Silane coupling agent modified cellulose acetate high temperature and drought resistant sand fixation agent and preparation method and use thereof

Abstract

The present invention discloses a silane coupling agent modified cellulose acetate high temperature and drought resistant sand-fixing agent and a preparation method and use. The high temperature and drought resistant sand-fixing agent is obtained by modifying cellulose acetate with a silane coupling agent. The preparation method comprises: subjecting a mixed reaction system comprising cellulose acetate, a silane coupling agent, and a solvent to vacuum heat treatment, and adjusting the pH value of the mixed reaction system to be neutral, to obtain a silane coupling agent modified cellulose acetate high temperature and drought resistant sand-fixing agent. The present invention adopts a silane coupling agent to enhance the mechanical strength and water absorption and water retention properties of cellulose acetate, and prepares a high temperature and drought resistant aminosilane coupling agent-cellulose acetate (SCA-CA) sand-fixing agent that can be used in arid desert areas, which has excellent high temperature thermal stability, high mechanical strength, and good water solubility, and can provide a reference for the toughening modification of cellulose acetate.

Description

Technical Field

[0001] The invention relates to a sand-fixing agent, in particular to a silane coupling agent-modified cellulose acetate (SCA-CA) high-temperature-resistant and drought-resistant sand-fixing agent and a preparation method and use thereof, belonging to the technical field of biopolymers and sand-fixing. Background Art

[0002] Desertification seriously threatens global ecological security and the sustainable development of human economy and society, affects 25% of the world's total land area, and threatens the lives of more than 1 billion people in more than 100 countries. It is a major environmental problem and development bottleneck facing the world, and China is one of the countries seriously harmed by desertification. Wind and sand activities are typical surface processes in desert areas. Therefore, it is of great significance to take necessary measures to prevent wind and sand and block sand.

[0003] The arid desert areas in northwest my country are hot and rainy all year round. For example, in the hinterland of the Taklimakan Desert, the annual precipitation in the area is low, about 36.6 mm, and the extreme maximum temperature is 45.6°C. Therefore, the sand fixation agent suitable for this area needs to have high temperature resistance and good water absorption and water retention properties.

[0004] Cellulose acetate (CA) is the most stable compound among cellulose ester compounds. It is the most commonly used of many cellulose derivatives due to its low price, non-toxicity, high transparency, good toughness, and easy molding and processing. However, CA has shortcomings such as poor high-temperature thermal stability, low mechanical strength, and poor water solubility during the application process. Therefore, CA often needs to be modified. Therefore, how to optimize the modification method of CA and seek a new technology that can improve the poor high-temperature thermal stability, low mechanical strength, and poor water solubility of acetate fiber has become the direction that industry researchers have been working on for a long time. Summary of the invention

[0005] The purpose of the present invention is to use a hydrophilic silane coupling agent to provide a high temperature and drought resistant silane coupling agent modified cellulose acetate (SCA-CA) sand fixation agent suitable for arid desert areas and a preparation method thereof, so as to improve the shortcomings of the prior art of cellulose acetate, such as poor high temperature thermal stability, low mechanical strength and poor water solubility.

[0006] The embodiment of the present invention provides a silane coupling agent-modified cellulose acetate high temperature and drought resistance sand fixation agent, which is obtained by modifying cellulose acetate with a silane coupling agent.

[0007] In some embodiments, the silane coupling agent includes an aminosilane coupling agent, and the aminosilane coupling agent includes any one or a combination of two or more of 3-aminopropyldiethoxymethylsilane, γ-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, etc.

[0008] An embodiment of the present invention also provides a method for preparing a high-temperature and drought-resistant sand-fixing agent of cellulose acetate modified by a silane coupling agent, which comprises: subjecting a mixed reaction system comprising cellulose acetate, a silane coupling agent, and a solvent to vacuum heat treatment, and adjusting the pH value of the mixed reaction system to neutral, to obtain a high-temperature and drought-resistant sand-fixing agent of cellulose acetate modified by a silane coupling agent.

[0009] The embodiment of the present invention also provides a silane coupling agent modified cellulose acetate high temperature and drought resistant sand fixation agent prepared by the above preparation method.

