A multi-element filler modified polyurethane hydrogen barrier coating and a preparation process thereof

Abstract

The application belongs to the field of organic coating, and particularly relates to a multi-element filler modified polyurethane hydrogen barrier coating and a preparation process. The chemical components of the polyurethane hydrogen barrier coating include: polyurethane prepolymer 59.5-61.3%, dispersant 20.3-23.1%, NbSe2 2.17-2.84%, curing agent 10.9-12.2%, silane modified graphene 1.62-2.26%, and Ti2SnC 1.08-1.52%. The sum of the mass percentages of the chemical components is 100%. The polyurethane hydrogen barrier coating has simple preparation process, compact structure and good hydrogen barrier effect.

Description

Technical Field

[0001] This invention relates to the field of organic coating technology, specifically to a multi-component filler-modified polyurethane hydrogen barrier coating and its preparation process. Background Technology

[0002] Hydrogen energy, as a clean and green energy source, has advantages such as being pollution-free, having a high calorific value, and being renewable and recyclable. It is hailed as the secondary energy source with the greatest development potential in the future. However, the problem of hydrogen damage in hydrogen energy storage and transportation materials is one of the key challenges currently hindering the industrialization of hydrogen energy. This is because when metal materials are used in high-pressure, hydrogen-rich environments for extended periods, hydrogen inevitably enters the interior of the materials through permeation and diffusion, making the materials prone to hydrogen embrittlement and hydrogen damage. This seriously affects the stable operation of hydrogen storage and transportation systems and can even lead to serious safety accidents, causing irreparable losses to people's lives and property.

[0003] Due to its excellent corrosion resistance and mechanical properties, 316L stainless steel is widely used in hydrogen storage equipment, reactor blanket structures and other fields. In order to mitigate the corrosion and damage of hydrogen and its isotopes to austenitic stainless steel, a hydrogen-blocking coating is generally prepared on the material surface to set up a hydrogen permeation barrier, which can slow down or prevent hydrogen and its isotopes from entering the substrate, thereby preventing hydrogen embrittlement and other phenomena. This is currently a relatively economical and effective method.

[0004] Currently, the hydrogen barrier coatings used on a large scale are mainly ceramic coatings, including oxide coatings (Er2O3, Al2O3, ZrO2, SiO2, TiO2, Cr2O3, etc.) and non-oxidizing coatings (TiN, Fe2N, AlN, TiC, SiC, etc.). They have good hydrogen barrier properties and are mainly prepared by magnetron sputtering, chemical vapor deposition, micro-arc oxidation, plasma spraying, sol-gel method, etc. However, their preparation processes are often complex and demanding, and they are not easy to apply on a large scale to pipes and irregular parts. In addition, this type of hydrogen barrier coating and substrate material also have problems such as low bonding, poor thermal shock resistance, and easy cracking and peeling.

[0005] Polyurethane coatings are widely used in the field of material surface protection due to their good flexibility, wear resistance, and weather resistance. However, there is relatively little research and application of polyurethane hydrogen barrier coatings in China. Developing and designing new polyurethane hydrogen barrier coatings and their preparation processes has important scientific significance and economic value. Summary of the Invention

[0006] To address the aforementioned defects and problems, this invention provides a multi-component filler-modified polyurethane hydrogen barrier coating and its preparation process. The preparation process is simple, the structure is dense, and the hydrogen barrier effect is good. It can be applied to the surface of 316L stainless steel materials as a polyurethane hydrogen barrier coating to meet the requirements of practical engineering applications.

[0007] The solution adopted by this invention to solve its technical problem is: a multi-component filler-modified polyurethane hydrogen barrier coating, wherein the chemical composition of the polyurethane hydrogen barrier coating is as follows (mass percentage): polyurethane prepolymer: 59.5-61.3%, dispersant: 20.3-23.1%, NbSe2: 2.17-2.84%, curing agent: 10.9-12.2%, silane-modified graphene: 1.62-2.26%, Ti2SnC: 1.08-1.52%, and the sum of the mass percentages of all chemical components is 100%.

[0008] Furthermore, the curing agent is 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), and the dispersant is ethyl acetate.

