Synergistic modified ethylene propylene diene monomer glove material with high chemical medium permeation resistance and preparation method thereof
By introducing dynamic covalent bonds, coordination structures, and organic-inorganic hybrid structures into the EPDM rubber matrix, a multi-layered synergistic network is formed, which solves the problems of insufficient penetration barrier performance and poor adhesive bonding of EPDM rubber gloves, and achieves higher resistance to chemical media penetration and structural stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING REAGENT LATEX PRODS
- Filing Date
- 2026-04-10
- Publication Date
- 2026-05-12
AI Technical Summary
Existing EPDM rubber gloves have insufficient penetration barrier properties when exposed to organic solvents and complex corrosive environments. Furthermore, problems such as loose bonding and bubbling during the impregnation molding process affect airtightness and long-term stability.
Dynamic covalent bonds, coordination structures, and organic-inorganic hybrid structures are introduced into the EPDM rubber matrix to form a multi-layered synergistic network. Through impregnation molding process, a multi-layered dense structure is formed, which improves the gas-liquid barrier performance and structural stability of the material.
It significantly improves the barrier properties against acids, alkalis and organic solvents, enhances the interfacial bonding strength and structural stability of the material, and improves the safety and durability of the gloves.
Smart Images
Figure CN122011606A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of rubber protective products and polymer materials technology, specifically to a synergistically modified EPDM rubber glove material with high resistance to chemical penetration and its preparation method. Background Technology
[0002] Dry box gloves, also known as operating box gloves, are typically installed in sealed, isolated boxes for operation in ultrapure environments such as those free of water, oxygen, and dust. They are widely used in fields such as pharmaceuticals, biotechnology, biosafety, electronic semiconductors, nuclear power, and precision manufacturing. Depending on the operating environment and performance requirements, existing dry box glove materials mainly include natural latex, nitrile rubber, EPDM rubber, chlorosulfonated polyethylene, and butyl rubber. Among these, EPDM rubber, due to its saturated hydrocarbon main chain and only a small number of unsaturated double bonds in the side chains, exhibits excellent ozone resistance, heat resistance, and weather resistance. It also demonstrates good stability in harsh environments such as strong oxidation and acid / alkali conditions, thus gradually becoming one of the important materials for high-end dry box gloves.
[0003] In existing technologies, EPDM rubber gloves are typically produced by mixing and dissolving a rubber paste, then using an impregnation molding process to form a layered rubber film on the mold surface, followed by vulcanization and curing to obtain the glove product. This method can achieve a certain degree of uniform glove thickness and surface density, but it still has some shortcomings: Firstly, traditional EPDM rubber systems mainly rely on fillers and vulcanization systems for performance improvement, resulting in a relatively simple internal structure. When facing organic solvents, small-molecule chemical media, and complex corrosive environments, its penetration barrier performance still has room for improvement. Secondly, existing formulation systems are prone to problems such as insufficient fluidity, loose bonding, and bubbling during the rubber layer molding process, affecting the glove's airtightness and long-term stability.
[0004] Currently, the production formulas and processes for high-performance dry box gloves are mainly controlled by foreign companies. Domestically, there is a lack of material systems and molding processes with independent intellectual property rights in the field of high-end chemical-resistant rubber gloves. Therefore, it is necessary to develop a rubber glove material and its preparation method with superior barrier properties, aging resistance, and processing performance, based on the existing EPDM rubber system, from the perspective of material structure design and process optimization, to meet the needs of high-end applications. Summary of the Invention
[0005] To overcome the problems of insufficient chemical barrier properties, simple material structure, and poor density and bonding of the rubber layer in EPDM gloves mentioned above, the present invention aims to provide a synergistically modified EPDM glove material with high resistance to chemical penetration and its preparation method. This invention employs the introduction of dynamic covalent bonds, coordination structures, and organic-inorganic hybrid structures into the EPDM matrix to construct a multi-layered synergistic network, combined with an impregnation molding process to form a multi-layered dense structure. This significantly improves the gas-liquid barrier properties and structural stability of the material, resulting in a significant improvement in chemical penetration resistance and overall performance.
