Chlorosulfonated polyethylene rubber with high heat resistance and preparation method thereof

Abstract

The invention discloses high-heat-resistance chlorosulfonated polyethylene rubber and a preparation method thereof, and belongs to the technical field of rubber preparation. The chlorosulfonated polyethylene rubber with high heat resistance is prepared from the following components in parts by weight: 84 to 96 parts of chlorosulfonated polyethylene rubber, 8 to 15 parts of vulcanizing agent, 30 to 43 parts of carbon black, 10 to 18 parts of chlorinated paraffin, 2 to 6 parts of heat-resistant aid, 1 to 4 parts of antioxidant, 1 to 2 parts of stearic acid and 0.5 to 2.2 parts of polyethylene wax. The chlorosulfonated polyethylene rubber prepared from the substances has excellent oxidation resistance and thermal stability.

Description

Technical Field

[0001] This invention belongs to the field of rubber preparation technology, specifically relating to high heat-resistant chlorosulfonated polyethylene rubber and its preparation method. Background Technology

[0002] Chlorosulfonated polyethylene rubber, as a specialty rubber material, has some applications in various industrial fields, but its heat resistance is significantly deficient, severely restricting its further development. Ordinary chlorosulfonated polyethylene rubber has a relatively low upper limit for long-term use, typically around 120℃. At higher temperatures, its molecular chain structure is prone to thermal degradation, leading to rapid aging. Under sustained high temperatures, the rubber's physical properties deteriorate significantly; key indicators such as tensile strength and elongation at break decrease markedly, hardness increases, and elasticity is lost, making it unable to maintain normal service performance. This insufficient heat resistance is particularly prominent in applications such as automotive engine components and high-temperature industrial pipeline seals. Components are easily damaged by high temperatures, causing leaks and other safety hazards, affecting equipment operation and potentially leading to accidents. Therefore, effectively improving the heat resistance of chlorosulfonated polyethylene rubber and overcoming its heat resistance defects has become a critical technical problem urgently needing to be solved in this field.

[0003] Patent CN119350736B discloses a heat-resistant rubber composition and a method for preparing synthetic rubber. The raw materials for the heat-resistant rubber composition include: nitrile rubber, ethylene propylene diene monomer (EPDM) rubber, reinforcing agent, antioxidant, activator, vulcanizing agent, vulcanization accelerator, co-crosslinking agent, and heat-resistant modifying agent. The heat-resistant modifying agent is composed of nano-ZrO2-doped octafunctional styrene-POSS and nano-HfO2-doped octafunctional styrene-POSS. The synthetic rubber is prepared using the above-mentioned heat-resistant rubber composition. The synthetic rubber prepared by this invention exhibits excellent heat resistance and wear resistance, stable mechanical properties, and a long service life. Although the synthetic rubber prepared according to the above method has excellent properties, there is still room for improvement in its heat resistance and oxidation resistance. Under extreme high temperature or long-term thermo-oxidative aging conditions, the interfacial interaction between nano-ions and the rubber matrix may weaken, leading to changes in heat conduction efficiency and local overheating that accelerates aging. At the same time, the antioxidant migrates faster and is consumed more at high temperatures, resulting in a decrease in its ability to capture free radicals and a deterioration in its antioxidant protection effect. This affects the performance stability of the rubber composition under complex and harsh working conditions, limiting its wider application. Summary of the Invention

[0004] The purpose of this invention is to provide a high-heat-resistant chlorosulfonated polyethylene rubber and its preparation method, in order to solve the technical problem of poor heat resistance and oxidation resistance of rubber in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a high heat-resistant chlorosulfonated polyethylene rubber, which is composed of the following components in parts by weight: 84-96 parts chlorosulfonated polyethylene rubber, 8-15 parts vulcanizing agent, 30-43 parts carbon black, 10-18 parts chlorinated paraffin, 2-6 parts heat-resistant additives, 1-4 parts antioxidants, 1-2 parts stearic acid and 0.5-2.2 parts polyethylene wax.

[0006] Preferably, the method for preparing the heat-resistant additive includes the following steps: Q1: Add p-hydroxyacetophenone and 3,5-bis(trifluoromethyl)benzaldehyde to a container containing ethanol, stir and mix, add sodium hydroxide aqueous solution, continue stirring the reaction at room temperature, after the reaction is completed, add to an ice water bath, adjust the pH, filter under reduced pressure, wash, filter again, and dry to obtain intermediate one; Q2: Morpholine and N,N-dimethylformamide were added to a container and stirred. Chloroacetyl chloride was added under ice bath conditions, and the mixture was stirred and reacted. The mixture was extracted, dried, and distilled under reduced pressure to obtain intermediate II. 5-Amino-1,3,4-thiadiazol-2-thiol, potassium carbonate, and acetonitrile were added to a container and stirred and mixed. Intermediate II was added, and the mixture was stirred and reacted at room temperature. The mixture was then distilled under reduced pressure to precipitate a solid. The solid was filtered, washed, and dried to obtain intermediate III. Q3: Add intermediate trichloromethane and chloroacetyl chloride to a container, stir and react, extract, dry, and distill under reduced pressure to obtain intermediate four; add intermediate one, potassium carbonate and acetonitrile to a container, heat and stir, add intermediate four, heat and reflux to react, after the reaction is complete, distill under reduced pressure, precipitate solid, filter, wash, dry, and purify to obtain heat-resistant additive.

