Naphthalene-containing nylon material, hydrogen storage container inner container and preparation methods of naphthalene-containing nylon material and hydrogen storage container inner container

Abstract

The invention relates to the technical field of nylon materials and hydrogen storage, and provides a naphthalene-containing nylon material, a hydrogen storage container liner and preparation methods thereof, the naphthalene-containing nylon material comprises the following raw material components: 100 mol parts of diacid monomer, 10-60 mol parts of naphthalene ring structure diacid / diester, and the balance of diacid containing benzene ring and / or aliphatic chain, 100 to 102 parts by mole of aliphatic chain diamine; the naphthalene nylon material is modified by blending with a modifying substance, and the modifying substance at least comprises one of a polyolefin elastomer, maleic anhydride and ethylene propylene diene monomer. The excellent barrier property of the naphthalene-containing nylon is utilized, and the material is applied to production of the inner container of the hydrogen storage container, so that the processing difficulty of the hydrogen storage container is reduced while the excellent barrier property is maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of nylon materials and hydrogen storage technology, and in particular to a naphthalene-containing nylon material, a hydrogen storage container liner and respective preparation methods thereof. Background Art

[0002] With growing global energy demand and heightened environmental awareness, hydrogen energy, thanks to its clean, renewable, and high energy density, is becoming a key research direction in the future energy sector. As a core component of hydrogen energy applications, hydrogen storage and transportation technologies are attracting significant attention. The development of efficient and safe hydrogen storage materials and equipment is considered crucial to breaking through the bottlenecks in hydrogen energy technology.

[0003] Currently, mainstream hydrogen storage technologies include high-pressure, liquid, and solid-state hydrogen storage. High-pressure hydrogen storage, due to its relatively mature technology and high storage density, has been widely used in areas such as fuel cell vehicles. However, this technology places extremely stringent demands on hydrogen storage containers, which must withstand operating pressures exceeding 35 MPa. This poses significant challenges to the material's airtightness, strength, and resistance to hydrogen embrittlement.

[0004] In high-pressure hydrogen storage containers, the inner liner is its core component, mainly responsible for blocking hydrogen leakage and ensuring airtightness. Traditional inner liner materials are mostly metal or composite materials. Although they have high strength, they have disadvantages such as high density, susceptibility to hydrogen permeation and embrittlement. In recent years, polymer materials have gradually become an important research direction for high-pressure hydrogen storage container liners due to their lightweight, excellent formability and chemical corrosion resistance. Among them, naphthalene-containing nylon has shown great potential as a material for hydrogen storage container liners due to its unique properties. Compared with traditional hydrogen storage container liners, naphthalene-containing nylon has many advantages such as low hydrogen permeability, strong chemical stability, excellent mechanical properties and stability over a wide temperature range. However, naphthalene-containing nylon also has certain limitations. Its high processing temperature and complex molding process limit its large-scale application.

[0005] Chinese patent CN106928452A discloses a long-chain semi-aromatic nylon material containing naphthalene rings and its preparation method. The material is prepared from the following components in molar parts: 18-20 parts of 2,6-naphthalene dicarboxylic acid, 20-22 parts of a long-chain diamine, 0.05-0.1 parts of a nucleating agent, 0.002-0.005 parts of a catalyst, and 600-1000 parts of a reaction solvent. The long-chain diamine is selected from one or more aliphatic diamines containing 8 or more carbon atoms in the main molecular chain. This invention's preparation method is simple and low-cost. The resulting long-chain semi-aromatic nylon material containing naphthalene rings exhibits excellent mechanical properties and heat resistance, but lacks the strong barrier properties and ease of processing required for hydrogen storage containers.

[0006] Chinese patent CN118955891A discloses a naphthalene-ring-containing bio-based polyamide copolymer material and its preparation method. The raw materials are composed of a naphthalene ring structure diacid / diester, a bio-based long carbon chain dibasic acid, a bio-based long carbon chain diamine, a catalyst, a nucleating agent, and deionized water, and discloses a preparation method for the above-mentioned copolymer material. This invention reduces the melting temperature of the material and improves its ductility, but in actual production, it still cannot meet the fluidity requirements of blow molding processing to make hydrogen storage containers. The present invention further improves the barrier properties and fluidity of naphthalene-containing nylon materials, and can simultaneously meet the dual requirements of hydrogen storage container manufacturing process and storage performance.

[0007] Therefore, it has become a practical need to provide a naphthalene-containing nylon material with good barrier properties and controllable strength and a preparation method thereof, so as to reduce the difficulty of processing hydrogen storage containers while maintaining excellent performance. Summary of the Invention

[0008] The purpose of the present invention is to provide a naphthalene-containing nylon material, a hydrogen storage container liner and their respective preparation methods, and to utilize the excellent barrier properties of naphthalene-containing nylon to apply it to the production of hydrogen storage container liners, thereby reducing the difficulty of hydrogen storage container processing while maintaining excellent barrier properties, and providing new ideas for the design and manufacture of high-pressure hydrogen storage containers.

[0009] To achieve the above objectives, the present invention provides a naphthalene-containing nylon material, a hydrogen storage container liner, and methods for preparing the same. The technical solution of the present invention is achieved as follows:

[0010] A naphthalene-containing nylon material comprises raw material components including: 100 molar parts of a dibasic acid monomer, wherein 10-60 molar parts of a naphthalene ring structure diacid / diester, and the remainder being a dibasic acid containing a benzene ring and / or a fatty chain, and 100-102 molar parts of a fatty chain diamine; the naphthalene-containing nylon material is modified by blending with a modifying substance, wherein the modifying substance comprises at least one of a polyolefin elastomer, maleic anhydride, and ethylene propylene diene monomer (EPDM) rubber.

