A filler dispersant, modified filler, and preparation method and application thereof

Abstract

The application provides a filler dispersant, modified filler and a preparation method and application thereof. The preparation method of the filler dispersant comprises the following steps: uniformly mixing sorbitan oleate and sulfur, removing unreacted sulfur after heating reaction under the protection of a protective gas, and obtaining the filler dispersant. The prepared filler dispersant can be added to rubber mixing on a mixing device, and can also be used to modify the filler, and the modified filler is added to rubber mixing or mixing. The prepared filler dispersant has hydroxyl groups and ether bonds, which can form hydrogen bonds with surface hydroxyl groups of white carbon black, reduce the surface energy of the white carbon black, improve the dispersity, enhance the interface action between rubber and the white carbon black, and compared with the use of a silane coupling agent alone, the use of the silane coupling agent and the filler dispersant together optimizes the comprehensive performance of the rubber compound, and the prepared rubber composite material has higher mechanical properties and lower rolling resistance.

Description

Technical Field

[0001] This invention relates to the field of rubber nanocomposite materials, and more specifically, to a filler dispersant, a modified filler, a preparation method thereof, and its application. Background Technology

[0002] In the rubber industry, the use of reinforcing fillers not only improves the strength of rubber products but also enhances the processing performance of the rubber compound, endowing the products with excellent properties such as abrasion resistance, tear resistance, heat resistance, cold resistance, and oil resistance, thus extending their service life. However, uneven dispersion of fillers in rubber can lead to reduced reinforcing performance, decreased abrasion resistance, and increased rolling resistance, resulting in increased fuel consumption and reduced mileage in automobiles. Carbon black and silica are the main reinforcing fillers. Silica can significantly reduce the rolling resistance of tires and improve their anti-skid performance; however, due to the large number of hydroxyl groups on the surface of silica, it is prone to agglomeration and has poor affinity with rubber. Therefore, it is necessary to solve the dispersion problem of silica in the rubber matrix in order to prepare high-performance silica / rubber nanocomposites.

[0003] Traditional dry mixing involves in-situ modification of silica using organosilane coupling agents during the mixing of fillers and rubber. While in-situ modification improves silica dispersion to some extent, it suffers from low modification efficiency and uneven filler dispersion. Furthermore, in-situ modification technology places stringent demands on equipment, resulting in high energy consumption and environmental dust pollution. In recent years, wet mixing has emerged, avoiding these problems. Chinese invention patents CN103203810A and CN105602047A demonstrate that wet mixing is superior to dry mixing in solving the silica dispersion problem. However, there is still room for improvement in the dispersion of silica within the rubber matrix.

[0004] Furthermore, carbon black produced using existing technologies as a reinforcing agent in tire rubber materials also suffers from poor dispersion, leading to increased hysteresis loss and rolling resistance. Therefore, improving the dispersibility of carbon black in rubber is also part of the technical challenges that need to be addressed. For example, Chinese invention patent CN111117301A utilizes complex chemical modification to effectively solve these problems, but this method suffers from complex processes, environmental pollution, and high costs. Therefore, it is essential to develop a filler modifier that is inexpensive, easy to prepare and use, and has excellent modification effects. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention provides a filler dispersant, a modified filler, its preparation method, and its application.

[0006] This invention uses sulfur to react with Span-80 to form polysulfide bonds, and obtains a filler dispersant with high activity through a low-cost and easy-to-prepare chemical reaction that can improve the dispersibility of fillers and enhance the interfacial interaction between rubber and fillers: a silane coupling agent is dissolved in an organic solvent, filler is added, and after grinding, the prepared filler dispersant is added, and the modified filler is obtained by grinding / or stirring.

[0007] The technical solution of this invention is as follows: Sulfur is used to open the double bonds in the Span-80 molecule to form polysulfide bonds. The hydroxyl groups and ether bonds inherent in Span-80 can form hydrogen bonds with the filler surface, reducing the filler surface energy. The modified filler disperses better in the rubber matrix, further improving the dynamic properties of the rubber compound. Simultaneously, after vulcanization, the polysulfide bonds of Span-80 break during the rubber crosslinking process, participating in the vulcanization reaction of the rubber system and grafting into the rubber crosslinking network, improving the interfacial interaction between the rubber and the filler, and enhancing the filler's reinforcing effect. Silane coupling agent-modified fillers can establish strong interactions between the rubber and the filler. However, due to activity limitations, a certain number of hydroxyl groups remain on the filler surface. The synthesized silica dispersant can further cover the hydroxyl groups on the filler surface, improving its dispersibility, and can also establish multiple interactions, further enhancing the filler's reinforcing performance.

[0008] One objective of this invention is to provide a method for preparing a filler dispersant, comprising:

[0009] Sorbitol oleate (Span-80) and sulfur were mixed evenly and heated under a protective gas atmosphere. Unreacted sulfur was then removed to obtain the filler dispersant.

[0010] In a preferred embodiment of the present invention,

[0011] The molar ratio of dehydrated sorbitan oleate to sulfur is 1:(0.5-5.5); preferably 1:(1-4).