[0007] The synthesis reaction formula for the heat-resistant additive in the above process is as follows:

[0008] The mass spectrometry analysis results of intermediate one were: m / z: 360.06 (100.0%), 361.06 (18.6%), 362.07 (1.6%); those of intermediate two were: m / z: 163.04 (100.0%), 165.04 (32.4%), 164.04 (6.9%), 166.04 (2.1%); those of intermediate three were: m / z: 260.04 (100.0%), 261.04 (11.8%), 262.04 (9.8%); and those of intermediate four were: m / z: 336.01 (100.0%), 338.01 (41.4%), 337.02 (11.1%), 339.01. (5.6%), 340.00 (3.1%), 337.01 (3.1%), 338.02 (1.2%); The mass spectrometry analysis results of the heat-resistant additives are: m / z: 660.09 (100.0%), 661.10 (29.6%), 662.09 (9.5%), 662.10 (5.7%), 661.09 (3.1%), 663.09 (2.9%).

[0009] Preferably, in Q1, the ratio of p-hydroxyacetophenone, 3,5-bis(trifluoromethyl)benzaldehyde, ethanol, and sodium hydroxide aqueous solution is (3.812-4.026) g : (8.317-8.764) g : (58-66) mL : (30-35) mL, the volume fraction of sodium hydroxide aqueous solution is 10 wt%, the reaction is continued to be stirred at room temperature for 3-4 days, and the pH is adjusted to 5-6 with 1 mol / L hydrochloric acid.

[0010] Preferably, in Q2, the ratio of morpholine, N,N-dimethylformamide, and chloroacetyl chloride is (0.472-0.535) g : (8-12) mL : (0.788-0.903) g, the reaction is stirred for 8-10 h, and then extracted with ethyl acetate; the ratio of 5-amino-1,3,4-thiadiazol-2-thiol, potassium carbonate, acetonitrile, and intermediate II is (0.711-0.764) g : (1.517-1.562) g : (10-20) mL : (0.882-0.924) g, the reaction is stirred at room temperature for 6-8 h.

[0011] Preferably, in Q3, the ratio of intermediate trichloromethane and chloroacetyl chloride is (0.752-0.793) g : (10-12) mL : (0.388-0.426) g, and the reaction is stirred for 8-10 h; the ratio of intermediate one, potassium carbonate, acetonitrile and intermediate four is (1.548-1.642) g : (1.782-1.946) g : (30-35) mL : (1.732-1.798) g, the reaction is heated to 80-82℃ and stirred for 2-3 h, and then heated to 80-84℃ and refluxed for 6-8 h.

[0012] Preferably, the method for preparing the antioxidant includes the following steps: S1: Chitosan oligosaccharide was added to 1-methyl-2-pyrrolidone, stirred and mixed, and then sodium iodide and sodium hydroxide aqueous solution were added. The mixture was stirred and reacted under ice bath conditions. Then iodomethane was added, and the mixture was heated under reflux to react, precipitate was formed, washed, filtered, and freeze-dried under vacuum to obtain a solid product. S2: 4,8-Dihydroxyquinoline-2-carboxylic acid was added to dimethyl sulfoxide, followed by N,N'-carbonyldiimidazole. After heating and stirring, the solid product was added and the reaction continued. After the reaction was completed, the precipitate was washed, filtered, and freeze-dried under vacuum to obtain the antioxidant.

[0013] The synthesis reaction formula for antioxidants in the above process is as follows:

[0014] Preferably, in S1, the ratio of chitosan oligosaccharide, 1-methyl-2-pyrrolidone, sodium iodide, sodium hydroxide aqueous solution and iodomethane is (4.88-5.22) g : (45-55) mL : (8.8-9.3) g : (28-32) mL : (28-34) mL, the mass fraction of sodium hydroxide aqueous solution is 15 wt%, the reaction is stirred for 30-45 minutes, and then heated to 60-65℃ and refluxed for 2-4 hours.

[0015] Preferably, in S2, the ratio of 4,8-dihydroxyquinoline-2-carboxylic acid, dimethyl sulfoxide, N,N'-carbonyldiimidazole and the solid product is (1.21-1.68) g : (10-15) mL : (0.56-0.68) g : (1.01-1.37) g, and the mixture is heated to 60-65°C and stirred for 10-12 h, and then the reaction is continued for another 10-12 h.

[0016] Preferably, the method for preparing the high heat-resistant chlorosulfonated polyethylene rubber includes the following steps: Step 1: Add chlorosulfonated polyethylene rubber to a mixer and masticate it. Then add stearic acid, antioxidant and heat-resistant additives in sequence. After mixing, add carbon black, chlorinated paraffin and polyethylene wax and mix thoroughly to obtain a mixture. Step 2: Place the mixture on a two-roll mill and pass it through the mill repeatedly. Then add the vulcanizing agent, mix evenly, press the mixture into a rubber sheet, and cool it to obtain the rubber sheet. Step 3: Add the rubber sheet to the flat vulcanizing machine, vulcanize, demold, and vulcanize again to obtain chlorosulfonated polyethylene rubber with high heat resistance.

