A hydrophobic and oil-resistant concrete modifier and its preparation method and application

Abstract

The present invention discloses a hydrophobic and oil-resistant concrete modifier, a preparation method and an application thereof, and belongs to the technical field of building materials. By weight, the components of the hydrophobic and oil-resistant concrete modifier include: 0.4 to 0.6 parts of a super-hydrophobic component, 0.3 to 0.7 parts of a hydrophobic and oleophobic modifier, 0.03 to 0.05 parts of a defoamer, 10 to 30 parts of water, and 1.5 to 2 times the total molar amount of the super-hydrophobic component and the hydrophobic and oleophobic modifier. The mass ratio of the super-hydrophobic component to the hydrophobic and oleophobic modifier is 4:6 to 7:3. The hydrophobic and oil-resistant concrete modifier provided by the present invention can be used as a concrete additive to prepare concrete that is both waterproof and oil-resistant.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and particularly relates to a hydrophobic and oil-resistant concrete modifier and a preparation method and application thereof. Background Art

[0002] In recent years, hydrophobic concrete has become a good way for concrete to avoid corrosion in marine environments. However, due to the impact of coastal industrial pollution and offshore oil field leakage, oil pollution often occurs in the marine environment. When hydrophobic concrete works in a marine environment, its surface is easily contaminated by oil, causing the hydrophobic surface to be destroyed and lose its hydrophobicity. This is because the surface tension of most oily pollutants is much lower than that of water. The low surface tension of the liquid makes it easy to penetrate into the concrete. Seawater entering the concrete will inevitably corrode the steel bars inside the concrete, resulting in a decrease in the mechanical strength of the concrete. Therefore, it is particularly important to design a concrete that is both waterproof and oil-repellent.

[0003] At present, super-hydrophobic concrete is mainly prepared by dipping method, brushing method and other methods, but this super-hydrophobic concrete can only achieve surface super-hydrophobic properties. If the coating peels off or wears, the concrete will still be hydrophilic. The modification of hydrocarbon modifiers (such as stearic acid) reduces the surface free energy of the super-hydrophobic surface, but it is still not enough to avoid the penetration of oily pollutants. Fluorine-containing organic coatings have a strong repellent effect on oily pollutants, which can prevent the solid surface from being damaged by oily pollutants and protect the hydrophobicity of the hydrophobic surface in an oily environment. However, the adhesion between the coating prepared in existing studies and the substrate is poor, and the coating surface is prone to lose its amphiphobicity due to wear. The closed coating blocks the pores of the concrete, which may cause an increase in the pressure inside the concrete, resulting in cracks on the coating surface and weakening the amphiphobicity of the concrete. The development of concrete with wear resistance and overall amphiphobic (super-hydrophobic and oleophobic) properties is an effective way to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a hydrophobic and oil-resistant concrete modifier. The hydrophobic and oil-resistant concrete modifier provided by the present invention is used as a concrete additive to enhance the amphiphobicity of concrete.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] One of the technical solutions of the present invention is to provide a hydrophobic and oil-resistant concrete modifier, which comprises, by weight:

[0007] 0.4-0.6 parts of super-hydrophobic component, 0.3-0.7 parts of hydrophobic oleophobic modifier, 0.03-0.05 parts of defoaming agent, 10-30 parts of water and 1.5-2 times the total molar amount of the super-hydrophobic component and the hydrophobic oleophobic modifier of alkaline organic matter, wherein the mass ratio of the super-hydrophobic component to the hydrophobic oleophobic modifier is 4:6-7:3;

[0008] The super hydrophobic component is a long-chain hydrocarbon fatty acid having 9 to 28 carbon atoms;

[0009] The hydrophobic and oleophobic modifier is a perfluoroalkyl acid having 4 to 12 carbon atoms;

[0010] The alkaline organic matter is one or more of triethanolamine, diethanolamine, N-methyldiethanolamine and monoethanolamine.

[0011] Preferably, the long-chain hydrocarbon fatty acid having 9 to 28 carbon atoms includes one or more of stearic acid, capric acid, oleic acid and ricinoleic acid.

[0012] Preferably, the perfluoroalkyl acid having 4 to 12 carbon atoms includes one or more of perfluorobutyric acid, perfluoropentanoic acid, perfluoroheptanoic acid, perfluorohexanoic acid, perfluorooctanoic acid and perfluorodecanoic acid.

[0013] Preferably, the defoaming agent comprises a polyether or a polyether-modified silicone defoaming agent.