[0009] Furthermore, the polyurethane prepolymer is a polyether-type polyurethane prepolymer; NbSe2 is nano-NbSe2; and Ti2SnC is nano-Ti2SnC.

[0010] Furthermore, the chemical composition of the multi-component filler-modified polyurethane hydrogen barrier coating is as follows by mass percentage: polyurethane prepolymer: 60.5%, curing agent: 11.5%, dispersant: 22.3%, NbSe2: 2.5%, silane-modified graphene: 1.9%, Ti2SnC: 1.3%, and the sum of the mass percentages of each chemical component is 100%.

[0011] Furthermore, a preparation process for a multi-component filler-modified polyurethane hydrogen barrier coating includes the following steps: (1) Pretreatment of 316L stainless steel material: Use a sandblasting machine to sandblast the 316L stainless steel material to remove oxide scale, grease, etc. until the metal luster is exposed, forming a rough surface with a frosted texture. Then wipe it clean with anhydrous ethanol or acetone, let it air dry naturally, and put it into a sealed bag for later use. (2) Weigh the polyurethane prepolymer and heat it to 75-85°C for later use; weigh the curing agent and heat it to 125-135°C until it melts for later use. (3) Weigh the dispersant, and then add silane-modified graphene, NbSe2 and Ti2SnC to the dispersant. Stir with a magnetic stirrer at a speed of 600~1000 rpm for 20~60 min to fully disperse silane-modified graphene, NbSe2 and Ti2SnC in the dispersant to obtain solution A. (4) Add the heated polyurethane prepolymer to solution A, stir with a magnetic stirrer at 800-1200 rpm for 40-90 min, and then remove the internal bubbles with ultrasound to obtain solution B. (5) Add the molten curing agent to solution B, stir with a magnetic stirrer at a speed of 450~750 rpm for 1.5~2.5 h, and then remove the air bubbles with ultrasound to obtain mixed solution C; (6) Using a spin coater, solution C is spin-coated onto the surface of 316L stainless steel material, and then placed in the air to dry naturally for more than 72 hours and cure naturally to obtain a polyurethane hydrogen barrier coating.

[0012] Furthermore, the thickness of the prepared polyurethane hydrogen barrier coating is 0.25–0.55 mm.

[0013] Furthermore, the polyurethane hydrogen-barrier coating is applied to 316L stainless steel.

[0014] The beneficial effects of this invention: The hydrogen-blocking performance of the polyurethane hydrogen-blocking coating depends not only on the composition of the hydrogen-blocking material, but also on the microstructure, defects, and stability of the coating. The multi-component filler-modified polyurethane hydrogen-blocking coating of this invention has a dense, defect-free structure and bonds firmly to the surface of 316L stainless steel. It exhibits significant blocking and shielding effects against the penetration of hydrogen and its isotopes. The multi-component fillers introduced into the polyurethane coating—silane-modified graphene, NbSe2, and Ti2SnC—work together to effectively improve the hydrogen-blocking effect of the polyurethane coating. First, the nanoscale sheets of silane-modified graphene directly block the penetration of hydrogen and its isotopes, and graphene also acts as a good hydrogen trap, thus preventing the penetration of hydrogen and its isotopes. Second, both NbSe2 and Ti2SnC are layered materials that can hinder the penetration of hydrogen and its isotopes. The penetration and diffusion of its isotopes in the polyurethane coating enhances its hydrogen barrier performance. Furthermore, nano-Ti2SnC combines the ceramic characteristics of high temperature resistance, high strength, and oxidation resistance with the metallic properties of high thermal conductivity and impact resistance, exhibiting excellent thermal shock resistance and high-temperature stability, thus endowing the polyurethane hydrogen barrier coating with superior overall performance. Third, the multi-component filler increases the density of the polyurethane coating, which is beneficial for improving the bonding between the polyurethane hydrogen barrier coating and 316L stainless steel, as well as the coating's hydrogen barrier effect. Through multi-component filler modification, the polyurethane hydrogen barrier coating bonds firmly to 316L stainless steel, resulting in a dense coating structure and excellent hydrogen barrier effect. This effectively reduces or even prevents hydrogen damage to 316L stainless steel, extending its service life. Simultaneously, the polyurethane hydrogen barrier coating has a scientifically formulated chemical composition, a simple preparation process, low cost, and is easy to implement, offering significant production advantages and social benefits. Attached Figure Description

[0015] Figure 1 This is a morphology diagram of the unmodified graphene used in this invention.