[0017] Preferably, in step one, the plasticizing process is completed for 1-2 minutes, followed by mixing for 1-2 minutes, and then thorough mixing for 6-10 minutes. In step two, the roller gap of the open mill is 1-2 mm, the roller temperature is 45-55℃, and the mill is passed through 3-5 times. When adding the vulcanizing agent, the roller gap is adjusted to 3-4 mm. During the pressing process, the roller gap is 2-3 mm. In step three, the vulcanization temperature is 160-170℃, the pressure is 15-20 MPa, the temperature during the post-vulcanization process is 150-160℃, and the time is 2-4 hours.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The present invention adds the prepared heat-resistant additives and antioxidants to chlorosulfonated polyethylene rubber, which can effectively improve the thermal stability and antioxidant properties of chlorosulfonated polyethylene rubber.

[0019] 2. The present invention adds the obtained heat-resistant additive to chlorosulfonated polyethylene rubber, which can effectively improve the thermal stability and long-term heat aging resistance of the rubber. The conjugated enone system and trifluoromethyl strong electron-withdrawing groups contained in the heat-resistant additive can effectively absorb and dissipate heat energy and inhibit the thermal degradation of the polymer backbone. At the same time, the nitrogen and sulfur atoms contained therein can interact with the sulfonyl chloride groups in the rubber or the free radicals generated by heat aging to form stable dynamic cross-linking points, which enhances the heat resistance of the network structure. In addition, the rigid aromatic rings and flexible heterocycles contained in the heat-resistant additive are well dispersed and cross-linked in the rubber matrix, which not only increases the thermal decomposition temperature of the rubber, but also helps it maintain excellent mechanical properties and dimensional stability at high temperatures.

[0020] 3. This invention applies the prepared antioxidant to chlorosulfonated polyethylene rubber, which can effectively improve the long-term antioxidant and thermo-oxidative aging resistance of the rubber. The ortho-phenolic hydroxyl groups contained in the antioxidant can quickly capture alkyl free radicals and alkoxy free radicals generated during the thermo-oxidative aging of rubber, interrupting the chain oxidation reaction. At the same time, the nitrogen and oxygen heterocyclic structures contained can strongly complex the catalytic aging metal ions present in the rubber, passivating their activity. In addition, the chitosan oligosaccharide used is rich in active groups, which can not only provide additional free radical scavenging sites, but its polymer chain structure can also form a local physical barrier in the rubber matrix, hindering the diffusion and penetration of oxygen, thereby achieving long-lasting and stable antioxidant protection, and ultimately effectively delaying the hardening, catalytic and mechanical property decline of the rubber, and extending the service life of the rubber. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flowchart of the preparation of chlorosulfonated polyethylene rubber in this invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: This example discloses a method for preparing a heat-resistant additive, including the following steps: Q1: 3.914 g of p-hydroxyacetophenone and 8.535 g of 3,5-bis(trifluoromethyl)benzaldehyde were added to a container containing 62 mL of ethanol. After stirring and mixing, 32.5 mL of 10 wt% sodium hydroxide aqueous solution was added. The reaction was continued to be stirred at room temperature for 4 days. After the reaction was completed, the mixture was placed in an ice-water bath, and the pH was adjusted to 5 with 1 mol / L hydrochloric acid. The mixture was then filtered under reduced pressure, washed, filtered again, and dried to obtain intermediate one. Q2: Add 0.503 g of morpholine and 10 mL of N,N-dimethylformamide to a container, stir, add 0.845 g of chloroacetyl chloride under ice bath conditions, stir and react for 10 h, extract with ethyl acetate, dry, and distill under reduced pressure to obtain intermediate II; add 0.732 g of 5-amino-1,3,4-thiadiazol-2-thiol, 1.534 g of potassium carbonate and 15 mL of acetonitrile to a container, stir and mix, add 0.901 g of intermediate II, stir and react at room temperature for 8 h, distill under reduced pressure, precipitate solid, filter, wash, and dry to obtain intermediate III; Q3: Add 0.772g of intermediate III, 11mL of dichloromethane and 0.403g of chloroacetyl chloride to a container, stir and react for 10h, extract, dry and distill under reduced pressure to obtain intermediate IV; add 1.595g of intermediate I, 1.829g of potassium carbonate and 32.5mL of acetonitrile to a container, heat to 80℃ and stir for 3h, add 1.765g of intermediate IV, heat to 80℃ and reflux for 8h, after the reaction is completed, distill under reduced pressure, precipitate solid, filter, wash, dry and purify to obtain heat-resistant additive.

[0025] This embodiment discloses a method for preparing an antioxidant, including the following steps: S1: Add 5.05 g of chitosan oligosaccharide to 50 mL of 1-methyl-2-pyrrolidone, stir and mix, then add 9.1 g of sodium iodide and 30 mL of 15 wt% sodium hydroxide aqueous solution. Stir and react for 45 minutes under ice bath conditions, then add 31 mL of iodomethane, heat to 60 °C and reflux for 4 h, precipitate, wash, filter, and freeze dry under vacuum to obtain solid product; S2: 1.44 g of 4,8-dihydroxyquinoline-2-carboxylic acid was added to 12.5 mL of dimethyl sulfoxide, followed by 0.63 g of N,N'-carbonyldiimidazole. The mixture was heated to 60 °C and stirred for 12 h. Then, 1.18 g of solid product was added, and the reaction was continued for another 12 h. After the reaction was completed, the precipitate was collected, washed, filtered, and freeze-dried under vacuum to obtain the antioxidant.

