Graphene vulcanized capsule and preparation method thereof

Abstract

The invention relates to the technical field of tire curing bladder production, in particular to a graphene curing bladder and a preparation method thereof. The preparation method comprises the following steps: preparing an imidazole ionic liquid from bromoethane, an imidazole derivative and normal hexane; graphene and imidazole ionic liquid are mixed and ground, bromoethane is added after grinding is finished, and dispersion liquid is obtained after stirring is finished; stirring and swelling butyl rubber, then adding the dispersion liquid, heating, introducing a bromination accelerant, and obtaining reaction completion liquid after the ultrasonic stirring reaction is finished; drying the reaction completion liquid to obtain graphene dispersion glue; mixing butyl rubber, chloroprene rubber, graphene dispersion glue, a filling agent, a softening agent, a processing aid, an activating agent and a vulcanizing agent to obtain mixed rubber; and putting the rubber compound into a mold for vulcanization molding to obtain the graphene vulcanized capsule. The graphene vulcanized capsule prepared by the invention is good in heat-conducting property, good in processability, high in proportion control precision and good in physical and mechanical properties, and the graphene cannot fly off during mixing.

Description

Technical Field

[0001] The invention relates to the technical field of tire vulcanization bladder production, and in particular to a graphene vulcanization bladder and a preparation method thereof. Background Art

[0002] During the tire vulcanization process, the vulcanization bladder plays the role of inflating and shaping, transferring superheated water pressure, ensuring that the rubber fills the mold cavity to reach the required contour, and transferring the heat required for tire vulcanization. Therefore, the vulcanization bladder needs to have good mechanical properties to meet the process requirements of repeated inflation and deflation cycles under high temperature and high pressure conditions. It also needs to have good thermal conductivity to meet the process requirements of quickly transferring heat to the tire.

[0003] The invention patent with application number 201711417488.8 discloses a method for preparing a high thermal conductivity tire vulcanization bladder, comprising the following steps: step 1, ingredients, the proportion of each component is: butyl rubber 95, chloroprene rubber 4-5, N375 carbon black 15-20, acetylene carbon black 35-45, graphene 7-15, alkane oil 7-10, stearic acid 0.5-1.5, zinc oxide 5-7, resin 8-10; step 2, first stage mixing; step 3, rubber filtering; step 4, second stage mixing; step 5, molding; step 6, vulcanization; step 7, polishing; step 8, finished product inspection. The prepared high thermal conductivity tire vulcanization bladder further improves the thermal conductivity coefficient on the basis of ensuring the stability of its various physical and mechanical properties, thereby achieving the purpose of saving energy and reducing costs. However, the above technical solution has the following problems: 1. Graphene is easy to agglomerate and difficult to process. It is difficult to disperse evenly in the rubber matrix during mixing, which reduces the thermal conductivity of the tire curing bladder; 2. Graphene is very light and easy to fly away during the mixing process, resulting in a waste of raw materials, which not only increases production costs but also reduces the accuracy of ratio control; 3. Due to the significant reduction in the amount of carbon black used as a filler, the physical and mechanical properties of the tire curing bladder obtained are still reduced; In summary, there is an urgent need to provide a tire curing bladder with good thermal conductivity, good processing performance, no scattering of graphene during mixing, high ratio control accuracy and good physical and mechanical properties. Summary of the invention

[0004] In order to solve at least one of the above technical problems, the present invention provides a method for preparing a graphene sulfurization capsule, comprising the following steps: Step S100, ethyl bromide, an imidazole derivative and n-hexane are mixed, ultrasonically stirred under nitrogen protection, and heated to perform condensation reflux reaction, and after the reaction is completed, an imidazole ionic liquid is obtained; Step S200, mixing graphene and imidazolium ionic liquid, grinding under nitrogen protection, adding ethyl bromide after grinding, ultrasonic stirring, and obtaining a dispersion after stirring; Step S300, adding butyl rubber to n-hexane, stirring and swelling, then adding dispersion, heating and introducing bromination accelerator, ultrasonically stirring for reaction, and obtaining a reaction completion liquid after the reaction is completed; Step S400, drying the reaction completed liquid to obtain a graphene dispersion glue; Step S500, mixing butyl rubber, chloroprene rubber, graphene dispersion rubber, filler, softener, processing aid, activator and vulcanizer to obtain a mixed rubber; Step S600, placing the mixed rubber into a mold for vulcanization molding to obtain a graphene vulcanization capsule.