[0006] The objective of this invention can be achieved through the following technical solutions:
[0007] A synergistically modified EPDM rubber glove material with high resistance to chemical penetration, the glove material comprising the following raw materials in parts by weight: 60-120 parts of synergistically modified EPDM rubber; 5-12 parts of zinc oxide; 3-6 parts of dicumyl peroxide; 0.5-3 parts of sulfur; 2-5 parts of accelerator A; 1-4 parts of accelerator B; 1-5 parts of antioxidant; 10-30 parts of carbon black; 1-5 parts of silane coupling agent; and 60-100 parts of organic solvent. The synergistically modified EPDM rubber is formed by the condensation reaction of EPDM rubber with 2-acetylpyridine and terephthaloyl dihydrazide to construct a hydrazone dynamic covalent network, and forming a coordination structure with ferulic acid and lanthanum chloride. Simultaneously, it is synergistically modified by the hydrolysis and condensation polymerization of vinyltrimethoxysilane to introduce an organic-inorganic hybrid structure.
[0008] Optionally, the synergistically modified EPDM rubber comprises the following raw materials in parts by weight: 50-100 parts of EPDM rubber; 0.5-5 parts of 2-acetylpyridine; 0.5-6 parts of terephthaloyl dihydrazide; 0.5-5 parts of ferulic acid; 0.1-2 parts of lanthanum chloride; and 1-6 parts of vinyltrimethoxysilane.
[0009] Optionally, the preparation method of synergistically modified EPDM rubber includes the following steps:
[0010] (1) After plasticizing EPDM rubber, it is mixed with 2-acetylpyridine and heated and stirred to make it uniformly dispersed in the rubber matrix to obtain a pre-modified rubber intermediate;
[0011] (2) Add terephthaloyl dihydrazide to the pre-modified rubber intermediate to form a dynamic covalent network structure of hydrazone, and at the same time add ferulic acid and lanthanum chloride to carry out a complexation reaction to construct a coordination crosslinking structure and obtain a synergistic network rubber intermediate;
[0012] (3) Add vinyltrimethoxysilane to the synergistic network rubber intermediate and carry out hydrolysis and polycondensation reaction to form an organic-inorganic hybrid network structure in the rubber matrix to obtain synergistic modified EPDM rubber.
[0013] Optionally, the reaction conditions in step (1) are: plasticizing temperature of 60-100℃, mixing temperature of 50-80℃, and stirring time of 20-60min.
[0014] Optionally, the reaction conditions in step (2) are a reaction temperature of 60–120°C and a reaction time of 1–4 h.
[0015] Optionally, the reaction conditions for step (3) are a hydrolysis condensation temperature of 50–90°C, a reaction time of 1–3 h, and a pH of 4–6.
[0016] Optionally, accelerator A is a mixture of accelerator dibenzothiazole and accelerator 2-mercaptobenzothiazole in a mass ratio of (1-3):(1-2); accelerator B is a mixture of accelerator tetramethylthiuram disulfide and accelerator dipentylthiuram tetrasulfide in a mass ratio of (1-2):(1-1.5); and antioxidant is a mixture of 2,6-di-tert-butyl-p-cresol and antioxidant diphenylamine in a mass ratio of (1-2):(1-1.5).
[0017] Optionally, a method for preparing a synergistically modified EPDM rubber glove material with high resistance to chemical penetration, the preparation method comprising the following steps:
[0018] (1) Preparation of compound rubber: Zinc oxide, accelerator A, accelerator B, antioxidant, carbon black and silane coupling agent are mixed evenly according to the weight parts and stirred for 10-30 minutes. Then, after the synergistic modified EPDM rubber is plasticized, it is added to the above mixture in the rubber mixing mill for mixing until the material is evenly dispersed and there is no loose powder. Finally, dicumyl peroxide and sulfur are added and the mixture is continued to obtain compound rubber.
