Deep eutectic solvent modified ceria reinforced neoprene rubber composite and preparation method thereof
By modifying the surface of nano-cerium oxide with a glycerol-based deep eutectic solvent, the problem of dispersing nano-cerium oxide in chloroprene rubber matrix was solved, and the high strength and aging resistance of the composite material were improved. Moreover, the process is simple and environmentally friendly.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- QINGDAO UNIV OF SCI & TECH
- Filing Date
- 2026-05-12
- Publication Date
- 2026-06-12
AI Technical Summary
In existing technologies, nano-cerium oxide has poor compatibility with the chloroprene rubber matrix and is prone to agglomeration. Traditional modification methods are cumbersome and environmentally polluting, failing to fully explore its synergistic potential with chloroprene rubber.
The surface of nano-cerium oxide was modified with glycerol-based deep eutectic solvent (DES) to form a stable coating layer through hydrogen bonding, thereby improving its dispersibility in chloroprene rubber and preparing a deep eutectic solvent modified cerium oxide reinforced chloroprene rubber composite material.
It significantly improves the tensile strength and aging resistance of composite materials, shortens the vulcanization time, reduces production costs, and achieves a green and environmentally friendly modification effect.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of rubber composite materials technology, specifically to a deep eutectic solvent-modified cerium oxide reinforced chloroprene rubber composite material and its preparation method. The cerium oxide is modified using environmentally friendly DES, and the two can produce a significant synergistic effect in the chloroprene rubber system. Background Technology
[0002] Nano-cerium oxide is a rare earth oxide with redox capabilities, capable of capturing free radicals and absorbing HCl gas generated during rubber aging, showing significant potential in inhibiting the thermo-oxidative aging of chloroprene rubber. However, the extremely high surface energy of nano-cerium oxide makes it poorly compatible with the chloroprene rubber matrix, and it is prone to agglomeration. Existing surface modification techniques mostly rely on traditional silane coupling agents or complex chemical grafting treatments. For example, Chinese Patent 202411469443.5 discloses a method for preparing modified cerium oxide nano-abrasives, which includes the following steps: pretreating cerium carbonate to obtain cerium oxide nanoparticles; mixing the cerium oxide nanoparticles with a toluene solution containing a silane coupling agent, heating and stirring in an oil bath, centrifuging, washing with ethanol, and drying to obtain a cerium oxide intermediate; preparing a short-chain organic acid into an aqueous solution, mixing the cerium oxide intermediate with the short-chain organic acid aqueous solution, heating and stirring in an oil bath, centrifuging, washing with ethanol, and drying to obtain the cerium oxide intermediate; the mass ratio of cerium oxide nanoparticles to silane coupling agent is (30:1) - (5:1); the mass ratio of cerium oxide intermediate to short-chain organic acid is (30:1) - (5:1). The method for preparing modified cerium oxide nanomaterials disclosed in Chinese Patent 202411183356.3 includes the following steps: dissolving nano-cerium oxide in anhydrous ethanol and sonicating it to uniformly disperse it in the anhydrous ethanol; after sonication, soaking the nano-cerium oxide in sodium periodate solution; then adding ethylene glycol to terminate the reaction; treating the nano-cerium oxide with nitric acid; adjusting the solution to neutral after treatment; collecting the precipitate by centrifugation; adding the precipitate to ultrapure water for dialysis to obtain modified cerium oxide nanomaterials.The modified cerium oxide support preparation method disclosed in Chinese Patent 202310586110.X is as follows: (a) CeO2 nanoparticles (CeO2-P): Cerium salt and strong base are dispersed in water, stirred at room temperature for 10-60 min, then transferred to a hydrothermal reactor, and hydrothermally reacted at 110-140℃ for 10-24 h. The solid product is collected by centrifugation, washed with distilled water and dried. The dried sample is calcined at 200-600℃ for 0.5-3 h. The calcined sample is dispersed in water, a reducing agent is added, stirred at room temperature for 1-5 h, and the solid sample is collected and dried to obtain the product; (b) CeO2 nanorods (CeO2-R): Cerium salt and strong base are dispersed in water, stirred at room temperature for 10-60 min, then transferred to a hydrothermal reactor, and hydrothermally reacted at 80-110℃ for 10-24 h. (c) CeO2 nanoblocks (CeO2-C): Cerium salt and strong base are dispersed in water and stirred at room temperature for 10-60 min. The mixture is then transferred to a hydrothermal reactor and hydrothermally reacted at 150-200℃ for 10-24 h. The solid product is collected by centrifugation, washed with distilled water, and dried. The dried sample is then calcined at 200-600℃ for 0.5-3 h. The calcined sample is dispersed in water, a reducing agent is added, and the mixture is stirred at room temperature for 1-5 h. The solid sample is then collected and dried.Chinese Patent 202110475128.3 discloses a method for modifying a cerium oxide support, in which the unmodified cerium oxide support is modified in the presence of an inert gas and water vapor. 