Plastic liner carbon fiber full-winding composite gas cylinder and preparation method thereof

Abstract

The invention provides a plastic liner carbon fiber full-winding composite gas cylinder and a preparation method thereof, and relates to the technical field of hydrogen storage cylinders. The carbon fiber fully-wound composite gas cylinder with the plastic inner container is formed by alternately winding carbon fibers impregnated with impregnation slurry in a spiral winding mode and an annular winding mode, the single-layer thickness of an annular winding layer and the single-layer thickness of a spiral winding layer are both 0.35-0.38 mm, the number of the annular winding layers is 30-32, and the number of the spiral winding layers is 34-36. Compared with an existing metal inner container full-winding gas cylinder, the gas cylinder has the advantages that the problem that the inner container is prone to hydrogen embrittlement when hydrogen is stored is solved, compared with a plastic inner container fiber full-winding gas cylinder, the bearing capacity is improved, meanwhile, the thickness is reduced, the weight of the gas cylinder is reduced, and the gas cylinder is high in gas tightness, good in interface bonding performance and long in fatigue life.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen storage cylinders, and in particular relates to a plastic liner carbon fiber fully wrapped composite cylinder and a preparation method thereof. Background Art

[0002] In recent years, hydrogen has received widespread attention as a clean energy source, and hydrogen storage technology has also developed accordingly. There are four main types of hydrogen storage cylinders: Type I all-metal cylinders, Type II metal liner fiber hoop-wrapped cylinders, Type III metal liner fiber fully wrapped cylinders, and Type IV plastic liner fiber fully wrapped cylinders.

[0003] With the development of hydrogen storage cylinders, Type I and Type II cylinders are gradually being replaced by Type III and Type IV cylinders. At present, the manufacturing process of Type III and Type IV cylinders is mainly: after impregnating carbon fiber tow with epoxy resin, it is longitudinally and circumferentially wound on aluminum alloy or plastic liner, and then demolded after curing and molding. Metal liner fiber fully wrapped cylinders have the advantages of large volume-to-weight ratio and corrosion resistance, but the liner is prone to hydrogen embrittlement when storing hydrogen, and there is a potential difference between the aluminum liner and the carbon fiber layer in the Type III cylinder, and direct contact is prone to corrosion. Therefore, it is necessary to add an anti-galvanic corrosion layer between the aluminum liner and the carbon fiber winding layer, which increases the weight of the cylinder. The plastic liner of the Type IV cylinder is generally made of polymer materials such as polyamide PA6 and high-density polyethylene HDPE, and the winding layer is generally carbon fiber or glass fiber. The two are of different types, resulting in poor interface bonding between the liner and the outer layer, and peeling and delamination at the joint, which leads to leakage. In addition, in order to improve the quality of hydrogen storage, the internal pressure needs to be increased, so the radius and wall thickness of the gas cylinder need to be increased. The mass of the gas cylinder increases, and the increase in hydrogen storage density is therefore limited. Reducing the wall thickness will bring the risk of gas leakage.

[0004] Therefore, it is necessary to improve the existing plastic liner carbon fiber fully wrapped composite gas cylinder. Summary of the invention

[0005] The purpose of the present invention is to provide a plastic liner carbon fiber fully wrapped composite gas cylinder and a preparation method thereof in view of the deficiencies in the prior art, which at least solves some of the problems existing in the prior art.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A plastic liner carbon fiber fully wound composite gas cylinder, comprising a plastic liner, a valve seat and a composite material winding layer, wherein the composite material winding layer is coated on the outside of the plastic liner; the composite material winding layer is formed by alternately winding carbon fiber impregnated with an impregnation slurry through spiral winding and annular winding;

[0008] The single-layer thickness of the annular winding layer and the spiral winding layer are both 0.35-0.38 mm, the number of layers of the annular winding layer is 30-32 layers, and the number of layers of the spiral winding layer is 34-36 layers.

[0009] Furthermore, the winding angle of the spiral winding layer is 30 to 37°; and the angle of the annular winding layer is 88 to 90°.

