A conductive graphene-acetylene carbon black-silicone rubber composite material and a preparation method thereof

Abstract

The present application relates to the technical field of conductive silicone rubber, and particularly relates to a conductive graphene-ethyne carbon black-silicone rubber composite material and a preparation method thereof, the conductive graphene-ethyne carbon black-silicone rubber composite material comprises the following raw materials in parts by weight: 100 parts of silicone rubber, 40-50 parts of modified ethyne carbon black, 3-5 parts of phosphorus-doped conductive graphene, 2-4 parts of hydroxyl silicone oil, 2-5 parts of vulcanizing agent, 1-3 parts of triallyl isocyanurate, 2-4 parts of zinc oxide and 0.3-0.7 parts of stearic acid. The conductive graphene-ethyne carbon black-silicone rubber composite material prepared by the present application has excellent conductivity and good mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of conductive silicone rubber technology, specifically to a conductive graphene-acetylene black-silicone rubber composite material and its preparation method. Background Technology

[0002] Conductive silicone rubber is a composite material that combines the excellent elasticity of silicone rubber with the conductivity of conductive fillers. Conductive silicone rubber is characterized by high elasticity and good conductivity, and also possesses excellent temperature resistance, aging resistance, and chemical corrosion resistance. Therefore, it is often used in the manufacture of connectors for large metal parts, grounding strips, aviation cables, electronic components, etc. The conductivity mechanism of silicone rubber can be summarized as follows: (1) Carbon black: Adding an appropriate amount of carbon black to silicone rubber can increase conductivity and improve the mechanical properties of the conductive material; (2) Conductive particle fillers: Conductive particles such as metals, carbon powder, and silver can be used to fill silicone rubber to obtain conductivity; (3) Conductive thermoplastic polymers: Silicone rubber can be combined with conductive thermoplastic polymers to form composite materials with conductivity; (4) Additives: Adding specific additives, such as metal oxides and metal silicates, to silicone rubber can also obtain conductivity. However, conductive fillers in silicone rubber often suffer from poor dispersion, resulting in poor elasticity of the silicone rubber.

[0003] Patent CN103937258A discloses a method for preparing highly resilient conductive silicone rubber. This method includes modifying carbon nanotubes or conductive carbon black to serve as conductive fillers, mixing raw silicone rubber with the modified conductive fillers, heat-treating, then refining on a two-roll mill while adding vulcanizing agents and crosslinking aids, mixing thoroughly, and finally vulcanizing to obtain highly resilient conductive silicone rubber. The conductive silicone rubber raw materials, by weight, are: 100 parts raw silicone rubber, 5-40 parts modified conductive fillers, 0.01-5 parts vulcanizing agent, and 0.01-5 parts crosslinking aids. This invention uses surfactants, silane coupling agents, or polysiloxanes to modify the conductive fillers, resulting in conductive silicone rubber with good conductivity, high resilience, low compression set, and good mechanical properties. However, the effect of surfactants, silane coupling agents, or polysiloxanes on improving the dispersibility of the conductive fillers is limited.

[0004] Patent CN118440504A discloses a tear-resistant, high-elasticity conductive silicone rubber and its preparation method, as well as a fabric with a tear-resistant, high-elasticity conductive silicone rubber circuit. The tear-resistant, high-elasticity conductive silicone rubber is made from the following raw materials in parts by weight: 80-120 parts silicone rubber, 30-50 parts conductive filler, 10-50 parts chitosan, 2-3 parts waterproofing agent, 4-8 parts hydroxyl silicone oil, 0.5-1 part crosslinking agent, 1-2 parts accelerator, and 0.5-1 part antioxidant. Each part of the conductive filler is prepared by mixing carbon nanotubes and nano-silver in a weight ratio of (15-35):6. The tear-resistant, high-elasticity conductive silicone rubber prepared by the above formula has good tear resistance, high elasticity, waterproofness, skin affinity, conductivity, and durability. However, the strong water absorption of chitosan may reduce the tensile strength of the conductive silicone rubber.

