Rigid polyurethane foam material for high-temperature pipelines and its preparation method

Abstract

This invention belongs to the field of polyurethane technology, specifically relating to rigid polyurethane foam materials for high-temperature resistant pipelines and their preparation method. The polyurethane foam is made from component A and component B in a mass ratio of 100:(130~150). Component A includes the following raw materials by mass percentage: polyether polyol A: 7~36%; polyether polyol B: 13~35%; polyether polyol C: 13~37%; catalyst: 3~8%; additives: 3~14%; dispersant: 0.3~4.2%; foam stabilizer: 1.3~2.5%; pentane blowing agent: 6~15%. Component B is polymethylene polyphenyl isocyanate. By using specific polyether blends, adding nano-zirconia and dispersants, and optimizing the ratio of component A to component B, the high-temperature resistance, compressive strength, and dimensional stability of the polyurethane foam are significantly improved, making it suitable for the preparation of pipeline insulation materials.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane technology, specifically relating to rigid polyurethane foam materials for high-temperature resistant pipelines and their preparation methods. Background Technology

[0002] Rigid polyurethane foam pipe is a building material made of polyol and isocyanate as two components. It is mainly used in building insulation and waterproofing, as well as pipeline corrosion protection and insulation. This material can be quickly formed through on-site spraying and has significant characteristics such as high closed-cell rate, good insulation effect, and wide applicability. It is especially suitable for petrochemical hot oil transportation pipelines, steam heating pipelines, and high-temperature fluid transportation systems in metallurgical plants.

[0003] Conventional rigid polyurethane insulation materials typically have a temperature resistance range of -50℃ to 120℃. However, in specific scenarios involving the transportation of high-temperature media such as petroleum and chemical products, the temperature of the medium inside the pipeline may exceed 150℃ or even higher. If the high-temperature resistance of the insulation material is insufficient, the insulation layer is prone to softening, decomposition, or even combustion under such high-temperature working environments for extended periods. This not only leads to the failure of the insulation function but may also cause safety accidents.

[0004] Therefore, developing a high-performance polyurethane insulation material suitable for high-temperature scenarios has significant practical importance and application value. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a rigid polyurethane foam material for high-temperature pipelines. By using specific polyether compounding, adding nano-zirconia and dispersants, and optimizing the ratio of component A to component B, the high-temperature resistance, compressive strength, and dimensional stability of polyurethane foam are significantly improved, making it suitable for the preparation of pipeline insulation materials.

[0006] Another objective of this invention is to provide a method for preparing rigid polyurethane foam material for high-temperature resistant pipes.

[0007] The technical solution adopted in this invention is as follows:

[0008] The high-temperature resistant rigid polyurethane foam material for pipes is made of component A and component B in a mass ratio of 100:(130~150), wherein component A comprises the following raw materials by mass percentage:

[0009] Polyether polyol A: 7~36%;

[0010] Polyether polyol B: 13~35%;

[0011] Polyether polyol C: 13~37%;

[0012] Catalyst: 3~8%;

[0013] Additives: 3~14%;

[0014] Dispersant: 0.3~4.2%;

[0015] Foam stabilizer: 1.3~2.5%;

[0016] Pentane foaming agent: 6~15%;

[0017] Component B is polymethylene polyphenyl isocyanate;

[0018] The initiator of the polyether polyol A includes sucrose, with a functionality of 6-8 and a hydroxyl value of 500-600 mgKOH / g;

[0019] The initiator of the polyether polyol B includes pentaerythritol, with a functionality of 4-8 and a hydroxyl value of 500-600 mgKOH / g;

[0020] The initiator of the polyether polyol C includes o-toluenediamine, with a functionality of 3-4 and a hydroxyl value of 500-600 mgKOH / g.

[0021] The polyether polyol A is prepared by using sucrose as a single initiator or a combination of sucrose and trimethylolpropane as a composite initiator, and undergoing a ring-opening polymerization reaction with propylene oxide under the action of potassium hydroxide catalyst. The reaction product is neutralized with phosphoric acid, and then obtained by adsorption, dehydration and filtration.