[0012] In a preferred embodiment of the present invention,

[0013] The protective gas is at least one of nitrogen and argon;

[0014] Unreacted sulfur is removed by first vacuuming to remove hydrogen sulfide gas, then dissolving it in a solvent and filtering it; the solvent is a solvent that can dissolve Span-80 and does not react with it, preferably at least one of cyclohexane and ethanol;

[0015] The reaction temperature is 125–155℃; preferably 130–150℃.

[0016] The reaction time is 0.5–5 h; preferably 1–4 h.

[0017] The solvent removal method is rotary evaporation, and the rotary evaporation temperature is the temperature commonly used in the prior art, such as 40°C.

[0018] The second objective of this invention is to provide a filler dispersant prepared by the above method.

[0019] The prepared filler dispersant can be added to the rubber for mixing in a mixing device (such as an open mill), or it can be used to modify the filler, and the modified filler can be added to the rubber for mixing or blending.

[0020] The third objective of this invention is to provide a modified filler.

[0021] The modified filler includes the filler dispersant and the filler; preferably, the filler further includes an organic solvent; more preferably, the filler further includes a silane coupling agent; the filler is preferably at least one of silica and carbon black; when the modified filler is composed of the filler dispersant and the filler, the modified filler is a solid-phase direct modified filler; when the modified filler is composed of the filler dispersant, the filler and the organic solvent, the modified filler is a liquid-phase organic solution modified filler; when the modified filler is composed of the filler dispersant, the filler, the organic solvent and the silane coupling agent, the modified filler is a silane coupling agent modified filler.

[0022] The silica is a commercially available precipitated or fumed silica commonly used in the field, such as silica 1165, VN3, etc.; the carbon black is a commercially available carbon black commonly used in the field, such as carbon black N220, N330, N660, etc.

[0023] When there is silica in the filler, a silane coupling agent must be added. If there is only carbon black and no silica in the filler, a silane coupling agent is not required.

[0024] In a preferred embodiment of the present invention,

[0025] The silane coupling agent is a conventional organosilane coupling agent in the art, preferably one of bis-[γ-(triethoxysilane)propyl]tetrasulfide (Si69), bis-[γ-(triethoxysilane)propyl]disulfide (Si75), 3-thiocyanopropyltriethoxysilane, γ-mercaptopropyltriethoxysilane (KH580), γ-aminopropyltriethoxysilane (KH550), and γ-methacryloyloxypropyltrimethoxysilane (KH570);

[0026] The organic solvent is a good solvent for rubber, preferably at least one of aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, and ether solvents; the aliphatic hydrocarbon solvent is preferably at least one of solvent oil, cycloalkanes, substituted cycloalkanes, straight-chain or branched alkanes, and the cycloalkanes are preferably cyclohexane; the aromatic hydrocarbon solvent is preferably at least one of benzene, toluene, and xylene; the ether solvent is preferably tetrahydrofuran.

[0027] In a preferred embodiment of the present invention,

[0028] The mass ratio of filler to organic solvent is 1:(3-100), preferably 1:(6-20), and more preferably 1:(10-20);

[0029] The amount of silane coupling agent used is 3-20% of the filler mass, preferably 6-18%;

[0030] The amount of filler dispersant used is 0.5-20% of the filler mass, preferably 0.8-15%, and more preferably 5-10%.

[0031] The fourth objective of this invention is to provide a method for preparing a modified filler, comprising:

[0032] The modified filler is obtained by mixing the raw materials evenly according to the specified dosage ratio.

[0033] Preferably,

[0034] When the filler is silica, the silane coupling agent is dissolved in an organic solvent, silica is added and ground or stirred, and then the filler dispersant is added. After grinding or stirring, the modified filler is obtained. When adding the filler, it is preferable to grind for 5-10 minutes and stir at a speed of 300-1000 r / min for 5-10 minutes. When adding the filler dispersant, it is preferable to grind for 5-10 minutes and stir at a speed of 300-1000 r / min for 5-10 minutes.

[0035] When the filler is carbon black, the modified filler is obtained by adding the filler dispersant and carbon black to an organic solvent and grinding or stirring; preferably, grinding for 5 to 10 minutes and stirring at a speed of 300 to 1000 r / min for 5 to 10 minutes.

[0036] When the filler is carbon black and silica, the silane coupling agent is dissolved in an organic solvent, silica is added first for grinding or stirring, then the filler dispersant is added and stirred evenly, and finally carbon black is added. After grinding or stirring, the modified filler is obtained. When adding the filler, it is preferable to grind for 5-10 minutes and stir at a speed of 300-1000 r / min for 5-10 minutes. When adding the filler dispersant, it is preferable to grind for 5-10 minutes and stir at a speed of 300-1000 r / min for 5-10 minutes.

[0037] The fifth objective of this invention is to provide an application of a filler dispersant or modified filler in rubber.

[0038] Filler dispersants can be added directly to rubber as components for mixing. Before adding filler dispersants, the filler should be added to the rubber and mixed evenly. Filler dispersants can improve the dispersion of fillers in the rubber matrix.

[0039] Modified fillers can be prepared by first obtaining a masterbatch, and then adding other components to the masterbatch for mixing.

