Composite carbon fiber felt and preparation method thereof

Abstract

The invention relates to the field of D06M13 / 513, in particular to a composite carbon fiber felt and a preparation method thereof.The composite carbon fiber felt is prepared from, by weight, 200-300 parts of composite carbon fibers, 3-15 parts of organosiloxane and 15-45 parts of a finishing agent; the organosiloxane is vinyl-containing organosiloxane and epoxy-group-containing organosiloxane, and due to the introduction of the organosiloxane, the heat resistance of the graphene-carbon nanotube composite fiber felt is enhanced. The finishing agent comprises the following raw materials: an anionic surfactant, a zwitterionic surfactant and water, and by controlling the weight ratio of the anionic surfactant to the zwitterionic surfactant to the water, the smoothness of the composite fibrofelt is adjusted, and the friction resistance of the composite fibrofelt is enhanced. And meanwhile, the prepared fibrofelt has enhanced mechanical strength and binding capacity between the fibrofelt and high-molecular compounds.

Description

Technical Field

[0001] The present invention relates to the field of D06M13 / 513, and in particular to a composite carbon fiber felt and a preparation method thereof. Background Art

[0002] Carbon fiber possesses excellent mechanical and electrical properties and can be used as a reinforcement material in combination with resins, metals, ceramics, and carbon to create advanced composite materials, finding widespread application in various fields. As novel carbon-based fiber materials, carbon nanotube fibers and graphene-based fibers have attracted widespread attention for their unique structure and excellent performance.

[0003] Carbon nanotube fibers have a porous network structure, which can leverage their large specific surface area to tightly integrate graphene sheets within the interstices of the tube bundle, thereby enhancing their mechanical self-supporting properties. Chinese patent CN107988656A discloses a method for preparing graphene-carbon nanotube composite fibers. This involves combining carbon nanotube aggregates with graphene, and then subjecting the wound, collected carbon nanotube fibers with attached graphene sheets to a bundle-twisting process. This method increases the tensile strength of the graphene-carbon nanotube composite fibers and strengthens the interfacial bonding between the graphene and carbon nanotubes. However, the heat resistance of the modified fibers needs to be improved.

[0004] CN110230196A provides a graphene-carbon nanotube composite fiber felt and a preparation method thereof, comprising introducing a silane coupling agent to prepare modified graphene-carbon nanotube composite fibers, arranging the fibers into a felt shape, and obtaining a graphene-carbon nanotube composite fiber felt. The composite fiber felt has high mechanical strength and interfacial bonding strength with polymer materials, but its heat resistance and friction resistance, which need to be improved, limit its widespread application in aerospace, defense, and civilian industries requiring high temperatures and high physical stability. Therefore, preparing a composite fiber felt with excellent heat resistance and friction resistance while maintaining high mechanical strength and interfacial bonding strength with polymer materials has practical application significance. Summary of the Invention

[0005] In order to solve the above problems, the first aspect of the present invention provides a composite carbon fiber felt, wherein the raw materials for preparation include at least the following components in parts by weight: 200-300 parts of composite carbon fiber, 3-15 parts of organosiloxane, and 15-45 parts of finishing agent.

[0006] The composite carbon fiber felt is selected from any one of graphene-carbon nanotube composite carbon fiber, graphene / polyacrylonitrile composite carbon fiber, and biomass tar / nanosilver / polyacrylonitrile composite carbon fiber. Among them, the graphene-carbon nanotube composite carbon fiber has good flexibility and low production cost. Although the mechanical strength of the polyacrylonitrile-based composite carbon fiber has been improved, its chemical stability and friction resistance need to be improved.

[0007] In order to ensure that the prepared composite carbon fiber felt has a certain heat resistance foundation, as a preferred technical solution of the present invention, the composite carbon fiber is a graphene-carbon nanotube composite carbon fiber, while effectively improving the mechanical self-supporting performance of the simple graphene fiber structure, wherein the graphene-carbon nanotube composite fiber has a length of 25-45 mm;

[0008] The graphene-carbon nanotube composite carbon fibers described in the present invention can be purchased commercially or prepared by methods familiar to those skilled in the art. The present invention does not impose any particular restrictions on the source of the graphene-carbon nanotube composite carbon fibers.