[0005] In step S100 of the above technical solution, ethyl bromide, imidazole derivatives and n-hexane are used to prepare imidazole ionic liquid. The solvent n-hexane contained in the ionic liquid and the remaining ethyl bromide that does not participate in the reaction do not need to be removed. In the subsequent step S300, n-hexane can be used as a solvent for butyl rubber, and the remaining ethyl bromide can be used as a brominating agent for butyl rubber. In step S200, after the graphene and the ionic liquid are mixed, they are ground and modified to load imidazole groups on the surface of the graphene. After the grinding and modification are completed, a certain amount of ethyl bromide is added to prepare for the subsequent bromination of butyl rubber. In step S300, the butyl rubber is first swollen with n-hexane, and then a dispersion is added. The n-hexane in the dispersion further swells the butyl rubber to form a glue solution. After heating, the bromination accelerator and the ethyl bromide in the dispersion act synergistically to partially brominate the butyl rubber to obtain a butyl rubber containing butyl rubber and In the bromination process of the butyl rubber glue liquid, the graphene with imidazole groups loaded on the surface and the remaining imidazole ion liquid are uniformly dispersed in the glue liquid to obtain a reaction completion liquid. In step S400, the reaction completion liquid is dried to remove the solvent to obtain a graphene dispersion rubber. The graphene dispersion rubber uses butyl rubber and brominated butyl rubber as rubber matrices and contains uniformly dispersed graphene and imidazole groups inside. In step 500, butyl rubber, chloroprene rubber, graphene dispersion rubber and the remaining additives are mixed. Since the graphene dispersion rubber uses butyl rubber and brominated butyl rubber as rubber matrices, it can be quickly mixed with butyl rubber and chloroprene rubber to uniformly obtain a mixed rubber, and the graphene and imidazole groups are uniformly distributed in the mixed rubber. In step S600, the mixed rubber is vulcanized and formed in a mold to obtain a tire vulcanization bladder with high thermal conductivity, excellent physical and mechanical properties and service life.

[0006] The tire vulcanization bladder of the present invention contains brominated butyl rubber and graphene and imidazole groups uniformly dispersed in a rubber matrix. The brominated butyl rubber can improve the processing performance of the vulcanization bladder, enhance the aging resistance and thermal stability, shorten the vulcanization time, and improve the production efficiency; the uniformly dispersed imidazole groups can improve the processing performance, shorten the vulcanization time, improve the mixing effect and production efficiency, and can also enhance the mechanical strength and elongation at break of the butyl rubber, and improve the use stability and service life of the tire vulcanization bladder; the uniformly dispersed graphene can greatly improve the thermal conductivity of the tire vulcanization bladder, increase the heat transfer speed during tire vulcanization, reduce the tire vulcanization time, improve the production efficiency and equipment utilization rate, save energy and reduce consumption, and can also greatly reduce the use amount of fillers, and improve the physical and mechanical properties and service life of the tire vulcanization bladder.

[0007] Preferably, in step S100, the imidazole derivative is at least one of N-methylimidazole and N-vinylimidazole; in step S200, the graphene is at least one of conventional graphene, graphene oxide and reduced graphene oxide; in step S300, the bromination promoter is at least one of hydrogen bromide and bromine gas; in step S500, the filler includes at least one of N220 carbon black and acetylene carbon black, the softener is castor oil, the processing aid is stearic acid, the activator is zinc oxide, and the vulcanizing agent is a vulcanizing resin.

[0008] Preferably, in step S100, during mixing, ethyl bromide is first added dropwise to the imidazole derivative, and n-hexane is added after the addition is completed; in step S500, during mixing, butyl rubber, chloroprene rubber, graphene dispersion rubber, filler, softener, processing aid and activator are first mixed in one stage, and the rubber is filtered after the first mixing is completed. After the filtering is completed, vulcanized resin is added to perform second-stage mixing, and a mixed rubber is obtained after the second-stage mixing is completed.

[0009] Preferably, in step S100, the molar ratio of ethyl bromide to imidazole derivative is (1.5-2):1, and the mass ratio of the total mass of ethyl bromide and imidazole derivative to n-hexane is 1:(1-5); in step S200, the mass ratio of graphene, imidazole ionic liquid and ethyl bromide is (50-70):100:1; in step S300, the mass ratio of butyl rubber, n-hexane, dispersion liquid and bromination accelerator is 100:(400-600):(150-250):(0.1-0.2); in step S500, the mass ratio of butyl rubber, chloroprene rubber, graphene dispersion rubber, filler, softener, processing aid, activator and vulcanizer is (70-80):5:(15-35):(50-65):(6-8):(0.5-1.5):(5-7):(6-8).