[0022] The polyether polyol B is prepared by using pentaerythritol as a single initiator or a combination of pentaerythritol and sucrose as a composite initiator, and undergoing a ring-opening polymerization reaction with propylene oxide under the action of potassium hydroxide catalyst. The reaction product is neutralized with phosphoric acid, and then obtained by adsorption, dehydration and filtration.

[0023] The polyether polyol C is prepared by ring-opening polymerization of propylene oxide with o-toluenediamine as a single initiator or a combination of o-toluenediamine and triethanolamine as a composite initiator under the action of potassium hydroxide catalyst. The reaction product is neutralized with phosphoric acid, and then obtained by adsorption, dehydration and filtration.

[0024] The catalyst is a mixture of pentamethyldiethylenetriamine (PC-5), N,N-dimethylcyclohexylamine (PC-8) and tris(dimethylaminopropyl)hexahydrotriazine (PC-41) in a mass ratio of (1-2):(1-6):(1-3).

[0025] The additive is nano-zirconia with a particle size of 20-50 nm.

[0026] The dispersant is sodium polyacrylate.

[0027] The foam stabilizer is a polyether-modified silicone surfactant, preferably TEGOSTAB B 8407, TEGOSTAB B 8460 or TEGOSTAB B84823 from Evonik Specialty Chemicals (Shanghai) Co., Ltd.

[0028] The pentane blowing agent is one or more of cyclopentane, isopentane, or n-pentane.

[0029] The preparation method of the high-temperature resistant rigid polyurethane foam material for pipelines includes the following steps:

[0030] Polyether polyol A, polyether polyol B, polyether polyol C, foam stabilizer, catalyst, additives, dispersant, and pentane blowing agent are mixed sequentially and stirred at room temperature for 1-2 hours to obtain component A (combined polyether). When using, component A and component B are mixed in the weight ratio, foamed and cured to obtain rigid polyurethane foam material for high-temperature pipelines.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] (1) By introducing high-temperature resistant nano-zirconia material into the combined polyether system, the present invention significantly improves the compressive strength and dimensional stability of rigid polyurethane foam products under long-term high temperature environment, effectively solving the problem of easy failure of insulation materials under high temperature conditions, and is particularly suitable for the field of high temperature pipeline insulation.

[0033] (2) The nano-zirconia particles selected in this invention have small particle size and good nanoscale dispersion compatibility with the combined polyether; at the same time, by adding an appropriate amount of sodium polyacrylate dispersant, the dispersion effect of nano-zirconia in the combined polyether is further enhanced, the storage stability of the combined polyether is greatly improved, and the agglomeration or precipitation of nano-zirconia is effectively avoided.

[0034] (3) The polyether polyols selected in this invention all have hydroxyl values ​​above 500 mg KOH / g. Compared with the conventional rigid foam polyether's hydroxyl value range of 300-500 mg KOH / g, their molecular weight is lower, resulting in a higher content of hard segments in the polyurethane product, which helps to improve the material's high-temperature resistance. Among them, the sucrose polyether polyol is selected as a product with ultra-high functionality (6-8), the pentaerythritol polyether polyol has a regular molecular structure, and has both excellent dimensional stability and low viscosity, which can balance the overall viscosity of the system. The o-toluene diamine polyether polyol contains benzene rings in its molecular structure, which can also enhance the high-temperature resistance of the product. Through the special selection and optimization of the compounding ratio of the above three polyether polyols, the comprehensive high-temperature resistance of the product is further improved.

[0035] (4) The present invention adopts a scheme of high excess of polymethylene polyphenyl isocyanate of component B, which can promote the formation of polyurea structure with excellent thermal stability and heat resistance. At the same time, by precisely adjusting the ratio of components A and B, the high temperature resistance of the product is further optimized, ensuring its long-term stable operation under high temperature conditions. Detailed Implementation

[0036] The present invention will be further described below with reference to the embodiments, but these embodiments do not limit the implementation of the present invention.

[0037] Unless otherwise specified, the raw materials used in the examples and comparative examples are all commercially available materials, and the process methods used in the examples and comparative examples are all conventional methods in the art.

[0038] The following is a description of some of the raw materials used in the examples and comparative examples:

[0039] Nano-zirconia with a particle size of 35±15nm.