[0040] The masterbatch is preferably prepared by uniformly mixing a rubber solution and the modified filler, followed by solvent removal; wherein, solvent removal can be performed using any method known in the art.

[0041] Preferably,

[0042] The rubber solution is a solution-polymerized rubber solution or a solution obtained by dissolving rubber in a solvent; the solution-polymerized rubber is preferably solution-polymerized styrene-butadiene rubber or other solution-polymerized rubbers; the rubber is preferably at least one of natural rubber, cis-butadiene rubber, and butyl rubber; the solvent is a good solvent for rubber, preferably cyclohexane or n-hexane;

[0043] The concentration of the rubber solution is 5–30 wt%; preferably 10–20 wt%.

[0044] The mass ratio of rubber in the rubber solution to filler in the modified filler is 1:(0.3-1.2); preferably 1:(0.4-0.8).

[0045] The other components mixed with the masterbatch include activators, antioxidants, accelerators and vulcanizing agents. After uniform mixing, vulcanization can yield vulcanized rubber.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] This invention uses sulfur pre-vulcanized Span-80 to form polysulfide bonds. During the crosslinking process, the polysulfide bonds break and the residual crosslinking reaction is grafted into the rubber crosslinking network. The hydroxyl and ether bonds that it has can form hydrogen bonds with the hydroxyl groups on the surface of silica, reducing the surface energy of silica. This improves dispersibility and enhances the interfacial interaction between rubber and silica.

[0048] This invention employs a combination of filler dispersants and silane coupling agents to modify silica in an organic solvent. The filler dispersant improves the uniformity and stability of silica dispersion in the organic solvent, reduces its surface energy, and results in better dispersion of the modified silica in the rubber matrix, as well as enhanced interfacial interaction between the rubber and silica. Compared to using silane coupling agents alone, the combined use of both optimizes the overall performance of the rubber compound, resulting in higher mechanical properties and lower rolling resistance.

[0049] This invention utilizes a self-made filler dispersant to modify carbon black in an organic solvent. The modified carbon black exhibits better dispersion in the rubber matrix, enhanced interfacial interaction, and further improved reinforcing effect. The rubber composite material exhibits lower rolling resistance, significantly reduced compression heat generation, and improved wear resistance. Attached Figure Description

[0050] Figure 1Infrared spectra of the filler dispersants and Span-80 prepared in Examples 1-3;

[0051] Figure 2 The vulcanization curves of the compound rubbers prepared in Examples 1-3 and Comparative Example 1 are shown.

[0052] Figure 3 The particle size distribution diagrams are for the modified silica prepared in Example 4 and Comparative Example 2.

[0053] Figure 4 RPA diagrams of the compound prepared in Example 4 and Comparative Example 2;

[0054] Figure 5 RPA diagrams of the vulcanizates prepared in Example 4 and Comparative Example 2;

[0055] Figure 6 RPA diagrams of the rubber compounds prepared in Example 5 and Comparative Example 3;

[0056] Figure 7 RPA diagrams of the vulcanizates prepared in Example 5 and Comparative Example 3;

[0057] Figure 8 RPA diagrams of the rubber compounds prepared in Example 6 and Comparative Example 4;

[0058] Figure 9 RPA diagrams of the vulcanizates prepared in Example 6 and Comparative Example 4;

[0059] Figure 10 RPA diagrams of the rubber compounds prepared in Example 7 and Comparative Example 5;

[0060] Figure 11 RPA diagrams of the vulcanizates prepared in Example 7 and Comparative Example 5;

[0061] Figure 12 RPA diagrams of the rubber compounds prepared in Example 8 and Comparative Example 6;

[0062] Figure 13 The RPA diagrams are for the vulcanized rubbers prepared in Example 8 and Comparative Example 6. Detailed Implementation

[0063] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0064] All raw materials used in the examples are commercially available.

[0065] The main raw material specifications are as follows:

[0066] Solution-polymerized styrene-butadiene rubber SSBR4602 / 6430, produced by Shengxi'ao Polymer Co., Ltd.

[0067] 1165MP silica, Rhodia (Qingdao) Co., Ltd., France;

[0068] Si75, Nanjing Deneng Chemical Co., Ltd.;

[0069] Span-80, Wuxi Yatai United Chemical Co., Ltd.;

[0070] Zinc oxide, Shanghai Maclean Biochemical Technology Co., Ltd.

[0071] Stearic acid, Shanghai Maclean Biochemical Technology Co., Ltd.;

[0072] Anti-aging agent 4020, Shanghai Yuanye Biotechnology Co., Ltd.;

[0073] Accelerator CZ, Tianjin No. 1 Organic Chemical Plant;

[0074] Accelerator DPG, Tianjin No. 1 Organic Chemical Plant;

[0075] Sulfur, Shandong Tianshun Chemical Co., Ltd.

[0076] The relevant performance testing methods and instruments used in the embodiments are shown in Table 1:

[0077] Table 1. Relevant performance testing methods and instruments

[0078]

[0079] *RPA test method: Compound rubber at 60℃, 1Hz, strain 0.28-200%; vulcanized rubber at 60℃, 10Hz, strain range 0.28-42%. All parts mentioned in the following examples and comparative examples are by weight.