[0016] Figure 2 This is a morphology diagram of the silane-modified graphene prepared in this invention. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Example 1: In a specific embodiment of the present invention, the chemical composition of the multi-component filler-modified polyurethane hydrogen barrier coating is as follows by mass percentage: polyether-type polyurethane prepolymer: 60.8%, dispersant (ethyl acetate): 22.7%, NbSe2: 2.35%, curing agent (MOCA): 11.24%, silane-modified graphene: 1.68%, Ti2SnC: 1.23%, and the sum of the mass percentages of each chemical component is 100%.

[0019] Its preparation process includes the following steps: (1) Pretreatment of 316L stainless steel material: Use a sandblasting machine to sandblast the 316L stainless steel material to remove oxide scale, grease, etc. until the metal luster is exposed, forming a rough surface with a frosted texture. Then wipe it clean with anhydrous ethanol, let it air dry naturally, and put it into a sealed bag for later use. (2) Weigh out the polyether-type polyurethane prepolymer and heat it to 82°C for later use; weigh out the curing agent (MOCA) and heat it to 128°C until it melts for later use; (3) Weigh the dispersant, and then add silane-modified graphene, NbSe2 and Ti2SnC to the dispersant. Stir with a magnetic stirrer at 800 rpm for 30 min to fully disperse silane-modified graphene, NbSe2 and Ti2SnC in the dispersant to obtain solution A. (4) Add the heated and prepared polyether polyurethane prepolymer to solution A, stir at 900 rpm for 50 min using a magnetic stirrer, and then remove the internal air bubbles by ultrasound to obtain solution B. (5) Add the molten curing agent (MOCA) to solution B, stir at 500 rpm for 2.5 h using a magnetic stirrer, and then remove the bubbles by ultrasound to obtain mixed solution C; (6) Using a spin coater, the mixed solution C is spin-coated onto the surface of 316L stainless steel material with a coating thickness of 0.45 mm. Then, it is placed in the air to dry naturally for 96 hours and cured naturally to obtain the polyurethane hydrogen barrier coating.

[0020] Example 2 describes a multi-component filler-modified polyurethane hydrogen barrier coating and its preparation process, focusing on the differences from Example 1.

[0021] In this embodiment, the chemical composition of the multi-component filler-modified polyurethane hydrogen barrier coating by mass percentage is as follows: polyether polyurethane prepolymer: 61.3%, dispersant (ethyl acetate): 21.5%, NbSe2: 2.75%, curing agent (MOCA): 11.0%, silane-modified graphene: 1.93%, Ti2SnC: 1.52%, and the sum of the mass percentages of each chemical component is 100%.

[0022] Its preparation process includes the following steps: (1) Pretreatment of 316L stainless steel material: Use a sandblasting machine to sandblast the 316L stainless steel material to remove oxide scale, grease, etc. until the metal luster is exposed, forming a rough surface with a frosted texture. Then wipe it clean with anhydrous ethanol, let it air dry naturally, and put it into a sealed bag for later use. (2) Weigh out the polyether-type polyurethane prepolymer and heat it to 80°C for later use; weigh out the curing agent (MOCA) and heat it to 130°C until it melts for later use. (3) Weigh out the dispersant (ethyl acetate), then add silane-modified graphene, NbSe2 and Ti2SnC to the dispersant, and stir with a magnetic stirrer at 900 rpm for 25 min to fully disperse silane-modified graphene, NbSe2 and Ti2SnC in the dispersant to obtain solution A; (4) Add the heated polyether polyurethane prepolymer to solution A, stir at 800 rpm for 70 min using a magnetic stirrer, and then remove the internal air bubbles by ultrasound to obtain solution B. (5) Add the molten curing agent (MOCA) to solution B, stir at 750 rpm for 1.5 h using a magnetic stirrer, and then remove the bubbles by ultrasound to obtain mixed solution C; (6) Using a spin coater, the mixed solution C is spin-coated onto the surface of 316L stainless steel material with a coating thickness of 0.30 mm. Then, it is placed in the air to dry naturally for 72 hours and cured naturally to obtain the polyurethane hydrogen barrier coating.

