Polyurethane grouting material with low water sensitivity in normal-temperature environment and preparation method of polyurethane grouting material

Abstract

The invention belongs to the field of polyurethane high polymer materials, and particularly relates to a low-water-sensitivity polyurethane grouting material in a normal-temperature environment and a preparation method of the low-water-sensitivity polyurethane grouting material. The grouting material comprises a component A and a component B in a mass part ratio of 1: 1. The component A is prepared from 20 to 30 parts of acrylate grafted polyether polyol, 40 to 60 parts of cashew nut shell oil polyether polyol, 1 to 5 parts of a catalyst, 1 to 3 parts of a plasticizer, 0.5 to 1.5 parts of a foam stabilizer, 1 to 3 parts of water and 10 to 20 parts of a flame retardant; and the component B is polyisocyanate. The low-water-sensitivity polyurethane grouting material provided by the invention can be rapidly diffused in concrete crack pores, is insensitive to water, can reduce the probability of reaction between slurry and external water, improves the foaming stability of the polyurethane grouting material in a water-rich environment, regulates a proper foaming ratio, forms a polyurethane consolidated body with high strength, and has good water-sensitivity. The coating has the advantages of impermeability, high strength, high adhesion and the like.

Description

Technical Field

[0002] The invention belongs to the field of polyurethane polymer materials, and in particular relates to a low water-sensitivity polyurethane grouting material under normal temperature and a preparation method thereof. Background Art

[0004] Polyurethane grouting materials are widely used in highway crack repair, foundation reinforcement, waterproofing and plugging projects due to their excellent performance, convenient construction and application. After the polyurethane grouting materials are injected into the rock and soil cracks through the grouting equipment, due to the low initial viscosity, the slurry can diffuse into extremely small rock cracks, and a cross-linking and curing reaction occurs on the surface of the cracks, and the originally broken and loose structure is cemented into a complete load-bearing body through the formation of a network skeleton structure.

[0005] Traditional polyurethane grouting materials can be divided into oil-soluble polyurethane and water-soluble polyurethane. Oil-soluble polyurethane has high solidification strength and good impermeability, but the grouting liquid is not easy to clean. If it is not cleaned in time, it will cause blockage to equipment and tools, and the price is relatively high; water-soluble polyurethane grouting materials have good hydrophilicity, good working performance, low viscosity, and can be easily poured into fine cracks and pores, but the strength after curing is relatively low, which is not suitable for engineering parts with high structural strength requirements.

[0006] At present, relevant researchers have conducted a lot of research and development work on the preparation of polyurethane grouting materials. For example, patent CN115637041A discloses a high-expansion two-component polyurethane grouting material with adjustable curing time and a preparation method thereof. By adjusting the ratio of the catalyst and the foam stabilizer in component B, a polyurethane grouting material with adjustable curing time, high expansion rate and high non-volatile content is obtained. Patent CN110372844A discloses a polyurethane grouting material, a preparation method and application. By using an amino polyol with a self-catalytic effect to react with polyisocyanate, the requirements of rapid curing and foaming molding can be met. The obtained polyurethane grouting material has good toughness, excellent bonding effect, cooling, self-catalysis, and both lipophilic and hydrophilic grouting characteristics. Patent CN110511352A discloses a filling, reinforcement and water-blocking polyurethane grouting material and a preparation method thereof. By using relatively small molecular weight polyether polyol and polymethylene polyphenyl isocyanate as main raw materials, a solvent-free two-component foaming polyurethane grouting material with the characteristics of high strength, good toughness, short solidification time, high foaming rate and good bonding performance is prepared.

[0007] There is often a water-rich environment in railway tunnel construction projects. Since the polyether polyol in conventional polyurethane grouting materials has a certain affinity with external water, its reaction with isocyanate in the system is relatively uncontrollable, and isocyanate reacts quickly with water to produce carbon dioxide, and the volume expands rapidly. The uniformity and support of the pore structure of the formed solid body are poor, the self-strength is low, the adhesion to the concrete cracks is also weak, and the filling and reinforcement effect is poor. The performance of existing polyurethane grouting materials cannot meet the requirements of the above application fields well. The development of a polyurethane grouting material with low water sensitivity has become a problem that needs to be solved urgently. Summary of the invention

[0009] The purpose of the present invention is to solve the above problems and provide a polyurethane grouting material with low water sensitivity under normal temperature environment, and a preparation method of the grouting material.

