetrating network. The calcium sulfide / hollow burr-shaped manganese dioxide nanosphere filler cannot be effectively embedded in the polymer network, and the stress transfer efficiency is greatly reduced. At the same time, there is no cross-linking reaction between sodium alginate and calcium ions, resulting in insufficient mechanical strength of the polymer. Ultimately, the tensile strength, tear strength, and resilience are reduced to the lowest level, while the compression set is increased.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A preparation process for an environmentally friendly rubber additive NS, characterized in that, Includes the following steps: Step 1: Hollow manganese dioxide nanospheres are formed by redox reaction using sodium thiosulfate pentahydrate as a precursor, polyvinylpyrrolidone as a structure directing agent and stabilizer, and potassium permanganate as a strong oxidant. Step 2: Using hexadecyltrimethylammonium bromide as a surfactant and urea as an alkaline regulator, a micelle template is constructed in an aqueous solution. Tetraethyl orthosilicate is used as a silicon source and hydrolyzed to generate silica sol, which is then directionally deposited on the surface of hollow manganese dioxide nanospheres and grows burr-like protrusions to obtain hollow burr-like manganese dioxide nanospheres. Step 3: Using calcium acetate as the calcium source, diphenylthiourea as the sulfur source, oleic acid, oleylamine, and trioctylamine as dispersants and solvents, a homogeneous reaction system is constructed. Diphenylthiourea undergoes thermal decomposition to generate sulfur ions, which react with calcium ions in situ on the surface of hollow, burr-like manganese dioxide to obtain calcium sulfide / hollow, burr-like manganese dioxide nanospheres. Step 4: Using sodium alginate and epoxy resin as the crosslinking backbone, and castor oil polyether polyol and isocyanate as polyurethane prepolymer raw materials, crosslinking polymerization is carried out to obtain an interpenetrating polymer. Step 5: Mix the styrene-acrylic emulsion, calcium sulfide / hollow spiky manganese dioxide nanospheres and modified accelerator NS evenly at 35-40℃, stir thoroughly, then add the interpenetrating polymer, continue stirring for 20-30 minutes, cool naturally to room temperature, let stand to separate into layers, separate the solid and liquid, and dry at 40-45℃ to obtain an environmentally friendly rubber additive NS.

2. The preparation process of the environmentally friendly rubber additive NS according to claim 1, characterized in that, The ratio of the styrene-acrylic emulsion, calcium sulfide / hollow spiky manganese dioxide nanospheres, modification accelerator NS, and interpenetrating polymer is 30-40g: 14-16g: 3-5g: 1-2g.

3. The preparation process of the environmentally friendly rubber additive NS according to claim 1, characterized in that, The specific preparation steps for the hollow manganese dioxide nanospheres are as follows: Mixed solutions A and B were added to a reaction vessel and stirred at 20-25°C and 500-600 rpm for 20 min. Then, concentrated hydrochloric acid with a concentration of 6 mol / L was added, and the reaction was continued with stirring for 2-4 h. The mixture was then centrifuged at 3000-3200 rpm for 3-5 min. The precipitate was washed once with a polyvinylpyrrolidone solution with a concentration of 0.8 mmol / L by centrifugation. The collected precipitate was redispersed in 1-2 L of a polyvinylpyrrolidone solution with a concentration of 0.8 mmol / L. Deionized water and potassium permanganate were then added, and the mixture was heated to 60-70°C and stirred for 5-8 min. The mixture was then filtered, washed, and vacuum dried to obtain hollow manganese dioxide nanospheres.

4. The preparation process of the environmentally friendly rubber additive NS according to claim 3, characterized in that, The ratio of the amounts of mixed solution A, mixed solution B, concentrated hydrochloric acid, deionized water and potassium permanganate is 900-920g: 1000-1100g: 500-520mL: 12-14L: 220-230g.

5. The preparation process of the environmentally friendly rubber additive NS according to claim 3, characterized in that, The mixed solution A is obtained by stirring and mixing 992-1000g of sodium thiosulfate pentahydrate and 5-6L of deionized water; the mixed solution B is obtained by stirring and mixing 1130-1150g of polyvinylpyrrolidone and 5-6L of deionized water.

6. The preparation process of the environmentally friendly rubber additive NS according to claim 1, characterized in that, The specific preparation steps for the hollow, spiky manganese dioxide nanospheres are as follows: Hexadecyltrimethylammonium bromide, urea, hollow manganese dioxide nanospheres, and deionized water were added to a reaction vessel and stirred for 30-40 min at 20-25℃ and 500-600 r / min. Then isopropanol and tetraethyl orthosilicate were added, and stirring was continued for another 30-40 min. The mixture was then heated to 70-80℃ and reacted for 16-18 h. After filtration, washing, and vacuum drying, the mixture was transferred to a muffle furnace and calcined at 550-600℃ for 6-7 h to obtain hollow, spiky manganese dioxide nanospheres. The ratio of hexadecyltrimethylammonium bromide, urea, hollow manganese dioxide nanospheres, deionized water, isopropanol, and tetraethyl orthosilicate is 20-22g: 12-14g: 20-30g: 600-700mL: 600-700mL: 28-30mL.

7. The preparation process of the environmentally friendly rubber additive NS according to claim 1, characterized in that, The specific preparation steps for the calcium sulfide / hollow spiky manganese dioxide nanospheres are as follows: Deionized water, calcium acetate, oleic acid, hollow spiky manganese dioxide nanospheres, oleylamine, and trioctylamine were added to a reaction vessel and stirred at 120-130℃ and 200-220 r / min for 10-12 min to remove deionized water and unreacted organic solvents. Then, diphenylthiourea and anhydrous ethanol were added, and stirring was continued for 10-12 min to remove ethanol. The mixture was then transferred to a muffle furnace and calcined at 340-360℃ for 1-2 h under nitrogen protection. The product was dispersed in ethanol to precipitate it, centrifuged at 8000-9000 r / min for 3-5 min, washed, and vacuum dried to obtain calcium sulfide / hollow spiky manganese dioxide nanospheres.

8. The preparation process of the environmentally friendly rubber additive NS according to claim 7, characterized in that, The ratio of deionized water, calcium acetate, oleic acid, hollow spiky manganese dioxide nanospheres, oleylamine, trioctylamine, diphenylthiourea, anhydrous ethanol, and ethanol is 40-50 mL: 1.58-1.62 g: 20-22 mL: 30-32 g: 120-130 mL: 60-70 mL: 6.85-6.95 g: 100-120 mL: 200-300 mL.

9. The preparation process of the environmentally friendly rubber additive NS according to claim 1, characterized in that, The specific preparation steps of the interpenetrating polymer are as follows: Sodium alginate, epoxy resin, and deionized water were added to a reaction vessel and stirred for 20-30 minutes at 20-25°C and 500-600 r / min. Then, castor oil polyether polyol, isocyanate, and acetone were added and ultrasonically dispersed for 40-60 minutes. Next, a 0.3-0.4% (w / w) dibutyltin dilaurate solution was added, and the mixture was heated to 50-60°C and stirred for 2-4 hours. The mixture was then filtered, and the filter cake was washed 2-4 times with deionized water and dried at 40-45°C to obtain an interpenetrating polymer.

10. The preparation process of the environmentally friendly rubber additive NS according to claim 1, characterized in that, The ratio of sodium alginate, epoxy resin, deionized water, sesame oil polyether polyol, isocyanate, acetone and dibutyltin dilaurate solution is 12-15g: 5-7g: 50-60mL: 70-80mL: 90-100mL: 500-600mL: 4-5mL.