[0010] Preferably, in step S100, the ultrasonic power is 200-500W, the ultrasonic frequency is 20-25kHz, the reaction temperature is 40-50°C, and the reaction time is 12-48h; in step S200, the grinding time is 4-8h, the ultrasonic stirring time is 15-30 minutes, the ultrasonic power is 200-500W, and the ultrasonic frequency is 20-25kHz; in step S300, the reaction temperature is 30-35°C, the ultrasonic power is 200-500W, the ultrasonic frequency is 20-25kHz, and the reaction time is 30-60min; in step S400, the drying temperature is 80-100°C; in step S500, the mixing temperature is 90-120°C, the mixing time is 15-30min, the vulcanization temperature is 160-200°C, and the vulcanization time is 20-30min.

[0011] Preferably, in step S400, the reaction completion liquid, stearic acid, zinc oxide and 6PPD are mixed and stirred uniformly and then dried to obtain a graphene dispersion rubber; the mass ratio of stearic acid, zinc oxide, 6PPD and butyl rubber in step S300 is (0.5-1): (0.5-2): (0.1-0.5): 100.

[0012] In the above technical solution, adding stearic acid, zinc oxide and 6PPD to the reaction completed liquid can improve the storage and use stability of the graphene dispersion rubber, further improve the processing performance, and improve the mixing effect.

[0013] Preferably, in step S200, the graphene is graphene oxide, and its preparation comprises the following steps: Step S210, mixing cyclohexane and manganese stearate aqueous solution, stirring by ultrasonic means to obtain an emulsion, adding graphite to the emulsion, and continuing ultrasonic stirring to obtain an emulsified dispersion; the concentration of the manganese stearate aqueous solution is 10-15wt%, and the mass ratio of cyclohexane, manganese stearate aqueous solution and graphite is 100:25:(5-20); Step S220, spreading the emulsified dispersion in a glass container, performing magnetic stirring, and irradiating with ultraviolet light to induce an oxidation reaction, and obtaining a graphene oxide dispersion after the reaction is completed; Step S230, centrifuging, washing, and drying the graphene oxide dispersion to obtain graphene oxide.

[0014] In the above technical scheme, cyclohexane, manganese stearate aqueous solution and graphite are ultrasonically stirred to obtain an emulsified dispersion, and graphite is evenly dispersed in the emulsified dispersion. Then, the emulsified dispersion is spread and irradiated with ultraviolet light to induce an oxidation reaction, so that high-quality graphene oxide with a uniform degree of oxidation can be obtained.

[0015] Preferably, in step S210, the mesh size of the graphite is 200-1000 mesh; the ultrasonic frequency is 20-25 kHz, the stirring time of the emulsion is 5-10 min, and the stirring time of the emulsified dispersion is 5-10 min; in step S220, the power of the ultraviolet lamp is 290-310 W, the wavelength of the ultraviolet light is 380-395 nm, and the ultraviolet light irradiation time is 5-10 h.

[0016] Preferably, in step S200, the graphene is reduced graphene oxide, and its preparation comprises the following steps: Step S240, mixing graphene oxide and deionized water, adding zinc chloride and sodium borohydride in sequence under ultrasonic stirring, filtering, washing and drying after the reaction to obtain reduced graphene oxide; the mass ratio of graphene oxide, deionized water, zinc chloride and sodium borohydride is 4: (500-1000): (1-2): (0.3-0.5), the ultrasonic frequency is 20-25 kHz, and the stirring time is 10-15 min.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects: 1. The present invention mixes butyl rubber, chloroprene rubber, graphene dispersion rubber and remaining additives. The graphene dispersion rubber uses butyl rubber and brominated butyl rubber as rubber matrices, and can be quickly mixed with butyl rubber and chloroprene rubber to uniformly obtain a mixed rubber. Graphene and imidazole groups are uniformly distributed in the mixed rubber. After vulcanization, a tire vulcanization bladder with high thermal conductivity, excellent physical and mechanical properties and service life can be obtained; 2. In the present invention, after mixing graphene and ionic liquid, grinding and modifying to obtain a reaction completion liquid, using the reaction completion liquid to partially brominate butyl rubber, and then drying to obtain a graphene dispersion rubber. During the preparation process, there is no problem of graphene scattering, and the amount of feed can be accurately controlled; 3. The tire vulcanization bladder of the present invention is mainly composed of butyl rubber, and contains brominated butyl rubber and graphene and imidazole groups uniformly dispersed in the rubber matrix. The brominated butyl rubber can improve the processing performance of the vulcanization bladder, enhance the aging resistance and thermal stability, shorten the vulcanization time, and improve the production efficiency; the uniformly dispersed imidazole groups can improve the processing performance, shorten the vulcanization time, improve the mixing effect and production efficiency, and can also enhance the mechanical strength and elongation at break of butyl rubber, and improve the use stability and service life of the tire vulcanization bladder; the uniformly dispersed graphene can greatly improve the thermal conductivity of the tire vulcanization bladder, increase the heat transfer rate during tire vulcanization, reduce the vulcanization time of the tire, improve the production efficiency and equipment utilization rate, save energy and reduce consumption, and can also greatly reduce the amount of filler used, and improve the physical and mechanical properties and service life of the tire vulcanization bladder; In summary, the graphene vulcanization capsule provided by the present invention has good thermal conductivity, good processing performance, no scattering of graphene during mixing, high ratio control accuracy and good physical and mechanical properties. DETAILED DESCRIPTION