[0011] Furthermore, the naphthalene ring structure diacid / diester includes at least one of 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid dimethyl ester, 2,6-naphthalene dicarboxylic acid dimethyl ester, 2,7-naphthalene dicarboxylic acid dimethyl ester, and 2,6-naphthalene dicarboxylic acid diethyl ester.

[0012] Furthermore, the dibasic acid containing a benzene ring and / or a fatty chain includes at least one of terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid.

[0013] Furthermore, the fatty chain diamine includes at least one of hexamethylenediamine, decanediamine, dodecanediamine, and tetradecanediamine.

[0014] Furthermore, the raw material components of the naphthalene-containing nylon material also include a catalyst and a nucleating agent, and the catalyst and the nucleating agent account for 0.05-0.1 molar parts in total.

[0015] Furthermore, the raw material components of the naphthalene-containing nylon material also include deionized water, and the deionized water is 100-500 parts by mole.

[0016] Furthermore, a method for preparing a naphthalene-containing nylon material is provided, which is used to prepare the above-mentioned naphthalene-containing nylon material, and the preparation method comprises the following steps:

[0017] S1: placing the above raw material components in a high-temperature and high-pressure reactor, sealing the high-temperature and high-pressure reactor, starting the stirring device, and filling the reactor with inert gas to replace the residual air therein, repeating the gas replacement 5-10 times. After the replacement is completed, 0.5-0.8 MPa of inert gas is retained in the reactor as a protective gas;

[0018] S2: Heat the high temperature and high pressure polymerization reactor to 90-120°C with a stirring rate of 200-300 r / min and maintain this temperature for 1-2 hours;

[0019] S3: The high-temperature and high-pressure polymerization reactor is heated and stirred continuously. After the pressure in the reactor reaches 1.5-2.5 MPa, the solvent system is released to keep the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 240-280°C and maintained for 2-3 hours, the reactor is depressurized to normal pressure within 1.5-3 hours, and the stirring speed is reduced to 10-50 r / min. At this time, the temperature in the reactor is controlled to be maintained at 240-280°C for 2-3 hours, and then the temperature is kept unchanged and vacuumed to -0.1 MPa for 3-5 hours to obtain the naphthalene-containing nylon material.

[0020] Furthermore, after step S3, step S4 is added: blending and modifying the naphthalene-containing nylon material obtained in step S3 with the modified substance through a twin-screw extruder.

[0021] A hydrogen storage container liner comprises an outer layer, an adhesive layer and a barrier layer, wherein the barrier layer is attached to the inner surface and / or outer surface of the outer layer via the adhesive layer, and the outer layer comprises a naphthalene-containing nylon material prepared according to the preparation method as claimed in claim 1.

[0022] A method for preparing a hydrogen storage container liner is used to prepare the above-mentioned hydrogen storage container liner, and the preparation method comprises the following steps:

[0023] Step 1: forming a container by blow molding the naphthalene-containing nylon material;

[0024] Step 2: Apply a solution containing at least one of polyethylene glycol, polyvinyl butyral, and polyacrylic acid as an adhesive to the inner surface of the container, and then cure it in a curing chamber at 70-100° C. for 40-80 minutes.

[0025] Compared with the prior art, the naphthalene-containing nylon material, hydrogen storage container liner and their respective preparation methods described in the present invention have the following advantages:

[0026] 1. The present invention provides a method for preparing a naphthalene-containing nylon material, which introduces naphthalene rings with excellent barrier properties into the nylon molecular chain, thereby significantly reducing the permeability of hydrogen.

[0027] 2. The method of the present invention reduces the melting temperature of naphthalene-containing nylon, improves the melt fluidity of the material, makes the naphthalene-containing nylon material easy to blow mold, and reduces the difficulty of manufacturing the inner liner of the hydrogen storage container.

[0028] 3. The present invention also improves the preparation process, making the preparation easier, and the obtained product has other better properties (such as yellowing resistance and impact resistance). BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic cross-sectional view of the inner liner of a hydrogen storage container made of naphthalene-containing nylon material according to the present invention;

[0030] Figure 2 It is the molecular chain structural formula of the naphthalene-containing nylon copolymer material described in the present invention.

[0031] Description of reference numerals:

[0032] 1. Inner liner of hydrogen storage container; 2. Outer layer; 3. Adhesive layer; 4. Barrier layer. DETAILED DESCRIPTION

[0033] The present invention provides a naphthalene-containing nylon material, the raw material components of which include:

[0034] 100 molar parts of dibasic acid monomer, of which 10-60 parts are naphthalene ring structure diacid / diester, and the rest are dibasic acid containing benzene ring and / or fatty chain; 100-102 molar parts of fatty chain diamine; 0.05-0.1 molar parts of catalyst and nucleating agent in total; 100-500 molar parts of deionized water.

[0035] The naphthalene ring structure diacid / diester includes at least one of 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid dimethyl ester, 2,6-naphthalene dicarboxylic acid dimethyl ester, 2,7-naphthalene dicarboxylic acid dimethyl ester, and 2,6-naphthalene dicarboxylic acid diethyl ester.

[0036] The dibasic acid containing a benzene ring and / or a fatty chain includes at least one of terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid.