[0009] As a preferred technical solution of the present invention, the preparation method of the graphene-carbon nanotube composite carbon fiber is as follows:

[0010] S1. Methanol, ferrocene, and hydrogen are introduced into a vertical furnace to grow carbon nanotube aggregates; wherein the reaction temperature of the vertical furnace is set to 1000-1500°C;

[0011] S2. The graphene is dispersed in ethanol to prepare a graphene ethanol solution having a concentration of 20 to 30 wt%;

[0012] S3. The carbon nanotube aggregates are immersed in a graphene ethanol solution around a guide roller for 1-5 min to form carbon nanotube fibers with graphene sheets attached;

[0013] S4. The carbon nanotube fibers with graphene sheets formed in S3 are pulled out of the graphene ethanol solution using a drafting roller at a pulling speed of 8-12 mm / s;

[0014] S5. The carbon nanotube fibers with graphene sheets pulled out of the graphene ethanol solution are dried at 60-90 ° C using a drying roller;

[0015] S6. The carbon nanotube fibers with attached graphene sheets after drying in S5 are wound and collected by a winding roller;

[0016] S7 by twisting machine S6 collected by winding carbon nanotube fibers with graphene sheets bundle twisting process, the twisting machine bundle number is 15, the twist is set to 200-300 twist / m, ie, the graphene - carbon nanotube composite fiber;

[0017] In one embodiment, the weight ratio of graphene, methanol and ferrocene is 1.2:(4-12):(0.001-0.009); preferably, the weight ratio of graphene, methanol and ferrocene is 1.2:8:0.005.

[0018] As a preferred technical solution of the present invention, the functional groups contained in the organosiloxane are selected from at least one of vinyl, methoxy, ethoxy, aminopropyl, epoxy, and aminoethyl; preferably, the organosiloxane is a vinyl-containing organosiloxane and an epoxy-containing organosiloxane; more preferably, the vinyl-containing siloxane is a vinyl-terminated polydimethylsiloxane with a CAS number of 68083-19-2 and a brand of Shanghai McLean; the epoxy-containing siloxane is an epoxycyclohexylcyclotetrasiloxane with a CAS number of 121225-98-7, purchased from Dongguan Weizimei New Material Technology Co., Ltd.

[0019] As a preferred technical solution of the present invention, the weight ratio of the vinyl-containing organosiloxane to the epoxy-containing organosiloxane is (1.5-3.5):(2-4); preferably, the weight ratio of the vinyl-containing siloxane to the epoxy-containing siloxane is 2:3.

[0020] Although the introduction of organosiloxane can improve the heat resistance of graphene-carbon nanotube composite carbon fibers, as the concentration of organosiloxane increases, the graphene-carbon nanotube composite carbon fibers are prone to material breakage and reduced mechanical strength. As a preferred technical solution of the present invention, the weight of the organosiloxane is 5-10 parts, for example, it can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.; by adjusting the weight of the organosiloxane, the modified composite carbon fibers can improve their heat resistance while ensuring their mechanical strength; preferably, the weight of the organosiloxane is 8 parts.

[0021] In order to improve the friction resistance of the prepared composite carbon fiber felt, as a preferred technical solution of the present invention, the raw materials of the finishing agent include anionic surfactants, zwitterionic surfactants and water, and the softness of the composite carbon fiber is improved by compounding the anionic surfactants and zwitterionic surfactants; the anionic surfactant is selected from one or more of Remibond A, sodium alkyl sulfonate, sodium alkyl sulfate, and sodium alkylaryl sulfonate; preferably, the anionic surfactant is Remibond A, purchased from Kandis Chemical (Hubei) Co., Ltd.; the zwitterionic surfactant is selected from one or more of carboxylic acid betaine, sulfobetaine, and phosphate betaine; preferably, the zwitterionic surfactant is dodecylethoxysulfobetaine, purchased from Shanghai Nosong Industrial Co., Ltd.

[0022] Adding a large proportion of zwitterionic surfactant will reduce the surface activity of the compound system and increase the cost. As a preferred technical solution of the present invention, the weight ratio of the anionic surfactant, the zwitterionic surfactant and water is (10-20): (0-2): (70-90); preferably, the weight ratio of the remibond A and dodecylethoxysulfobetaine and water is 15:1:84.