1) The inert gas is selected from at least one of argon and nitrogen; 2) The ratio of inert gas to cerium oxide support is 50-100 sccm: 500-1000 mg; 3) The volume ratio of water vapor to inert gas is 5-15:100; 4) The modification temperature is 600-800℃. Chinese Patent 202110259827.4 discloses a modified cerium oxide prepared by the following steps: Step A1, adding lanthanum cerium carbonate and deionized water in a mass ratio of 1:1 to a beaker, and then... (The text abruptly ends here, likely due to an incomplete translation or source material.) After ultrasonic dispersion for 20 min, concentrated hydrochloric acid was added dropwise to the flask to adjust the pH of the system to 3.5. After the addition was complete, the mixture was magnetically stirred for 15-20 min and then filtered. The filter cake was washed with deionized water until the washing liquid was neutral. Then, the filter cake was placed in a saturated sodium bicarbonate solution and aged in a constant temperature water bath at 50℃ for 2 h. After washing and filtering three times with deionized water, the mixture was finally spray-dried at an outlet temperature of 220℃ to obtain purified lanthanum cerium carbonate. Step A2: The purified lanthanum cerium carbonate and deionized water were added to a three-necked flask at a mass ratio of 1:1. The three-necked flask was then placed in a constant temperature water bath at 55℃. Hydrofluoric acid was then added to the three-necked flask, and the mixture was stirred at 100-200 r / min for 2 h. The resulting slurry was transferred to a planetary ball mill at a milling rate of 300 r / min and a ball-to-material ratio of 10:1 for 3.5 h. After milling, the mixture was aged for 4 h, washed with water, and filtered. The filter cake was dried in an 80°C constant temperature drying oven for 4 h, and then calcined in a box-type resistance furnace at 950°C for 5 h to obtain rare earth powder. In step A3, aminopropyltriethoxysilane and anhydrous ethanol were mixed evenly at a mass ratio of 2.5:100 and poured into a reaction vessel. Then, the rare earth powder was added to the reaction vessel. The mixture was stirred at 200-300 r / min at room temperature for 24 h. After the reaction, the mixture was filtered, and the filter cake was washed with distilled water 3-5 times. Finally, it was dried in a vacuum oven at 75-85°C to constant weight. An intermediate was obtained; in step A4, the intermediate was added to liquid paraffin at 80℃ and stirred for 10 minutes at a speed of 60-100 r / min. The mixture was then transferred to distilled water for dispersion, and stirred for 45 minutes at a speed of 3000 r / min. After cooling to room temperature, solidified microspheres were obtained. The solidified microspheres were transferred to a 1% (w / w) perfluorooctanoic acid (PFOA) solution and stirred for 36 hours at a speed of 100-200 r / min. The mixture was then filtered, and the precipitate was washed 3-5 times with deionized water. Finally, the precipitate was dissolved in chloroform, filtered again, and the filter cake was washed 3-5 times with a 40% (w / w) ethanol solution. Finally, the mixture was dried to constant weight in an oven at 80℃ to obtain modified cerium oxide. These modification methods are cumbersome, costly, and prone to generating or requiring the use of volatile organic compounds (VOCs), which do not conform to the current trend of green and environmentally friendly development.Meanwhile, the effectiveness of traditional coupling agents in further exploring the synergistic effect between nano-metal oxides and chloroprene rubber matrices has reached a bottleneck. Therefore, there is an urgent need to develop a novel, environmentally friendly modification method for cerium oxide with a unique modification mechanism. Summary of the Invention
[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and to develop and design a deep eutectic solvent-modified cerium oxide-reinforced chloroprene rubber composite material, providing a new green technology path for improving the comprehensive mechanical properties and aging resistance of chloroprene rubber products.
[0004] To achieve the above objectives, the deep eutectic solvent-modified cerium oxide reinforced chloroprene rubber composite material of the present invention includes chloroprene rubber, modified cerium oxide, carbon black, and additives and vulcanization system. By weight, 2-6 parts of modified cerium oxide (preferably 4 parts by weight), 40 parts of carbon black and 14.5 parts of additives and vulcanization system are added to every 100 parts of chloroprene rubber.
[0005] The modified cerium oxide is nano-cerium oxide that has been surface-modified with glycerol-based deep eutectic solvent (DES). The amount of glycerol-based DES used is 5%-15% of the mass of cerium oxide, preferably 10%.
[0006] The preferred amount of modified cerium oxide added to the composite material is 4 parts by weight;
[0007] The experimental results show that adding 4 parts by mass of cerium oxide modified with 10% glycerol-based DES can produce a significant synergistic effect between the interface modification and plasticizing effect of glycerol-based DES and the reinforcing and anti-aging function of cerium oxide, which increases the tensile strength of the composite material by 11.3%, achieves an aging coefficient of 0.79, effectively shortens the vulcanization time, and significantly reduces the number of aggregates.