[0037] The fatty chain diamine includes at least one of hexamethylenediamine, decanediamine, dodecanediamine and tetradecanediamine.

[0038] The catalyst includes at least one of sodium hypophosphite, sodium phosphite, potassium hypophosphite, magnesium hypophosphite, calcium hypophosphite or zinc hypophosphite.

[0039] The nucleating agent includes at least one of calcium carbonate, barium sulfate, silicon dioxide, titanium dioxide and talc.

[0040] Figure 2 It is the molecular chain structural formula of the naphthalene-containing nylon copolymer material described in the present invention.

[0041] The present invention also provides a method for preparing the above-mentioned naphthalene-containing nylon material, comprising the following steps:

[0042] Step one, weighing a naphthalene ring structure diacid / diester, a diprotic acid containing a benzene ring and / or an aliphatic chain, a fatty chain diamine, a catalyst, a nucleating agent, and deionized water in a high-temperature and high-pressure reactor according to the above components, sealing the high-temperature and high-pressure reactor, starting a stirring device, and filling the reactor with an inert gas to replace the air remaining therein, repeating the replacement gas 5-10 times, and retaining 0.5-0.8MPa of inert gas as a protective gas in the reactor after the replacement is completed;

[0043] Step 2: After the components are mixed, the high-temperature and high-pressure polymerization reactor is heated to 90-120°C, with a stirring rate of 200-300 r / min, and maintained at this temperature for 1-2 hours;

[0044] Step three, after the insulation is completed, the high-temperature and high-pressure polymerization reactor continues to be heated and stirred. After the pressure in the reactor reaches 1.5-2.5MPa, the solvent system is released to make the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 240-280°C and maintain for 2-3h, the reactor is depressurized to normal pressure within 1.5-3h, and the stirring speed is reduced to 10-50r / min. At this time, the temperature in the reactor is controlled to be maintained at 240-280°C for 2-3h, and then the temperature is kept unchanged, and the reactor is evacuated to -0.1MPa and maintained for 3-5h to obtain a naphthalene-containing nylon material.

[0045] Experiments show that in step 2, 90-120°C is more suitable for the salt formation temperature of the medium- and long-chain copolymer components containing naphthalene nylon, and the salt formation effect between the various reaction functional groups is better.

[0046] The naphthalene-containing nylon material is obtained by copolymerization modification, and its barrier properties are significantly improved. At the same time, the melting point of the material is lowered by copolymerization modification, which effectively improves its melt fluidity and is beneficial for blow molding. The process control of step three is adopted, which is conducive to obtaining naphthalene-containing nylon by copolymerizing naphthalene dicarboxylic acid / diester with long-chain dibasic acid, making preparation easier. Due to the molecular chain structure, the material prepared by the method of the present invention has a lower melting point, better melt fluidity at the polymerization temperature, and is easier to polymerize. At the same time, the naphthalene-containing nylon prepared with a maximum polymerization temperature of 280°C has the advantage of not being easy to yellow. Therefore, there is no need to add additional anti-yellowing agents, antioxidants and other additives, which can save preparation costs.

[0047] The present invention also provides a hydrogen storage container liner 1, such as Figure 1 As shown, it includes an outer layer 2, an adhesive layer 3 and a barrier layer 4. The outer layer 2 includes a naphthalene-containing nylon copolymer and a physically blended modified material thereof. The barrier layer 4 is attached to the inner surface and / or outer surface of the outer layer 2 through the adhesive layer 3.

[0048] The outer layer 2 of the hydrogen storage container liner 1 further comprises 1%-10% by weight of a modified substance, comprising at least one of a polyolefin elastomer, maleic anhydride, and EPDM rubber. This blending and modification further enhances the barrier properties and flowability of the naphthalene-containing nylon material. It also improves the material's impact resistance, ensuring the hydrogen storage container has excellent hydrogen storage performance under high pressure.

[0049] The thickness of the outer layer 2 is 50-5000 μm.

[0050] An adhesive layer 3 is further provided between the outer layer 2 and the barrier layer 4 , and the thickness of the adhesive layer 3 is 10-100 μm.

[0051] The adhesive layer 3 includes one or more of polyethylene glycol, polyvinyl butyral, and polyacrylic acid.

[0052] The barrier layer 4 includes polyvinyl alcohol and / or polyvinyl alcohol copolymer, and the thickness of the barrier layer 4 is 2-500 μm.

[0053] Nano-montmorillonite is added to the barrier layer 4 to enhance the barrier performance.

[0054] The particle size of the nano-montmorillonite is 0.01-10 μm; and the content of the nano-montmorillonite is 0.1-10% by weight.

[0055] The present invention also provides a method for preparing a hydrogen storage container liner 1 made of naphthalene-containing nylon material, comprising the following steps:

[0056] (1) forming a container by blow molding a naphthalene-containing nylon material;

[0057] (2) Apply a solution formed by one or more of polyethylene glycol, polyvinyl butyral, and polyacrylic acid as an adhesive to the inner surface of the container, and then cure it in a curing room at 70-100°C for 40-80 minutes.

[0058] To make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the embodiments described are part of the embodiments of the present invention, rather than all of the embodiments. The specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. It should be noted that, unless there is a conflict, the features in the embodiments and embodiments of the present invention may be combined with each other.

[0059] The following describes seven embodiments of the present invention in detail. At the same time, two comparative examples are also given for comparison of the effects.