[0026] This embodiment discloses a high heat-resistant chlorosulfonated polyethylene rubber, which is composed of the following components by weight: 90 parts chlorosulfonated polyethylene rubber, 11 parts zinc oxide, 36 parts carbon black, 14 parts chlorinated paraffin, 4 parts heat-resistant additives, 2.5 parts antioxidants, 1.5 parts stearic acid and 1.3 parts polyethylene wax.

[0027] See Figure 1 This embodiment discloses a method for preparing chlorosulfonated polyethylene rubber with high heat resistance, including the following steps: Step 1: Add chlorosulfonated polyethylene rubber to a mixer and plasticize for 2 minutes. Then add stearic acid, antioxidant and heat-resistant additive in sequence and mix for 1 minute. Add carbon black, chlorinated paraffin and polyethylene wax and mix thoroughly for 8 minutes to obtain the mixture. Step 2: Place the mixture on a two-roll mill and pass it through repeatedly. The roller gap of the two-roll mill is 2mm and the roller temperature is 50℃. Pass it through 5 times, then adjust the roller gap to 4mm. Then add zinc oxide, mix evenly, press the adhesive (roll gap is 2mm), and cool to obtain the film. Step 3: Add the rubber sheet to the flat vulcanizing machine, vulcanize at 170℃ and 20MPa, demold, and vulcanize at 150℃ for 4 hours to obtain high heat-resistant chlorosulfonated polyethylene rubber.

[0028] Example 2: This example discloses a method for preparing a heat-resistant additive, including the following steps: Q1: 3.812 g of p-hydroxyacetophenone and 8.317 g of 3,5-bis(trifluoromethyl)benzaldehyde were added to a container containing 66 mL of ethanol. After stirring and mixing, 35 mL of 10 wt% sodium hydroxide aqueous solution was added. The reaction was continued to be stirred at room temperature for 4 days. After the reaction was completed, the mixture was placed in an ice-water bath, and the pH was adjusted to 5 with 1 mol / L hydrochloric acid. The mixture was filtered under reduced pressure, washed, filtered again, and dried to obtain intermediate one. Q2: Add 0.472 g of morpholine and 8 mL of N,N-dimethylformamide to a container, stir, add 0.788 g of chloroacetyl chloride under ice bath conditions, stir and react for 10 h, extract with ethyl acetate, dry, and distill under reduced pressure to obtain intermediate II; add 0.711 g of 5-amino-1,3,4-thiadiazol-2-thiol, 1.517 g of potassium carbonate and 10 mL of acetonitrile to a container, stir and mix, add 0.882 g of intermediate II, stir and react at room temperature for 8 h, distill under reduced pressure, precipitate solid, filter, wash, and dry to obtain intermediate III; Q3: Add 0.752g of intermediate III, 12mL of dichloromethane and 0.426g of chloroacetyl chloride to a container, stir and react for 10h, extract, dry and distill under reduced pressure to obtain intermediate IV; add 1.548g of intermediate I, 1.782g of potassium carbonate and 30mL of acetonitrile to a container, heat to 80℃ and stir for 3h, add 1.732g of intermediate IV, heat to 80℃ and reflux for 8h, after the reaction is completed, distill under reduced pressure, precipitate solid, filter, wash, dry and purify to obtain heat-resistant additive.

[0029] This embodiment discloses a method for preparing an antioxidant, including the following steps: S1: Add 4.88 g of chitosan oligosaccharide to 55 mL of 1-methyl-2-pyrrolidone, stir and mix, then add 9.3 g of sodium iodide and 28 mL of 15 wt% sodium hydroxide aqueous solution. Stir and react for 45 minutes under ice bath conditions, then add 28 mL of iodomethane, heat to 60 °C and reflux for 4 h, precipitate, wash, filter, and freeze dry under vacuum to obtain solid product; S2: 1.21 g of 4,8-dihydroxyquinoline-2-carboxylic acid was added to 10 mL of dimethyl sulfoxide, followed by 0.56 g of N,N'-carbonyldiimidazole. The mixture was heated to 60 °C and stirred for 12 h. Then, 1.01 g of solid product was added, and the reaction was continued for another 12 h. After the reaction was completed, the precipitate was collected, washed, filtered, and freeze-dried under vacuum to obtain the antioxidant.

[0030] This embodiment discloses a high heat-resistant chlorosulfonated polyethylene rubber, which is composed of the following components by weight: 84 parts chlorosulfonated polyethylene rubber, 8 parts magnesium oxide, 30 parts carbon black, 18 parts chlorinated paraffin, 6 parts heat-resistant additives, 1 part antioxidant, 1 part stearic acid and 0.5 parts polyethylene wax.

[0031] See Figure 1 This embodiment discloses a method for preparing chlorosulfonated polyethylene rubber with high heat resistance, including the following steps: Step 1: Add chlorosulfonated polyethylene rubber to a mixer and plasticize for 2 minutes. Then add stearic acid, antioxidant and heat-resistant additive in sequence and mix for 1 minute. Add carbon black, chlorinated paraffin and polyethylene wax and mix thoroughly for 8 minutes to obtain the mixture. Step 2: Place the mixture on a two-roll mill and pass it through repeatedly. The roller gap of the two-roll mill is 2mm and the roller temperature is 50℃. Pass it through 5 times, then adjust the roller gap to 4mm. Then add magnesium oxide, mix evenly, press the mixture (roll gap is 2mm), and cool it to obtain a film. Step 3: Add the rubber sheet to the flat vulcanizing machine, vulcanize at 170℃ and 20MPa, demold, and vulcanize at 150℃ for 4 hours to obtain high heat-resistant chlorosulfonated polyethylene rubber.