[0023] Example 3 describes a multi-component filler-modified polyurethane hydrogen barrier coating and its preparation process, focusing on the differences from Example 1.

[0024] In this embodiment, the chemical composition of the multi-component filler-modified polyurethane hydrogen barrier coating by mass percentage is as follows: polyether polyurethane prepolymer: 59.5%, dispersant (ethyl acetate): 22.48%, NbSe2: 2.84%, curing agent (MOCA): 12.0%, silane-modified graphene: 2.06%, Ti2SnC: 1.12%, and the sum of the mass percentages of each chemical component is 100%.

[0025] Its preparation method includes the following steps: (1) Pretreatment of 316L stainless steel material: Use a sandblasting machine to sandblast the 316L stainless steel material to remove oxide scale, grease, etc. until the metal luster is exposed, forming a rough surface with a frosted texture. Then wipe it clean with anhydrous ethanol, let it air dry naturally, and put it into a sealed bag for later use. (2) Weigh out the polyether-type polyurethane prepolymer and heat it to 85°C for later use; weigh out the curing agent (MOCA) and heat it to 132°C until it melts for later use; (3) Weigh out the dispersant (ethyl acetate), then add silane-modified graphene, NbSe2 and Ti2SnC to the dispersant, and stir with a magnetic stirrer at 750 rpm for 40 min to fully disperse silane-modified graphene, NbSe2 and Ti2SnC in the dispersant to obtain solution A; (4) Add the heated and prepared polyether polyurethane prepolymer to solution A, stir at 1000 rpm for 45 min using a magnetic stirrer, and then remove the internal air bubbles by ultrasound to obtain solution B. (5) Add the molten curing agent (MOCA) to solution B, stir at 700 rpm for 2 hours using a magnetic stirrer, and then remove the bubbles by ultrasound to obtain mixed solution C; (6) Using a spin coater, the mixed solution C is spin-coated onto the surface of 316L stainless steel material with a coating thickness of 0.50 mm. Then, it is placed in the air to dry naturally for 120 hours and cured naturally to obtain the polyurethane hydrogen barrier coating.

[0026] Performance testing: Electrochemical hydrogen permeation experiments were conducted on the multi-component filler-modified polyurethane hydrogen barrier coating prepared in the above examples at room temperature. The results are as follows: 1. The multi-component filler-modified polyurethane hydrogen-blocking coating prepared according to the formulation and process described in Example 1 exhibits a hydrogen permeation blocking capacity 74 times that of 316L stainless steel, demonstrating excellent hydrogen blocking performance. The surface condition of the polyurethane hydrogen-blocking coating remained good after electrochemical hydrogen permeation testing. Furthermore, the adhesion strength test of the polyurethane hydrogen-blocking coating yielded a result of 3.47 MPa, further proving the strong bond between the coating and the 316L stainless steel.

[0027] 2. The multi-component filler-modified polyurethane hydrogen-blocking coating prepared according to the formulation and process described in Example 2 has a hydrogen permeation blocking capacity 80 times that of 316L stainless steel. The coating exhibits excellent hydrogen blocking effect, and the surface condition of the polyurethane hydrogen-blocking coating is good after electrochemical hydrogen permeation experiments. Furthermore, the adhesion strength test of the polyurethane hydrogen-blocking coating yielded a result of 3.50 MPa, which also proves that the coating is firmly bonded to the 316L stainless steel.

[0028] 3. The multi-component filler-modified polyurethane hydrogen-blocking coating prepared according to the formulation and process described in Example 3 has a hydrogen permeation blocking capacity 70 times that of 316L stainless steel. The coating exhibits excellent hydrogen blocking effect, and the surface condition of the polyurethane hydrogen-blocking coating is good after electrochemical hydrogen permeation experiments. Furthermore, the adhesion strength test of the polyurethane hydrogen-blocking coating yielded a result of 3.62 MPa, which also proves that the coating is firmly bonded to the 316L stainless steel.