[0014] The second technical solution of the present invention is to provide a method for preparing the above-mentioned hydrophobic and oil-resistant concrete modifier, the steps comprising:

[0015] First, the super-hydrophobic component, the hydrophobic and oleophobic modifier and water are mixed and heated to 70-90° C., then an alkaline organic matter is added, reacted at 70-90° C. for 30-60 minutes, cooled to 25-50° C., homogenized, preferably a defoaming agent is added, and the hydrophobic and oleophobic concrete modifier is obtained after stirring.

[0016] Preferably, the homogenizing stirring speed is 10000-30000 r / min, and the time is 30-60 min.

[0017] The third technical solution of the present invention is to provide an application of the above-mentioned hydrophobic and oil-resistant concrete modifier in the preparation of hydrophobic and oil-resistant concrete.

[0018] Preferably, the addition amount of the hydrophobic and oil-resistant concrete modifier is 0.5-3wt.% of the cementitious material in the concrete.

[0019] The beneficial technical effects of the present invention are as follows:

[0020] In the present invention, the hydrophobic and oil-resistant concrete modifier is hydrolyzed in concrete to react with calcium hydroxide to generate fatty acid calcium and perfluoroalkyl acid calcium, promote cement hydration, cause needle-like calcium sulfonate to interweave, thereby forming a needle-like micro-network, and the concrete surface is rough to form a Cassie-Baxter state, reducing the physical adsorption of liquid to concrete. At the same time, fatty acid calcium and perfluoroalkyl acid calcium have long hydrophobic chains and oleophobic chains, and point to the air to form a hydrophobic and oleophobic film layer on the concrete surface. Due to the strong electron-withdrawing properties of fluorine atoms, CH and CF groups show strong repulsion, which promotes more accumulation of fluorinated groups on the concrete surface, and the concrete surface shows low free energy group accumulation, and concrete shows super hydrophobic and oleophobic properties. The hydrophobic and oil-resistant concrete modifier is hydrolyzed in concrete to generate organic alcohol amines and cement hydration products to undergo complex reaction, promote cement hydration, and increase the early and late strength of concrete. Defoamers remove and suppress the redundant harmful large bubbles in concrete, thereby improving the strength of concrete.

[0021] The hydrophobic and oil-resistant concrete modifier provided by the invention can be used as a concrete additive to prepare concrete that is both waterproof and oil-resistant. DETAILED DESCRIPTION

[0022] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0023] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0024] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0025] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0026] Unless otherwise specified, the "parts" in the examples and comparative examples of the present invention are parts by weight, and the temperature range of the "room temperature" is 20±10°C.

[0027] The defoamer used in the examples and comparative examples of the present invention is the GK-XP polyether-modified organosilicon defoamer produced by Shijiazhuang Changan Yucai Building Materials Co., Ltd.

[0028] Example 1

[0029] A preparation method of a hydrophobic and oil-resistant concrete modifier comprises the following steps:

[0030] First, 10 parts of distilled water, 0.6 parts of n-decanoic acid and 0.4 parts of perfluorobutyric acid are added to the reactor. When the temperature is raised to 70°C, triethanolamine (1.6 times the total molar amount of n-decanoic acid and perfluorooctanoic acid) is added, and the reaction is carried out at 70°C with low-speed stirring for 30 minutes. The temperature is lowered to 25-50°C, and the prepared material is poured into an emulsifier. The speed of the high shear homogenizing emulsifier is set to 25000r / min, and the mixture is stirred for 60 minutes. The mixture is cooled to room temperature, 0.03 parts of a defoaming agent is added, and the mixture is stirred for 10 minutes. The obtained product is a hydrophobic and oleophobic concrete modifier.

[0031] Example 2

[0032] A preparation method of a hydrophobic and oil-resistant concrete modifier comprises the following steps:

[0033] First, 10 parts of distilled water, 0.5 parts of stearic acid and 0.5 parts of perfluorooctanoic acid are added to the reactor. When the temperature is raised to 70°C, diethanolamine (1.8 times the total molar amount of stearic acid and perfluorooctanoic acid) is added, and the mixture is stirred at a low speed and reacted at 70°C for 30 minutes. The mixture is cooled to 25-50°C, and the prepared material is poured into an emulsifier. The speed of the high shear homogenizing emulsifier is set to 30,000 r / min, and the mixture is stirred for 60 minutes. The mixture is cooled to room temperature, 0.03 parts of a defoaming agent is added, and the mixture is stirred for 10 minutes. The obtained product is a hydrophobic and oleophobic concrete modifier.