[0010] Furthermore, the material of the composite winding layer is composed of carbon fiber and impregnation slurry in a mass ratio of 10:(1-1.8); wherein,

[0011] The impregnation slurry comprises the following raw materials in parts by weight: 55-70 parts of epoxy resin, 10-20 parts of isophorone diisocyanate, 3.4-5 parts of dithiol compound, 3-5 parts of long-chain alkyl modified silane coupling agent, 5-8 parts of curing agent and 1-3 parts of accelerator.

[0012] Preferably, the impregnation slurry comprises the following raw materials in parts by weight: 67 parts of epoxy resin, 17 parts of isophorone diisocyanate, 4.2 parts of dithiol compound, 4.3 parts of long-chain alkyl-modified silane coupling agent, 6 parts of curing agent, and 2 parts of accelerator.

[0013] Furthermore, the linear density of the carbon fiber is 1.5 to 1.7 g / m.

[0014] Furthermore, the bismercapto compound is ethylene glycol bismercaptoacetate or 2,3-dimercaptosuccinic acid.

[0015] Furthermore, the long-chain alkyl modified silane coupling agent is prepared by modifying a bisaminosilane coupling agent with a C8-C12 saturated / unsaturated fatty acid ester.

[0016] Preferably, the bisaminosilane coupling agent is selected from any one of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane KH-792, N-aminoethyl-γ-aminopropyltriethoxysilane KH-791, and N-(β-aminoethyl)-γ-aminopropylmethyl-dimethoxysilane KH-602.

[0017] Preferably, the C8-C12 saturated / unsaturated fatty acid ester is prepared by reacting a straight-chain or branched saturated or unsaturated fatty acid with ethanol, propanol or butanol.

[0018] Preferably, the reaction molar ratio of the bisaminosilane coupling agent to the saturated / unsaturated fatty acid ester is 1:(1-1.1).

[0019] Preferably, the long-chain alkyl-modified silane coupling agent is prepared by the following method:

[0020] The bisaminosilane coupling agent is mixed with n-butanol, and then a saturated / unsaturated fatty acid ester is added, and the mixture is refluxed at 75-85° C. for 3-5 hours, distilled, and cooled to room temperature to obtain a long-chain alkyl-modified silane coupling agent.

[0021] Preferably, the curing agent is selected from any one or more of diaminodiphenylmethane, m-phenylenediamine, diaminodiphenyl sulfone, methylenebisphenylenediamine, and hexamethylenetetramine.

[0022] Preferably, the accelerator is selected from any one of an amine accelerator and a tin accelerator, including but not limited to triethylenediamine, dibutyltin dilaurate, and stannous octoate.

[0023] Another aspect of the present invention also provides a method for preparing a plastic liner carbon fiber fully wrapped composite gas cylinder, comprising the following steps:

[0024] (1) impregnating carbon fiber in an impregnation slurry and then winding the carbon fiber on a plastic liner to form a composite material winding layer;

[0025] (2) placing the plastic liner wrapped with the composite material wrapping layer into a curing furnace for curing, thereby obtaining the plastic liner carbon fiber fully wrapped composite gas cylinder.

[0026] Furthermore, in step (2), the curing temperature is 95 to 115° C. and the curing time is 3 to 5 hours.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. Compared with the existing metal liner fully wrapped gas cylinder, the plastic liner carbon fiber fully wrapped composite gas cylinder provided by the present invention avoids the problem of hydrogen embrittlement of the liner when storing hydrogen. Compared with the plastic liner fiber fully wrapped gas cylinder, it reduces the thickness while improving the carrying capacity, thereby reducing the weight of the gas cylinder, and has high air tightness and fatigue life.

[0029] 2. The plastic liner carbon fiber fully wrapped composite gas cylinder provided by the present invention designs the composite material winding layer into two winding methods and reasonably designs the thickness of the winding layer, which is beneficial to improving the uniform load-bearing of the gas cylinder body, while improving the load-bearing capacity and reducing the thickness of the winding layer, thereby reducing the weight of the gas cylinder; it also has a significant inhibitory effect on the expansion of cracks in the bottle body, thereby more effectively preventing hydrogen penetration and improving air tightness.