[0023] A second aspect of the present invention provides a method for preparing the composite carbon fiber felt, comprising at least the following steps:

[0024] (1) adding composite carbon fiber and organosiloxane into a reactor, stirring to completely mix, and then drying to obtain modified composite carbon fiber;

[0025] (2) After the modified composite carbon fiber is impregnated with a finishing agent, it is hot-pressed into a felt shape to obtain a composite carbon fiber felt.

[0026] As a preferred technical solution of the present invention, the preparation method of the composite carbon fiber felt comprises at least the following steps:

[0027] (1) adding composite carbon fiber and organosiloxane into a reactor, stirring at 50-65° C. for 25-50 minutes, and then drying at 110-130° C. for 10-30 seconds to obtain modified composite carbon fiber;

[0028] (2) The modified composite carbon fiber is impregnated with a finishing agent for 1-5 minutes. The impregnation time of the finishing agent affects the softness of the composite fiber felt, thereby affecting its friction resistance. If the impregnation time of the finishing agent is too long, the fiber cohesion will decrease, which may lead to a decrease in the interfacial bonding force between the modified composite fiber and the polymer material, affecting the mechanical strength of the material. The modified composite fiber is then hot-pressed into a felt shape, wherein the hot pressing temperature is 120-140°C and the pressure is 0.1-0.4Mpa to obtain a composite carbon fiber felt.

[0029] As a preferred technical solution of the present invention, the preparation method of the composite carbon fiber felt comprises at least the following steps:

[0030] (1) adding composite carbon fiber and organosiloxane into a reactor, stirring at 60°C for 40 minutes, and then drying at 120°C for 20 seconds to obtain modified composite carbon fiber;

[0031] (2) The modified composite carbon fiber was impregnated with a finishing agent for 3 minutes and then hot-pressed into a felt shape, wherein the hot-pressing temperature was 130° C. and the pressure was 0.25 MPa to obtain a composite carbon fiber felt.

[0032] Beneficial effects:

[0033] 1. On the basis of having a certain heat resistance, the graphene-carbon nanotube composite fiber has enhanced heat resistance of the composite carbon fiber felt due to the introduction of vinyl-containing organosiloxane and epoxy-containing organosiloxane.

[0034] 2. The composite carbon fiber felt prepared by controlling the weight of the organosiloxane to 5-10 parts has better heat resistance.

[0035] 3. By controlling the weight ratio of anionic surfactant, zwitterionic surfactant and water in the finishing agent to (10-20): (0-2): (70-90), the softness of the composite fiber felt is adjusted and its friction resistance is enhanced.

[0036] 4. Controlling the mechanical strength of the graphene-carbon nanotube composite fiber felt prepared by 200-300 parts by weight of composite carbon fibers, 3-15 parts by weight of organosiloxane, and 15-45 parts by weight of a finishing agent to increase.

[0037] 5. By controlling the impregnation time of the finishing agent, the bonding ability between the composite carbon fiber felt and the polymer material can be effectively improved. DETAILED DESCRIPTION

[0038] Example

[0039] Example 1

[0040] Example 1 of the present invention provides a composite carbon fiber felt, wherein the raw materials for preparing the felt include at least the following components, in parts by weight: 250 parts of graphene-carbon nanotube composite fibers, 7.5 parts of organosiloxane, and 30 parts of a finishing agent.

[0041] The length of the graphene-carbon nanotube composite fiber is 32 mm.

[0042] The preparation method of graphene-carbon nanotube composite carbon fiber is as follows:

[0043] S1. Carbon nanotube aggregates are grown using a vertical furnace; wherein methanol, ferrocene, and hydrogen are introduced into the vertical furnace to grow the carbon nanotube aggregates; wherein the reaction temperature of the vertical furnace is set to 1300°C;

[0044] S2. The graphene was dispersed in ethanol to prepare a graphene ethanol solution having a concentration of 25 wt%;

[0045] S3. The carbon nanotube aggregates are immersed in a graphene ethanol solution around a guide roller for 3 min to form carbon nanotube fibers with graphene sheets;

[0046] S4. The carbon nanotube fibers with graphene sheets formed in S3 are pulled out of the graphene ethanol solution using a drafting roller at a pulling speed of 10 mm / s;

[0047] S5. The carbon nanotube fibers with graphene sheets pulled out of the graphene ethanol solution are dried at 75 ° C using a drying roller;

[0048] S6. The carbon nanotube fibers with attached graphene sheets after drying in S5 are wound and collected by a winding roller;

[0049] S7. The carbon nanotube fibers with graphene sheets attached to the winding collected by the twisting machine S6 were bundled and twisted. The number of bundles of the twisting machine was 15, and the twist was set to 250 twists / m, to obtain the graphene - carbon nanotube composite fibers;

[0050] The weight ratio of graphene, methanol and ferrocene is 1.2:8:0.0005.