[0034] Example 3

[0035] A preparation method of a hydrophobic and oil-resistant concrete modifier comprises the following steps:

[0036] First, 10 parts of distilled water, 0.4 parts of oleic acid and 0.6 parts of perfluorooctanoic acid are added to the reactor. When the temperature is raised to 70°C, monoethanolamine (twice the total molar amount of oleic acid and perfluorooctanoic acid) is added, and the mixture is reacted at 70°C at a low speed for 30 minutes. The mixture is cooled to 25-50°C, and the prepared material is poured into an emulsifier. The speed of the high shear homogenizing emulsifier is set to 15000 r / min, and the mixture is stirred for 60 minutes. The mixture is cooled to room temperature, 0.04 parts of a defoaming agent is added, and the mixture is stirred for 10 minutes. The obtained product is a hydrophobic and oleophobic concrete modifier.

[0037] Example 4

[0038] A preparation method of a hydrophobic and oil-resistant concrete modifier comprises the following steps:

[0039] First, 10 parts of distilled water, 0.3 parts of n-decanoic acid and 0.7 parts of perfluoropentanoic acid are added to the reactor. When the temperature is raised to 70°C, 1.8 times the total molar amount of n-decanoic acid and perfluoropentanoic acid is added with N-methyldiethanolamine. The reaction is carried out at 70°C with low-speed stirring for 30 minutes. The temperature is lowered to 25-50°C. The prepared material is poured into an emulsifier. The speed of the high shear homogenizing emulsifier is set to 25000r / min. The mixture is stirred for 60 minutes. The mixture is cooled to room temperature, 0.03 parts of a defoaming agent is added, and the mixture is stirred for 10 minutes. The obtained product is a hydrophobic and oleophobic concrete modifier.

[0040] Comparative Example 1

[0041] A preparation method of a hydrophobic and oil-resistant concrete modifier comprises the following steps:

[0042] First, 10 parts of distilled water and 1 part of oleic acid were added to the reactor. When the temperature was raised to 70°C, monoethanolamine with a molar amount twice that of oleic acid was added. The mixture was stirred at a low speed and reacted at 70°C for 30 minutes. The mixture was cooled to 25-50°C. The prepared material was poured into an emulsifier. The speed of the high shear homogenizing emulsifier was set to 15000 r / min. The mixture was stirred for 60 minutes. The mixture was cooled to room temperature, 0.04 parts of a defoaming agent was added, and the mixture was stirred for 10 minutes. The obtained product was a hydrophobic and oleophobic concrete modifier.

[0043] Comparative Example 2

[0044] A preparation method of a hydrophobic and oil-resistant concrete modifier comprises the following steps:

[0045] First, 10 parts of distilled water, 0.8 parts of oleic acid and 0.2 parts of perfluorooctanoic acid are added to the reactor. When the temperature is raised to 70°C, monoethanolamine (twice the total molar amount of perfluorooctanoic acid) is added, and the reaction is carried out at 70°C with low-speed stirring for 30 minutes. The temperature is lowered to 25-50°C, and the prepared material is poured into an emulsifier. The speed of the high shear homogenizing emulsifier is set to 15000r / min, and the mixture is stirred for 60 minutes. The mixture is cooled to room temperature, 0.04 parts of a defoaming agent is added, and the mixture is stirred for 10 minutes. The obtained product is a hydrophobic and oleophobic concrete modifier.

[0046] Comparative Example 3

[0047] A preparation method of a hydrophobic and oil-resistant concrete modifier comprises the following steps:

[0048] First, 10 parts of distilled water and 1 part of perfluorooctanoic acid are added to the reactor. When the temperature is raised to 70°C, monoethanolamine (twice the total molar amount of perfluorooctanoic acid) is added, and the reaction is carried out at 70°C with low-speed stirring for 30 minutes. The temperature is lowered to 25-50°C, and the prepared material is poured into an emulsifier. The speed of the high shear homogenizing emulsifier is set to 15000r / min, and the mixture is stirred for 60 minutes. The mixture is cooled to room temperature, 0.04 parts of a defoaming agent is added, and the mixture is stirred for 10 minutes. The obtained product is a hydrophobic and oleophobic concrete modifier.

[0049] The hydrophobic and oleophobic concrete modifiers prepared in Examples 1-4 and Comparative Examples 1-3 were tested for their hydrophobic and oleophobic effects in concrete:

[0050] Concrete mix ratio: 380kg of Esheng PO42.5 cement, 677kg of machine-made sand (fineness modulus 2.7), 461kg of 5-10mm gravel, 692kg of 10-20mm gravel, 190kg of water, and the amount of hydrophobic and oleophobic concrete modifier added was 3wt% of the cementitious material. In addition, the hydrophobic and oleophobic concrete modifier was replaced with an equal mass of commercially available iron hydroxide anti-seepage agent as a comparison, and a blank group without adding the hydrophobic and oleophobic concrete modifier was set up.