[0005] Therefore, there is an urgent need in the market to develop a conductive silicone rubber composite material with better mechanical properties. Summary of the Invention

[0006] In view of the problems existing in the prior art, the purpose of this invention is to obtain a conductive silicone rubber composite material with excellent electrical conductivity and good mechanical properties.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides a conductive graphene-acetylene carbon black-silicone rubber composite material, comprising the following raw materials by weight: 100 parts silicone rubber, 40-50 parts modified acetylene carbon black, 3-5 parts phosphorus-doped conductive graphene, 2-4 parts hydroxyl silicone oil, 2-5 parts vulcanizing agent, 1-3 parts triallyl isocyanurate, 2-4 parts zinc oxide, and 0.3-0.7 parts stearic acid.

[0009] This application presents a conductive graphene-acetylene black-silicone rubber composite material prepared by blending silicone rubber, modified acetylene black, conductive graphene, hydroxyl silicone oil, vulcanizing agent, triallyl isocyanurate, zinc oxide, and stearic acid. The composite material exhibits excellent electrical conductivity and good mechanical properties.

[0010] In some embodiments, the silicone rubber is methyl vinyl silicone rubber.

[0011] In some embodiments, the method for preparing the modified acetylene black includes the following steps:

[0012] A1. Add carbon fiber and KH550 to a 90-95wt% ethanol aqueous solution, stir at room temperature for 2-3 hours, and dry to obtain pretreated carbon fiber.

[0013] A2. Add polycarbosilane to n-hexane and stir at room temperature for 30-60 minutes. Add acetylene black and the pretreated carbon fiber obtained in step A1. Stir at 55-70℃ until n-hexane is completely volatilized. Dry, grind, and sieve to obtain modified acetylene black.

[0014] Preferably, the mass ratio of the carbon fiber to KH550 is 1:(0.01-0.05).

[0015] This application involves treating carbon fibers with KH550, then encapsulating the pretreated carbon fibers together with acetylene black in polycarbosilane. The resulting modified acetylene black improves the overall performance of the conductive silicone rubber composite material. This is likely because, on the one hand, the introduction of KH550 enhances the compatibility between carbon fibers and polycarbosilane, making them more easily exposed on the surface of the modified acetylene black, which facilitates the construction of a conductive network structure with conductive graphene, thereby improving the conductivity of the conductive silicone rubber composite material; on the other hand, the acetylene black encapsulated in polycarbosilane has good compatibility with silicone rubber, which in turn improves the mechanical properties of the composite material.

[0016] In some embodiments, the number-average molecular weight of the polycarbosilane is 1000-1500.

[0017] In some embodiments, the mass ratio of the polycarbosilane to acetylene black is (0.1-0.4):1.

[0018] In some embodiments, the mass ratio of acetylene black to pretreated carbon fiber in step A2 is 1:(0.3-0.6).

[0019] This application enables conductive silicone rubber to possess both good mechanical properties and good electrical conductivity by limiting the molecular weight of polycarbosilane, the ratio of polycarbosilane to acetylene black, and the ratio of acetylene black to pretreated carbon fibers. This may be because the ratio allows the carbon fibers to be more easily exposed, thereby enabling the formation of a more complete conductive network inside the conductive silicone. Furthermore, polycarbosilane can effectively encapsulate acetylene black to enhance its compatibility with silicone rubber without significantly affecting the conductivity of acetylene black itself.

[0020] In some embodiments, the preparation method of the phosphorus-doped conductive graphene includes the following steps: dispersing conductive graphene in deionized water, adding formaldehyde, stirring for 20-30 min, adding phytic acid, stirring for 20-30 min to obtain a mixture, annealing the mixture at 170-190℃ for 10-14 h to obtain phosphorus-doped conductive graphene.

[0021] In some embodiments, the conductive graphene is SE1233 conductive graphene.