[0040] INOVOL R8243 (functionality 4, hydroxyl value 430mgKOH / g) was purchased from Shandong Yinuowei New Materials Co., Ltd.

[0041] INOVOL R6205 (functionality 4, hydroxyl value 380mgKOH / g) was purchased from Shandong Yinuowei New Materials Co., Ltd.

[0042] INOVOL R305 (functionality 3, hydroxyl value 340mgKOH / g) was purchased from Shandong Yinuowei New Materials Co., Ltd.

[0043] Polyether polyol A1 was prepared by ring-opening polymerization of propylene oxide with sucrose as a single initiator under the action of potassium hydroxide catalyst. The reaction product was neutralized with phosphoric acid, and then obtained by adsorption, dehydration and filtration. The functionality was 8, the hydroxyl value was 600 mg KOH / g, and the ring-opening polymerization temperature was 110℃.

[0044] Polyether polyol A2 is prepared by using sucrose and trimethylolpropane as a composite initiator and undergoing ring-opening polymerization with propylene oxide under the action of potassium hydroxide catalyst. The reaction product is neutralized with phosphoric acid, and then obtained by adsorption, dehydration and filtration. The functionality is 7.5, the hydroxyl value is 500 mg KOH / g, and the ring-opening polymerization temperature is 110℃.

[0045] Polyether polyol B1 was prepared by ring-opening polymerization of propylene oxide with pentaerythritol as a single initiator under the action of potassium hydroxide catalyst. The reaction product was neutralized with phosphoric acid, and then obtained by adsorption, dehydration and filtration. The functionality was 4, the hydroxyl value was 600 mg KOH / g, and the ring-opening polymerization temperature was 120℃.

[0046] Polyether polyol B2 uses pentaerythritol and sucrose as a composite initiator and undergoes ring-opening polymerization with propylene oxide under the action of potassium hydroxide catalyst. The reaction product is neutralized with phosphoric acid, and then obtained by adsorption, dehydration and filtration. It has a functionality of 6, a hydroxyl value of 500 mg KOH / g and a ring-opening polymerization temperature of 120℃.

[0047] Polyether polyol C1 was prepared by ring-opening polymerization of propylene oxide with o-toluenediamine as a single initiator under the action of potassium hydroxide catalyst. The reaction product was neutralized with phosphoric acid, and then obtained by adsorption, dehydration and filtration. The functionality was 4, the hydroxyl value was 600 mg KOH / g, and the ring-opening polymerization temperature was 120℃.

[0048] Polyether polyol C2 was prepared by using o-toluenediamine and triethanolamine as composite initiators and undergoing ring-opening polymerization with propylene oxide under the action of potassium hydroxide catalyst. The reaction product was neutralized with phosphoric acid, and then obtained by adsorption, dehydration and filtration. The functionality was 3.5, the hydroxyl value was 500 mg KOH / g, and the ring-opening polymerization temperature was 120℃.

[0049] Example 1

[0050] The aforementioned high-temperature resistant rigid polyurethane foam material for pipelines is made from component A and component B in a mass ratio of 100:150, wherein component A consists of the following raw materials in parts by mass:

[0051] Polyether polyol A1: 30 parts;

[0052] Polyether polyol B1: 50 parts;

[0053] Polyether polyol C1: 20 parts;

[0054] PC-5: 1 copy;

[0055] PC-8: 3 copies;

[0056] PC-41: 1.5 copies;

[0057] Nano-zirconia: 20 parts;

[0058] Sodium polyacrylate: 6 parts;

[0059] TEGOSTAB B 8407: 2 copies;

[0060] Cyclopentane: 10 parts;

[0061] Component B is polymethylene polyphenyl isocyanate;

[0062] The preparation method of the high-temperature resistant rigid polyurethane foam material for pipelines includes the following steps:

[0063] Polyether polyol A1, polyether polyol B1, polyether polyol C1, TEGOSTAB B 8407, PC-5, PC-8, PC-41, nano zirconium dioxide, sodium polyacrylate, and cyclopentane are mixed sequentially and stirred at room temperature for 2 hours to obtain component A (combined polyether). When using, component A is mixed with polymethylene polyphenyl isocyanate in the specified weight ratio, foamed and cured to obtain rigid polyurethane foam material for high-temperature resistant pipes.