[0030] 3. The plastic liner carbon fiber fully wrapped composite gas cylinder provided by the present invention optimizes the formula of the impregnation slurry, adds isophorone diisocyanate, long-chain alkyl modified silane coupling agent and dithiol compound to the slurry, introduces highly reactive groups such as isocyanic acid, and can form an interpenetrating cross-linked network with the epoxy resin, which can prevent the hydrogen in the plastic liner from diffusing outward and significantly reduce the hydrogen leakage rate of the gas cylinder; compared with conventional silane coupling agents, long-chain alkyl modified silane coupling agents are easier to interact, entangle or interpenetrate with the cross-linked network, thereby forming a dense protective layer and increasing air tightness; the three work together to greatly improve air tightness while also helping to improve load-bearing capacity, fatigue resistance and service life. DETAILED DESCRIPTION

[0031] The following non-limiting examples can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. The following content is only an exemplary description of the scope of the present invention, and those skilled in the art can make various changes and modifications to the invention of the present invention based on the disclosed content, and they should also fall within the scope of the present invention.

[0032] The present invention is further described below by way of specific examples. Unless otherwise specified, the various chemical reagents used in the examples of the present invention are obtained through conventional commercial channels.

[0033] Example 1

[0034] A plastic liner carbon fiber fully wrapped composite gas cylinder, comprising:

[0035] A plastic liner, a valve seat and a composite material winding layer, wherein the composite material winding layer is coated on the outside of the plastic liner;

[0036] The composite winding layer is formed by alternating spiral winding and annular winding of carbon fiber impregnated with an impregnation slurry, wherein the single layer thickness of the annular winding layer and the spiral winding layer is 0.350 mm; the number of layers of the annular winding layer is 30, and the winding angle is 88°; the number of layers of the spiral winding layer is 36, and the winding angle is 30°.

[0037] A method for preparing a plastic liner carbon fiber fully wrapped composite gas cylinder comprises the following steps:

[0038] (1) impregnating carbon fiber (linear density 1.65 g / m) into an impregnation slurry to obtain a prepreg (the mass ratio of carbon fiber to impregnation slurry in the prepreg is 10:1), and then winding the prepreg on a plastic liner (thickness 5 mm) to form a composite winding layer;

[0039] In this embodiment, the impregnation slurry contains the following raw materials: 55 parts of epoxy resin, 10 parts of isophorone diisocyanate, 3.4 parts of ethylene glycol dithioglycolate, 3 parts of long-chain alkyl-modified silane coupling agent, 5 parts of curing agent, and 1 part of accelerator; wherein,

[0040] The long-chain alkyl modified silane coupling agent is prepared by the following method: 1 mol of KH-791 is mixed with 0.5 mol of n-butanol, and then 1 mol of propyl octanoate is added, refluxed at 75° C. for 5 h, distilled, and cooled to room temperature to obtain the obtained product.

[0041] (2) Curing and molding

[0042] The plastic liner of the wound composite material winding layer is placed in a curing furnace for curing at a temperature of 95° C. for 5 hours to obtain the plastic liner carbon fiber fully wound composite gas cylinder.

[0043] Example 2

[0044] Another plastic liner carbon fiber fully wrapped composite gas cylinder, comprising:

[0045] A plastic liner, a valve seat and a composite material winding layer, wherein the composite material winding layer is coated on the outside of the plastic liner;

[0046] The composite winding layer is formed by alternating spiral winding and annular winding of carbon fiber impregnated with an impregnation slurry, wherein the single layer thickness of the annular winding layer and the spiral winding layer are both 0.368 mm; the number of layers of the annular winding layer is 32, and the winding angle is 90°; the number of layers of the spiral winding layer is 34, and the winding angle is 37°.