[0018] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict. Example 1

[0019] 163 parts by mass (1.5 molar parts) of ethyl bromide are added dropwise to 82 parts by mass (1 molar parts) of N-methylimidazole, and after the addition is completed, 500 parts by mass of n-hexane are added, and the mixture is ultrasonically stirred at 200 W and 20 kHz under nitrogen protection, and heated to 45° C. for condensation reflux reaction for 24 hours. After the reaction is completed, an imidazolium ionic liquid is obtained; 50 parts by mass of conventional graphene and 100 parts by mass of imidazole ionic liquid were mixed, and the mixture was ground under nitrogen protection for 5 hours. After the grinding, 1 part by mass of ethyl bromide was added, and ultrasonic stirring was performed at 200 W and 25 kHz for 15 minutes to obtain a dispersion; 100 parts by mass of butyl rubber are added to 500 parts by mass of n-hexane, and after stirring and swelling, 200 parts by mass of the dispersion liquid are added, and the mixture is heated to 35° C. and 0.1 parts by mass of hydrogen bromide is introduced, and the mixture is ultrasonically stirred and reacted for 40 minutes under the conditions of 200 W and 25 kHz, and a reaction completed liquid is obtained after the reaction is completed; The reaction solution was dried at 90°C to obtain a graphene dispersion; 80 parts by mass of butyl rubber, 5 parts by mass of chloroprene rubber, 25 parts by mass of graphene dispersion rubber, 20 parts by mass of N330 carbon black, 45 parts by mass of acetylene carbon black, 6 parts by mass of castor oil, 0.5 parts by mass of stearic acid and 5 parts by mass of zinc oxide are mixed at 110° C. for 10 min, and the rubber is filtered after the first mixing. After the filtering, 6 parts by mass of vulcanized resin are added and the mixture is mixed at 90° C. for 5 min in the second mixing stage to obtain a mixed rubber; The mixed rubber was placed in a mold and vulcanized at 180°C for 20 minutes to obtain a graphene vulcanized capsule. Example 2

[0020] 218 parts by mass (2 moles) of ethyl bromide are added dropwise to 82 parts by mass (1 mole) of N-methylimidazole, and after the addition is completed, 500 parts by mass of n-hexane are added, and the mixture is ultrasonically stirred at 200 W and 20 kHz under nitrogen protection, and heated to 45° C. for condensation reflux reaction for 24 hours. After the reaction is completed, an imidazolium ionic liquid is obtained; 70 parts by mass of conventional graphene and 100 parts by mass of imidazole ionic liquid were mixed, and the mixture was ground under nitrogen protection for 8 hours. After the grinding, 1 part by mass of ethyl bromide was added, and ultrasonic stirring was performed at 200 W and 25 kHz for 15 minutes to obtain a dispersion; 100 parts by mass of butyl rubber are added to 500 parts by mass of n-hexane, and after stirring and swelling, 150 parts by mass of the dispersion liquid are added, and the mixture is heated to 35° C. and 0.2 parts by mass of hydrogen bromide is introduced, and the mixture is ultrasonically stirred and reacted for 50 minutes under the conditions of 200 W and 25 kHz, and a reaction completed liquid is obtained after the reaction is completed; The reaction solution was dried at 90°C to obtain a graphene dispersion; 80 parts by mass of butyl rubber, 5 parts by mass of chloroprene rubber, 25 parts by mass of graphene dispersion rubber, 15 parts by mass of N330 carbon black, 45 parts by mass of acetylene carbon black, 8 parts by mass of castor oil, 1.5 parts by mass of stearic acid and 7 parts by mass of zinc oxide are mixed at 110° C. for 10 min, the rubber is filtered after the first mixing, and 6 parts by mass of vulcanized resin are added after the filtering, and the mixture is mixed at 90° C. for 5 min in the second mixing stage to obtain a mixed rubber after the second mixing stage; The mixed rubber was placed in a mold and vulcanized at 180°C for 20 minutes to obtain a graphene vulcanized capsule. Example 3