[0051] The organosiloxane is vinyl-containing siloxane and epoxy-containing siloxane, and the weight ratio of the two is 2:3.

[0052] The vinyl-containing siloxane is vinyl-terminated polydimethylsiloxane with a CAS number of 68083-19-2 and a brand of Shanghai McLean; the epoxy-containing siloxane is epoxycyclohexylcyclotetrasiloxane with a CAS number of 121225-98-7, purchased from Dongguan Weizimei New Material Technology Co., Ltd.

[0053] The raw materials of the finishing agent include anionic surfactants, zwitterionic surfactants and water; the anionic surfactant is Remibond A, purchased from Kandis Chemical (Hubei) Co., Ltd.; the zwitterionic surfactant is dodecylethoxysulfobetaine, purchased from Shanghai Nosong Industrial Co., Ltd.; the weight ratio of the anionic surfactant, zwitterionic surfactant and water is 15:1:84.

[0054] Example 1 of the present invention provides a composite carbon fiber felt, the preparation method of which is as follows:

[0055] (1) adding composite carbon fiber and organosiloxane into a reactor, stirring at 60°C for 40 minutes, and then drying at 120°C for 20 seconds to obtain modified composite carbon fiber;

[0056] (2) The modified composite carbon fiber was impregnated with a finishing agent for 3 minutes and then hot-pressed into a felt shape, wherein the hot-pressing temperature was 130° C. and the pressure was 0.25 MPa to obtain a composite carbon fiber felt.

[0057] Example 2

[0058] Example 2 of the present invention provides a composite carbon fiber felt, wherein the raw materials for preparing the felt include at least the following components, in parts by weight: 280 parts of graphene-carbon nanotube composite fibers, 10 parts of organosiloxane, and 40 parts of a finishing agent.

[0059] The length of the graphene-carbon nanotube composite carbon fiber is 43 mm.

[0060] S1. Growing carbon nanotube aggregates using a vertical furnace; wherein methanol, ferrocene, and hydrogen are introduced into the vertical furnace to grow the carbon nanotube aggregates; wherein the reaction temperature of the vertical furnace is set to 1500°C;

[0061] S2. The graphene was dispersed in ethanol to prepare a graphene ethanol solution having a concentration of 25 wt%;

[0062] S3. The carbon nanotube aggregates are immersed in the graphene ethanol solution around the guide roller for 5 min to form carbon nanotube fibers with graphene sheets;

[0063] S4. The carbon nanotube fibers with graphene sheets formed in S3 are pulled out of the graphene ethanol solution using a drafting roller at a pulling speed of 12 mm / s;

[0064] S5. The carbon nanotube fibers with graphene sheets pulled out of the graphene ethanol solution are dried at 90 ° C using a drying roller;

[0065] S6. The carbon nanotube fibers with attached graphene sheets after drying in S5 are wound and collected by a winding roller;

[0066] S7. The carbon nanotube fibers with graphene sheets attached to the winding collected by the twisting machine S6 were bundled and twisted. The number of bundles of the twisting machine was 15, and the twist was set to 300 twists / m, to obtain the graphene - carbon nanotube composite fibers;

[0067] The weight ratio of graphene, methanol and ferrocene is 1.2:10:0.009.

[0068] The organosiloxane is vinyl-containing siloxane and epoxy-containing siloxane, and the weight ratio of the two is 1:2.

[0069] The vinyl-containing siloxane is vinyl-terminated polydimethylsiloxane with a CAS number of 68083-19-2 and a brand of Shanghai McLean; the epoxy-containing siloxane is epoxycyclohexylcyclotetrasiloxane with a CAS number of 121225-98-7, purchased from Dongguan Weizimei New Material Technology Co., Ltd.