[0047] Another method for preparing a plastic liner carbon fiber fully wrapped composite gas cylinder comprises the following steps:

[0048] (1) impregnating carbon fiber (linear density 1.65 g / m) into an impregnation slurry to obtain a prepreg (the mass ratio of carbon fiber to impregnation slurry in the prepreg is 10:1.5), and then winding the prepreg on a plastic liner (thickness 5 mm) to form a composite winding layer;

[0049] In this embodiment, the impregnation slurry contains the following raw materials: 67 parts of epoxy resin, 17 parts of isophorone diisocyanate, 4.2 parts of 2,3-dimercaptosuccinic acid, 4.3 parts of long-chain alkyl-modified silane coupling agent, 6 parts of curing agent, and 2 parts of accelerator; wherein,

[0050] The long-chain alkyl modified silane coupling agent is prepared by the following method: 1 mol KH-602 is mixed with 0.5 mol n-butanol, and then 1 mol n-butyl dodecanoate is added, refluxed at 80° C. for 4 h, distilled, and cooled to room temperature to obtain the obtained product.

[0051] (2) Curing and molding

[0052] The plastic liner of the wound composite material winding layer is placed in a curing furnace for curing at a temperature of 105° C. for 4 hours to obtain the plastic liner carbon fiber fully wound composite gas cylinder.

[0053] Example 3

[0054] Another plastic liner carbon fiber fully wrapped composite gas cylinder, comprising:

[0055] A plastic liner, a valve seat and a composite material winding layer, wherein the composite material winding layer is coated on the outside of the plastic liner;

[0056] The composite winding layer is formed by alternating spiral winding and annular winding of carbon fiber impregnated with an impregnation slurry, wherein the single layer thickness of the annular winding layer and the spiral winding layer are both 0.380 mm; the number of layers of the annular winding layer is 32, and the winding angle is 90°; the number of layers of the spiral winding layer is 34, and the winding angle is 37°.

[0057] Another method for preparing a plastic liner carbon fiber fully wrapped composite gas cylinder comprises the following steps:

[0058] (1) impregnating carbon fiber (linear density 1.65 g / m) into an impregnation slurry to obtain a prepreg (the mass ratio of carbon fiber to impregnation slurry in the prepreg is 10:1.8), and then winding the prepreg on a plastic liner (thickness 5 mm) to form a composite winding layer;

[0059] In this embodiment, the impregnation slurry contains the following raw materials: 70 parts of epoxy resin, 20 parts of isophorone diisocyanate, 5 parts of 2,3-dimercaptosuccinic acid, 5 parts of long-chain alkyl-modified silane coupling agent, 8 parts of curing agent, and 3 parts of accelerator; wherein,

[0060] The long-chain alkyl modified silane coupling agent is prepared by the following method: 1 mol of KH-792 is mixed with 0.5 mol of n-butanol, and then 1 mol of ethyl tridecanoate is added, refluxed at 85° C. for 3 h, distilled, and cooled to room temperature to obtain the obtained product.

[0061] (2) Curing and molding

[0062] The plastic liner of the wound composite material winding layer is placed in a curing furnace for curing at a temperature of 115° C. for 3 hours to obtain the plastic liner carbon fiber fully wound composite gas cylinder.

[0063] Example 4

[0064] The difference between this embodiment and embodiment 2 is that the long-chain alkyl-modified silane coupling agent in the impregnation slurry is different. The specific preparation method is as follows: 1 mol of KH-602 is mixed with 0.5 mol of n-butanol, and then 1 mol of butyl heptanoate is added, refluxed at 80°C for 4 hours, distilled, and cooled to room temperature to obtain.

[0065] Example 5

[0066] The difference between this embodiment and embodiment 2 is that the long-chain alkyl-modified silane coupling agent in the impregnation slurry is different. The specific preparation method is as follows: 1 mol of KH-602 is mixed with 0.5 mol of n-butanol, and then 1 mol of n-butyl octadecanoate is added, refluxed at 80°C for 4 hours, distilled, and cooled to room temperature to obtain.