[0019] (2) Preparation of adhesive paste: After the compounded rubber is cut into pieces, it is added to an organic solvent that is being stirred for dissolution and dispersion, and stirring is continued until a uniform and stable adhesive paste is formed.
[0020] (3) Mold treatment: Clean and dry the molding mold. The mold is a ceramic hand mold, a stainless steel hand mold or a plaster hand mold. After drying, cool it to room temperature for later use.
[0021] (4) Immersion molding: Position the mold above the adhesive slurry using the equipment, and then immerse the mold completely in the adhesive slurry by vertical movement, so that the adhesive slurry is evenly attached to the surface of the mold. Then lift the mold and separate it from the adhesive slurry, so that the attached adhesive slurry forms a wet film on the surface of the mold and is initially cured to obtain a single-layer adhesive film.
[0022] (5) Repeated impregnation: The mold with the completed single-layer adhesive film is immersed in the adhesive again by vertical movement, so that the new adhesive covers the surface of the formed adhesive film. Then the mold is lifted and cured, so that the newly formed adhesive film is combined with the previous layer of adhesive film. The above process of immersion, lifting and curing is repeated 2 to 10 times to form a multi-layer structure adhesive film, wherein the thickness of each layer is 0.03 to 0.06 mm, and the total thickness is 0.4 to 0.8 mm;
[0023] (6) Demolding and molding: The multi-layer impregnated and cured film is removed from the mold to obtain a synergistically modified EPDM rubber glove material with the same surface structure as the mold.
[0024] The beneficial effects of this invention are:
[0025] This invention introduces a dynamic covalent network of hydrazinohydrazone formed by 2-acetylpyridine and terephthaloyl dihydrazide, a coordination crosslinking structure constructed by ferulic acid and lanthanum chloride, and an organic-inorganic hybrid network formed by the hydrolysis and condensation of vinyltrimethoxysilane into a EPDM rubber matrix. This achieves multi-scale synergistic crosslinking, resulting in a dense and dynamically adjustable network structure within the rubber. This significantly reduces the diffusion rate of small molecule chemical media in the material, thereby effectively improving its barrier properties against acids, alkalis, and organic solvents. Simultaneously, the synergistic effect between the multiple network structures enhances the interfacial bonding strength and structural stability of the material, improving its aging resistance and mechanical properties. Combined with the multi-layered dense structure formed by impregnation molding, the gloves exhibit uniform overall thickness, a smooth surface, and excellent airtightness, further enhancing the product's safety and durability. Attached Figure Description
[0026] The invention will now be further described with reference to the accompanying drawings.
[0027] Figure 1 The image shows a comparison of the infrared spectra of EPDM rubber and synergistically modified EPDM rubber. Detailed Implementation
[0028] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.
[0029] Example 1: The purpose of this example is to maximize the chemical resistance and airtightness of the material by improving the degree of construction of the collaborative network structure and the filler content.
[0030] S1, Preparation of synergistically modified EPDM rubber
[0031] 100 parts of EPDM rubber were plasticized on a two-roll mill at 100°C. Then, 5 parts of 2-acetylpyridine were added and stirred for 30 minutes to ensure uniform dispersion, resulting in a pre-modified rubber intermediate. Subsequently, 6 parts of terephthaloyl dihydrazide were added and reacted at 120°C for 4 hours to form a hydrazone dynamic covalent network. At the same time, 5 parts of ferulic acid and 2 parts of lanthanum chloride were added to carry out a complexation reaction to construct a coordination crosslinking structure, resulting in a synergistic network rubber intermediate. Finally, 6 parts of vinyltrimethoxysilane were added and subjected to a hydrolysis-condensation reaction at 90°C and pH 4 for 3 hours to form an organic-inorganic hybrid network structure, resulting in a synergistically modified EPDM rubber.