[0060] Example 1

[0061] Step 1, weighing 60 parts of 2,6-naphthalene dicarboxylic acid, 40 parts of adipic acid, 102 parts of hexamethylenediamine, 0.02 parts of sodium hypophosphite as a catalyst, 0.03 parts of calcium carbonate as a nucleating agent, and 500 parts of deionized water into a high-temperature and high-pressure reactor, sealing the high-temperature and high-pressure reactor, starting a stirring device, and filling the reactor with nitrogen to replace the residual air therein, repeating the gas replacement 10 times, and retaining 0.8 MPa of nitrogen in the reactor as a protective gas after the replacement is completed;

[0062] Step 2: After the components are mixed, the high-temperature and high-pressure polymerization reactor is heated to 120°C with a stirring rate of 300 r / min and maintained at this temperature for 2 hours;

[0063] Step 3: After the insulation is completed, the high-temperature and high-pressure polymerization reactor is continued to be heated and stirred. After the pressure in the reactor reaches 2.5 MPa, the solvent system is released to make the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 280°C and is maintained for 3 hours, the reactor is depressurized to normal pressure within 3 hours, and the stirring speed is reduced to 50 r / min. At this time, the temperature in the reactor is controlled to be maintained at 280°C for 3 hours, and then the temperature is kept unchanged and evacuated to -0.1 MPa for 5 hours to obtain a naphthalene-containing nylon material;

[0064] Step 4: By weight percentage, 3% of polyolefin elastomer, 3% of maleic anhydride, and 4% of EPDM rubber are used as modifying substances to blend and modify the naphthalene-containing nylon material obtained in step 3 through a twin-screw extruder to obtain a toughened modified naphthalene-containing nylon material.

[0065] In step five, the toughened, modified naphthalene-containing nylon material obtained in step four was blow-molded to form the outer layer of the hydrogen storage container liner. A 12% solids polyethylene glycol solution was applied to the inner surface of the outer layer, and the container was then placed in a 100°C curing chamber for 40 minutes. Finally, a barrier layer containing 10% nano-montmorillonite was applied to the inner surface at a coating weight of 1g / m2. After application, the container was cured in a 65°C curing chamber for 4 hours to obtain hydrogen storage container liner sample 1.

[0066] Example 2

[0067] Step 1, weighing 50 parts of 1,5-naphthalene dicarboxylic acid, 10 parts of terephthalic acid, 40 parts of sebacic acid, 101 parts of hexamethylenediamine, 0.02 parts of sodium phosphite as a catalyst, 0.05 parts of calcium carbonate as a nucleating agent, and 100 parts of deionized water in a high-temperature and high-pressure reactor, sealing the high-temperature and high-pressure reactor, starting a stirring device, and filling the reactor with nitrogen to replace the residual air therein, repeating the gas replacement 9 times, and retaining 0.7 MPa of nitrogen in the reactor as a protective gas after the replacement is completed;

[0068] Step 2: After the components are mixed, the high-temperature and high-pressure polymerization reactor is heated to 110° C., with a stirring rate of 250 r / min, and maintained at this temperature for 1.5 hours;

[0069] Step 3: After the insulation is completed, the high-temperature and high-pressure polymerization reactor is continued to be heated and stirred. After the pressure in the reactor reaches 2.0 MPa, the solvent system is released to make the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 280° C., it is maintained for 3 hours. The reactor is depressurized to normal pressure within 3 hours, and the stirring speed is reduced to 40 r / min. At this time, the temperature in the reactor is controlled to be maintained at 280° C. for 3 hours, and then the temperature is kept unchanged and evacuated to -0.1 MPa for 5 hours to obtain a naphthalene-containing nylon material.

[0070] Step 4: By weight percentage, 4% of polyolefin elastomer, 2% of maleic anhydride, and 4% of EPDM rubber are used as modifying substances to blend and modify the naphthalene-containing nylon material obtained in step 3 through a twin-screw extruder to obtain a toughened modified naphthalene-containing nylon material.

[0071] In step five, the toughened, modified naphthalene-containing nylon material obtained in step four was blow-molded to form the outer layer of the hydrogen storage container liner. A solution of 10% polyethylene glycol and 2% polyvinyl butyral ester was applied to the inner surface of the outer layer. The container was then placed in a 90°C curing chamber and aged for 50 minutes. Finally, a barrier layer containing 5% nano-montmorillonite was applied to the inner surface at a coating weight of 1g / m2. After application, the container was cured in a 55°C curing chamber for 5 hours. This yielded Sample 2 of the hydrogen storage container liner.

[0072] Example 3

[0073] Step 1, weighing 40 parts of dimethyl 2,6-naphthalene dicarboxylate, 20 parts of isophthalic acid, 40 parts of sebacic acid, 100 parts of decanediamine, 0.03 parts of sodium phosphite catalyst, 0.02 parts of calcium carbonate nucleating agent, and 200 parts of deionized water in a high-temperature and high-pressure reactor, sealing the high-temperature and high-pressure reactor, starting the stirring device, and filling the reactor with nitrogen to replace the residual air therein, repeating the gas replacement 8 times, and retaining 0.6 MPa of nitrogen in the reactor as a protective gas after the replacement is completed;

[0074] Step 2: After the components are mixed, the high-temperature and high-pressure polymerization reactor is heated to 100°C with a stirring rate of 200 r / min and maintained at this temperature for 2 hours;

[0075] Step 3: After the insulation is completed, the high-temperature and high-pressure polymerization reactor is continued to be heated and stirred. After the pressure in the reactor reaches 2.0 MPa, the solvent system is released to make the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 280° C., it is maintained for 3 hours. The reactor is depressurized to normal pressure within 3 hours, and the stirring speed is reduced to 40 r / min. At this time, the temperature in the reactor is controlled to be maintained at 280° C. for 3 hours, and then the temperature is kept unchanged and evacuated to -0.1 MPa for 5 hours to obtain a naphthalene-containing nylon material.