[0064] Example 2

[0065] The aforementioned high-temperature resistant rigid polyurethane foam material for pipes is made from component A and component B in a mass ratio of 100:130, wherein component A consists of the following raw materials in parts by mass:

[0066] Polyether polyol A2: 10 parts;

[0067] Polyether polyol B2: 40 parts;

[0068] Polyether polyol C2: 50 parts;

[0069] PC-5: 3.3 copies;

[0070] PC-8: 3.3 copies;

[0071] PC-41: 3.3 copies;

[0072] Nano-zirconia: 5 parts;

[0073] Sodium polyacrylate: 0.5 parts;

[0074] TEGOSTAB B 84823: 3 copies;

[0075] Isopentane: 20 parts;

[0076] Component B is polymethylene polyphenyl isocyanate;

[0077] The method for preparing the high-temperature resistant rigid polyurethane foam material for pipes involves sequentially mixing polyether polyol A2, polyether polyol B2, polyether polyol C2, TEGOSTAB B 84823, PC-5, PC-8, PC-41, nano-zirconia, sodium polyacrylate, and isopentane, and stirring at room temperature for 1 hour to obtain component A (combined polyether). In use, component A is mixed with polymethylene polyphenyl isocyanate in a specific weight ratio, and then foamed and cured to obtain the high-temperature resistant rigid polyurethane foam material for pipes.

[0078] Example 3

[0079] The aforementioned high-temperature resistant rigid polyurethane foam material for pipelines is made from component A and component B in a mass ratio of 100:140, wherein component A consists of the following raw materials in parts by mass:

[0080] Polyether polyol A2: 50 parts;

[0081] Polyether polyol B1: 20 parts;

[0082] Polyether polyol C2: 30 parts;

[0083] PC-5: 1 copy;

[0084] PC-8: 4 copies;

[0085] PC-41: 2 copies;

[0086] Nano-zirconia: 15 parts;

[0087] Sodium polyacrylate: 3 parts;

[0088] TEGOSTAB B 8460: 2.5 servings;

[0089] n-Pentane: 15 parts;

[0090] Component B is polymethylene polyphenyl isocyanate;

[0091] The method for preparing the high-temperature resistant rigid polyurethane foam material for pipes involves sequentially mixing polyether polyol A2, polyether polyol B1, polyether polyol C2, TEGOSTAB B 8460, PC-5, PC-8, PC-41, nano-zirconia, sodium polyacrylate, and n-pentane, and stirring at room temperature for 1.5 hours to obtain component A (combined polyether). In use, component A is mixed with polymethylene polyphenyl isocyanate at a specific weight ratio, and then foamed and cured to obtain the high-temperature resistant rigid polyurethane foam material for pipes.

[0092] Comparative Example 1

[0093] The difference from Example 1 is that nano-zirconia is not added to component A, otherwise it is the same as Example 1.

[0094] Comparative Example 2

[0095] The difference from Example 2 is that sodium polyacrylate is not added to component A, otherwise it is the same as Example 2.

[0096] Comparative Example 3

[0097] The rigid polyurethane foam material is made of component A and component B in a mass ratio of 100:140, wherein component A consists of the following raw materials in parts by mass:

[0098] INOVOL R8243: 50 copies;

[0099] INOVOL R6205: 20 copies;

[0100] INOVOL R305: 30 servings;

[0101] PC-5: 1 copy;

[0102] PC-8: 4 copies;

[0103] PC-41: 2 copies;

[0104] Nano-zirconia: 15 parts;

[0105] Sodium polyacrylate: 3 parts;

[0106] TEGOSTAB B 8460: 2.5 servings;

[0107] n-Pentane: 15 parts;

[0108] Component B is polymethylene polyphenyl isocyanate;

[0109] The preparation method of the rigid polyurethane foam material is the same as in Example 3.

[0110] Comparative Example 4

[0111] The rigid polyurethane foam material described herein differs from that in Example 1 in that it is made of component A and component B in a mass ratio of 100:100, otherwise it is the same as in Example 1.