[0080] Example 1

[0081] 50g (0.1168mol) of Span-80 was added to a three-necked flask, followed by 3.738g (0.1168mol) of sulfur. The mixture was then heated in an oil bath at 135℃ under nitrogen protection for 4 hours to obtain a black paste. The product was then vacuum-sealed to remove hydrogen sulfide gas, dissolved in cyclohexane, filtered to remove unreacted sulfur, and the solvent was removed by rotary evaporation at 40℃ to obtain the filler dispersant (Span-80 sulfur).

[0082] Four parts of the vulcanized Span-80 prepared above were added to 100 parts of solution-polymerized styrene-butadiene rubber on an open mill and mixed evenly. Then, three parts of zinc oxide, two parts of stearic acid and two parts of antioxidant 4020 were added and mixed evenly. Finally, the mixture was heat-treated at 150°C for 5 minutes to obtain the compound.

[0083] Example 2

[0084] 50g (0.1168mol) of Span-80 was added to a three-necked flask, followed by 9.346g (0.2921mol) of sulfur. The mixture was then heated in an oil bath at 140℃ under nitrogen protection for 3 hours to obtain a black paste. The product was then vacuum-sealed to remove hydrogen sulfide gas, dissolved in cyclohexane, filtered to remove unreacted sulfur, and the solvent was removed by rotary evaporation at 40℃ to obtain the filler dispersant (Span-80 sulfur).

[0085] Four parts of the vulcanized Span-80 prepared above were added to 100 parts of solution-polymerized styrene-butadiene rubber on an open mill and mixed evenly. Then, three parts of zinc oxide, two parts of stearic acid and two parts of antioxidant 4020 were added and mixed evenly. Finally, the mixture was heat-treated at 150°C for 5 minutes to obtain the compound.

[0086] Example 3

[0087] 50g (0.1168mol) of Span-80 was added to a three-necked flask, followed by 3.738g (0.4672mol) of sulfur. The mixture was then heated in an oil bath at 150°C under nitrogen protection for 1 hour to obtain a black paste. The product was then vacuum-sealed to remove hydrogen sulfide gas, dissolved in anhydrous ethanol, filtered to remove unreacted sulfur, and the solvent was removed by rotary evaporation at 40°C to obtain the filler dispersant (Span-80 sulfur).

[0088] Four parts of the vulcanized Span-80 prepared above were added to 100 parts of solution-polymerized styrene-butadiene rubber on an open mill and mixed evenly. Then, three parts of zinc oxide, two parts of stearic acid and two parts of antioxidant 4020 were added and mixed evenly. Finally, the mixture was heat-treated at 150°C for 5 minutes to obtain the compound.

[0089] Comparative Example 1

[0090] Add 4 parts Si75 to 100 parts solution-polymerized styrene-butadiene rubber on a two-roll mill and mix evenly. Then add 3 parts zinc oxide, 2 parts stearic acid and 2 parts antioxidant 4020 and mix evenly. Finally, heat treat at 150°C for 5 minutes to obtain the compound.

[0091] Example 4

[0092] Span-80 vulcanizate prepared using Example 3;

[0093] 800 parts of cyclohexane, 14 parts of Si75, and 80 parts of silica were added sequentially to a colloid mill and ground for 5 minutes. Then, 4 parts of Span-80 vulcanizate were added and ground for another 5 minutes. The mixture was then discharged to obtain the modified filler. The modified filler was mixed with 1000 parts of solution-polymerized styrene-butadiene rubber (containing 100 parts of solution-polymerized styrene-butadiene rubber and 900 parts of cyclohexane) solution and stirred until homogeneous. The solvent was removed using hot water at a temperature above 95°C, and the mixture was dried to obtain the masterbatch.

[0094] The obtained masterbatch was mixed evenly with 3 parts zinc oxide, 2 parts stearic acid, and 2 parts antioxidant 4020, and then heat-treated at 150°C for 5 minutes. After cooling, 1.7 parts accelerator CZ, 1.8 parts accelerator DPG, and 1.7 parts sulfur were added to the material on a two-roll mill. After standing for 12 hours, the mixture was vulcanized at 150°C on a flat vulcanizing plate until it reached the correct vulcanization temperature, thus obtaining vulcanized rubber.

[0095] Comparative Example 2

[0096] The difference from Example 4 is that Span-80 vulcanizate was not added;

[0097] Except for the differences mentioned above, all other conditions in Comparative Example 2 were the same as in Example 4, resulting in vulcanized rubber.

[0098] Example 5

[0099] Span-80 vulcanizate prepared using Example 3;

[0100] On a two-roll mill, 80 parts of silica and 5 parts of Si75 were added to 100 parts of solution-polymerized styrene-butadiene rubber and mixed thoroughly. Then, 15 parts of Span-80 vulcanizing agent were added and mixed thoroughly. Next, 3 parts of zinc oxide, 2 parts of stearic acid, and 2 parts of antioxidant 4020 were added and mixed thoroughly. The mixture was then heat-treated at 150°C for 5 minutes. After cooling, 1.7 parts of accelerator CZ, 1.8 parts of accelerator DPG, and 1.7 parts of sulfur were added to the material on the two-roll mill. After resting for 12 hours, the mixture was vulcanized at 150°C on a flat vulcanizing plate until it reached the correct vulcanization stage, yielding the vulcanized rubber.