[0076] Step 4: By weight percentage, 5% of polyolefin elastomer, 2% of maleic anhydride, and 3% of EPDM rubber are used as modifying substances to blend and modify the naphthalene-containing nylon material obtained in step 3 through a twin-screw extruder to obtain a toughened modified naphthalene-containing nylon material.

[0077] In step five, the toughened, modified naphthalene-containing nylon material obtained in step four was blow-molded to form the outer layer of the hydrogen storage container liner. A mixed solution of 8% polyethylene glycol, 2% polyvinyl butyral, and 2% polyacrylic acid was applied to the inner surface of the outer layer. The container was then placed in a 90°C curing chamber and aged for 50 minutes. Finally, a barrier layer containing 1% nano-montmorillonite was applied to the inner surface at a coating weight of 1g / m2. After application, the container was cured in a 45°C curing chamber for 6 hours. This yielded hydrogen storage container liner sample three.

[0078] Example 4

[0079] Step 1, weighing 30 parts of dimethyl 2,7-naphthalene dicarboxylate, 20 parts of isophthalic acid, 50 parts of dodecanedioic acid, 102 parts of decanediamine, 0.03 parts of sodium phosphite catalyst, 0.02 parts of calcium carbonate nucleating agent, and 150 parts of deionized water in a high-temperature and high-pressure reactor, sealing the high-temperature and high-pressure reactor, starting the stirring device, and filling the reactor with nitrogen to replace the residual air therein, repeating the gas replacement 7 times, and retaining 0.5 MPa of nitrogen in the reactor as a protective gas after the replacement is completed;

[0080] Step 2: After the components are mixed, the high-temperature and high-pressure polymerization reactor is heated to 90°C with a stirring rate of 250 r / min and maintained at this temperature for 2 hours;

[0081] Step 3: After the insulation is completed, the high-temperature and high-pressure polymerization reactor is continued to be heated and stirred. After the pressure in the reactor reaches 1.5 MPa, the solvent system is released to make the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 270°C and then maintained for 3 hours, the reactor is depressurized to normal pressure within 3 hours, and the stirring speed is reduced to 50 r / min. At this time, the temperature in the reactor is controlled to be maintained at 270°C for 3 hours, and then the temperature is kept unchanged and evacuated to -0.1 MPa for 5 hours to obtain a naphthalene-containing nylon material;

[0082] Step 4: By weight percentage, 10% of polyolefin elastomer is used as a modifying substance to blend and modify the naphthalene-containing nylon material obtained in step 3 through a twin-screw extruder to obtain a toughened modified naphthalene-containing nylon material.

[0083] In step five, the toughened, modified naphthalene-containing nylon material obtained in step four was blow-molded to form the outer layer of the hydrogen storage container liner. A mixed solution of 8% polyethylene glycol, 2% polyvinyl butyral, and 2% polyacrylic acid was applied to the inner surface of the outer layer. The container was then placed in a 70°C curing chamber and aged for 70 minutes. Finally, a barrier layer containing 0.5% nano-montmorillonite was applied to the inner surface at a coating weight of 1g / m2. After application, the container was cured in a 35°C curing chamber for 6 hours. This yielded hydrogen storage container liner sample four.

[0084] Example 5

[0085] Step 1, weighing 10 parts of diethyl 2,6-naphthalate, 10 parts of terephthalic acid, 20 parts of isophthalic acid, 60 parts of dodecanedioic acid, 102 parts of dodecanediamine, 0.03 parts of sodium phosphite as a catalyst, 0.02 parts of calcium carbonate as a nucleating agent, and 200 parts of deionized water in a high-temperature and high-pressure reactor, sealing the high-temperature and high-pressure reactor, starting a stirring device, and filling the reactor with nitrogen to replace the residual air therein, repeating the gas replacement 6 times, and retaining 0.5 MPa of nitrogen in the reactor as a protective gas after the replacement is completed;

[0086] Step 2: After the components are mixed, the high-temperature and high-pressure polymerization reactor is heated to 90°C with a stirring rate of 200 r / min and maintained at this temperature for 2 hours;

[0087] Step 3: After the insulation is completed, the high-temperature and high-pressure polymerization reactor is continued to be heated and stirred. After the pressure in the reactor reaches 1.5 MPa, the solvent system is released to make the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 260° C. and is maintained for 3 hours, the reactor is depressurized to normal pressure within 3 hours, and the stirring speed is reduced to 50 r / min. At this time, the temperature in the reactor is controlled to be maintained at 260° C. for 3 hours, and then the temperature is kept unchanged and evacuated to -0.1 MPa and maintained for 3 hours to obtain a naphthalene-containing nylon material;

[0088] Step 4: 10% by weight of maleic anhydride is used as a modifying substance to blend and modify the naphthalene-containing nylon material obtained in step 3 through a twin-screw extruder to obtain a toughened modified naphthalene-containing nylon material.