[0067] Example 6

[0068] The difference between this embodiment and embodiment 2 is that the long-chain alkyl-modified silane coupling agent in the impregnation slurry is replaced by an equal amount of KH-602.

[0069] Example 7

[0070] The difference between this embodiment and embodiment 2 is that the impregnation slurry is different. In the impregnation slurry of this embodiment, no long-chain alkyl-modified silane coupling agent is added.

[0071] Example 8

[0072] The difference between this embodiment and embodiment 2 is that the impregnation slurry is different. In the impregnation slurry of this embodiment, isophorone diisocyanate is not added.

[0073] Example 9

[0074] The difference between this embodiment and embodiment 2 is that the impregnation slurry is different. In the impregnation slurry of this embodiment, 2,3-dimercaptosuccinic acid is not added.

[0075] Comparative Example 1

[0076] The difference between this embodiment and embodiment 2 is that the thickness of the spiral winding layer and the annular winding layer are different. In this comparative example, the number of layers of the annular winding layer is 29, and the number of layers of the spiral winding layer is 37.

[0077] Comparative Example 2

[0078] The difference between this embodiment and embodiment 2 is that the thickness of the spiral winding layer and the annular winding layer are different. In this comparative example, the number of layers of the annular winding layer is 33, and the number of layers of the spiral winding layer is 33.

[0079] Comparative Example 3

[0080] The difference between this embodiment and embodiment 2 is that the composite material winding layer is only a spiral winding layer, the number of winding layers is 66 layers, and the thickness of a single layer is 0.368 mm.

[0081] Comparative Example 4

[0082] The difference between this embodiment and embodiment 2 is that the composite material winding layer is only an annular winding layer, the number of winding layers is 66, and the thickness of a single layer is 0.368 mm.

[0083] Test example

[0084] The hydrogen permeability coefficient, minimum bursting pressure, and fatigue life tests were performed on the plastic liner carbon fiber fully wrapped composite gas cylinders obtained in the above examples and comparative examples. The hydrogen permeability coefficient was tested in accordance with GB / T4261 0-2023; the minimum bursting pressure and fatigue life were tested in accordance with GB / T42612-2023.

[0085] The test results are shown in Table 1 below.

[0086] Table 1

[0087] Group Minimum bursting pressure (MPa) <![CDATA[Hydrogen permeability coefficient cm 3 ·cm / (cm 2 ·s·Pa)]]> Cycle times (times) Example 1 176 <![CDATA[1.4×10 -15 ]]> 48278 Example 2 179 <![CDATA[0.9×10 -15 ]]> 48605 Example 3 178 <![CDATA[1.1×10 -15 ]]> 48477 Example 4 165 <![CDATA[5.8×10 -15 ]]> 46233 Example 5 168 <![CDATA[5.1×10 -15 ]]> 45261 Example 6 166 <![CDATA[5.5×10 -15 ]]> 43365 Example 7 165 <![CDATA[6.0×10 -15 ]]> 42860 Example 8 162 <![CDATA[7.6×10 -15 ]]> 44171 Example 9 168 <![CDATA[6.6×10 -15 ]]> 43510 Comparative Example 1 161 <![CDATA[3.8×10 -15 ]]> 45635 Comparative Example 2 175 <![CDATA[2.1×10 -15 ]]> 46078 Comparative Example 3 163 <![CDATA[3.8×10 -15 ]]> 46906 Comparative Example 4 164 <![CDATA[3.6×10 -15 ]]> 45606

[0088] The results show that the minimum bursting pressure of the plastic liner carbon fiber fully wrapped composite gas cylinder obtained in Examples 1-3 of the present invention is 176MPa or above, which meets the requirements; the hydrogen permeability coefficient is small and the air tightness is good, that is, the interface bonding between the composite material wrapping layer and the plastic liner is good; the gas cylinder is cyclically inflated at 70MPa until the gas cylinder leaks, and the measured cycle number is more than 48,000 times, and the fatigue life is high.