[0029] In summary, the multi-component filler-modified polyurethane hydrogen barrier coating provided by this invention has a dense structure, good hydrogen barrier effect, and simple preparation process. It can be applied to the surface of 316L stainless steel to meet the requirements of practical engineering applications.

[0030] The above description is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-component filler-modified polyurethane hydrogen-barrier coating, characterized in that, The polyurethane hydrogen-blocking coating is applied to the surface of 316L stainless steel. The chemical composition of the polyurethane hydrogen-blocking coating, by mass percentage, is as follows: polyurethane prepolymer: 59.5–61.3%, dispersant: 20.3–23.1%, NbSe2: 2.17–2.84%, curing agent: 10.9–12.2%, silane-modified graphene: 1.62–2.26%, Ti2SnC: 1.08–1.52%, with the sum of all chemical components being 100%. The chemical modifier is 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), and the dispersant is ethyl acetate; the polyurethane prepolymer is a polyether-type polyurethane prepolymer; NbSe2 is nano-NbSe2; Ti2SnC is nano-Ti2SnC; the silane-modified graphene, nano-NbSe2, and nano-Ti2SnC are used as multi-component fillers to increase the density of the polyurethane hydrogen barrier coating and improve the adhesion between the polyurethane hydrogen barrier coating and the surface of the 316L stainless steel material.

2. The multi-component filler-modified polyurethane hydrogen barrier coating according to claim 1, characterized in that, The chemical composition of the multi-component filler-modified polyurethane hydrogen barrier coating is as follows (mass percentage): polyurethane prepolymer: 60.5%, curing agent: 11.5%, dispersant: 22.3%, NbSe2: 2.5%, silane-modified graphene: 1.9%, Ti2SnC: 1.3%, with the sum of the mass percentages of each chemical component being 100%.

3. The multi-component filler-modified polyurethane hydrogen barrier coating according to claim 1, characterized in that, The application of the polyurethane hydrogen barrier coating on 316L stainless steel.

4. A preparation process for a multi-component filler-modified polyurethane hydrogen barrier coating, applied to the preparation of any of the multi-component filler-modified polyurethane hydrogen barrier coatings described in claims 1-3, characterized in that, Includes the following steps, (1) Pretreatment of 316L stainless steel material: Use a sandblasting machine to sandblast the 316L stainless steel material to remove oxide scale, grease, etc. until the metal luster is exposed, forming a rough surface with a frosted texture. Then wipe it clean with anhydrous ethanol or acetone, let it air dry naturally, and put it into a sealed bag for later use. (2) Weigh the polyurethane prepolymer and heat it to 75-85°C for later use; weigh the curing agent and heat it to 125-135°C until it melts for later use. (3) Weigh the dispersant, and then add silane-modified graphene, NbSe2 and Ti2SnC to the dispersant. Stir with a magnetic stirrer at a speed of 600~1000 rpm for 20~60 min to fully disperse silane-modified graphene, NbSe2 and Ti2SnC in the dispersant to obtain solution A. (4) Add the heated polyurethane prepolymer to solution A, stir with a magnetic stirrer at 800-1200 rpm for 40-90 min, and then remove the internal bubbles with ultrasound to obtain solution B. (5) Add the molten curing agent to solution B, stir with a magnetic stirrer at a speed of 450~750 rpm for 1.5~2.5 h, and then remove the air bubbles with ultrasound to obtain mixed solution C; (6) Using a spin coater, solution C is spin-coated onto the surface of 316L stainless steel material, and then placed in the air to dry naturally for more than 72 hours to cure naturally, thus obtaining a polyurethane hydrogen barrier coating.

5. The preparation process of a multi-component filler-modified polyurethane hydrogen barrier coating according to claim 4, characterized in that, The prepared polyurethane hydrogen barrier coating has a thickness of 0.25–0.55 mm.

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