[0089] In step five, the toughened, modified naphthalene-containing nylon material obtained in step four was blow-molded to form the outer layer of the hydrogen storage container liner. A mixed solution of 8% polyethylene glycol, 2% polyvinyl butyral, and 2% polyacrylic acid was applied to the inner surface of the outer layer. The container was then placed in a 70°C curing chamber and aged for 80 minutes. Finally, a barrier layer containing 0.1% nano-montmorillonite was applied to the inner surface at a coating weight of 1g / m2. After application, the container was cured in a 65°C curing chamber for 4 hours. This yielded hydrogen storage container liner sample five.

[0090] Example 6

[0091] Step 1, weighing 30 parts of dimethyl 2,7-naphthalene dicarboxylate, 70 parts of tetradecanedioic acid, 102 parts of dodecane diamine, 0.03 parts of sodium phosphite as a catalyst, 0.02 parts of calcium carbonate as a nucleating agent, and 300 parts of deionized water into a high-temperature and high-pressure reactor, sealing the high-temperature and high-pressure reactor, starting a stirring device, and filling the reactor with nitrogen to replace the residual air therein, repeating the gas replacement 5 times, and retaining 0.5 MPa of nitrogen in the reactor as a protective gas after the replacement is completed;

[0092] Step 2: After the components are mixed, the high-temperature and high-pressure polymerization reactor is heated to 90°C with a stirring rate of 200 r / min and maintained at this temperature for 2 hours;

[0093] Step 3: After the insulation is completed, the high-temperature and high-pressure polymerization reactor is continued to be heated and stirred. After the pressure in the reactor reaches 1.5 MPa, the solvent system is released to make the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 250° C. and is maintained for 3 hours, the reactor is depressurized to normal pressure within 3 hours, and the stirring speed is reduced to 50 r / min. At this time, the temperature in the reactor is controlled to be maintained at 250° C. for 3 hours, and then the temperature is kept unchanged and evacuated to -0.1 MPa and maintained for 3 hours to obtain a naphthalene-containing nylon material;

[0094] Step 4: By weight percentage, 10% of EPDM rubber is used as a modifying substance to blend and modify the naphthalene-containing nylon material obtained in step 3 through a twin-screw extruder to obtain a toughened modified naphthalene-containing nylon material.

[0095] In step five, the toughened, modified naphthalene-containing nylon material obtained in step four was blow-molded to form the outer layer of the hydrogen storage container liner. A mixed solution of 8% polyethylene glycol, 2% polyvinyl butyral, and 2% polyacrylic acid was applied to the inner surface of the outer layer. The container was then placed in a 70°C curing chamber and aged for 80 minutes. Finally, a barrier layer containing 0.1% nano-montmorillonite was applied to the inner surface at a coating weight of 1g / m2. After application, the container was cured in a 65°C curing chamber for 4 hours. This yielded hydrogen storage container liner sample six.

[0096] Example 7

[0097] Step 1, weighing 20 parts of dimethyl 1,5-naphthalene dicarboxylate, 80 parts of tetradecanedioic acid, 102 parts of tetradecanediamine, 0.05 parts of sodium phosphite as a catalyst, 0.05 parts of calcium carbonate as a nucleating agent, and 200 parts of deionized water in a high-temperature and high-pressure reactor, sealing the high-temperature and high-pressure reactor, starting a stirring device, and filling the reactor with nitrogen to replace the residual air therein, repeating the gas replacement 10 times, and after the replacement is completed, retaining 0.5 MPa of nitrogen in the reactor as a protective gas;

[0098] Step 2: After the components are mixed, the high-temperature and high-pressure polymerization reactor is heated to 90°C with a stirring rate of 200 r / min and maintained at this temperature for 2 hours;

[0099] Step 3: After the insulation is completed, the high-temperature and high-pressure polymerization reactor is continued to be heated and stirred. After the pressure in the reactor reaches 1.5 MPa, the solvent system is released to make the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 240°C and then maintained for 3 hours, the reactor is depressurized to normal pressure within 3 hours, and the stirring speed is reduced to 50 r / min. At this time, the temperature in the reactor is controlled to be maintained at 240°C for 3 hours, and then the temperature is kept unchanged and evacuated to -0.1 MPa for 3 hours to obtain a naphthalene-containing nylon material;

[0100] Step 4: By weight percentage, 10% of EPDM rubber is used as a modifying substance to blend and modify the naphthalene-containing nylon material obtained in step 3 through a twin-screw extruder to obtain a toughened modified naphthalene-containing nylon material.

[0101] In step five, the toughened, modified naphthalene-containing nylon material obtained in step four was blow-molded to form the outer layer of the hydrogen storage container liner. A mixed solution of 8% polyethylene glycol, 2% polyvinyl butyral, and 2% polyacrylic acid was applied to the inner surface of the outer layer. The container was then placed in a 70°C curing chamber and aged for 80 minutes. Finally, a barrier layer containing 0.1% nano-montmorillonite was applied to the inner surface at a coating weight of 1g / m2. After application, the container was cured in a 65°C curing chamber for 4 hours to produce hydrogen storage container liner sample seven.