[0021] 163 parts by mass (1.5 molar parts) of ethyl bromide are added dropwise to 82 parts by mass (1 molar parts) of N-methylimidazole, and after the addition is completed, 300 parts by mass of n-hexane are added, and the mixture is ultrasonically stirred at 200 W and 20 kHz under nitrogen protection, and heated to 45° C. for condensation reflux reaction for 24 hours. After the reaction is completed, an imidazolium ionic liquid is obtained; 70 parts by mass of conventional graphene and 100 parts by mass of imidazole ionic liquid were mixed, and the mixture was ground under nitrogen protection for 5 hours. After the grinding, 1 part by mass of ethyl bromide was added, and ultrasonic stirring was performed at 200 W and 25 kHz for 15 minutes to obtain a dispersion; 100 parts by mass of butyl rubber are added to 600 parts by mass of n-hexane, and after stirring and swelling, 250 parts by mass of dispersion liquid are added, and the mixture is heated to 35° C. and 0.1 parts by mass of bromine gas is introduced, and the mixture is ultrasonically stirred and reacted for 40 minutes under the conditions of 200 W and 25 kHz, and a reaction completed liquid is obtained after the reaction is completed; The reaction solution was dried at 90°C to obtain a graphene dispersion; 70 parts by mass of butyl rubber, 5 parts by mass of chloroprene rubber, 35 parts by mass of graphene dispersion rubber, 15 parts by mass of N330 carbon black, 40 parts by mass of acetylene carbon black, 6 parts by mass of castor oil, 0.5 parts by mass of stearic acid and 5 parts by mass of zinc oxide are mixed at 110° C. for 10 min, and the rubber is filtered after the first mixing. After the filtering, 6 parts by mass of vulcanized resin are added and the mixture is mixed at 90° C. for 5 min in the second mixing stage to obtain a mixed rubber; The mixed rubber was placed in a mold and vulcanized at 180°C for 20 minutes to obtain a graphene vulcanized capsule. Example 4

[0022] 163 parts by mass (1.5 molar parts) of ethyl bromide are added dropwise to 94 parts by mass (1 molar parts) of N-vinyl imidazole, and after the addition is completed, 600 parts by mass of n-hexane are added, and the mixture is ultrasonically stirred at 200 W and 20 kHz under nitrogen protection, and heated to 45° C. for condensation reflux reaction for 24 hours. After the reaction is completed, an imidazolium ionic liquid is obtained; 60 parts by mass of conventional graphene and 100 parts by mass of imidazole ionic liquid were mixed, and the mixture was ground under nitrogen protection for 6 hours. After the grinding, 1 part by mass of ethyl bromide was added, and ultrasonic stirring was performed at 200 W and 25 kHz for 15 minutes to obtain a dispersion; 100 parts by mass of butyl rubber are added to 400 parts by mass of n-hexane, and after stirring and swelling, 200 parts by mass of the dispersion liquid are added, and the mixture is heated to 35° C. and 0.2 parts by mass of hydrogen bromide are introduced, and the mixture is ultrasonically stirred and reacted for 40 minutes under the conditions of 200 W and 25 kHz, and a reaction completed liquid is obtained after the reaction is completed; The reaction solution was dried at 90°C to obtain a graphene dispersion; 75 parts by mass of butyl rubber, 5 parts by mass of chloroprene rubber, 30 parts by mass of graphene dispersion rubber, 20 parts by mass of N330 carbon black, 35 parts by mass of acetylene carbon black, 6 parts by mass of castor oil, 0.5 parts by mass of stearic acid and 5 parts by mass of zinc oxide are mixed at 110° C. for 10 min, and the rubber is filtered after the first mixing. After the filtering, 6 parts by mass of vulcanized resin are added and the mixture is mixed at 90° C. for 5 min in the second mixing stage to obtain a mixed rubber; The mixed rubber was placed in a mold and vulcanized at 180°C for 20 minutes to obtain a graphene vulcanized capsule. Example 5