[0010] The invention discloses a low water-sensitive polyurethane grouting material under normal temperature environment, characterized in that the grouting material comprises component A and component B, and the mass ratio thereof is 1:1, and the component A comprises: 20 to 30 parts of acrylate grafted polyether polyol, 40 to 60 parts of cashew nut shell oil polyether polyol, 1 to 5 parts of catalyst, 1 to 3 parts of plasticizer, 0.5 to 1.5 parts of foam stabilizer, 1 to 3 parts of water, and 10 to 20 parts of flame retardant; the component B is polyisocyanate.

[0011] The acrylate grafted polyether polyol is prepared by free radical polymerization of acrylate and polyether polyol, the acrylate is lauryl methacrylate, and the polyether polyol is a polyether polyol based on PO-EO copolyether triol, and the hydroxyl value is 230-400 mg KOH / g.

[0012] The functionality of the cashew nut shell oil polyether polyol is 2-3, and the hydroxyl value is 600-700 mg KOH / g.

[0013] The catalyst is one or more of a tertiary amine catalyst and an organic metal catalyst, and the organic metal catalyst includes one or more of organic tin, organic zirconium, and organic platinum; the organic metal catalyst preferentially catalyzes the reaction of alcohol hydroxyl group and polyisocyanate.

[0014] The foam stabilizer is a water-soluble organic silicone compound.

[0015] The flame retardant is one of ammonium polyphosphate, melamine, tetrabromobisphenol A, aluminum hydroxide, magnesium hydroxide and antimony trioxide.

[0016] The polyisocyanate is polyphenyl polymethylene polyisocyanate (PAPI).

[0017] The method for preparing a low water-sensitivity polyurethane grouting material is characterized by comprising the following steps:

[0018] (1) The acrylate grafted polyether polyol, the cashew nut shell liquid polyether polyol and the optional catalyst, plasticizer, foam stabilizer and flame retardant are uniformly mixed, and a measured amount of water is added and stirred at high speed to mix uniformly to obtain the component A.

[0019] (2) Component A and component B are mixed in a mass ratio of 1:1 to obtain the low water-sensitivity polyurethane grouting material.

[0020] The invention discloses an application of the low water-sensitivity polyurethane grouting material in grouting and plugging of a water-rich tunnel.

[0021] The positive effects of the low water-sensitivity polyurethane grouting material provided by the present invention under normal temperature environment are:

[0022] In the low water-sensitive polyurethane grouting material provided by the present invention, the acrylate grafted polyether polyol contains a long-chain alkyl group and has strong hydrophobicity; the cashew nut shell oil polyether polyol has a long cardanol fatty chain compared to the ordinary polyether polyol, has good hydrophobicity, and can maintain low water sensitivity during the curing process with isocyanate, reduce the foaming ratio, and thus improve the mechanical properties of the final polyurethane system. In addition, the cashew nut shell oil polyether polyol has a fast curing speed with isocyanate and has an aromatic structure. The dispersion force of the benzene ring structure can exclude water molecules bound to the surface of the substrate, enhance the slurry infiltration effect, and further improve the adhesion at the interface of the wet substrate.

[0023] The positive effects of the method for preparing a low water-sensitive polyurethane grouting material under normal temperature provided by the present invention are:

[0024] The hydrophobic capacity of the polyurethane grouting material is improved by increasing the proportion of hydrophobic groups in the polyether polyol composition; and a proper amount of water is pre-dispersed in the polyether polyol component so that the isocyanate in the system component B reacts preferentially with the well-dispersed water inside the component A during the preparation of the polyurethane grouting material, thereby improving the foaming stability of the polyurethane grouting material in a water-rich environment and facilitating the regulation of an appropriate foaming ratio. The formed polyurethane solid body has high strength and has the advantages of impermeability, high strength, high adhesion, etc., and can effectively play a role in water blocking and reinforcement. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the embodiments.

[0027] Embodiment 1:

[0028] (I) The mass fractions of each raw material in the polyurethane grouting material are:

[0029] Component A:

[0030] Acrylate grafted polyether polyol (hydroxyl value 230mg KOH / g), 20 parts;

[0031] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 400mg KOH / g), 60 parts;

[0032] Catalyst, 3 parts;

[0033] Plasticizer, 1 part;

[0034] Foam stabilizer, 0.5 parts;

[0035] Water, 2 parts;

[0036] Flame retardant, 10 parts.

[0037] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0038] The mass ratio of component A to component B is 1:1.

[0039] (ii) The preparation steps include:

[0040] (1) A certain amount of acrylate grafted polyether polyol, cashew nut shell liquid polyether polyol, catalyst, plasticizer, foam stabilizer and flame retardant are uniformly mixed, and a certain amount of water is added and stirred at high speed to mix uniformly to obtain component A.