[0070] The raw materials of the finishing agent include anionic surfactants, zwitterionic surfactants and water; the anionic surfactant is Remibond A, purchased from Kandis Chemical (Hubei) Co., Ltd.; the zwitterionic surfactant is dodecylethoxysulfobetaine, purchased from Shanghai Nosong Industrial Co., Ltd.; the weight ratio of the anionic surfactant, zwitterionic surfactant and water is 10:1:39.

[0071] Example 2 of the present invention provides a composite carbon fiber felt, the preparation method of which is as follows:

[0072] (1) adding composite carbon fiber and organosiloxane into a reactor, stirring at 65°C for 50 minutes, and then drying at 130°C for 30 seconds to obtain modified composite carbon fiber;

[0073] (2) The modified composite carbon fiber was impregnated with a finishing agent for 5 minutes and then hot-pressed into a felt-like state, wherein the hot-pressing temperature was 130° C. and the pressure was 0.25 MPa, thereby obtaining a composite carbon fiber.

[0074] Example 3

[0075] Example 1 of the present invention provides a composite carbon fiber felt, wherein the raw materials for preparing the felt include at least the following components, in parts by weight: 220 parts of graphene-carbon nanotube composite carbon fibers, 5 parts of organosiloxane, and 20 parts of a finishing agent.

[0076] The length of the graphene-carbon nanotube composite carbon fiber is 20 mm.

[0077] S1. Carbon nanotube aggregates are grown using a vertical furnace; wherein methanol, ferrocene, and hydrogen are introduced into the vertical furnace to grow the carbon nanotube aggregates; wherein the reaction temperature of the vertical furnace is set to 1000°C;

[0078] S2. The graphene was dispersed in ethanol to prepare a graphene ethanol solution having a concentration of 25 wt%;

[0079] S3. The carbon nanotube aggregates are immersed in the graphene ethanol solution around the guide roller for 1 min to form carbon nanotube fibers with graphene sheets;

[0080] S4. The carbon nanotube fibers with graphene sheets formed in S3 are pulled out of the graphene ethanol solution using a drafting roller at a pulling speed of 8 mm / s;

[0081] S5. The carbon nanotube fibers with graphene sheets pulled out of the graphene ethanol solution are dried at 60 ° C using a drying roller;

[0082] S6. The carbon nanotube fibers with attached graphene sheets after drying in S5 are wound and collected by a winding roller;

[0083] S7. The carbon nanotube fibers with graphene sheets attached to the winding collected by the twisting machine S6 were bundled and twisted. The number of bundles of the twisting machine was 15, and the twist was set to 200 twists / m, to obtain the graphene - carbon nanotube composite fibers;

[0084] The weight ratio of graphene, methanol and ferrocene is 1.2:5:0.003.

[0085] The organosiloxane is vinyl-containing siloxane and epoxy-containing siloxane, and the weight ratio of the two is 1:2.

[0086] The vinyl-containing siloxane is vinyl-terminated polydimethylsiloxane with a CAS number of 68083-19-2 and a brand of Shanghai McLean; the epoxy-containing siloxane is epoxycyclohexylcyclotetrasiloxane with a CAS number of 121225-98-7, purchased from Dongguan Weizimei New Material Technology Co., Ltd.

[0087] The raw materials of the finishing agent include anionic surfactants, zwitterionic surfactants and water; the anionic surfactant is Remibond A, purchased from Kandis Chemical (Hubei) Co., Ltd.; the zwitterionic surfactant is dodecylethoxysulfobetaine, purchased from Shanghai Nosong Industrial Co., Ltd.; the weight ratio of the anionic surfactant, zwitterionic surfactant and water is 5:1:44.

[0088] Example 3 of the present invention provides a composite carbon fiber felt, the preparation method of which is as follows:

[0089] (1) adding composite carbon fiber and organosiloxane into a reactor, stirring at 50°C for 30 minutes, and then drying at 110°C for 10 seconds to obtain modified composite carbon fiber;

[0090] (2) The modified composite carbon fiber was impregnated with a finishing agent for 1 minute and then hot-pressed into a felt shape, wherein the hot-pressing temperature was 130° C. and the pressure was 0.25 MPa, to obtain a composite carbon fiber felt.