[0032] Example 3: This example discloses a method for preparing a heat-resistant additive, including the following steps: Q1: 4.026 g of p-hydroxyacetophenone and 8.764 g of 3,5-bis(trifluoromethyl)benzaldehyde were added to a container containing 58 mL of ethanol. After stirring and mixing, 30 mL of 10 wt% sodium hydroxide aqueous solution was added. The reaction was continued to be stirred at room temperature for 4 days. After the reaction was completed, the mixture was placed in an ice-water bath, and the pH was adjusted to 5 with 1 mol / L hydrochloric acid. The mixture was filtered under reduced pressure, washed, filtered again, and dried to obtain intermediate one. Q2: Add 0.535g of morpholine and 12mL of N,N-dimethylformamide to a container, stir, add 0.903g of chloroacetyl chloride under ice bath conditions, stir and react for 10h, extract with ethyl acetate, dry, and distill under reduced pressure to obtain intermediate II; add 0.764g of 5-amino-1,3,4-thiadiazol-2-thiol, 1.562g of potassium carbonate and 20mL of acetonitrile to a container, stir and mix, add 0.924g of intermediate II, stir and react at room temperature for 8h, distill under reduced pressure, precipitate solid, filter, wash, and dry to obtain intermediate III; Q3: Add 0.793g of intermediate III, 10mL of dichloromethane and 0.388g of chloroacetyl chloride to a container, stir and react for 10h, then extract, dry and distill under reduced pressure to obtain intermediate IV; add 1.642g of intermediate I, 1.946g of potassium carbonate and 35mL of acetonitrile to a container, heat to 80℃ and stir for 3h, then add 1.798g of intermediate IV, heat to 80℃ and reflux for 8h. After the reaction is complete, distill under reduced pressure, precipitate the solid, filter, wash, dry and purify to obtain the heat-resistant additive.

[0033] This embodiment discloses a method for preparing an antioxidant, including the following steps: S1: Add 5.22g of chitosan oligosaccharide to 45mL of 1-methyl-2-pyrrolidone, stir and mix, then add 8.8g of sodium iodide and 32mL of 15wt% sodium hydroxide aqueous solution. Stir and react for 45 minutes under ice bath conditions, then add 34mL of iodomethane, heat to 60℃ and reflux for 4h, precipitate, wash, filter, and freeze dry under vacuum to obtain solid product; S2: 1.68 g of 4,8-dihydroxyquinoline-2-carboxylic acid was added to 15 mL of dimethyl sulfoxide, followed by 0.68 g of N,N'-carbonyldiimidazole. The mixture was heated to 60 °C and stirred for 12 h. Then, 1.37 g of solid product was added, and the reaction was continued for another 12 h. After the reaction was completed, the precipitate was collected, washed, filtered, and freeze-dried under vacuum to obtain the antioxidant.

[0034] This embodiment discloses a high heat-resistant chlorosulfonated polyethylene rubber, which is composed of the following components by weight: 96 parts chlorosulfonated polyethylene rubber, 15 parts lead oxide, 43 parts carbon black, 10 parts chlorinated paraffin, 2 parts heat-resistant additives, 4 parts antioxidants, 2 parts stearic acid and 2.2 parts polyethylene wax.

[0035] See Figure 1 This embodiment discloses a method for preparing chlorosulfonated polyethylene rubber with high heat resistance, including the following steps: Step 1: Add chlorosulfonated polyethylene rubber to a mixer and plasticize for 2 minutes. Then add stearic acid, antioxidant and heat-resistant additive in sequence and mix for 1 minute. Add carbon black, chlorinated paraffin and polyethylene wax and mix thoroughly for 8 minutes to obtain the mixture. Step 2: Place the mixture on a two-roll mill and pass it through repeatedly. The roller gap of the two-roll mill is 2mm and the roller temperature is 50℃. Pass it through 5 times, then adjust the roller gap to 4mm. Then add lead oxide, mix evenly, press the adhesive (roll gap is 2mm), cool, and obtain the film. Step 3: Add the rubber sheet to the flat vulcanizing machine, vulcanize at 170℃ and 20MPa, demold, and vulcanize at 150℃ for 4 hours to obtain high heat-resistant chlorosulfonated polyethylene rubber.