[0008] The carbon black is carbon black N326;
[0009] The additives and vulcanization system, by weight, include the following components: 4 parts magnesium oxide, 5 parts zinc oxide, 0.5 parts accelerator NA-22 and 0.5 parts accelerator TMTD, 2 parts antioxidant 4010NA, 1 part stearic acid and 1.5 parts polyethylene wax AC-617.
[0010] The specific process of the preparation method of the deep eutectic solvent modified cerium oxide reinforced chloroprene rubber composite material involved in this invention includes modification, mixing, and vulcanization, as follows:
[0011] (1) Nano-cerium oxide is mixed with a glycerol-based deep eutectic solvent and surface modified to obtain modified cerium oxide;
[0012] (2) After plasticizing the chloroprene rubber in a mixer or open mill, add modified cerium oxide, carbon black, additives and vulcanization system in sequence, mix evenly, and vulcanize at 160°C to obtain the composite material.
[0013] The deep eutectic solvent-modified cerium oxide involved in this invention utilizes glycerol-based DES adsorbed onto the surface of nano-cerium oxide via hydrogen bonding to form a stable coating layer. This differs from traditional coupling agents that rely on covalent bonding and easily generate harmful byproducts through chemical modification. It employs a green and environmentally friendly hydrogen bonding physical / semi-chemical mechanism, fundamentally preventing particle aggregation and avoiding the environmental pollution risks associated with traditional modification methods. Specifically:
[0014] Glyceryl-based DES, a low-toxicity, non-volatile green solvent, is adsorbed onto the surface of nano-cerium oxide through strong intermolecular hydrogen bonding, effectively shielding the high surface energy of cerium oxide. FTIR analysis shows that the modified cerium oxide exhibits a significant CO bond absorption peak in the 900-1100 cm⁻¹ region, and the intensity of the -OH absorption peak near 3430 cm⁻¹ increases, confirming the successful grafting of DES molecules.
[0015] The cerium oxide in the deep eutectic solvent modified cerium oxide reinforced chloroprene rubber composite material and its preparation method involved in this invention is not limited to cerium oxide and can be replaced by other rare earth oxides.
[0016] Compared with existing technologies, this invention addresses the environmental pollution and performance improvement bottlenecks of traditional coupling agent modification by introducing environmentally friendly glycerol-based DES onto the surface of cerium oxide. The introduction of glycerol-based DES and the inherent properties of cerium oxide produce a significant synergistic effect in the chloroprene rubber system. Based on a unique hydrogen bonding mechanism, it replaces traditional covalent bond modification, effectively shielding and reducing particle polarity, solving the dispersion problem of cerium oxide in the rubber matrix, significantly improving the dispersibility of cerium oxide in the rubber matrix, eliminating the need for traditional coupling agents, and achieving green preparation. The use of environmentally friendly DES to modify cerium oxide is simple, environmentally friendly, and significantly improves the comprehensive mechanical properties and aging resistance of chloroprene rubber products. Attached Figure Description
[0017] Figure 1 This is a comparison of the FTIR spectra of cerium oxide before and after DES modification, as per the present invention.
[0018] Figure 2 The images shown are SEM images of the micro-sections of the composite material prepared in Example 2 of this invention, where (a) is the 0CeO2 group, (b) is the 4CeO2 group, and (c) is the 4CeO2-DES group.
[0019] Figure 3This is a graph showing the trend of tensile strength and hardness of the composite material prepared in Example 2 of the present invention. Detailed Implementation
[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0021] Example 1:
[0022] The process of preparing the eutectic solvent-modified cerium oxide reinforced chloroprene rubber composite material involved in this embodiment is as follows:
[0023] modified
[0024] Add 10% by weight of glycerol-based DES to nano-cerium oxide, stir thoroughly to mix and perform surface modification to obtain modified cerium oxide;
[0025] Mixing and vulcanization
[0026] 100 parts by weight of chloroprene rubber, 4 parts by weight of modified cerium oxide, 40 parts by weight of carbon black N326 and 14.5 parts by weight of additives and vulcanization system are mixed and placed on a two-roll mill for uniform mixing. The mixture is then vulcanized at 160°C for the positive vulcanization time to obtain the composite material.
[0027] The composite material was tested and found to have a tensile strength of 24.68 MPa and a tensile product coefficient of 8548.41.
[0028] After a 100℃×72h thermo-oxidative aging test, the aging coefficient of the composite material was 0.79, demonstrating excellent high-temperature resistance.