[0101] Comparative Example 3

[0102] The difference from Example 5 is that Span-80 vulcanizate was not added;

[0103] Apart from the differences mentioned above, all other conditions in Comparative Example 3 were the same as in Example 5, resulting in a vulcanized rubber.

[0104] Example 6

[0105] Span-80 vulcanizate prepared using Example 3;

[0106] 800 parts of cyclohexane, 4 parts of Span-80 sulfurized compound, and 50 parts of carbon black were added sequentially to a colloid mill. The mixture was ground for 10 minutes and then discharged to obtain the modified filler.

[0107] The modified filler was mixed with 1000 parts of solution-polymerized styrene-butadiene rubber solution (containing 100 parts of solution-polymerized styrene-butadiene rubber and 900 parts of cyclohexane) until homogeneous. The solvent was removed by hot water at 95°C or higher, and the mixture was dried to obtain the masterbatch.

[0108] The obtained masterbatch was mixed evenly with 3 parts zinc oxide, 2 parts stearic acid, and 2 parts antioxidant 4020, and then heat-treated at 150°C for 5 minutes. After cooling, 1.7 parts accelerator CZ, 1.8 parts accelerator DPG, and 1.7 parts sulfur were added to the material on a two-roll mill. After standing for 12 hours, the mixture was vulcanized at 150°C on a flat vulcanizing plate until it reached the correct vulcanization temperature, thus obtaining vulcanized rubber.

[0109] Comparative Example 4

[0110] The difference from Example 6 is that Span-80 vulcanizate was not added;

[0111] Apart from the differences mentioned above, all other conditions in Comparative Example 4 were the same as in Example 6, resulting in vulcanized rubber.

[0112] Example 7

[0113] Span-80 vulcanizate prepared using Example 3;

[0114] On a two-roll mill, 50 parts carbon black and 4 parts Span-80 vulcanizing agent were added to 100 parts solution-polymerized styrene-butadiene rubber and mixed evenly. Then, 3 parts zinc oxide, 2 parts stearic acid, and 2 parts antioxidant 4020 were added and mixed evenly. The mixture was then heat-treated at 150°C for 5 minutes. After cooling, 1.7 parts accelerator CZ, 1.8 parts accelerator DPG, and 1.7 parts sulfur were added to the material on the two-roll mill. After resting for 12 hours, the mixture was vulcanized at 150°C on a flat vulcanizing plate until it reached the correct vulcanization temperature, yielding the vulcanized rubber.

[0115] Comparative Example 5

[0116] The difference from Example 7 is that Span-80 vulcanizate was not added;

[0117] Except for the differences mentioned above, all other conditions in Comparative Example 5 were the same as in Example 7, resulting in a vulcanized rubber.

[0118] Example 8

[0119] Span-80 vulcanizate prepared using Example 3;

[0120] 800 parts of cyclohexane, 4 parts of Si75, and 40 parts of silica were added sequentially to a colloid mill and ground for 5 minutes. Then, 4 parts of Span-80 sulfurized (prepared in Example 3) were added and ground for 5 minutes. Finally, 20 parts of carbon black were added and ground for 10 minutes before the material was discharged to obtain the modified filler.

[0121] The modified filler was mixed with 1000 parts of solution-polymerized styrene-butadiene rubber solution (containing 100 parts of solution-polymerized styrene-butadiene rubber and 900 parts of cyclohexane) until homogeneous. The solvent was removed by hot water at 95°C or higher, and the mixture was dried to obtain the masterbatch.

[0122] The obtained masterbatch was mixed evenly with 3 parts zinc oxide, 2 parts stearic acid, and 2 parts antioxidant 4020, and then heat-treated at 150°C for 5 minutes. After cooling, 1.7 parts accelerator CZ, 1.8 parts accelerator DPG, and 1.7 parts sulfur were added to the material on a two-roll mill. After standing for 12 hours, the mixture was vulcanized at 150°C on a flat vulcanizing plate until it reached the correct vulcanization temperature, thus obtaining vulcanized rubber.

[0123] Comparative Example 6

[0124] The difference from Example 8 is that Span-80 vulcanizate was not added;

[0125] Apart from the differences mentioned above, all other conditions in Comparative Example 6 were the same as in Example 8, resulting in a vulcanized rubber.

[0126] Figure 1 The images show the infrared spectra of the filler dispersant (Span-80 vulcanizate) and Span-80 prepared in Examples 1-3. The spectra show that at 3003 cm⁻¹... -1 The peak at 1658 cm⁻¹ is the absorption peak of the stretching vibration of CH on unsaturated carbon. -1 The peak at that point is the stretching vibration peak of the C=C double bond. As can be seen from the figure, these two peaks disappeared after sulfidation, indicating that sulfur successfully opened the double bonds in the Span-80 long molecular chain, and the double bonds disappeared, indicating that sulfur was successfully grafted into the molecular chain.