[0036] Example 4: This example discloses a method for preparing a heat-resistant additive, including the following steps: Q1: 3.866 g of p-hydroxyacetophenone and 8.428 g of 3,5-bis(trifluoromethyl)benzaldehyde were added to a container containing 60 mL of ethanol. After stirring and mixing, 31 mL of 10 wt% sodium hydroxide aqueous solution was added. The reaction was continued to be stirred at room temperature for 4 days. After the reaction was completed, the mixture was placed in an ice-water bath, and the pH was adjusted to 5 with 1 mol / L hydrochloric acid. The mixture was filtered under reduced pressure, washed, filtered again, and dried to obtain intermediate one. Q2: Add 0.488g of morpholine and 9mL of N,N-dimethylformamide to a container, stir, add 0.796g of chloroacetyl chloride under ice bath conditions, stir and react for 10h, extract with ethyl acetate, dry, and distill under reduced pressure to obtain intermediate II; add 0.728g of 5-amino-1,3,4-thiadiazol-2-thiol, 1.528g of potassium carbonate and 12mL of acetonitrile to a container, stir and mix, add 0.893g of intermediate II, stir and react at room temperature for 8h, distill under reduced pressure, precipitate solid, filter, wash, and dry to obtain intermediate III; Q3: Add 0.768g of intermediate III, 10.5mL of dichloromethane and 0.414g of chloroacetyl chloride to a container, stir and react for 10h, then extract, dry and distill under reduced pressure to obtain intermediate IV; add 1.569g of intermediate I, 1.803g of potassium carbonate and 31mL of acetonitrile to a container, heat to 80℃ and stir for 3h, then add 1.748g of intermediate IV, heat to 80℃ and reflux for 8h. After the reaction is complete, distill under reduced pressure, precipitate the solid, filter, wash, dry and purify to obtain the heat-resistant additive.

[0037] This embodiment discloses a method for preparing an antioxidant, including the following steps: S1: Add 4.96 g of chitosan oligosaccharide to 48 mL of 1-methyl-2-pyrrolidone, stir and mix, then add 9.2 g of sodium iodide and 31 mL of 15 wt% sodium hydroxide aqueous solution. Stir and react for 45 minutes under ice bath conditions, then add 29 mL of iodomethane, heat to 60 °C and reflux for 4 h, precipitate, wash, filter, and freeze dry under vacuum to obtain solid product; S2: 1.36 g of 4,8-dihydroxyquinoline-2-carboxylic acid was added to 11 mL of dimethyl sulfoxide, followed by 0.59 g of N,N'-carbonyldiimidazole. The mixture was heated to 60 °C and stirred for 12 h. Then, 1.09 g of solid product was added, and the reaction was continued for another 12 h. After the reaction was completed, the precipitate was collected, washed, filtered, and freeze-dried under vacuum to obtain the antioxidant.

[0038] This embodiment discloses a high heat-resistant chlorosulfonated polyethylene rubber, which is composed of the following components by weight: 87 parts chlorosulfonated polyethylene rubber, 9 parts lead tetroxide, 33 parts carbon black, 12 parts chlorinated paraffin, 3 parts heat-resistant additives, 2 parts antioxidants, 1.2 parts stearic acid and 0.8 parts polyethylene wax.

[0039] See Figure 1 This embodiment discloses a method for preparing chlorosulfonated polyethylene rubber with high heat resistance, including the following steps: Step 1: Add chlorosulfonated polyethylene rubber to a mixer and plasticize for 2 minutes. Then add stearic acid, antioxidant and heat-resistant additive in sequence and mix for 1 minute. Add carbon black, chlorinated paraffin and polyethylene wax and mix thoroughly for 8 minutes to obtain the mixture. Step 2: Place the mixture on a two-roll mill and pass it through repeatedly. The roller gap of the two-roll mill is 2mm and the roller temperature is 50℃. Pass it through 5 times, then adjust the roller gap to 4mm. Then add lead tetroxide, mix evenly, press the adhesive (roll gap is 2mm), and cool to obtain the film. Step 3: Add the rubber sheet to the flat vulcanizing machine, vulcanize at 170℃ and 20MPa, demold, and vulcanize at 150℃ for 4 hours to obtain high heat-resistant chlorosulfonated polyethylene rubber.

[0040] Example 5: This example discloses a method for preparing a heat-resistant additive, including the following steps: Q1: 3.971 g of p-hydroxyacetophenone and 8.663 g of 3,5-bis(trifluoromethyl)benzaldehyde were added to a container containing 64 mL of ethanol. After stirring and mixing, 34 mL of 10 wt% sodium hydroxide aqueous solution was added. The reaction was continued to be stirred at room temperature for 4 days. After the reaction was completed, the mixture was placed in an ice-water bath, and the pH was adjusted to 5 with 1 mol / L hydrochloric acid. The mixture was then filtered under reduced pressure, washed, filtered again, and dried to obtain intermediate one. Q2: Add 0.517 g of morpholine and 11 mL of N,N-dimethylformamide to a container, stir, add 0.863 g of chloroacetyl chloride under ice bath conditions, stir and react for 10 h, extract with ethyl acetate, dry, and distill under reduced pressure to obtain intermediate II; add 0.751 g of 5-amino-1,3,4-thiadiazol-2-thiol, 1.551 g of potassium carbonate and 18 mL of acetonitrile to a container, stir and mix, add 0.911 g of intermediate II, stir and react at room temperature for 8 h, distill under reduced pressure, precipitate solid, filter, wash, and dry to obtain intermediate III; Q3: Add 0.781g of intermediate III, 11.5mL of dichloromethane and 0.397g of chloroacetyl chloride to a container, stir and react for 10h, extract, dry and distill under reduced pressure to obtain intermediate IV; add 1.617g of intermediate I, 1.921g of potassium carbonate and 34mL of acetonitrile to a container, heat to 80℃ and stir for 3h, add 1.781g of intermediate IV, heat to 80℃ and reflux for 8h, after the reaction is completed, distill under reduced pressure, precipitate solid, filter, wash, dry and purify to obtain heat-resistant additive.