[0022] The unique two-dimensional honeycomb structure of conductive graphene endows it with extremely high electron mobility. However, the strong van der Waals forces and π-π interactions between graphene sheets make them prone to stacking and agglomeration, resulting in uneven dispersion in composite materials and affecting the stability of the composite's electrical conductivity and mechanical properties. Furthermore, insufficient interfacial bonding strength between graphene and the matrix in the composite material also reduces charge transport efficiency. To address these issues, this application obtains phosphorus-doped conductive graphene by reacting conductive graphene, formaldehyde, and phytic acid. The reaction mechanism is as follows: formaldehyde can partially reduce oxygen-containing functional groups (such as carboxyl and epoxy groups) in graphene oxide, restoring the conjugated structure of graphene, while simultaneously promoting phosphorus doping. Introducing phosphorus atoms into graphene can improve the conductivity of conductive graphene. Furthermore, phosphorus atoms can form strong hydrogen bonds with the amino groups on the KH550 segments of modified acetylene black, which can promote the dispersion of conductive graphene in silicone rubber and improve the mechanical properties of conductive silicone rubber. Moreover, the carbon fibers dispersed in the system can be interwoven in the conductive network, reducing defects in the conductive network by accelerating the movement of electrons, thereby improving the conductivity of the composite material.

[0023] In some embodiments, the mass ratio of the conductive graphene to phytic acid is 1:(0.1-0.4).

[0024] This application enables conductive silicone rubber to have better conductivity by limiting the ratio of conductive graphene and phytic acid. This may be because limiting the ratio of the two can solve the problem of increasing non-conductive groups such as P=O or POP due to phytic acid residue, which leads to an increase in graphene lattice defects and a decrease in conductivity.

[0025] Another aspect of the present invention provides a method for preparing a conductive graphene-acetylene black-silicone rubber composite material, comprising the following steps:

[0026] S1. Put silicone rubber into a two-roll mill. After wrapping the rolls, add modified acetylene black and hydroxyl silicone oil alternately. Then add phosphorus-doped conductive graphene, zinc oxide and stearic acid. After the material is fully fed, add vulcanizing agent and triallyl isocyanurate. Mix for 25-30 minutes. Adjust the roll gap to 6-8 mm. Roll 5-8 times. Cut into sheets, cool to room temperature, and let stand for 24-48 hours to obtain the compound.

[0027] S2. Use a flat vulcanizing machine to vulcanize the compound. The first vulcanization conditions are 175-185℃ and vulcanization time is 11-14 minutes. Use an oven to perform the second vulcanization at 200-210℃ and keep warm for 3-5 hours to obtain a conductive graphene-acetylene black-silicone rubber composite material.

[0028] Preferably, the vulcanizing agent is DCP.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The conductive graphene-acetylene black-silicone rubber composite material prepared by blending silicone rubber, modified acetylene black, conductive graphene, hydroxyl silicone oil, vulcanizing agent, triallyl isocyanurate, zinc oxide and stearic acid has excellent conductivity and good mechanical properties.

[0031] (2) In this invention, carbon fibers are pretreated with KH550 to obtain pretreated carbon fibers, which are then wrapped together with acetylene black in polycarbosilane. On the one hand, the introduction of KH550 can improve the compatibility between carbon fibers and polycarbosilane, making them easier to expose on the surface of modified acetylene black, which is conducive to building a conductive network structure with conductive graphene, thereby improving the conductivity of conductive silicone rubber composite material. On the other hand, acetylene black wrapped in polycarbosilane has good compatibility with silicone rubber, which is conducive to improving the mechanical properties of composite material.

[0032] (3) The present invention can improve the conductivity of conductive graphene by introducing phosphorus atoms on graphene, thereby improving the conductivity of conductive silicone rubber composite material. Furthermore, phosphorus atoms can generate strong hydrogen bonding with amino groups on KH550, which can promote the dispersion of conductive graphene in silicone rubber and improve the mechanical and conductivity properties of conductive silicone rubber. Detailed Implementation

[0033] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0034] In the following examples and comparative examples, except for the modified acetylene black and phosphorus-doped conductive graphene, all other compounds and related reagents used were commercially available. Specifically, the methyl vinyl silicone rubber (CAS number 67762-94-1, number-average molecular weight 480,000-800,000) was purchased from Hubei Xingyan New Material Technology Co., Ltd.; the acetylene black (50% compression grade) was purchased from Tianjin Yihuachang New Material Technology Co., Ltd.; the polycarbosilane-1 (number-average molecular weight 1000-1500) was purchased from Beijing Huawirui Chemical Technology Co., Ltd.; the polycarbosilane-2 (number-average molecular weight 1000-2000) was purchased from Shanghai Buwei Applied Materials Technology Co., Ltd.; the carbon fiber (length 150-300 μm) was purchased from Hangzhou Gaoke Composite Materials Co., Ltd.; and the SE1233 conductive graphene was purchased from Liaoyang Xingwang Graphite Products Co., Ltd.