[0127] Table 2. Elemental content of Span-80 vulcanizate in Examples 1-3

[0128] Example 1 17.42 67.66 8.72 5.51 Example 2 16.32 63.36 8.17 10.78 Example 3 16.35 63.49 8.18 10.27

[0129] Elemental analysis was performed on Span-80 sulfurized to determine the amount of sulfur incorporated. After the reaction, the product was vacuum-treated to remove volatile H2S, then dissolved in cyclohexane and filtered to remove unreacted elemental sulfur. Table 2 shows that the mass percentages of sulfur in Examples 1-3 were 5.51%, 10.78%, and 10.27%, respectively, indicating successful grafting of sulfur into the molecular chain. Furthermore, mass calculations revealed that in Examples 2 and 3, an average of 3 or 4 sulfur atoms were linked between two Span-80 molecules, further demonstrating the presence of polysulfide bonds in the pre-sulfurized Span-80.

[0130] Table 3. Molecular weights of Span-80 vulcanized and Span-80 in Examples 1-3

[0131] S80 1543 1559 1577 1.010 3.59 Example 1 1998 2380 3161 1.191 4.91 Example 2 2609 3107 3673 1.191 6.08 Example 3 2464 3008 3591 1.051 5.99

[0132] Table 3 shows that the Xn of Span-80 before vulcanization was 3.59, while after vulcanization, Span-80 contained more high-polymer content, and the Xn increased significantly. This indicates that elemental sulfur can successfully open double bonds and crosslink the Span-80 monomer.

[0133] Figure 2 The vulcanization curves of the rubber compounds in Examples 1-3 and Comparative Example 1 show that all samples underwent vulcanization without the addition of a vulcanization system, resulting in an increase in torque. However, the rubber compound in Comparative Example 1 with added Si75 exhibited a faster vulcanization rate, while the rubber compound with added vulcanized Span-80 showed a slower vulcanization rate and a longer vulcanization time, ultimately resulting in a higher torque (MH). This indicates that polysulfide bonds are formed between the vulcanized Span-80 compounds, which can break and participate in rubber vulcanization.

[0134] Figure 3 The particle size distribution diagrams for the modified silica prepared in Example 4 and Comparative Example 2 are shown. Since silica 1165MP is granulated silica, the particle size after granulation is over several hundred micrometers, therefore the particle size of pure silica was not characterized. The particle size distribution diagrams show that the modified silica particle size distribution contains two distinct bulk density peaks. One peak's center is generally located at 10 μm, representing the grinding particle size of the colloid mill particles. The other peak corresponds to a larger particle size, ranging from several hundred to several thousand micrometers, representing the particle size of the aggregates formed after the silica particles are ground and re-agglomerated. The distribution and size of these aggregates are related to the degree of silica modification. It can be seen that compared to the modified silica in Example 4, the modified silica in Comparative Example 2 has more aggregate particles and a larger particle size. The modified silica in Example 4 exhibits the weakest agglomeration phenomenon, with the lowest proportion of agglomerates and relatively smaller agglomerated particle sizes.

[0135] Figure 4 The RPA diagrams for the rubber compounds prepared in Example 4 and Comparative Example 2 show the changes in storage modulus with strain. Figure 5 The RPA diagrams for the vulcanizates prepared in Example 4 and Comparative Example 2 show the change of the loss tangent with strain. The decrease in the dynamic modulus of the compound is called the Payne effect, which is caused by the disruption of the filler network structure in the rubber compound. The Payne effect is generally measured by ΔG′. The better the filler dispersion and the weaker the filler network, the smaller the Payne effect. Figure 4 As can be seen, the Payne effect of the compound in Example 4 is significantly lower than that in Comparative Example 2, and the filler in the compound prepared in Example 4 is more uniformly dispersed; from Figure 5 It can be seen that the 6.8% loss factor of the vulcanizate in Example 4 is significantly lower than that of the 26.8% loss factor in the comparative example. This value reflects the magnitude of the rolling resistance of the material.

[0136] Table 4. Properties of the vulcanizates from Example 4 and Comparative Example 2

[0137]

[0138] As shown in Table 4, the vulcanizate of Example 4 exhibits better mechanical properties, with tensile strength, 300% elongation stress, and tear strength all slightly higher than those of Comparative Example 2 vulcanizate. Furthermore, the ratio of 300% to 100% elongation stress is known as the reinforcing factor, which characterizes the reinforcing effect of the filler on the rubber. Data shows that the filler reinforcing factor of Example 4 vulcanizate is significantly higher than that of Comparative Example 2, and the composite material also has the highest tear strength, reflecting a stronger interfacial bond between the filler and the rubber. The compression heat generation temperature of Example 4 vulcanizate is lower than that of Comparative Example 2 vulcanizate, due to the better dispersion of silica and lower frictional heat generation of the filler in Example 4. Example 4 vulcanizate also demonstrates advantages in abrasion resistance. Combined with RPA analysis, the addition of Span 80 vulcanizate further enhances the modification effect of the modified silica, strengthening the interfacial interaction between the rubber and silica and resulting in more uniform silica dispersion and a better reinforcing effect.