[0032] S2, Preparation of compound rubber and adhesive paste
[0033] 12 parts zinc oxide, 5 parts accelerator A, 4 parts accelerator B, 5 parts antioxidant, 30 parts carbon black and 5 parts silane coupling agent were mixed evenly and stirred for 30 minutes. Then, the mixture was mixed with the above-mentioned synergistically modified EPDM rubber in a rubber mixing mill. Subsequently, 6 parts dicumyl peroxide and 3 parts sulfur were added and the mixture was further mixed to obtain a compound. The compound was cut into sheets and then added to 100 parts organic solvent and stirred to dissolve, thus obtaining a uniform rubber paste.
[0034] S3, Dip molding
[0035] The cleaned and dried mold is immersed in the adhesive, allowing the adhesive to adhere, form a wet film, and cure. This immersion is repeated 10 times, so that each layer is 0.06 mm thick, and the total thickness reaches 0.8 mm. The mold is then demolded to obtain the glove material.
[0036] Example 2: The purpose of this example is to achieve the best balance between impermeability, mechanical properties and processing performance.
[0037] S1, Preparation of synergistically modified EPDM rubber
[0038] After plasticizing 75 parts of EPDM rubber at 80℃, 2.5 parts of 2-acetylpyridine were added and stirred for 40 min to obtain a pre-modified rubber intermediate. Then, 3 parts of terephthaloyl dihydrazide were added and reacted at 90℃ for 2 h to form a dynamic covalent network. At the same time, 2.5 parts of ferulic acid and 1 part of lanthanum chloride were added to carry out a complexation reaction to obtain a synergistic network rubber intermediate. Then, 3 parts of vinyltrimethoxysilane were added and reacted at 70℃ and pH 5 for 2 h to form a hybrid network structure to obtain a synergistically modified EPDM rubber. Figure 1 The infrared spectrum of unmodified EPDM rubber mainly ranges from 2920 to 2850 cm⁻¹. -1 The –CH2– stretching vibration peak at 1460–1375 cm⁻¹ -1 The bending vibration peak indicates that its structure is mainly composed of saturated alkyl chains and lacks polar functional groups; after modification, the peak is at 1720 cm⁻¹. -1A distinct C=O absorption peak appears nearby, in the range of 1620–1660 cm⁻¹. -1 The presence of a C=N characteristic peak at 1500–1600 cm⁻¹ indicates the successful formation of the hydrazone structure; simultaneously, the peak at 1500–1600 cm⁻¹... -1 The enhanced aromatic ring vibrations indicate the introduction of a small molecule structure containing an aromatic ring; at 1100 cm⁻¹ -1 The presence of strong Si–O–Si absorption peaks nearby indicates that silanes have undergone condensation polymerization to form an inorganic network; 3200–3500 cm⁻¹ -1 The presence of a broad peak indicates the presence of hydrogen bonds or coordination interactions; in summary, the synergistic modification successfully constructed a multi-network structure.
[0039] S2, Preparation of compound rubber and adhesive paste
[0040] Mix 8 parts zinc oxide, 3 parts accelerator A, 2 parts accelerator B, 3 parts antioxidant, 15 parts carbon black and 2 parts silane coupling agent, and then mix with the above-mentioned synergistically modified EPDM rubber. Then add 4 parts dicumyl peroxide and 2 parts sulfur and continue mixing to obtain a compound. Cut the compound into sheets and dissolve in 80 parts organic solvent to obtain a rubber paste.
[0041] S3 Dip Molding:
[0042] The mold is immersed in the adhesive to form an adhesive film. The immersion is repeated 6 times to make the thickness of a single layer 0.04mm and the total thickness 0.6mm. The glove material is then obtained by demolding.
[0043] Example 3: The purpose of this example is to improve the material's flexibility and processing fluidity while ensuring basic impermeability.