[0023] 218 parts by mass (2 moles) of ethyl bromide are added dropwise to 94 parts by mass (1 mole) of N-vinyl imidazole, and after the addition is completed, 700 parts by mass of n-hexane are added, and the mixture is ultrasonically stirred at 200 W and 20 kHz under nitrogen protection, and heated to 45° C. for condensation reflux reaction for 24 hours. After the reaction is completed, an imidazolium ionic liquid is obtained; 70 parts by mass of conventional graphene and 100 parts by mass of imidazole ionic liquid were mixed, and the mixture was ground under nitrogen protection for 6 hours. After the grinding, 1 part by mass of ethyl bromide was added, and ultrasonic stirring was performed at 200 W and 25 kHz for 15 minutes to obtain a dispersion; 100 parts by mass of butyl rubber are added to 400 parts by mass of n-hexane, and after stirring and swelling, 250 parts by mass of dispersion liquid are added, and the mixture is heated to 35° C. and 0.1 parts by mass of bromine gas is introduced, and the mixture is ultrasonically stirred and reacted for 40 minutes under the conditions of 200 W and 25 kHz, and a reaction completed liquid is obtained after the reaction is completed; The reaction solution was dried at 90°C to obtain a graphene dispersion; 80 parts by mass of butyl rubber, 5 parts by mass of chloroprene rubber, 25 parts by mass of graphene dispersion rubber, 15 parts by mass of N330 carbon black, 45 parts by mass of acetylene carbon black, 7 parts by mass of castor oil, 1 part by mass of stearic acid and 6 parts by mass of zinc oxide are mixed at 110° C. for 10 min, and the rubber is filtered after the first mixing. After the filtering, 6 parts by mass of vulcanized resin are added and the mixture is mixed at 90° C. for 5 min in the second mixing stage to obtain a mixed rubber; The mixed rubber was placed in a mold and vulcanized at 180°C for 20 minutes to obtain a graphene vulcanized capsule. Example 6

[0024] This embodiment is based on Example 1, and differs from Example 1 in that the reaction completed liquid is mixed and stirred with 0.5 parts by mass of stearic acid, 1 part by mass of zinc oxide, and 0.1 parts by mass of 6PPD, and then dried at 90° C. to obtain a graphene dispersion gel. Example 7

[0025] This embodiment is based on embodiment 6, and the difference from embodiment 6 is that conventional graphene is replaced with graphene oxide, and the preparation steps of graphene oxide are as follows: 100 parts by mass of cyclohexane and 25 parts by mass of a 10 wt % aqueous solution of manganese stearate were mixed, and ultrasonically stirred at 200 W and 25 kHz for 5 min to obtain an emulsion, 10 parts by mass of 400-mesh graphite was added to the emulsion, and ultrasonic stirring was continued for 6 min to obtain an emulsified dispersion; The emulsified dispersion was spread in a glass container and magnetically stirred, and irradiated with an ultraviolet lamp for 6 hours at a power of 300 W and a wavelength of 380 nm to induce an oxidation reaction, and after the reaction was completed, a graphene oxide dispersion was obtained; Step S230, centrifuging, washing, and drying the graphene oxide dispersion to obtain graphene oxide. Example 8

[0026] This embodiment is based on embodiment 6, and the difference from embodiment 6 is that conventional graphene is replaced with redox graphene, and the preparation steps of redox graphene are as follows: 100 parts by mass of cyclohexane and 25 parts by mass of a 10 wt % aqueous solution of manganese stearate were mixed, and ultrasonically stirred at 200 W and 25 kHz for 5 min to obtain an emulsion, 10 parts by mass of 400-mesh graphite was added to the emulsion, and ultrasonic stirring was continued for 6 min to obtain an emulsified dispersion; The emulsified dispersion was spread in a glass container and magnetically stirred, and irradiated with an ultraviolet lamp for 8 hours at a power of 300 W and a wavelength of 380 nm to induce an oxidation reaction, and after the reaction was completed, a graphene oxide dispersion was obtained; The graphene oxide dispersion is centrifuged, washed, and dried to obtain graphene oxide; 4 parts by mass of graphene oxide and 800 parts by mass of deionized water were mixed, and ultrasonically stirred at 200 W and 25 kHz. 1 part by mass of zinc chloride and 0.3 parts by mass of sodium borohydride were added in sequence, and the mixture was stirred for 10 minutes. After the reaction, the reduced graphene oxide was obtained by filtering, washing with water, and drying.

[0027] Comparative Example 1 95 parts by mass of butyl rubber, 5 parts by mass of chloroprene rubber, 35 parts by mass of N330 carbon black, 60 parts by mass of acetylene carbon black, 6 parts by mass of castor oil, 0.5 parts by mass of stearic acid and 5 parts by mass of zinc oxide are mixed at 110° C. for 15 min, and the rubber is filtered after the first mixing. After the filtering, 10 parts by mass of vulcanized resin are added and the mixture is mixed at 90° C. for 15 min in the second mixing stage to obtain a mixed rubber; The mixed rubber was placed into a mold and vulcanized at 180°C for 40 min to obtain a conventional vulcanization bladder.