[0010] Furthermore, an embodiment of the present invention also provides the use of the aforementioned silane coupling agent-modified cellulose acetate high temperature and drought resistant sand fixation agent in the field of sand fixation.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] The present invention adopts a silane coupling agent to enhance the mechanical strength and water absorption and retention performance of cellulose acetate, and prepares a high temperature and drought resistant aminosilane coupling agent-cellulose acetate (SCA-CA) sand fixation agent which can be used in arid desert areas. The SCA-CA sand fixation agent has excellent high temperature thermal stability, high mechanical strength and good water solubility, and can provide a reference for the strengthening and toughening modification of cellulose acetate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a schematic diagram of the preparation of a silane coupling agent modified cellulose acetate (SCA-CA) sand fixation agent in a typical embodiment of the present invention. DETAILED DESCRIPTION

[0015] Aiming at the problems of poor high temperature thermal stability, low mechanical strength and poor water solubility of cellulose acetate, the inventors have proposed the technical solution of the present invention after long-term research and extensive practice, which mainly utilizes silane coupling agents to enhance the mechanical strength and water absorption and water retention properties of cellulose acetate. The technical solution, its implementation process and principle will be further explained as follows. However, it should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described in the following (embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here.

[0016] As another aspect of the technical solution of the present invention, a silane coupling agent modified cellulose acetate (SCA-CA) high temperature and drought resistant sand fixation agent is provided, which is obtained by modifying cellulose acetate with a silane coupling agent.

[0017] The degree of substitution of the cellulose acetate used in the present invention is 1.72 to 3.03.

[0018] The general molecular formula of silane coupling agent (SCA) is R n SiX 4-n (R: functional group, X: methoxy, ethoxy or ethoxy groups that are easily hydrolyzed) are hydrophilic. n Si(OH) 4-n When reacting with hydroxyl groups in cellulose, amino groups in polymer matrix or other functional groups, it may react with them to enhance the structural stability of polymer. The most outstanding types of silane coupling agents are γ-aminopropyltriethoxysilane (APTES, KH550), N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (KH792), 3-aminopropyldiethoxymethylsilane (apems, KH902), γ-glyceroyloxypropyltrimethoxysilane (KH560), 3-aminopropyldimethoxysilane (APDMES, KH660), etc.

[0019] In the present invention, the silane coupling agent used is an aminosilane coupling agent, for example, preferably any one or a combination of two or more of 3-aminopropyldiethoxymethylsilane (APDEMS, KH902), γ-aminopropyltriethoxysilane (APTES, KH550), N-2-aminoethyl-3-aminopropyltrimethoxysilane (KH792), etc., but not limited thereto.

[0020] The reaction mechanism of the present invention using silane coupling agent to modify cellulose acetate is that the amino group (-NH 2) groups can interact with the polar carbonyl (-CO) and oxycarbonyl (-COO) of CA, and the silicon in the aminosilane coupling agent is also covalently bonded to the hydroxyl group of CA through the oxygen atom to form a silanized surface, thereby preparing a structurally stable and viscous hydrophilic liquid. When used for sand fixation, aminosilane coupling agent can enhance the solution stability, curing strength and water absorption and retention properties of CA after treatment. Its carbonyl group can react with inorganic ions in the sand to enhance sand fixation, and can be used as a new chemical sand fixation agent in arid desert areas.

[0021] In some embodiments, the molar ratio of the silane coupling agent used in the modification treatment to cellulose acetate can be 0.5 to 2:1, that is, relative to cellulose acetate, the added amount of aminosilane coupling agent (the ratio of mass to the mass of cellulose acetate) can be 0.5:1, 1:1, 1.5:1, 2:1, etc.

[0022] The silane coupling agent modified cellulose acetate high temperature and drought resistant sand fixation agent has strong high temperature thermal stability, the final pyrolysis temperature is 400°C to 500°C, the compressive strength of the sand fixation sample is between 4 and 5.5 MPa, and the permeability coefficient is between 5.5 x 10 - 4 cm / s~1x 10 -3 Between cm / s.

[0023] As another aspect of the technical solution of the present invention, the preparation method of the high temperature and drought-resistant sand-fixing agent of cellulose acetate modified by a silane coupling agent comprises: subjecting a mixed reaction system comprising cellulose acetate, a silane coupling agent, and a solvent to vacuum heat treatment, and adjusting the pH value of the mixed reaction system to neutral, to obtain the high temperature and drought-resistant sand-fixing agent of cellulose acetate modified by a silane coupling agent.

[0024] The types of silane coupling agents used are as described above and will not be repeated here.

[0025] The preparation steps of the present invention also include: mixing cellulose acetate, a silane coupling agent, a solvent, and hydrochloric acid to make the pH value of the mixed reaction system 4, or adding HCl to the mixed reaction system to adjust the pH value to 4.