[0044] S1, Preparation of synergistically modified EPDM rubber
[0045] After masticating 50 parts of EPDM rubber at 60℃, 0.5 parts of 2-acetylpyridine were added and stirred for 20 min to obtain a pre-modified rubber intermediate. Then, 0.5 parts of terephthaloyl dihydrazide were added and reacted at 60℃ for 1 h to form a dynamic covalent network. At the same time, 0.5 parts of ferulic acid and 0.1 parts of lanthanum chloride were added to carry out a complexation reaction to obtain a synergistic network rubber intermediate. Then, 1 part of vinyltrimethoxysilane was added and reacted at 50℃ and pH 6 for 1 h to obtain synergistically modified EPDM rubber.
[0046] S2, Preparation of compound rubber and adhesive paste
[0047] Mix 5 parts zinc oxide, 2 parts accelerator A, 1 part accelerator B, 1 part antioxidant, 10 parts carbon black and 1 part silane coupling agent, and then mix with the above-mentioned synergistically modified EPDM rubber. Then add 3 parts dicumyl peroxide and 0.5 parts sulfur and continue mixing to obtain a compound. Cut the compound into sheets and dissolve in 60 parts organic solvent to obtain a rubber paste.
[0048] S3, Dip molding
[0049] The mold is immersed in the adhesive to form an adhesive film. The immersion is repeated twice to make the thickness of a single layer 0.03mm and the total thickness 0.4mm. The glove material is then obtained by demolding.
[0050] Comparative Example 1: The purpose of this comparative example is to verify the effect of introducing only a dynamic covalent network on the material properties.
[0051] S1, Preparation of synergistically modified EPDM rubber
[0052] After plasticizing 75 parts of EPDM rubber at 80℃, 2.5 parts of 2-acetylpyridine were added and mixed for 40 min to obtain a pre-modified rubber intermediate; then 3 parts of terephthaloyl dihydrazide were added and reacted at 90℃ for 2 h to form a dynamic covalent network structure. Without adding ferulic acid, lanthanum chloride and vinyltrimethoxysilane, a single dynamic covalent network modified EPDM rubber was obtained.
[0053] S2, Preparation of compound rubber and adhesive paste
[0054] Mix 8 parts zinc oxide, 3 parts accelerator A, 2 parts accelerator B, 3 parts antioxidant, 15 parts carbon black and 2 parts silane coupling agent, and then mix with the above modified EPDM rubber. Then add 4 parts dicumyl peroxide and 2 parts sulfur and continue mixing to obtain a compound. Cut the compound into sheets and dissolve in 80 parts organic solvent to obtain a paste.
[0055] S3, Dip molding
[0056] The mold is immersed in the adhesive to form an adhesive film. The immersion is repeated 6 times to make the thickness of a single layer 0.04mm and the total thickness 0.6mm. The glove material is then obtained by demolding.
[0057] Comparative Example 2: The purpose of this comparative example is to verify the effect of introducing only the coordination crosslinking structure on the material properties.
[0058] S1, Preparation of synergistically modified EPDM rubber
[0059] After plasticizing 75 parts of EPDM rubber at 80℃, 2.5 parts of ferulic acid and 1 part of lanthanum chloride were directly added, and the mixture was reacted at 90℃ for 2 hours to carry out a complexation reaction to construct a coordination crosslinking structure. Without adding 2-acetylpyridine, terephthaloyl dihydrazide and vinyltrimethoxysilane, a single coordination structure modified EPDM rubber was obtained.
[0060] S2, Preparation of compound rubber and adhesive paste
[0061] Mix 8 parts zinc oxide, 3 parts accelerator A, 2 parts accelerator B, 3 parts antioxidant, 15 parts carbon black and 2 parts silane coupling agent, and then mix with the above modified EPDM rubber. Then add 4 parts dicumyl peroxide and 2 parts sulfur and continue mixing to obtain a compound. Cut the compound into sheets and dissolve in 80 parts organic solvent to obtain a paste.
[0062] S3, Dip molding
[0063] The mold is immersed in the adhesive to form an adhesive film. The immersion is repeated 6 times to make the thickness of a single layer 0.04mm and the total thickness 0.6mm. The glove material is then obtained by demolding.
[0064] Comparative Example 3: The purpose of this comparative example is to verify the changes in material properties without the introduction of a synergistic structure of small organic molecules.