[0139] Figure 6 The RPA diagrams are for the rubber compounds prepared in Example 5 and Comparative Example 3. Figure 7 The RPA diagrams are for the vulcanizates prepared in Example 5 and Comparative Example 3. Figure 6 As can be seen, the Payne effect of the compound in Example 5 is significantly lower than that of the control rubber in Comparative Example 3; Figure 7 As can be seen, for the vulcanized rubber loss factor corresponding to 6.8% strain, the vulcanized rubber of Example 5 is significantly lower than that of the vulcanized rubber of Example 3. Vulcanized Span-80 further enhances the interfacial bonding between the rubber matrix and the silica by participating in rubber crosslinking and forming hydrogen bonds with silica, thus reducing the loss factor of the composite material and decreasing the rolling resistance.

[0140] Table 5. Properties of the vulcanizates from Example 5 and Comparative Example 3

[0141]

[0142] As shown in Table 5, the mechanical properties of the vulcanizate in Example 5 are significantly higher than those in Comparative Example 3. The 300% elongation and tear stress are significantly improved, while the reinforcing factor and tensile strength are comparable. Vulcanizate Span-80 is beneficial for enhancing the interfacial bonding between silica and rubber. Furthermore, the table shows that the compression heat of the vulcanizate in Example 5 is significantly lower than that in Comparative Example 3, which is also a result of the dual effect of vulcanizate Span-80. The abrasion volume of the vulcanizate in Example 5 is significantly lower than that in Comparative Example 3, and the abrasion resistance of the material is greatly improved. Vulcanizate Span-80 can improve the dispersion of silica and enhance the interfacial interaction between fillers and rubber, significantly improving the abrasion resistance of the composite material and enhancing the reinforcing effect.

[0143] Figure 8 The RPA diagrams are for the rubber compounds prepared in Example 6 and Comparative Example 4. Figure 9 The RPA diagrams are for the vulcanizates prepared in Example 6 and Comparative Example 4. Figure 8As can be seen, the Payne effect of the compound in Example 6 is lower than that of the control rubber in Comparative Example 4. This indicates that Span-80 vulcanizate can improve the dispersibility of carbon black in the rubber matrix and reduce the filler network structure. With increasing Span-80 vulcanizate dosage, the Payne effect of the compound decreases accordingly. Figure 9 As can be seen, the loss factor corresponding to 6.8% strain of the vulcanized Span-80 vulcanizate in Example 6 is lower than that of the control sample in Comparative Example 4.

[0144] Table 6 shows the properties of the vulcanizates from Example 6 and Comparative Example 4.

[0145]

[0146] As shown in Table 6, the mechanical properties of the vulcanizate in Example 6, including tensile strength, 300% tensile stress, and tensile strength, are significantly improved compared to the control rubber in Comparative Example 4. The tear strength is also higher than that of the control rubber in Comparative Example 4. Vulcanizing Span-80 can improve carbon black dispersion, significantly reduce the compression heat of the vulcanizate in Example 6, and greatly improve its abrasion resistance.

[0147] Figure 10 The RPA diagrams are for the rubber compounds prepared in Example 7 and Comparative Example 5. Figure 11 The figures show the RPA (Reduction of Power) of the vulcanizates prepared in Example 7 and Comparative Example 5. As can be seen from the figures, the Payne effect of the compound in Example 7 is significantly lower than that in Comparative Example 5. Furthermore, the Span-80 vulcanizate in Example 7 significantly reduces the dynamic loss of the vulcanizate. Due to the more uniform dispersion of carbon black and fewer aggregates, the loss factor of the vulcanizate is significantly reduced.

[0148] Table 7. Properties of the vulcanizates from Example 7 and Comparative Example 5

[0149]

[0150] As shown in Table 7, the mechanical properties of the vulcanizate of Example 7 with an appropriate amount of Span-80 vulcanization are higher than those of the comparative sample of Example 5. The 300% tensile stress and reinforcing factor of the vulcanizate of Example 7 are also higher, while the tear strength is similar. In addition, the addition of Span-80 vulcanization is beneficial to the dispersion of carbon black, and the compression heat of the vulcanizate of Example 7 is significantly reduced, as is the Akron abrasion volume.

[0151] Figure 12 The RPA diagrams are for the rubber compounds prepared in Example 8 and Comparative Example 6. Figure 13 RPA diagrams of the vulcanized rubbers prepared in Example 8 and Comparative Example 6. (Source: [Insert Source Here]) Figure 12 It is evident that the adhesive prepared in Example 8 exhibits a reduced Payne effect, weaker interactions between fillers, and better filler dispersion; Figure 13It is evident that the vulcanizate of Example 8 exhibits low dynamic losses under various strains. The loss factor of the vulcanizate at 6.8% strain is positively correlated with its rolling resistance; the smaller this value, the lower the rolling resistance as a tread material, resulting in greater energy savings. The loss factor of the vulcanizate of Example 8 is lower than that of the vulcanizate of Comparative Example 6, indicating that the filler in the vulcanizate of Example 8 is not only better dispersed but also has enhanced bonding with the rubber.

[0152] Table 8 shows the properties of the vulcanizates from Example 8 and Comparative Example 6.