[0041] This embodiment discloses a method for preparing an antioxidant, including the following steps: S1: Add 5.12 g of chitosan oligosaccharide to 52 mL of 1-methyl-2-pyrrolidone, stir and mix, then add 8.9 g of sodium iodide and 29 mL of 15 wt% sodium hydroxide aqueous solution. Stir and react for 45 minutes under ice bath conditions, then add 32 mL of iodomethane, heat to 60 °C and reflux for 4 h, precipitate, wash, filter, and freeze dry under vacuum to obtain solid product; S2: 1.72 g of 4,8-dihydroxyquinoline-2-carboxylic acid was added to 14 mL of dimethyl sulfoxide, followed by 0.66 g of N,N'-carbonyldiimidazole. The mixture was heated to 60 °C and stirred for 12 h. Then, 1.27 g of solid product was added, and the reaction was continued for another 12 h. After the reaction was completed, the precipitate was collected, washed, filtered, and freeze-dried under vacuum to obtain the antioxidant.

[0042] This embodiment discloses a high heat-resistant chlorosulfonated polyethylene rubber, which is composed of the following components by weight: 93 parts chlorosulfonated polyethylene rubber, 14 parts zinc oxide, 40 parts carbon black, 16 parts chlorinated paraffin, 5 parts heat-resistant additives, 3 parts antioxidants, 1.8 parts stearic acid and 1.8 parts polyethylene wax.

[0043] See Figure 1 This embodiment discloses a method for preparing chlorosulfonated polyethylene rubber with high heat resistance, including the following steps: Step 1: Add chlorosulfonated polyethylene rubber to a mixer and plasticize for 2 minutes. Then add stearic acid, antioxidant and heat-resistant additive in sequence and mix for 1 minute. Add carbon black, chlorinated paraffin and polyethylene wax and mix thoroughly for 8 minutes to obtain the mixture. Step 2: Place the mixture on a two-roll mill and pass it through repeatedly. The roller gap of the two-roll mill is 2mm and the roller temperature is 50℃. Pass it through 5 times, then adjust the roller gap to 4mm. Then add zinc oxide, mix evenly, press the adhesive (roll gap is 2mm), and cool to obtain the film. Step 3: Add the rubber sheet to the flat vulcanizing machine, vulcanize at 170℃ and 20MPa, demold, and vulcanize at 150℃ for 4 hours to obtain high heat-resistant chlorosulfonated polyethylene rubber.

[0044] Comparative Example 1: Compared with Example 1, Comparative Example 1 did not add antioxidants during the preparation of chlorosulfonated polyethylene rubber, and all other conditions remained unchanged.

[0045] Comparative Example 2: Compared with Example 1, Comparative Example 2 did not add heat-resistant additives during the preparation of chlorosulfonated polyethylene rubber, and all other conditions remained unchanged.

[0046] Performance testing: The chlorosulfonated polyethylene rubbers prepared in Examples 1-5 and Comparative Examples 1-2 were subjected to performance tests. The heat resistance of the samples was tested according to GB / T 3512-2014, the compression set was tested according to GB / T 7759.1-2015, the aging resistance was tested according to GB / T 7762-2014, and the tensile properties were tested according to GB / T 528-2009. The test results are shown in Table 1. Table 1

[0047] As shown in Table 1, the chlorosulfonated polyethylene rubber with excellent thermal stability and antioxidant properties can be prepared by using the methods of Examples 1-5. A comparison between Comparative Example 1 and Examples 1-5 reveals that the use of antioxidants can effectively improve the antioxidant and thermal oxidation resistance of the rubber; a comparison between Comparative Example 2 and Examples 1-5 reveals that the use of heat-resistant additives can effectively improve the thermal stability and thermal oxidation resistance of the rubber.

[0048] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0049] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A chlorosulfonated polyethylene rubber with high heat resistance, characterized in that, It is composed of the following components by weight: 84-96 parts chlorosulfonated polyethylene rubber, 8-15 parts vulcanizing agent, 30-43 parts carbon black, 10-18 parts chlorinated paraffin, 2-6 parts heat-resistant additives, 1-4 parts antioxidants, 1-2 parts stearic acid, and 0.5-2.2 parts polyethylene wax. The heat-resistant additives are prepared from p-hydroxyacetophenone, 3,5-bis(trifluoromethyl)benzaldehyde, morpholine, chloroacetyl chloride, 5-amino-1,3,4-thiadiazole-2-thiol, and potassium carbonate. The antioxidants are prepared from chitosan oligosaccharide, 1-methyl-2-pyrrolidone, iodomethane, and N,N'-carbonyldiimidazole.