[0065] S1, Preparation of synergistically modified EPDM rubber:
[0066] After plasticizing 75 parts of EPDM rubber at 80℃, without adding 2-acetylpyridine, terephthaloyl dihydrazide and ferulic acid, only 1 part of lanthanum chloride and 3 parts of vinyltrimethoxysilane were added. The mixture was reacted at 70℃ and pH 5 for 2 hours to carry out hydrolysis condensation and simple coordination, resulting in modified EPDM rubber without the participation of organic small molecules.
[0067] S2, Preparation of compound rubber and adhesive paste
[0068] Mix 8 parts zinc oxide, 3 parts accelerator A, 2 parts accelerator B, 3 parts antioxidant, 15 parts carbon black and 2 parts silane coupling agent, and then mix with the above modified EPDM rubber. Then add 4 parts dicumyl peroxide and 2 parts sulfur and continue mixing to obtain a compound. Cut the compound into sheets and dissolve in 80 parts organic solvent to obtain a paste.
[0069] S3, Dip molding
[0070] The mold is immersed in the adhesive to form an adhesive film. The immersion is repeated 6 times to make the thickness of a single layer 0.04mm and the total thickness 0.6mm. The glove material is then obtained by demolding.
[0071] Performance testing:
[0072] 1. Test method for resistance to chemical penetration
[0073] The prepared glove material was cut into samples of uniform thickness and fixed in a permeation testing device. One side was in contact with a selected chemical medium (including a 30% sulfuric acid solution, a 10% sodium hydroxide solution, and organic solvents such as toluene), while the other side was kept in a cavity or inert gas environment. The time and rate of chemical medium permeation through the material were recorded under constant temperature conditions. The permeation time and amount of different samples were compared to evaluate their resistance to chemical medium permeation.
[0074] 2. Air tightness test method
[0075] The prepared glove material was sealed and installed in an airtightness testing device. Air or nitrogen was introduced into the glove under a certain pressure difference. The amount of gas leakage or pressure change per unit time was recorded. The airtightness of the material was evaluated by the gas leakage rate. The lower the leakage rate, the higher the material density and the better the gas barrier performance.
[0076] 3. Aging resistance test method
[0077] The prepared glove material is placed in a hot air aging chamber and aged for a certain time (e.g., 72h) at a certain temperature (e.g., 100℃). After being taken out, its tensile strength and elongation at break are tested and compared with the performance before aging. The aging resistance of the material is evaluated by the performance retention rate. The higher the performance retention rate, the better the structural stability of the material.
[0078] 4. Mechanical property testing methods
[0079] The prepared glove material was cut into dumbbell-shaped specimens according to standard dimensions and subjected to tensile testing on an electronic universal testing machine. The tensile strength, elongation at break and elastic modulus were recorded. The comprehensive mechanical properties of the material were evaluated by comparing the mechanical property indicators of different samples. The higher the value, the better the strength and toughness of the material.
[0080] Table 1 Performance test results of different samples
[0081] sample Permeation time (min, toluene) <![CDATA[Gas leakage rate (×10 -3 mbar·L / s)]]> Tensile strength (MPa) Strength retention rate after aging (%) Example 1 185 1.8 14.5 88 Example 2 230 1.2 16.8 93 Example 3 150 2.5 12.2 82 Comparative Example 1 110 3.6 10.5 75 Comparative Example 2 95 4.2 9.8 72 Comparative Example 3 80 5.0 9.0 68
[0082] As shown in Table 1, there are significant differences in the chemical permeation resistance of different samples. Example 2 exhibits a permeation time of 230 min, significantly higher than Examples 1 and 3, and far superior to the comparative examples. This indicates that the dynamic covalent network, coordination structure, and organic-inorganic hybrid structure constructed through multiple synergistic modifications can effectively improve the internal density of the material and significantly reduce the diffusion rate of small-molecule organic solvents in the rubber, thereby enhancing permeation resistance. In contrast, the comparative examples, due to the use of only a single modification or the lack of synergistic effects from small organic molecules, have a relatively simple internal network structure, resulting in a significant decrease in permeation barrier capacity.