[0029] Example 2:
[0030] The vulcanization characteristics test of the deep eutectic solvent modified cerium oxide reinforced chloroprene rubber composite material involved in this embodiment was conducted. To provide a visual demonstration, four control composite materials were prepared. Based on the same mass parts of chloroprene rubber, carbon black N326, additives, and vulcanization system as in Example 1, the composite materials were prepared with no cerium oxide (CeO2), 2 parts by mass, 4 parts by mass, and 6 parts by mass of CeO2 added, respectively, using the same process. These were designated as the 0CeO2 group, 2CeO2 group, 4CeO2 group, and 6CeO2 group, respectively. The composite material prepared in Example 1 was designated as the 4CeO2-DES group.
[0031] The results of its vulcanization characteristics test are shown in the table below:
[0032]
[0033] It is evident that the composite material of Example 1 exhibits improvements in physical properties, aging resistance, and processability. Specifically:
[0034] physical properties
[0035] The 4CeO2-DES group exhibited the best reinforcing effect, with tensile strength increasing from 22.17 MPa to 24.68 MPa (an increase of 11.3%) and stress at 100% elongation increasing by 21.4%. This is due to the excellent dispersibility brought about by hydrogen bonding, which allows the DES molecular structure to form a good interfacial interlock with the neoprene molecular chain, and together with the rigid cerium oxide particles, it achieves synergistic reinforcement of the matrix mechanical properties.
[0036] Aging resistance
[0037] The aging coefficient of the 4CeO2-DES group was increased to 0.79, which is 17.9% higher than that of the unmodified system. The hardness change rate after aging was only 3.5%. This is because the green coating layer of DES promotes the uniform nano-dispersion of cerium oxide in the chloroprene rubber matrix, which greatly increases its contact area with the matrix and achieves the synergistic effect of physical dispersion and chemical anti-oxidation.
[0038] Processing performance
[0039] The positive sulfidation time t of the 4CeO2-DES group 90 The production time was shortened by approximately 17.6% because, in addition to being a unique surface modifier, glycerol-based DES also plays an excellent role in environmentally friendly plasticizing, reducing the viscosity of the rubber compound (ML reduction) and significantly improving production efficiency.
Claims
1. A eutectic solvent-modified cerium oxide reinforced chloroprene rubber composite material, characterized in that, It includes chloroprene rubber, modified cerium oxide, carbon black, and additives and vulcanization systems.
2. The eutectic solvent-modified cerium oxide reinforced chloroprene rubber composite material according to claim 1, characterized in that, By weight, 2-6 parts modified cerium oxide, 40 parts carbon black, and 14.5 parts additives and vulcanization system are added to every 100 parts of chloroprene rubber.
3. The eutectic solvent-modified cerium oxide reinforced chloroprene rubber composite material according to claim 2, characterized in that, The amount of modified cerium oxide is 4 parts by mass.
4. A deep eutectic solvent-modified cerium oxide-reinforced chloroprene rubber composite material according to any one of claims 1-3, characterized in that, The modified cerium oxide is nano-cerium oxide that has been surface-modified with a glycerol-based deep eutectic solvent, and the amount of glycerol-based DES used is 5%-15% of the mass of cerium oxide; The carbon black is carbon black N326; The additives and vulcanization system, by weight, include: 4 parts magnesium oxide, 5 parts zinc oxide, 0.5 parts accelerator NA-22 and 0.5 parts accelerator TMTD, 2 parts antioxidant 4010NA, 1 part stearic acid and 1.5 parts polyethylene wax AC-617.
5. The eutectic solvent-modified cerium oxide reinforced chloroprene rubber composite material according to claim 4, characterized in that, The amount of glycerol-based DES used is 10% of the mass of cerium oxide.
6. The eutectic solvent-modified cerium oxide reinforced chloroprene rubber composite material according to claim 4, characterized in that, Cerium oxide was replaced with other rare earth oxides.
7. A method for preparing a eutectic solvent-modified cerium oxide-reinforced chloroprene rubber composite material, characterized in that, The process includes the following steps: (1) Nano-cerium oxide is mixed with a glycerol-based deep eutectic solvent and surface modified to obtain modified cerium oxide; (2) After plasticizing the chloroprene rubber, modified cerium oxide, carbon black, additives and vulcanization system are added in sequence, mixed and vulcanized to obtain the composite material.
8. The eutectic solvent-modified cerium oxide reinforced chloroprene rubber composite material according to claim 7, characterized in that, Deep eutectic solvent-modified cerium oxide uses glycerol-based DES to adsorb onto the surface of nano-cerium oxide through hydrogen bonding, forming a coating layer. Based on the physical / semi-chemical mechanism of hydrogen bonding, it blocks the aggregation between particles and shields the surface energy of cerium oxide.
9. A deep eutectic solvent-modified cerium oxide reinforced chloroprene rubber composite material according to claim 7 or 8, characterized in that, Cerium oxide was replaced with other rare earth oxides.