[0102] Comparative Example 1

[0103] Step 1: Weigh 100 parts of adipic acid, 102 parts of hexamethylenediamine, 0.02 parts of sodium hypophosphite as a catalyst, 0.03 parts of calcium carbonate as a nucleating agent, and 200 parts of deionized water in a high-temperature and high-pressure reactor, seal the high-temperature and high-pressure reactor, start the stirring device, and fill the reactor with nitrogen to replace the residual air therein. Repeat the gas replacement 10 times. After the replacement is completed, 0.8 MPa of nitrogen is retained in the reactor as a protective gas;

[0104] Step 2: After the components are mixed, the high-temperature and high-pressure polymerization reactor is heated to 120°C with a stirring rate of 300 r / min and maintained at this temperature for 2 hours;

[0105] Step 3: After the insulation is completed, the high-temperature and high-pressure polymerization reactor is continued to be heated and stirred. After the pressure in the reactor reaches 2.5 MPa, the solvent system is released to make the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 280°C and is maintained for 3 hours, the reactor is depressurized to normal pressure within 3 hours, and the stirring speed is reduced to 50 r / min. At this time, the temperature in the reactor is controlled to be maintained at 280°C for 3 hours, and then the temperature is kept unchanged and evacuated to -0.1 MPa for 5 hours to obtain a naphthalene-containing nylon material;

[0106] Step 4: By weight percentage, 3% of polyolefin elastomer, 3% of maleic anhydride, and 4% of EPDM rubber are used as modifying substances to blend and modify the naphthalene-containing nylon material obtained in step 3 through a twin-screw extruder to obtain a toughened modified naphthalene-containing nylon material.

[0107] In step five, the toughened, modified naphthalene-containing nylon material obtained in step four was blow-molded to form the outer layer of the hydrogen storage container liner. A 12% solids polyethylene glycol solution was applied to the inner surface of the outer layer, and the container was then placed in a 100°C curing chamber for 40 minutes. Finally, a barrier layer containing 10% nano-montmorillonite was applied to the inner surface at a coating weight of 1g / m2. After application, the container was cured in a 65°C curing chamber for 4 hours to produce a first comparative hydrogen storage container liner.

[0108] Comparative Example 2

[0109] Step 1: Weigh 20 parts of terephthalic acid, 20 parts of isophthalic acid, 60 parts of dodecanedioic acid, 102 parts of dodecanediamine, 0.03 parts of sodium phosphite as a catalyst, 0.02 parts of calcium carbonate as a nucleating agent, and 200 parts of deionized water in a high-temperature and high-pressure reactor, seal the high-temperature and high-pressure reactor, start the stirring device, and fill the reactor with nitrogen to replace the residual air therein. Repeat the gas replacement 6 times. After the replacement is completed, retain 0.5 MPa of nitrogen in the reactor as a protective gas;

[0110] Step 2: After the components are mixed, the high-temperature and high-pressure polymerization reactor is heated to 90°C with a stirring rate of 200 r / min and maintained at this temperature for 2 hours;

[0111] Step 3: After the insulation is completed, the high-temperature and high-pressure polymerization reactor is continued to be heated and stirred. After the pressure in the reactor reaches 1.5 MPa, the solvent system is released to make the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 260° C. and is maintained for 3 hours, the reactor is depressurized to normal pressure within 3 hours, and the stirring speed is reduced to 50 r / min. At this time, the temperature in the reactor is controlled to be maintained at 260° C. for 3 hours, and then the temperature is kept unchanged and evacuated to -0.1 MPa and maintained for 3 hours to obtain a naphthalene-containing nylon material;

[0112] Step 4: 10% by weight of maleic anhydride is used as a modifying substance to blend and modify the naphthalene-containing nylon material obtained in step 3 through a twin-screw extruder to obtain a toughened modified naphthalene-containing nylon material.

[0113] In step five, the toughened, modified naphthalene-containing nylon material obtained in step four was blow-molded to form the outer layer of the hydrogen storage container liner. A mixed solution of 8% polyethylene glycol, 2% polyvinyl butyral, and 2% polyacrylic acid was applied to the inner surface of the outer layer. The container was then placed in a 70°C curing chamber and aged for 80 minutes. Finally, a barrier layer containing 0.1% nano-montmorillonite was applied to the inner surface at a coating weight of 1g / m2. After application, the container was cured in a 65°C curing chamber for 4 hours to produce a second comparative hydrogen storage container liner.

[0114] Table 1 Comparison table of components and modified substances of Examples 1-7 and Comparative Examples 1-2

[0115] Table 2 Comparison table of process parameters of process steps 1-3 of Examples 1-7 and Comparative Examples 1-2

[0116]

[0117] Table 3 Comparison of the manufacturing process (step 5) of the adhesive layer and barrier layer of the hydrogen storage container of Examples 1-7 and Comparative Examples 1-2

[0118]

[0119] Table 4 Barrier properties and fluidity test results of Examples 1-7 and Comparative Examples 1-2

[0120]

[0121] As can be seen from the comparison of Tables 1-3, Example 1 and Comparative Example 1 differ only in components. Comparative Example 1 replaces all 60 parts of 2,6-naphthalenedicarboxylic acid in Example 1 with adipic acid, thereby eliminating the naphthalene ring structure diacid / diester and directly reflecting the effect of the presence of the naphthalene ring structure diacid / diester. Similarly, Example 5 and Comparative Example 2 also differ only in components. Comparative Example 2 replaces all 10 parts of diethyl 2,6-naphthalenedicarboxylate in Example 5 with terephthalic acid, thereby directly reflecting the difference in properties brought about by diethyl 2,6-naphthalenedicarboxylate.