[0089] The minimum bursting pressure of the gas cylinders obtained in Comparative Examples 1 and 2 is significantly lower than that in Example 2, indicating that by controlling the thickness of the spiral winding layer and the annular winding layer, the thickness of the winding layer can be reduced as much as possible to reduce the weight of the gas cylinder while maintaining a high load-bearing capacity and good air tightness.

[0090] The minimum bursting pressure, air tightness, and number of cycles of the gas cylinders obtained in Examples 4-8 are all lower than those in Example 2, indicating that the composition of the impregnation slurry has a great influence on the performance of the gas cylinder. The use of the impregnation slurry provided by the present invention helps to improve the carrying capacity, air tightness, interface bonding and service life of the gas cylinder.

[0091] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A plastic liner carbon fiber fully wrapped composite gas cylinder, characterized in that: It comprises a plastic liner, a valve seat and a composite material winding layer, wherein the composite material winding layer is coated on the outside of the plastic liner; the composite material winding layer is formed by alternately winding a carbon fiber impregnated with an impregnation slurry through spiral winding and annular winding, wherein the single layer thickness of the annular winding layer and the spiral winding layer is 0.35-0.38 mm, the number of layers of the annular winding layer is 30-32, and the number of layers of the spiral winding layer is 34-36; The impregnation slurry comprises the following raw materials in parts by weight: 55-70 parts of epoxy resin, 10-20 parts of isophorone diisocyanate, 3.4-5 parts of dithiol compound, 3-5 parts of long-chain alkyl modified silane coupling agent, 5-8 parts of curing agent and 1-3 parts of accelerator.

2. The plastic liner carbon fiber fully wrapped composite gas cylinder according to claim 1, characterized in that: The winding angle of the spiral winding layer is 30-37°; the angle of the annular winding layer is 88-90°.

3. The plastic liner carbon fiber fully wrapped composite gas cylinder according to claim 1, characterized in that: The material of the composite material winding layer is composed of carbon fiber and impregnation slurry in a mass ratio of 10:(1-1.8).

4. The plastic liner carbon fiber fully wrapped composite gas cylinder according to claim 1, characterized in that: The impregnation slurry comprises the following raw materials in parts by weight: 67 parts of epoxy resin, 17 parts of isophorone diisocyanate, 4.2 parts of dithiol compound, 4.3 parts of long-chain alkyl-modified silane coupling agent, 6 parts of curing agent, and 2 parts of accelerator.

5. The plastic liner carbon fiber fully wrapped composite gas cylinder according to claim 1, characterized in that: The dithiol compound is ethylene glycol dithioacetate or 2,3-dimercaptosuccinic acid.

6. The plastic liner carbon fiber fully wrapped composite gas cylinder according to claim 1, characterized in that: The long-chain alkyl modified silane coupling agent is prepared by modifying a bisaminosilane coupling agent with C8-C12 saturated / unsaturated fatty acid ester.

7. The plastic liner carbon fiber fully wrapped composite gas cylinder according to claim 6, characterized in that: The bisaminosilane coupling agent is selected from any one of KH-792, KH-791 and KH-602.

8. The plastic liner carbon fiber fully wrapped composite gas cylinder according to claim 6, characterized in that: The C8-C12 saturated / unsaturated fatty acid ester is prepared by reacting a straight-chain or branched saturated or unsaturated fatty acid with ethanol, propanol or butanol.

9. The method for preparing a composite gas cylinder with a plastic liner and fully wrapped carbon fiber according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) impregnating carbon fiber in an impregnation slurry and then winding the carbon fiber on a plastic liner to form a composite material winding layer; (2) placing the plastic liner wrapped with the composite material wrapping layer into a curing furnace for curing, thereby obtaining the plastic liner carbon fiber fully wrapped composite gas cylinder.

10. The method for preparing a composite gas cylinder with a plastic liner and fully wrapped carbon fiber according to claim 9, characterized in that: The curing temperature is 95-115° C. and the curing time is 3-5 hours.