[0051] Performance test: 1. Test the compressive strength of concrete specimens after standard curing for 28 days in accordance with the provisions of GB / T50081-2002 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete". 2. Test in accordance with the standard of acid resistance test for resin concrete. After standard curing for 28 days, bake the concrete specimens at 105℃ for 48 hours, cool them in a dryer and weigh them. Soak the weighed specimens in a container filled with kerosene for 30 days, take out the specimens, remove the kerosene on the surface of the specimens, weigh them again to determine the kerosene permeability (i.e. weight gain rate), and break the weighed concrete specimens to determine the oil penetration depth. 2. Polish the surface of the concrete specimens after standard curing for 28 days with 600-grit sandpaper. The contact angle of different sample surfaces is measured using an optical contact angle meter (DSA30). The drop size of each drop is 5μL. The first frame of the drop on the concrete surface is selected to test the contact angle. The error deviation is about ±2°. The performance test results are shown in Table 1.

[0052] Table 1 Performance test results of hydrophobic and oleophobic concrete modifier

[0053] Concrete No. Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Commercially available anti-seepage agents Blank Group Hydrophobic contact angle (degrees) 155 152 150 148 156 155 138 131 <90 Oleophobic contact angle (degrees) 130 143 142 141 0 20 137 110 <90 Kerosene penetration depth (mm) 10 6.6 8.4 8.5 35 30 14 13 56 Kerosene penetration rate (%) 2 1.7 2.3 2.2 4 3.4 2.8 2.7 5 28d compressive strength (Mpa) 35.2 35.0 34.8 34.2 36.4 36.0 36.2 35.6 36.6

[0054] It can be seen from Table 1 that the hydrophobic angle and oleophobic angle of the concrete to which the hydrophobic and oleophobic concrete modifier prepared in the embodiment of the present invention is added are greater than 140°, and the oil permeability height ratio of the commercially available iron hydroxide anti-seepage agent is increased by more than 50%, and the oil absorption rate ratio is increased by more than 60%. Compared with the comparative example, it is found that when the mass ratio of the super-hydrophobic component to the hydrophobic and oleophobic modifier is outside the range of 4:6 to 7:3, the hydrophobic and oleophobic properties are significantly reduced.

[0055] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A hydrophobic and oil-resistant concrete modifier, characterized in that: By weight, the components are: 0.4-0.6 parts of super-hydrophobic component, 0.3-0.7 parts of hydrophobic oleophobic modifier, 0.03-0.05 parts of defoaming agent, 10-30 parts of water and 1.5-2 times the total molar amount of the super-hydrophobic component and the hydrophobic oleophobic modifier of alkaline organic matter, wherein the mass ratio of the super-hydrophobic component to the hydrophobic oleophobic modifier is 4:6-7:3; The super hydrophobic component is a long-chain hydrocarbon fatty acid having 9 to 28 carbon atoms; The hydrophobic and oleophobic modifier is a perfluoroalkyl acid having 4 to 12 carbon atoms; The alkaline organic matter is one or more of triethanolamine, diethanolamine, N-methyldiethanolamine and monoethanolamine; The long-chain hydrocarbon fatty acid having 9 to 28 carbon atoms includes one or more of stearic acid, capric acid, oleic acid and ricinoleic acid; The perfluoroalkyl acid having 4 to 12 carbon atoms includes one or more of perfluorobutyric acid, perfluoropentanoic acid, perfluoroheptanoic acid, perfluorohexanoic acid, perfluorooctanoic acid and perfluorodecanoic acid.

2. The hydrophobic and oil-resistant concrete modifier according to claim 1, characterized in that: The defoaming agent includes polyether or polyether-modified silicone defoaming agent.

3. A method for preparing the hydrophobic and oil-resistant concrete modifier according to any one of claims 1 to 2, characterized in that the steps include: First, a super-hydrophobic component, a hydrophobic and oleophobic modifier and water are mixed and heated to 70-90° C., then an alkaline organic matter is added, reacted at 70-90° C. for 30-60 min, cooled to 25-50° C., homogenized, and finally a defoamer is added, and the hydrophobic and oleophobic concrete modifier is obtained after stirring.

4. The preparation method according to claim 3, characterized in that: The homogenizing stirring speed is 10000-30000 r / min, and the time is 30-60 min.

5. Use of the hydrophobic and oil-resistant concrete modifier according to any one of claims 1 to 2 in the preparation of hydrophobic and oil-resistant concrete.

6. The use according to claim 5, characterized in that: The addition amount of the hydrophobic and oil-resistant concrete modifier is 0.5-3wt.% of the cementitious material in the concrete.