[0035] Preparation Example 1

[0036] The preparation method of modified acetylene black-1 includes the following steps:

[0037] A1. Add 10g of carbon fiber and 0.3g of KH550 to 80g of 93wt% ethanol aqueous solution, stir at room temperature for 2.5h, and dry to obtain pretreated carbon fiber;

[0038] A2. Add 2.5g of polycarbosilane-1 to 100g of n-hexane, stir at room temperature for 45min, add 10g of acetylene black and 4.5g of the pretreated carbon fiber obtained in step A1, stir at 65℃ until the n-hexane evaporates completely, dry, grind and pass through a 200-mesh sieve to obtain modified acetylene black-1.

[0039] Preparation Example 2

[0040] The preparation method of modified acetylene black-2 is the same as that of preparation example 1, except that the amount of polycarbosilane-1 added is 5g.

[0041] Preparation Example 3

[0042] The preparation method of modified acetylene black-3 is the same as that of preparation example 1, except that the amount of pretreated carbon fiber added in step A2 is 2g.

[0043] Preparation Example 4

[0044] The preparation method of modified acetylene black-4 is the same as that of preparation example 1, except that polycarbosilane-1 is replaced by polycarbosilane-2 in equal amounts.

[0045] Preparation Example 5

[0046] The preparation method of phosphorus-doped conductive graphene-1 includes the following steps: 10g of SE1233 conductive graphene is dispersed in 70g of deionized water, 2ml of formaldehyde is added, and the mixture is stirred for 25min. Then, 2.5g of phytic acid is added and stirred for 25min to obtain a mixture. The mixture is then annealed at 180℃ for 12h to obtain phosphorus-doped conductive graphene-1.

[0047] Preparation Example 6

[0048] The preparation method of phosphorus-doped conductive graphene-2 ​​is the same as that in preparation example 4, except that the amount of phytic acid added is 5g.

[0049] Example 1

[0050] A conductive graphene-acetylene black-silicone rubber composite material, by weight, comprises the following raw materials: 100 parts methyl vinyl silicone rubber, 45 parts modified acetylene black-1, 4 parts phosphorus-doped conductive graphene-1, 3 parts hydroxyl silicone oil, 3 parts DCP, 2 parts triallyl isocyanurate, 3 parts zinc oxide, and 0.5 parts stearic acid.

[0051] The preparation method of the conductive graphene-acetylene black-silicone rubber composite material in this embodiment includes the following steps:

[0052] S1. Add methyl vinyl silicone rubber to the open mill. After wrapping the rolls, add modified acetylene black-1 and hydroxyl silicone oil alternately. Then add phosphorus-doped conductive graphene-1, zinc oxide and stearic acid. After the material is fully fed, add DCP and triallyl isocyanurate. Mix for 27 minutes, adjust the roll gap to 7 mm, roll 6 times, cut into sheets, cool to room temperature, and let stand for 36 hours to obtain the compound.

[0053] S2. The compound was vulcanized using a flat vulcanizing machine. The first vulcanization condition was 180℃ for 12 minutes. The second vulcanization condition was 205℃ for 4 hours using an oven to obtain a conductive graphene-acetylene black-silicone rubber composite material.

[0054] Example 2

[0055] A conductive graphene-acetylene black-silicone rubber composite material, by weight, comprises the following raw materials: 100 parts methyl vinyl silicone rubber, 40 parts modified acetylene black-1, 3 parts phosphorus-doped conductive graphene-1, 2 parts hydroxyl silicone oil, 2 parts DCP, 1 part triallyl isocyanurate, 2 parts zinc oxide, and 0.3 parts stearic acid.