[0028] Comparative Example 2 95 parts by mass of butyl rubber, 5 parts by mass of chloroprene rubber, 8 parts by mass of conventional graphene, 20 parts by mass of N330 carbon black, 35 parts by mass of acetylene carbon black, 6 parts by mass of castor oil, 0.5 parts by mass of stearic acid and 5 parts by mass of zinc oxide are mixed at 110° C. for 15 min, and the rubber is filtered after the first mixing. After the filtering, 6 parts by mass of vulcanized resin are added and the mixture is mixed at 90° C. for 15 min in the second mixing stage to obtain a mixed rubber; The mixed rubber was placed in a mold and vulcanized at 180°C for 40 minutes to obtain a graphene vulcanized capsule.

[0029] Comparative Example 3 80 parts by mass of butyl rubber, 5 parts by mass of chloroprene rubber, 15 parts by mass of brominated butyl rubber, 8 parts by mass of graphene, 20 parts by mass of N330 carbon black, 35 parts by mass of acetylene carbon black, 6 parts by mass of castor oil, 0.5 parts by mass of stearic acid and 5 parts by mass of zinc oxide are mixed at 110° C. for 10 min, and the rubber is filtered after the first mixing. After the filtering, 6 parts by mass of vulcanized resin are added and the mixture is mixed at 90° C. for 5 min in the second mixing stage to obtain a mixed rubber; The mixed rubber was placed in a mold and vulcanized at 180°C for 30 minutes to obtain a graphene vulcanized capsule.

[0030] Performance Testing The thermal conductivity of the vulcanized bladders in Examples 1-8 and Comparative Examples 1-3 was tested, and the physical and mechanical properties of the vulcanized bladders in Examples 1-8 and Comparative Examples 1-3 were tested before and after thermal oxidative aging. The thermal oxidative aging conditions were aging at 185° C. in a hot air oven for 48 h. The test results are shown in Table 1.

[0031] As can be seen from Table 1, the thermal conductivity of the graphene sulfurized capsules in Examples 1-8 is 0.415-0.462 W / m·k, which is much higher than the conventional vulcanization bladder without graphene in Comparative Example 1, and also higher than the graphene vulcanization bladders in which graphene is directly fed and mixed in Comparative Examples 2 and 3; before thermal oxidative aging, the physical and mechanical properties of the graphene vulcanization bladders in Examples 1-8 are the same as those of the conventional vulcanization bladder without graphene in Comparative Example 1, and higher than those of the graphene vulcanization bladders in which graphene is directly fed and mixed in Comparative Examples 2 and 3; after thermal oxidative aging, the tensile strength retention rate of the graphene vulcanization bladders in Examples 1-8 is much higher than that of the conventional vulcanization bladder 1 without graphene in Comparative Example 1, and also higher than that of the graphene vulcanization bladders in which graphene is directly fed and mixed in Comparative Examples 2 and 3, and the elongation retention rate, 100% tensile stress retention rate and 300% tensile stress retention rate are the same as those of Comparative Examples 1-3.

[0032] The embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement modes and shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a graphene vulcanization capsule, characterized in that: The following steps are involved: Step S100, ethyl bromide, an imidazole derivative and n-hexane are mixed, ultrasonically stirred under nitrogen protection, and heated to perform condensation reflux reaction, and after the reaction is completed, an imidazole ionic liquid is obtained; Step S200, mixing graphene and imidazolium ionic liquid, grinding under nitrogen protection, adding ethyl bromide after grinding, ultrasonic stirring, and obtaining a dispersion after stirring; Step S300, adding butyl rubber to n-hexane, stirring and swelling, then adding dispersion, heating and introducing bromination accelerator, ultrasonically stirring for reaction, and obtaining a reaction completion liquid after the reaction is completed; Step S400, drying the reaction completed liquid to obtain a graphene dispersion glue; Step S500, mixing butyl rubber, chloroprene rubber, graphene dispersion rubber, filler, softener, processing aid, activator and vulcanizer to obtain a mixed rubber; Step S600, placing the mixed rubber into a mold for vulcanization molding to obtain a graphene vulcanization capsule.

2. The method for preparing a tire curing bladder according to claim 1, characterized in that: In step S100, the imidazole derivative is at least one of N-methylimidazole and N-vinylimidazole; in step S200, the graphene is at least one of conventional graphene, graphene oxide and reduced graphene oxide; in step S300, the bromination promoter is at least one of hydrogen bromide and bromine gas; in step S500, the filler includes at least one of N220 carbon black and acetylene carbon black, the softener is castor oil, the processing aid is stearic acid, the activator is zinc oxide, and the vulcanizing agent is vulcanized resin.