[0041] (2) Component A and component B are fully mixed to obtain a low water-sensitive polyurethane grouting material.

[0042] Embodiment 2:

[0043] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0044] Component A:

[0045] Acrylate grafted polyether polyol (hydroxyl value 230mg KOH / g), 30 parts;

[0046] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 400mg KOH / g), 50 parts;

[0047] Catalyst, 3 parts;

[0048] Plasticizer, 1 part;

[0049] Foam stabilizer, 1 part;

[0050] Water, 2 parts;

[0051] Flame retardant, 20 parts.

[0052] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0053] The mass ratio of component A to component B is 1:1.

[0054] (ii) The preparation steps are the same as those in Example 1.

[0055] Embodiment 3:

[0056] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0057] Component A:

[0058] Acrylate grafted polyether polyol (hydroxyl value 400mg KOH / g), 30 parts;

[0059] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 700mg KOH / g), 50 parts;

[0060] Catalyst, 3 parts;

[0061] Plasticizer, 1 part;

[0062] Foam stabilizer, 1.5 parts;

[0063] Water, 3 parts;

[0064] Flame retardant, 20 parts.

[0065] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0066] The mass ratio of component A to component B is 1:1.

[0067] (ii) The preparation steps are the same as those in Example 1.

[0068] Embodiment 4:

[0069] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0070] Component A:

[0071] Acrylate grafted polyether polyol (hydroxyl value 400mg KOH / g), 30 parts;

[0072] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 700mg KOH / g), 50 parts;

[0073] Catalyst, 3 parts;

[0074] Plasticizer, 3 parts;

[0075] Foam stabilizer, 1.5 parts;

[0076] Water, 3 parts;

[0077] Flame retardant, 20 parts.

[0078] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0079] The mass ratio of component A to component B is 1:1.

[0080] (ii) The preparation steps are the same as those in Example 1.

[0081] Embodiment 5:

[0082] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0083] Component A:

[0084] Acrylate grafted polyether polyol (hydroxyl value 350mg KOH / g), 30 parts;

[0085] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 700mg KOH / g), 50 parts;

[0086] Catalyst, 3 parts;

[0087] Plasticizer, 1 part;

[0088] Foam stabilizer, 1.5 parts;

[0089] Water, 1 part;

[0090] Flame retardant, 20 parts.

[0091] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0092] The mass ratio of component A to component B is 1:1.

[0093] (ii) The preparation steps are the same as those in Example 1.

[0094] Embodiment 6:

[0095] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0096] Component A:

[0097] Acrylate grafted polyether polyol (hydroxyl value 350mg KOH / g), 30 parts;

[0098] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 700mg KOH / g), 50 parts;

[0099] Catalyst, 3 parts;

[0100] Plasticizer, 1 part;

[0101] Foam stabilizer, 1.5 parts;

[0102] Water, 3 parts;

[0103] Flame retardant, 15 parts.

[0104] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0105] The mass ratio of component A to component B is 1:1.

[0106] (ii) The preparation steps are the same as those in Example 1.

[0107] Comparative Example 1:

[0108] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0109] Component A:

[0110] Acrylate grafted polyether polyol (hydroxyl value 230 mg KOH / g), 5 parts;

[0111] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 400mg KOH / g), 60 parts;

[0112] Catalyst, 3 parts;

[0113] Plasticizer, 1 part;

[0114] Foam stabilizer, 0.5 parts;

[0115] Water, 2 parts;

[0116] Flame retardant, 10 parts.

[0117] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0118] The mass ratio of component A to component B is 1:1.

[0119] (ii) The preparation steps are the same as those in Example 1.

[0120] Comparative Example 2:

[0121] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0122] Component A:

[0123] Acrylate grafted polyether polyol (hydroxyl value 230 mg KOH / g), 30 parts;

[0124] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 400mg KOH / g), 5 parts;

[0125] Catalyst, 3 parts;

[0126] Plasticizer, 1 part;

[0127] Foam stabilizer, 1 part;

[0128] Water, 2 parts;

[0129] Flame retardant, 20 parts.

[0130] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0131] The mass ratio of component A to component B is 1:1.

[0132] (ii) The preparation steps are the same as those in Example 1.

[0133] Comparative Example 3:

[0134] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0135] Component A:

[0136] Acrylate grafted polyether polyol (hydroxyl value 400mg KOH / g), 30 parts;

[0137] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 700mg KOH / g), 30 parts;

[0138] Catalyst, 0 parts;

[0139] Plasticizer, 1 part;

[0140] Foam stabilizer, 1.5 parts;

[0141] Water, 3 parts;

[0142] Flame retardant, 20 parts.