[0083] In terms of airtightness, Example 2 exhibits the lowest gas leakage rate, at only 1.2 × 10⁻⁶. -3 The mbar·L / s ratio is significantly better than other examples and comparative examples, indicating that the multi-scale network structure formed after synergistic modification can effectively reduce micropores and defects inside the material and improve the overall structural density. Although Example 1 has a lower leakage rate, it is slightly lower than the overall performance of Example 2 due to the high crosslinking density and the large local structural rigidity. In contrast, the comparative example lacks the synergistic effect of multiple networks, resulting in a loose internal structure of the material, making it easier for gas to pass through and leading to a significant increase in leakage rate.
[0084] In terms of mechanical properties, the tensile strength of Example 2 reached 16.8 MPa, which was significantly higher than that of Example 1 and Example 3. This indicates that a reasonable ratio of dynamic covalent bonds and coordination structures can enhance the structural stability of the material while ensuring flexibility, and achieve a synergistic improvement in strength and toughness. Example 1 had better strength but slightly affected flexibility due to its higher degree of crosslinking. Example 3 had limited enhancement effect due to its lower degree of modification. The comparative example had significantly reduced overall mechanical properties due to its simple structure.
[0085] In terms of aging resistance, Example 2 achieved a strength retention rate of 93%, demonstrating excellent structural stability, indicating that the multiple synergistic network can effectively inhibit the breakage and degradation of molecular chains during thermo-oxidative aging. Although Examples 1 and 3 also have certain aging resistance, they are both lower than Example 2. Due to the lack of synergistic modified structure, the comparative example is more prone to performance degradation during aging, and the retention rate is significantly reduced.
[0086] In summary, by constructing a synergistically modified EPDM rubber system containing dynamic covalent bonds, coordination structures, and organic-inorganic hybrid structures, and combining it with impregnation molding to form a multi-layered dense structure, the chemical permeability resistance, air tightness, mechanical properties, and aging resistance of the material can be significantly improved. Among them, Example 2 achieves the best balance among various properties and exhibits the best comprehensive performance.
Claims
1. A synergistically modified EPDM rubber glove material with high resistance to chemical penetration, characterized in that, The glove material comprises the following raw materials in parts by weight: 60-120 parts of synergistically modified EPDM rubber; 5-12 parts of zinc oxide; 3-6 parts of dicumyl peroxide; 0.5-3 parts of sulfur; 2-5 parts of accelerator A; 1-4 parts of accelerator B; 1-5 parts of antioxidant; 10-30 parts of carbon black; 1-5 parts of silane coupling agent; and 60-100 parts of organic solvent. The synergistically modified EPDM rubber is formed by condensing EPDM rubber with 2-acetylpyridine and terephthaloyl dihydrazide to construct a dynamic covalent network of hydrazone, and forming a coordination structure with ferulic acid and lanthanum chloride. Simultaneously, it is synergistically modified by introducing an organic-inorganic hybrid structure through the hydrolysis and condensation polymerization of vinyltrimethoxysilane.
2. The synergistically modified EPDM rubber glove material with high resistance to chemical penetration according to claim 1, characterized in that, The synergistically modified EPDM rubber comprises the following raw materials in parts by weight: 50-100 parts of EPDM rubber; 0.5-5 parts of 2-acetylpyridine; 0.5-6 parts of terephthaloyl dihydrazide; 0.5-5 parts of ferulic acid; 0.1-2 parts of lanthanum chloride; and 1-6 parts of vinyltrimethoxysilane.