2. The high heat-resistant chlorosulfonated polyethylene rubber according to claim 1, characterized in that, The preparation method of the heat-resistant additive includes the following steps: Q1: Add p-hydroxyacetophenone and 3,5-bis(trifluoromethyl)benzaldehyde to a container containing ethanol, stir and mix, add sodium hydroxide aqueous solution, continue stirring the reaction at room temperature, after the reaction is completed, add to an ice water bath, adjust the pH, filter under reduced pressure, wash, filter again, and dry to obtain intermediate one; Q2: Morpholine and N,N-dimethylformamide were added to a container and stirred. Chloroacetyl chloride was added under ice bath conditions, and the mixture was stirred and reacted. The mixture was extracted, dried, and distilled under reduced pressure to obtain intermediate II. 5-Amino-1,3,4-thiadiazol-2-thiol, potassium carbonate, and acetonitrile were added to a container and stirred and mixed. Intermediate II was added, and the mixture was stirred and reacted at room temperature. The mixture was then distilled under reduced pressure to precipitate a solid. The solid was filtered, washed, and dried to obtain intermediate III. Q3: Add intermediate trichloromethane and chloroacetyl chloride to a container, stir and react, extract, dry, and distill under reduced pressure to obtain intermediate four; add intermediate one, potassium carbonate and acetonitrile to a container, heat and stir, add intermediate four, heat and reflux to react, after the reaction is complete, distill under reduced pressure, precipitate solid, filter, wash, dry, and purify to obtain heat-resistant additive.

3. The high heat-resistant chlorosulfonated polyethylene rubber according to claim 2, characterized in that, In Q1, the ratio of the amounts of p-hydroxyacetophenone, 3,5-bis(trifluoromethyl)benzaldehyde, ethanol and sodium hydroxide aqueous solution is (3.812-4.026) g : (8.317-8.764) g : (58-66) mL : (30-35) mL.

4. The high heat-resistant chlorosulfonated polyethylene rubber according to claim 2, characterized in that, In Q2, the ratio of morpholine, N,N-dimethylformamide and chloroacetyl chloride is (0.472-0.535) g : (8-12) mL : (0.788-0.903) g; the ratio of 5-amino-1,3,4-thiadiazole-2-thiol, potassium carbonate, acetonitrile and intermediate II is (0.711-0.764) g : (1.517-1.562) g : (10-20) mL : (0.882-0.924) g.

5. The high heat-resistant chlorosulfonated polyethylene rubber according to claim 2, characterized in that, In Q3, the ratio of intermediate trichloromethane and chloroacetyl chloride is (0.752-0.793) g : (10-12) mL : (0.388-0.426) g; the ratio of intermediate one, potassium carbonate, acetonitrile and intermediate four is (1.548-1.642) g : (1.782-1.946) g : (30-35) mL : (1.732-1.798) g.

6. The high heat-resistant chlorosulfonated polyethylene rubber according to claim 1, characterized in that, The method for preparing the antioxidant includes the following steps: S1: Chitosan oligosaccharide was added to 1-methyl-2-pyrrolidone, stirred and mixed, and then sodium iodide and sodium hydroxide aqueous solution were added. The mixture was stirred and reacted under ice bath conditions. Then iodomethane was added, and the mixture was heated under reflux to react, precipitate was formed, washed, filtered, and freeze-dried under vacuum to obtain a solid product. S2: 4,8-Dihydroxyquinoline-2-carboxylic acid was added to dimethyl sulfoxide, followed by N,N'-carbonyldiimidazole. After heating and stirring, the solid product was added and the reaction continued. After the reaction was completed, the precipitate was washed, filtered, and freeze-dried under vacuum to obtain the antioxidant.

7. The high heat-resistant chlorosulfonated polyethylene rubber according to claim 6, characterized in that, In S1, the ratio of chitosan oligosaccharide, 1-methyl-2-pyrrolidone, sodium iodide, sodium hydroxide aqueous solution and iodomethane is (4.88-5.22) g : (45-55) mL : (8.8-9.3) g : (28-32) mL : (28-34) mL.

8. The high heat-resistant chlorosulfonated polyethylene rubber according to claim 6, characterized in that, In S2, the ratio of 4,8-dihydroxyquinoline-2-carboxylic acid, dimethyl sulfoxide, N,N'-carbonyldiimidazole and the solid product is (1.21-1.68) g : (10-15) mL : (0.56-0.68) g : (1.01-1.37) g.

9. The method for preparing high heat-resistant chlorosulfonated polyethylene rubber according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Add chlorosulfonated polyethylene rubber to a mixer and masticate it. Then add stearic acid, antioxidant and heat-resistant additives in sequence. After mixing, add carbon black, chlorinated paraffin and polyethylene wax and mix thoroughly to obtain a mixture. Step 2: Place the mixture on a two-roll mill and pass it through the mill repeatedly. Then add the vulcanizing agent, mix evenly, press the mixture into a rubber sheet, and cool it to obtain the rubber sheet. Step 3: Add the rubber sheet to the flat vulcanizing machine, vulcanize, demold, and vulcanize again to obtain chlorosulfonated polyethylene rubber with high heat resistance.

10. The method for preparing high heat-resistant chlorosulfonated polyethylene rubber according to claim 9, characterized in that, In step one, plasticizing takes 1-2 minutes, mixing takes 1-2 minutes, and thorough mixing takes 6-10 minutes. In step two, the roller gap of the open mill is 1-2 mm, the roller temperature is 45-55℃, and it passes through the mill 3-5 times. When adding the vulcanizing agent, the roller gap is adjusted to 3-4 mm. During the pressing process, the roller gap is 2-3 mm. In step three, the vulcanization temperature is 160-170℃, the pressure is 15-20 MPa, the temperature during the post-vulcanization process is 150-160℃, and the time is 2-4 hours.

Images