[0143] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0144] The mass ratio of component A to component B is 1:1.

[0145] (ii) The preparation steps are the same as those in Example 1.

[0146] Comparative Example 4:

[0147] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0148] Component A:

[0149] Acrylate grafted polyether polyol (hydroxyl value 400mg KOH / g), 30 parts;

[0150] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 700mg KOH / g), 50 parts;

[0151] Catalyst, 3 parts;

[0152] Plasticizer, 3 parts;

[0153] Foam stabilizer, 1.5 parts;

[0154] Water, 0 parts;

[0155] Flame retardant, 20 parts.

[0156] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0157] The mass ratio of component A to component B is 1:1.

[0158] (ii) The preparation steps are the same as those in Example 1.

[0159] Comparative Example 5:

[0160] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0161] Component A:

[0162] Acrylate grafted polyether polyol (hydroxyl value 350mg KOH / g), 30 parts;

[0163] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 700mg KOH / g), 50 parts;

[0164] Catalyst, 3 parts;

[0165] Plasticizer, 1 part;

[0166] Foam stabilizer, 1.5 parts;

[0167] Water, 10 parts;

[0168] Flame retardant, 20 parts.

[0169] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0170] The mass ratio of component A to component B is 1:1.

[0171] (ii) The preparation steps are the same as those in Example 1.

[0172] Comparative Example 6:

[0173] 1. The mass fractions of each raw material in the polyurethane grouting material are:

[0174] Component A:

[0175] Acrylate grafted polyether polyol (hydroxyl value 350mg KOH / g), 30 parts;

[0176] Cashew nut shell liquid polyether polyol (functionality 3, hydroxyl value 700mg KOH / g), 50 parts;

[0177] Catalyst, 3 parts;

[0178] Plasticizer, 1 part;

[0179] Foam stabilizer, 1.5 parts;

[0180] Water, 3 parts;

[0181] Flame retardant, 15 parts.

[0182] Component B: Polyisocyanate polyphenyl polymethylene polyisocyanate (PAPI).

[0183] The mass ratio of component A to component B is 1:1.

[0184] (II) Preparation steps:

[0185] (1) A certain amount of acrylate grafted polyether polyol, cashew nut shell liquid polyether polyol, catalyst, plasticizer, foam stabilizer and flame retardant are uniformly mixed, a certain amount of water is added and stirred with a glass rod for 2 to 5 seconds to obtain component A.

[0186] (2) Component A is mixed with component B to obtain a low water-sensitivity polyurethane grouting material.

[0187] Effect description:

[0188] According to Examples 1-6 and Comparative Examples 1-6, polyurethane grouting materials were prepared, and the setting time and foaming ratio of the polyurethane grouting materials under the same normal temperature and water-rich environment conditions, and the compressive strength of the formed polyurethane solid body were tested with reference to the standard JC / T 2041-2020 "Polyurethane Grouting Materials"; the bonding strength between the polyurethane grouting materials and the wet concrete base was tested with reference to the standard GB / T 16777-2008 "Test Methods for Building Waterproof Coatings". The test results are shown in Table 1.

[0189] Table 1 Performance test results of polyurethane grouting materials prepared in Examples 1-6 and Comparative Examples 1-6

[0190]

[0191] It can be seen from the data in Table 1 that the polyurethane grouting materials prepared in Examples 1-6 have obvious advantages over the comparative example.

[0192] The long dodecyl chain in the acrylate grafted polyether polyol has multiple non-polar bonds such as carbon-carbon bonds and carbon-hydrogen bonds, which makes it non-polar as a whole, and the interaction force between it and polar water molecules is very weak; in addition, due to the steric hindrance effect and the van der Waals force, the long-chain alkyl groups tend to aggregate with each other, showing good hydrophobicity. The introduction of an appropriate proportion of acrylate grafted polyether polyol can increase the number of long-chain alkyl groups in the system, increase the proportion of hydrophobic groups, reduce the reaction rate and self-foaming ratio of the polyurethane grouting material with external water in a water-rich environment, and improve the strength of the material. Compared with Example 1, the mass fraction of acrylate grafted polyether polyol in Comparative Example 1 is too small, the foaming ratio of the polyurethane grouting material is high, the pore structure is deteriorated, and the strength of the consolidated body is low, which cannot meet the requirements of practical applications.