[0153]

[0154] As shown in Table 8, the vulcanizate of Example 8 exhibits superior mechanical properties compared to the vulcanizate of Comparative Example 6, with a higher modulus, higher 300% tensile stress, and greater tensile and tear strength. This indicates that Span-80 vulcanizate provides better surface modification of the filler, establishes the most chemical bonds with the rubber, has the strongest interfacial bonding, and provides the best reinforcing performance. The Payne effect shows that the filler modified by Span-80 vulcanizate in Example 8 is most uniformly dispersed in the rubber matrix, with minimal stress concentration effect. Therefore, the rubber composite material exhibits superior mechanical properties macroscopically. Furthermore, Table 8 shows that the compression heat generation temperature of the vulcanizate of Example 8 is lower than that of the vulcanizate of Comparative Example 6. The Span-80 vulcanizate-modified filler has good dispersibility, resulting in less frictional heat generation between fillers. The vulcanizate of Example 8 has a smaller wear volume and improved abrasion resistance. The addition of Span-80 vulcanizate leads to better filler modification, increases the number of coupling bridging points between the filler and rubber, and improves the abrasion resistance of the vulcanizate.

Claims

1. A modified filler for use in rubber, the modified filler comprising a filler and a filler dispersant; the method for preparing the filler dispersant comprises: The dehydrated sorbitan oleate and sulfur were mixed evenly, heated and reacted under a protective gas atmosphere, and then the unreacted sulfur was removed to obtain the filler dispersant. The filler is at least one of silica and carbon black.

2. The modified filler as described in claim 1, characterized in that: The molar ratio of dehydrated sorbitan oleate to sulfur is 1:(0.5~5.5).

3. The modified filler as described in claim 2, characterized in that: The molar ratio of dehydrated sorbitan oleate to sulfur is 1:(1~4).

4. The modified filler as described in claim 1, characterized in that: The protective gas is at least one of nitrogen and argon; and / or, Unreacted sulfur is removed by first vacuuming to remove hydrogen sulfide gas, then dissolving it in a solvent and filtering; the solvent is at least one of cyclohexane and ethanol; and / or... The reaction temperature is 125~155℃; and / or, The reaction time is 0.5 to 5 hours.

5. The modified filler as described in claim 4, characterized in that: The reaction temperature is 130~150℃; and / or, The reaction time is 1 to 4 hours.

6. The modified filler as described in claim 1, characterized in that: The modified filler also includes organic solvents and silane coupling agents.

7. The modified filler as described in claim 6, characterized in that: The silane coupling agent is at least one selected from bis-[γ-(triethoxysilyl)propyl]tetrasulfide, bis-[γ-(triethoxysilyl)propyl]disulfide, 3-thiocyanopropyltriethoxysilane, γ-mercaptopropyltriethoxysilane, γ-aminopropyltriethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane; and / or, The organic solvent is at least one of aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, and ether solvents.

8. The modified filler as described in claim 7, characterized in that: The aliphatic hydrocarbon solvent is at least one of solvent oil, cycloalkanes, substituted cycloalkanes, straight-chain or branched alkanes; the aromatic hydrocarbon solvent is at least one of benzene, toluene, and xylene; and the ether solvent is tetrahydrofuran.

9. The modified filler as described in claim 6, characterized in that: The mass ratio of filler to organic solvent is 1:(3~100); and / or, The amount of silane coupling agent used is 3-20% of the filler mass; and / or, The amount of dispersant used for fillers is 0.5% to 20% of the filler mass.

10. The modified filler according to claim 9, characterized in that: The mass ratio of filler to organic solvent is 1:(6~20); and / or, The amount of silane coupling agent used is 6-18% of the filler mass; and / or, The amount of dispersant used for the filler is 0.8~15% of the filler mass.

11. The modified filler according to claim 10, characterized in that: The mass ratio of filler to organic solvent is 1:(10~20); and / or, The amount of dispersant used for the filler is 5-10% of the filler mass.

12. A method for preparing a modified filler as described in any one of claims 1 to 11, the method comprising: The modified filler is obtained by mixing the raw materials evenly according to the dosage ratio.

13. The application of a modified filler as described in any one of claims 1 to 11 or a modified filler obtained by the preparation method described in claim 12 in rubber.

14. The application as described in claim 13, characterized in that: The modified filler is directly added to the rubber and mixed evenly, or it is first made into a masterbatch and then added to other components and mixed evenly. The masterbatch is prepared by uniformly mixing a rubber solution and the modified filler and then removing the solvent; the rubber solution is a solution polymerized rubber solution or a solution prepared by dissolving rubber in a solvent.

15. The application as described in claim 14, characterized in that: The solution polymerized rubber is solution polymerized styrene-butadiene rubber; and / or... The rubber is at least one of natural rubber, butadiene rubber, and butyl rubber; and / or... The solvent is cyclohexane or n-hexane; and / or, The concentration of the rubber solution is 5~30wt%; and / or, The mass ratio of rubber in the rubber solution to filler in the modified filler is 1:(0.3~1.2).

16. The application as described in claim 15, characterized in that: The concentration of the rubber solution is 10~20wt%; and / or, The mass ratio of rubber in the rubber solution to filler in the modified filler is 1:(0.4~0.8).

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