[0056] The preparation method of the conductive graphene-acetylene black-silicone rubber composite material in this embodiment includes the following steps:

[0057] S1. Add methyl vinyl silicone rubber to the open mill. After wrapping the rolls, add modified acetylene black-1 and hydroxyl silicone oil alternately. Then add phosphorus-doped conductive graphene-1, zinc oxide and stearic acid. After the material is fully consumed, add DCP and triallyl isocyanurate. Mix for 25 minutes, adjust the roll gap to 6 mm, roll 5 times, cut into sheets, cool to room temperature, and let stand for 24 hours to obtain the compound.

[0058] S2. The compound was vulcanized using a flat vulcanizing machine. The first vulcanization condition was 175℃ for 14 minutes. The second vulcanization condition was 200℃ for 5 hours using an oven to obtain a conductive graphene-acetylene black-silicone rubber composite material.

[0059] Example 3

[0060] A conductive graphene-acetylene black-silicone rubber composite material, by weight, comprises the following raw materials: 100 parts methyl vinyl silicone rubber, 50 parts modified acetylene black-1, 5 parts phosphorus-doped conductive graphene-1, 4 parts hydroxyl silicone oil, 5 parts DCP, 3 parts triallyl isocyanurate, 4 parts zinc oxide, and 0.7 parts stearic acid.

[0061] The preparation method of the conductive graphene-acetylene black-silicone rubber composite material in this embodiment includes the following steps:

[0062] S1. Add methyl vinyl silicone rubber to the open mill. After wrapping the rolls, add modified acetylene black-1 and hydroxyl silicone oil alternately. Then add phosphorus-doped conductive graphene-1, zinc oxide and stearic acid. After the material is fully consumed, add DCP and triallyl isocyanurate. Mix for 30 minutes, adjust the roll gap to 8 mm, roll 8 times, cut into sheets, cool to room temperature, and let stand for 48 hours to obtain the compound.

[0063] S2. The compound was vulcanized using a flat vulcanizing machine. The first vulcanization condition was 185℃ for 11 minutes. The second vulcanization condition was 210℃ for 3 hours using an oven to obtain a conductive graphene-acetylene black-silicone rubber composite material.

[0064] Example 4

[0065] A conductive graphene-acetylene black-silicone rubber composite material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified acetylene black-1 is replaced with modified acetylene black-2 in equal amounts.

[0066] Example 5

[0067] A conductive graphene-acetylene black-silicone rubber composite material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified acetylene black-1 is replaced with modified acetylene black-3 in equal amounts.

[0068] Example 6

[0069] A conductive graphene-acetylene black-silicone rubber composite material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that modified acetylene black-1 is replaced with modified acetylene black-4 in equal amounts.

[0070] Example 7

[0071] A conductive graphene-acetylene black-silicone rubber composite material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that phosphorus-doped conductive graphene-1 is replaced by phosphorus-doped conductive graphene-2 ​​in an equal amount.

[0072] Comparative Example 1

[0073] A conductive graphene-acetylene black-silicone rubber composite material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that the modified acetylene black-1 is replaced with an equal amount of acetylene black.

[0074] Comparative Example 2

[0075] A conductive graphene-acetylene black-silicone rubber composite material and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that phosphorus-doped conductive graphene-1 is replaced with an equal amount of SE1233 conductive graphene.

[0076] Performance testing

[0077] The performance of the conductive graphene-acetylene black-silicone rubber composite materials obtained in the above embodiments and comparative examples was tested:

[0078] (1) Mechanical properties: The impact elasticity of conductive graphene-acetylene black-silicone rubber composite material was tested according to GB / T1681—2009, the tensile stress-strain properties of conductive graphene-acetylene black-silicone rubber composite material were tested according to GB / T528—2009, and the tear strength of conductive graphene-acetylene black-silicone rubber composite material was tested according to GB / T529—2008 to determine its mechanical properties.

[0079] (2) Conductivity: The volume resistivity of conductive graphene-acetylene black-silicone rubber composite material was tested according to GB / T1692—2008 to determine its conductivity.