3. The method for preparing a tire curing bladder according to claim 1, characterized in that: In step S100, during mixing, ethyl bromide is first added dropwise to the imidazole derivative, and n-hexane is added after the addition is completed; in step S500, during mixing, butyl rubber, chloroprene rubber, graphene dispersion rubber, filler, softener, processing aid and activator are first mixed in one stage, and the rubber is filtered after the first mixing is completed. After the filtering of the rubber, a vulcanized resin is added to perform a second mixing stage, and a mixed rubber is obtained after the second mixing is completed.

4. The method for preparing a tire curing bladder according to claim 1, characterized in that: In step S100, the molar ratio of ethyl bromide to imidazole derivative is (1.5-2):1, and the mass ratio of the total mass of ethyl bromide and imidazole derivative to n-hexane is 1:(1-5); in step S200, the mass ratio of graphene, imidazole ionic liquid and ethyl bromide is (50-70):100:1; in step S300, the mass ratio of butyl rubber, n-hexane, dispersion liquid and bromination accelerator is 100:(400-600):(150-250):(0.1-0.2); in step S500, the mass ratio of butyl rubber, chloroprene rubber, graphene dispersion rubber, filler, softener, processing aid, activator and vulcanizer is (70-80):5:(15-35):(50-65):(6-8):(0.5-1.5):(5-7):(6-8).

5. The method for preparing a tire curing bladder according to claim 1, characterized in that: In step S100, the ultrasonic power is 200-500W, the ultrasonic frequency is 20-25kHz, the reaction temperature is 40-50°C, and the reaction time is 12-48h; in step S200, the grinding time is 4-8h, the ultrasonic stirring time is 15-30 minutes, the ultrasonic power is 200-500W, and the ultrasonic frequency is 20-25kHz; in step S300, the reaction temperature is 30-35°C, the ultrasonic power is 200-500W, the ultrasonic frequency is 20-25kHz, and the reaction time is 30-60min; in step S400, the drying temperature is 80-100°C; in step S500, the mixing temperature is 90-120°C, the mixing time is 15-30min, the vulcanization temperature is 160-200°C, and the vulcanization time is 20-30min.

6. The method for preparing a tire curing bladder according to claim 1, characterized in that: In step S400, the reaction solution, stearic acid, zinc oxide and 6PPD are mixed and stirred evenly and then dried to obtain a graphene dispersion rubber; the mass ratio of stearic acid, zinc oxide, 6PPD and butyl rubber in step S300 is (0.5-1): (0.5-2): (0.1-0.5):

100.

7. The method for preparing a tire curing bladder according to claim 1, characterized in that: In step S200, the graphene is graphene oxide, and its preparation includes the following steps: Step S210, mixing cyclohexane and manganese stearate aqueous solution, stirring by ultrasonic means to obtain an emulsion, adding graphite to the emulsion, and continuing ultrasonic stirring to obtain an emulsified dispersion; the concentration of the manganese stearate aqueous solution is 10-15wt%, and the mass ratio of cyclohexane, manganese stearate aqueous solution and graphite is 100:25:(5-20); Step S220, spreading the emulsified dispersion in a glass container, performing magnetic stirring, and irradiating with ultraviolet light to induce an oxidation reaction, and obtaining a graphene oxide dispersion after the reaction is completed; Step S230, centrifuging, washing, and drying the graphene oxide dispersion to obtain graphene oxide.

8. The method for preparing a tire curing bladder according to claim 7, characterized in that: In step S210, the mesh size of the graphite is 200-1000 meshes; the ultrasonic frequency is 20-25 kHz, the stirring time of the emulsion is 5-10 min, and the stirring time of the emulsified dispersion is 5-10 min; in step S220, the power of the ultraviolet lamp is 290-310 W, the wavelength of the ultraviolet light is 380-395 nm, and the ultraviolet light irradiation time is 5-10 h.

9. The method for preparing a tire curing bladder according to claim 1, characterized in that: In step S200, the graphene is reduced graphene oxide, and its preparation includes the following steps: Step S240, mixing graphene oxide and deionized water, adding zinc chloride and sodium borohydride in sequence under ultrasonic stirring, filtering, washing and drying after the reaction to obtain reduced graphene oxide; the mass ratio of graphene oxide, deionized water, zinc chloride and sodium borohydride is 4: (500-1000): (1-2): (0.3-0.5), the ultrasonic frequency is 20-25 kHz, and the stirring time is 10-15 min.

10. A graphene sulfurization capsule, characterized in that: The graphene vulcanization capsule is prepared by the preparation method of any one of claims 1 to 9.

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