[0193] Compared with ordinary polyether polyols, cashew nut shell oil polyether polyols have cardanol fatty long chains, have good hydrophobicity, and can maintain low water sensitivity during curing with isocyanate, reduce foaming ratio, thereby improving the mechanical properties of the final polyurethane system. In addition, cashew nut shell oil polyether polyols and isocyanate cure fast, and have aromatic structures, and the dispersion force of the benzene ring structure can exclude water molecules bound to the substrate surface, enhance the slurry infiltration effect, and further improve the interfacial adhesion. Compared with Example 2, the amount of cashew nut shell oil polyether polyol added in Comparative Example 2 is insufficient, and the compressive strength and bonding strength of the polyurethane grouting material formed are both low.

[0194] Compared with Example 3, no catalyst is added in Comparative Example 3, and the solidification time is longer, which will lead to poor blocking effect on moving water in actual use, and the slower reaction speed will make the surface pore structure loose, and the strength of the consolidated body will be significantly reduced.

[0195] Pre-dispersing an appropriate amount of water in the polyether polyol component at a high speed can ensure that the isocyanate in the B component reacts preferentially with the internal water, reasonably control the foaming ratio, and avoid undesirable phenomena such as bubble collapse. Compared with Example 4, in Comparative Example 4, component A is not internally watered, and part of the isocyanate reacts directly with external moisture, resulting in uneven size and poor stability of the formed pores, and the strength of the solid body is low. At the same time, the amount of internal water should not be too much. Compared with Example 5, the amount of water added to component A in Comparative Example 5 is too much, the foaming process is more intense, and there are also defects such as uneven pore size, thin pore wall, poor stability, and low overall strength.

[0196] Compared with Example 6, in the preparation step, the comparative example 6 does not sufficiently stir and mix the water at a high speed, which will result in uneven foam pore size of the consolidated body, poor strength stability of the consolidated body, and the overall performance of the grouting material cannot meet the requirements.

[0197] In summary, within the scope of the formula claimed in the present invention, the performance of the polyurethane grouting material in all aspects can meet the requirements. When the formula exceeds the scope of the present invention, some performances of the polyurethane grouting material will be obviously insufficient.

Claims

1. A low water sensitivity polyurethane grouting material under normal temperature environment, characterized in that The grouting material comprises component A and component B, and the mass ratio thereof is 1:

1. The component A comprises: 20-30 parts of acrylate grafted polyether polyol, 40-60 parts of cashew nut shell oil polyether polyol, 1-5 parts of catalyst, 1-3 parts of plasticizer, 0.5-1.5 parts of foam stabilizer, 1-3 parts of water, and 10-20 parts of flame retardant; the component B is polyisocyanate.

2. The low water sensitivity polyurethane grouting material under normal temperature environment according to claim 1, characterized in that The acrylate grafted polyether polyol is prepared by free radical polymerization of acrylate and polyether polyol, the acrylate is lauryl methacrylate, and the polyether polyol is a polyether polyol based on PO-EO copolyether triol, and the hydroxyl value is 230-400 mg KOH / g.

3. The low water sensitivity polyurethane grouting material under normal temperature environment according to claim 1, characterized in that The functionality of the cashew nut shell oil polyether polyol is 2-3, and the hydroxyl value is 600-700 mg KOH / g.

4. The low water sensitivity polyurethane grouting material under normal temperature environment according to claim 1, characterized in that The catalyst is one or more of a tertiary amine catalyst and an organic metal catalyst, and the organic metal catalyst includes one or more of organic tin, organic zirconium, and organic platinum; the organic metal catalyst preferentially catalyzes the reaction of alcohol hydroxyl group and polyisocyanate.

5. The low water sensitivity polyurethane grouting material under normal temperature environment according to claim 1, characterized in that The foam stabilizer is a water-soluble organic silicone compound.

6. The low water sensitivity polyurethane grouting material under normal temperature environment according to claim 1, characterized in that The flame retardant is one of ammonium polyphosphate, melamine, tetrabromobisphenol A, aluminum hydroxide, magnesium hydroxide and antimony trioxide.

7. The low water sensitivity polyurethane grouting material under normal temperature environment according to claim 1, characterized in that The polyisocyanate is polyphenyl polymethylene polyisocyanate (PAPI).

8. The method for preparing a low water-sensitivity polyurethane grouting material according to claim 1, characterized in that The following steps are involved: (1) Evenly mix acrylate grafted polyether polyol, cashew nut shell liquid polyether polyol and optional catalyst, plasticizer, foam stabilizer and flame retardant, add measured water and stir at high speed to evenly mix to obtain component A. (2) Component A and component B are mixed in a mass ratio of 1:1 to obtain the low water-sensitivity polyurethane grouting material.

9. Use of a low water-sensitivity polyurethane grouting material according to claims 1-7 in grouting and plugging of water-rich tunnels.

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