[0080] The test results are shown in Table 1:

[0081] Table 1

[0082]

[0083] As shown in Table 1, the conductive graphene-acetylene black-silicone rubber composites of Examples 1-3 exhibit excellent electrical conductivity and good mechanical properties. A comparison of Examples 4, 6, and 1 shows that changing the polycarbosilane or its molecular weight deteriorates the conductivity of the acetylene black encapsulated in the polycarbosilane, thus reducing the conductivity of the conductive graphene-acetylene black-silicone rubber composite. A comparison of Examples 5 and 1 shows that changing the ratio of pretreated carbon fibers to acetylene black makes the carbon fibers less exposed, further reducing the conductivity of the conductive graphene-acetylene black-silicone rubber composite. A comparison between Example 7 and Example 1 shows that changing the ratio of conductive graphene to phytic acid introduces more non-conductive groups such as P=O or POP due to phytic acid residue, leading to an increase in graphene lattice defects and a decrease in the conductivity of the conductive graphene-acetylene black-silicone rubber composite material. A comparison between Comparative Example 1 and Example 1 shows that the conductive graphene-acetylene black-silicone rubber composite material has poor mechanical properties when acetylene black is not modified. A comparison between Comparative Example 2 and Example 1 shows that the conductive graphene-acetylene black-silicone rubber composite material has poor conductivity and mechanical properties when SE1233 conductive graphene is used directly.

[0084] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A conductive graphene-acetylene black-silicone rubber composite material, characterized in that, By weight, it includes the following raw materials: 100 parts silicone rubber, 40-50 parts modified acetylene black, 3-5 parts phosphorus-doped conductive graphene, 2-4 parts hydroxyl silicone oil, 2-5 parts vulcanizing agent, 1-3 parts triallyl isocyanurate, 2-4 parts zinc oxide, and 0.3-0.7 parts stearic acid. The method for preparing the modified acetylene carbon black includes the following steps: A1. Add carbon fiber and KH550 to a 90-95wt% ethanol aqueous solution, stir at room temperature for 2-3 hours, and dry to obtain pretreated carbon fiber. A2. Add polycarbosilane to n-hexane and stir at room temperature for 30-60 minutes. Add acetylene black and the pretreated carbon fiber obtained in step A1. Stir at 55-70°C until n-hexane is completely volatilized. Dry, grind, and sieve to obtain modified acetylene black. The number-average molecular weight of the polycarbosilane is 1000-1500; The mass ratio of the polycarbosilane to acetylene black is (0.1-0.4):1; The mass ratio of acetylene black to pretreated carbon fiber in step A2 is 1:(0.3-0.6); The preparation method of the phosphorus-doped conductive graphene includes the following steps: dispersing conductive graphene in deionized water, adding formaldehyde, stirring for 20-30 min, adding phytic acid, stirring for 20-30 min, obtaining a mixture, keeping the mixture at 170-190℃ for 10-14 h, annealing, and obtaining phosphorus-doped conductive graphene. The mass ratio of the conductive graphene to phytic acid is 1:(0.1-0.4).

2. The conductive graphene-acetylene black-silicone rubber composite material according to claim 1, characterized in that, The silicone rubber is methyl vinyl silicone rubber.

3. The conductive graphene-acetylene black-silicone rubber composite material according to claim 1, characterized in that, The conductive graphene is SE1233 conductive graphene.

4. A method for preparing the conductive graphene-acetylene black-silicone rubber composite material according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Put silicone rubber into a two-roll mill. After wrapping the rolls, add modified acetylene black and hydroxyl silicone oil alternately. Then add phosphorus-doped conductive graphene, zinc oxide and stearic acid. After the material is fully fed, add vulcanizing agent and triallyl isocyanurate. Mix for 25-30 minutes. Adjust the roll gap to 6-8 mm. Roll 5-8 times. Cut into sheets, cool to room temperature, and let stand for 24-48 hours to obtain the compound. S2. Use a flat vulcanizing machine to vulcanize the compound. The first vulcanization conditions are 175-185℃ and vulcanization time is 11-14 minutes. Use an oven to perform the second vulcanization at 200-210℃ and keep warm for 3-5 hours to obtain a conductive graphene-acetylene black-silicone rubber composite material.

Images