[0122] Analyzing Table 4, the hydrogen permeability coefficients of Sample 1 and Comparative Sample 1, as well as the data after one and two years, show that introducing a naphthalene ring structure into the nylon material molecular chain can effectively improve the hydrogen barrier rate of the hydrogen storage container liner. At the same time, the naphthalene-containing nylon material has excellent dimensional stability and low water absorption due to the planar stacking of the naphthalene ring structure. The hydrogen permeability coefficients of Samples 1, 6, and 7, as well as the data after one and two years, show that the higher the content of naphthalene ring structure in the molecular chain, the better the barrier performance of the material. The hydrogen permeability coefficients of Sample 5 and Comparative Sample 2, as well as the data after one and two years, show that replacing the benzene ring structure in the molecular chain with an equal proportion of naphthalene rings significantly improves the barrier performance of the material. The hydrogen permeability coefficients of Samples 2, 3, 4, and 5, as well as the data after one and two years, show that as the content of naphthalene rings in the molecular chain decreases, the barrier performance of the material gradually decreases.

[0123] At the same time, the melt index of each group of samples shows that the higher the naphthalene ring structure content, the lower the melt index value. The higher the melt index, the better the material's fluidity, but this may sacrifice certain mechanical properties. The lower the melt index, the better the material's mechanical properties, but this may increase processing difficulty. Selecting an appropriate melt index should be based on a comprehensive consideration of the container's shape, thickness, usage requirements, and the capabilities of the blow molding equipment. In the embodiments of the present invention, the melt index is already in the relatively high value range (greater than 10), the material has good fluidity, is easy to form into complex shapes, and can meet the needs of thin-walled container production.

[0124] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A naphthalene-containing nylon material, characterized in that: The raw material components of the naphthalene-containing nylon material include: 100 molar parts of a dibasic acid monomer, of which 10-60 molar parts are a naphthalene ring structure diacid / diester, and the rest are a dibasic acid containing a benzene ring and / or a fatty chain, and 100-102 molar parts of a fatty chain diamine; the naphthalene-containing nylon material is modified by blending with a modifying substance, and the modifying substance includes at least one of a polyolefin elastomer, maleic anhydride, and ethylene propylene diene monomer (EPDM) rubber.

2. The naphthalene-containing nylon material according to claim 1, characterized in that: The naphthalene ring structure diacid / diester includes at least one of 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid dimethyl ester, 2,6-naphthalene dicarboxylic acid dimethyl ester, 2,7-naphthalene dicarboxylic acid dimethyl ester and 2,6-naphthalene dicarboxylic acid diethyl ester.

3. The naphthalene-containing nylon material according to claim 1, characterized in that: The dibasic acid containing a benzene ring and / or a fatty chain includes at least one of terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid.

4. The naphthalene-containing nylon material according to claim 1, characterized in that The fatty chain diamine includes at least one of hexamethylenediamine, decanediamine, dodecanediamine and tetradecanediamine.

5. The naphthalene-containing nylon material according to claim 1, characterized in that: The raw material components of the naphthalene-containing nylon material further include a catalyst and a nucleating agent, and the catalyst and the nucleating agent together account for 0.05-0.1 molar parts.

6. The naphthalene-containing nylon material according to claim 1, characterized in that: The raw material components of the naphthalene-containing nylon material also include deionized water, and the deionized water is 100-500 parts by mole.

7. A method for preparing a naphthalene-containing nylon material, characterized in that: For preparing the naphthalene-containing nylon material according to any one of claims 1 to 6, the preparation method comprises the following steps: S1: placing the raw material components in a high-temperature and high-pressure reactor, sealing the high-temperature and high-pressure reactor, starting a stirring device, and filling the reactor with inert gas to replace the residual air therein, repeating the gas replacement 5-10 times. After the replacement is completed, 0.5-0.8 MPa of inert gas is retained in the reactor as a protective gas; S2: Heat the high temperature and high pressure polymerization reactor to 90-120°C with a stirring rate of 200-300 r / min and maintain this temperature for 1-2 hours; S3: The high-temperature and high-pressure polymerization reactor is heated and stirred continuously. After the pressure in the reactor reaches 1.5-2.5 MPa, the solvent system is released to keep the reactor in a constant pressure state. After the temperature in the reactor continues to rise to 240-280°C and maintained for 2-3 hours, the reactor is depressurized to normal pressure within 1.5-3 hours, and the stirring speed is reduced to 10-50 r / min. At this time, the temperature in the reactor is controlled to be maintained at 240-280°C for 2-3 hours, and then the temperature is kept unchanged and vacuumed to -0.1 MPa for 3-5 hours to obtain the naphthalene-containing nylon material.

8. The preparation method according to claim 7, characterized in that After step S3, step S4 is added: blending and modifying the naphthalene-containing nylon material obtained in step S3 with the modified substance through a twin-screw extruder.

9. A hydrogen storage container liner, comprising an outer layer (2), an adhesive layer (3) and a barrier layer (4), wherein the barrier layer (4) is attached to the inner surface and / or outer surface of the outer layer (2) through the adhesive layer (3), characterized in that: The outer layer (2) comprises a naphthalene-containing nylon material prepared by the preparation method according to one of claims 7 and 8.

10. A method for preparing a hydrogen storage container liner, characterized in that: For preparing the hydrogen storage container liner (1) according to claim 9, the preparation method comprises the following steps: Step 1: forming a container by blow molding the naphthalene-containing nylon material; Step 2: Apply a solution containing at least one of polyethylene glycol, polyvinyl butyral, and polyacrylic acid as an adhesive to the inner surface of the container, and then cure it in a curing chamber at 70-100° C. for 40-80 minutes.

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