[0091] Comparative Example 1

[0092] Comparative Example 1 of the present invention provides a composite carbon fiber felt, and its specific implementation is the same as that of Example 1, except that the organosiloxane in the composite carbon fiber felt is a vinyl-containing organosiloxane.

[0093] Comparative Example 2

[0094] Comparative Example 2 of the present invention provides a composite carbon fiber felt, and its specific implementation is the same as that of Example 1, except that the weight ratio of the anionic surfactant, the zwitterionic surfactant and water in the finishing agent in the composite carbon fiber felt is 0:18:82.

[0095] Performance testing methods

[0096] (1) Determination of thermal conductivity: The specific method refers to GBT 8722-2008 - Determination of thermal conductivity of graphite materials at medium temperature. The lower the thermal conductivity, the better the heat resistance of the prepared composite carbon fiber felt.

[0097] (2) Friction fastness and surface resistivity before and after friction: The friction fastness and surface resistivity before and after friction of the prepared composite carbon fiber felt were tested, and the ratio of the surface resistivity after friction to the surface resistivity before friction was calculated to evaluate its friction resistance. Specifically, according to the national standard GB / T 250-2008, the surface resistivity was measured before and after friction, and each sample was tested 3 times, and the average value was taken; and the samples after 150 frictions were evaluated according to the level of the "Gray Sample Card for Evaluating Discoloration", and the results are listed in Table 1. The higher the level of friction fastness, the better the friction resistance. At the same time, the lower the ratio of the surface resistivity of the composite carbon fiber felt after friction to the surface resistivity before friction, the better its friction resistance.

[0098] Performance test data

[0099] The performance of the graphene-carbon nanotube composite fiber felts prepared in Examples 1-3 and Comparative Examples 1-2 was evaluated.

[0100] See Table 1, which shows the heat resistance and friction resistance test data of the graphene-carbon nanotube composite fiber felts prepared in Examples 1-3 and Comparative Examples 1-2.

[0101]

Claims

1. A composite carbon fiber felt, characterized in that: The raw materials for preparation include at least the following components in parts by weight: 200-300 parts of composite carbon fibers, 3-15 parts of organic siloxane, and 15-45 parts of finishing agents.

2. A composite carbon fiber felt according to claim 1, characterized in that: The composite carbon fiber is a graphene-carbon nanotube fiber, and the length of the graphene-carbon nanotube composite fiber is 25-45 nm.

3. A composite carbon fiber felt according to claim 1, characterized in that: The functional group contained in the organosiloxane is at least one selected from vinyl, methoxy, ethoxy, aminopropyl, epoxy, and aminoethyl.

4. A composite carbon fiber felt according to claim 1 or 3, characterized in that: The organosiloxane is a vinyl-containing organosiloxane and an epoxy-containing organosiloxane.

5. A composite carbon fiber felt according to claim 4, characterized in that: The weight portion of the organosiloxane is 5-10 parts; the weight ratio of the vinyl-containing organosiloxane to the epoxy-containing organosiloxane is (1.5-3.5):(2-4).

6. The composite carbon fiber felt according to claim 1, characterized in that: The raw materials of the finishing agent include anionic surfactant, zwitterionic surfactant and water.

7. The composite carbon fiber felt according to claim 6, characterized in that: The weight ratio of the anionic surfactant, the zwitterionic surfactant and water is (10-20): (0-2)：(70-90)。 8. The composite carbon fiber felt according to claim 1, characterized in that: The anionic surfactant is selected from one or more of Remibond A, sodium alkyl sulfonate, sodium alkyl sulfate, and sodium alkylaryl sulfonate; the zwitterionic surfactant is selected from one or more of carboxylic acid betaine, sulfobetaine, and phosphate betaine.

9. A method for preparing a composite carbon fiber felt according to any one of claims 1 to 8, characterized in that: At least the following steps are included: S1. The composite carbon fiber and the organosiloxane were added to a container for physical blending, stirred to mix completely and then dried to obtain a modified composite carbon fiber; S2. After the modified composite carbon fiber is impregnated with a finishing agent, it is hot-pressed into a felt-like state to obtain a composite carbon fiber felt.

10. The method for preparing a composite carbon fiber felt according to claim 9, characterized in that: The drying temperature is 110-130℃ and the drying time is 10-30s.

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