[0112] The rigid polyurethane foam materials prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests, and the test methods are as follows:

[0113] Appearance of component A: After placing component A at room temperature for 7 days, observe the changes in its appearance;

[0114] Compressive strength: Tested in accordance with GB / T 8813-2008;

[0115] Dimensional deformation rate: Samples with dimensions of 10cm×10cm×2.5cm were placed at corresponding temperatures (150℃ or -50℃) for 48h, and the dimensional deformation rate of the samples was measured and calculated. The calculation formula is: (volume after placement - initial volume) / initial volume × 100%.

[0116] The test results are shown in Table 1.

[0117] Table 1 Performance Test Results

[0118]

[0119] As shown in Table 1, the rigid polyurethane foam materials prepared in Examples 1-3 exhibit significantly improved compressive strength and dimensional stability compared to the product in Comparative Example 1 (without nano-zirconia), demonstrating a clear advantage. Comparative Example 2, lacking a dispersant, not only showed a small amount of particles and precipitation but also negatively impacted the mechanical properties of the product. The rigid polyurethane foam materials prepared in Comparative Example 3 using conventional polyether polyols and Comparative Example 4 using a non-excessive B component method showed significantly lower compressive strength and dimensional stability than the products obtained in Examples 1-3, indicating a substantial performance difference.

Claims

1. A rigid polyurethane foam material for high-temperature resistant pipes, characterized in that, It is made from component A and component B in a mass ratio of 100:(130~150), wherein component A comprises the following raw materials by mass percentage: Polyether polyol A: 7~36%; Polyether polyol B: 13~35%; Polyether polyol C: 13~37%; Catalyst: 3~8%; Additives: 3~14%; Dispersant: 0.3~4.2%; Foam stabilizer: 1.3~2.5%; Pentane foaming agent: 6~15%; Component B is polymethylene polyphenyl isocyanate; The polyether polyol A is prepared by ring-opening polymerization of propylene oxide with sucrose as a single initiator or by a combination of sucrose and trimethylolpropane as a composite initiator under the action of potassium hydroxide catalyst. The functionality is 6-8 and the hydroxyl value is 500-600 mgKOH / g. The polyether polyol B is prepared by ring-opening polymerization of propylene oxide with pentaerythritol as a single initiator or a combination of pentaerythritol and sucrose as a composite initiator under the action of potassium hydroxide catalyst. The functionality is 4~8 and the hydroxyl value is 500~600mgKOH / g. The polyether polyol C is prepared by ring-opening polymerization of propylene oxide with o-toluenediamine as a single initiator or a combination of o-toluenediamine and triethanolamine as a composite initiator under the action of potassium hydroxide catalyst. The functionality is 3-4 and the hydroxyl value is 500-600 mgKOH / g. The additive is nano-zirconia; The dispersant is sodium polyacrylate.

2. The rigid polyurethane foam material for high-temperature resistant pipelines according to claim 1, characterized in that, The catalyst is a mixture of pentamethyldiethylenetriamine, N,N-dimethylcyclohexylamine and tris(dimethylaminopropyl)hexahydrotriazine, with a mixing mass ratio of (1-2):(1-6):(1-3).

3. The rigid polyurethane foam material for high-temperature resistant pipelines according to claim 1, characterized in that, The particle size of the additive is 20-50 nm.

4. The rigid polyurethane foam material for high-temperature resistant pipelines according to claim 1, characterized in that, The foam stabilizer is a polyether-modified organosilicon surfactant.

5. The rigid polyurethane foam material for high-temperature resistant pipelines according to claim 1, characterized in that, The pentane blowing agent is one or more of cyclopentane, isopentane, or n-pentane.

6. A method for preparing a rigid polyurethane foam material for high-temperature pipelines as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Polyether polyol A, polyether polyol B, polyether polyol C, foam stabilizer, catalyst, additives, dispersant, and pentane blowing agent are mixed sequentially and stirred at room temperature for 1-2 hours to obtain component A. When using, component A and component B are mixed in the weight ratio, foamed and cured to obtain rigid polyurethane foam material for high-temperature pipelines.

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