3. A synergistically modified EPDM rubber glove material with high resistance to chemical penetration according to claim 1 or 2, characterized in that, The preparation method of the synergistically modified EPDM rubber includes the following steps: (1) After plasticizing EPDM rubber, it is mixed with 2-acetylpyridine and heated and stirred to make it uniformly dispersed in the rubber matrix to obtain a pre-modified rubber intermediate; (2) Add terephthaloyl dihydrazide to the pre-modified rubber intermediate to form a dynamic covalent network structure of hydrazone, and at the same time add ferulic acid and lanthanum chloride to carry out a complexation reaction to construct a coordination crosslinking structure and obtain a synergistic network rubber intermediate; (3) Add vinyltrimethoxysilane to the synergistic network rubber intermediate and carry out hydrolysis and polycondensation reaction to form an organic-inorganic hybrid network structure in the rubber matrix to obtain synergistic modified EPDM rubber.
4. The synergistically modified EPDM rubber glove material with high resistance to chemical penetration according to claim 3, characterized in that, The reaction conditions for step (1) are: plasticizing temperature of 60-100℃, mixing temperature of 50-80℃, and stirring time of 20-60min.
5. The synergistically modified EPDM rubber glove material with high resistance to chemical penetration according to claim 3, characterized in that, The reaction conditions for step (2) are a reaction temperature of 60-120℃ and a reaction time of 1-4h.
6. The synergistically modified EPDM rubber glove material with high resistance to chemical penetration according to claim 3, characterized in that, The reaction conditions for step (3) are: hydrolysis condensation temperature of 50-90℃, reaction time of 1-3h, and pH of 4-6.
7. The synergistically modified EPDM rubber glove material with high resistance to chemical penetration according to claim 1, characterized in that, Accelerator A is a mixture of accelerator dibenzothiazole and accelerator 2-mercaptobenzothiazole in a mass ratio of (1-3):(1-2); accelerator B is a mixture of accelerator tetramethylthiuram disulfide and accelerator dipentylthiuram tetrasulfide in a mass ratio of (1-2):(1-1.5); and antioxidant is a mixture of 2,6-di-tert-butyl-p-cresol and antioxidant diphenylamine in a mass ratio of (1-2):(1-1.5).
8. A method for preparing a synergistically modified EPDM rubber glove material with high resistance to chemical penetration, characterized in that, The preparation method includes the following steps: (1) Preparation of compound rubber: Zinc oxide, accelerator A, accelerator B, antioxidant, carbon black and silane coupling agent are mixed evenly according to the weight parts and stirred for 10-30 minutes. Then, after the synergistic modified EPDM rubber is plasticized, it is added to the above mixture in the rubber mixing mill for mixing until the material is evenly dispersed and there is no loose powder. Finally, dicumyl peroxide and sulfur are added and the mixture is continued to obtain compound rubber. (2) Preparation of adhesive paste: After the compounded rubber is cut into pieces, it is added to an organic solvent that is being stirred for dissolution and dispersion, and stirring is continued until a uniform and stable adhesive paste is formed. (3) Mold treatment: Clean and dry the molding mold. The mold is a ceramic hand mold, a stainless steel hand mold or a plaster hand mold. After drying, cool it to room temperature for later use. (4) Immersion molding: Position the mold above the adhesive slurry using the equipment, and then immerse the mold completely in the adhesive slurry by vertical movement, so that the adhesive slurry is evenly attached to the surface of the mold. Then lift the mold and separate it from the adhesive slurry, so that the attached adhesive slurry forms a wet film on the surface of the mold and is initially cured to obtain a single-layer adhesive film. (5) Repeated impregnation: The mold with the completed single-layer adhesive film is immersed in the adhesive again by vertical movement, so that the new adhesive covers the surface of the formed adhesive film. Then the mold is lifted and cured, so that the newly formed adhesive film is combined with the previous layer of adhesive film. The above process of immersion, lifting and curing is repeated 2 to 10 times to form a multi-layer structure adhesive film, wherein the thickness of each layer is 0.03 to 0.06 mm, and the total thickness is 0.4 to 0.8 mm; (6) Demolding and molding: The multi-layer impregnated and cured film is removed from the mold to obtain a synergistically modified EPDM rubber glove material with the same surface structure as the mold.