[0026] As one of the preferred schemes, the molar ratio of the silane coupling agent to cellulose acetate added in the mixed reaction system can be 0.5 to 2:1, that is, the added amount of the aminosilane coupling agent relative to cellulose acetate (the ratio of mass to the mass of cellulose acetate) can be 0.5:1, 1:1, 1.5:1, 2:1, etc.

[0027] As one of the preferred solutions, the solvent may be a combination of ethanol and water, wherein the mass ratio of ethanol to water is in the range of 80:20 to 80:40 w / w.

[0028] As one of the preferred schemes, the temperature of the vacuum heat treatment is 105°C to 150°C, for example, it can be 105°C, 125°C or 150°C, and the time is 0.5 to 2h, for example, it can be 0.5h, 1h, 1.5h, 2h, etc.

[0029] Another aspect of the embodiments of the present invention further provides a silane coupling agent modified cellulose acetate high temperature and drought resistant sand fixation agent prepared by the aforementioned preparation method.

[0030] Correspondingly, another aspect of an embodiment of the present invention further provides the use of any of the aforementioned silane coupling agent-modified cellulose acetate high temperature and drought resistant sand fixation agents in the field of sand fixation, such as the preparation of sand fixation materials or sand fixation devices.

[0031] Through the above technical scheme, the present invention adopts silane coupling agent to enhance the mechanical strength and water absorption and water retention properties of cellulose acetate, and prepares a high temperature and drought resistant aminosilane coupling agent-cellulose acetate (SCA-CA) sand fixation agent that can be used in arid desert areas. The SCA-CA sand fixation agent has excellent high temperature thermal stability, high mechanical strength, and good water solubility, and can provide a reference for the strengthening and toughening modification of cellulose acetate.

[0032] In order to make the purpose, technical scheme and application of the present invention clearer, the technical scheme of the present invention is further described in detail below in conjunction with several preferred embodiments and drawings. The described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention. The implementation conditions used in the following embodiments can be further adjusted according to actual needs, and the unspecified implementation conditions are usually the conditions in conventional experiments.

[0033] Example 1

[0034] 20 g of cellulose acetate (substitution degree of 1.72-1.95) was added to an aminosilane coupling agent (N-2-aminoethyl-3-aminopropyltrimethoxysilane) solution (ethanol / water: 80 / 20, w / w), the molar ratio of silane coupling agent to cellulose acetate was 1:2, HCl was added, pH was adjusted to 4, stirred for 3 h, and vacuum heat treated at 105 ° C for 1 hour. The reaction process is as follows: Figure 1 As shown. Then, distilled water was added to the obtained reaction system to adjust the pH value to neutral, and a silane coupling agent modified cellulose acetate (SCA-CA) high temperature and drought resistant sand fixation agent was obtained. The sand fixation sample was 7.07mx7.07mx7.07m in size, with at least 3 samples in each group.

[0035] Example 2

[0036] 20 g of cellulose acetate (degree of substitution: 2.22-2.76) was added to an aminosilane coupling agent (N-2-aminoethyl-3-aminopropyltrimethoxysilane) solution (ethanol / water: 80 / 20, w / w), the molar ratio of silane coupling agent to cellulose acetate was 1:1, HCl was added, pH was adjusted to 4, stirred for 3 h, and vacuum heat treated at 105 ° C for 1 hour. The reaction process is as follows: Figure 1 As shown. Then, distilled water was added to the obtained reaction system to adjust the pH value to neutral, and a silane coupling agent modified cellulose acetate (SCA-CA) high temperature and drought resistant sand fixation agent was obtained. The sand fixation sample was 7.07mx7.07mx7.07m in size, with at least 3 samples in each group.

[0037] Example 3

[0038] 20 g of cellulose acetate (degree of substitution: 2.76-3.03) was added to an aminosilane coupling agent (N-2-aminoethyl-3-aminopropyltrimethoxysilane) solution (ethanol / water: 80 / 20, w / w), the molar ratio of silane coupling agent to cellulose acetate was 2:1, HCl was added, pH was adjusted to 4, stirred for 3 h, and vacuum heat treated at 105 ° C for 1 hour. The reaction process is as follows: Figure 1 As shown. Then, distilled water was added to the obtained reaction system to adjust the pH value to neutral, and a silane coupling agent modified cellulose acetate (SCA-CA) high temperature and drought resistant sand fixation agent was obtained. The sand fixation sample was 7.07mx7.07mx7.07m in size, with at least 3 samples in each group.

[0039] The inventors of this case also tested the high temperature thermal stability, mechanical strength, water solubility and other properties of the sand-fixing agent obtained in the above examples, and the results are as follows:

[0040] In Example 1, the high temperature thermal stability, the final pyrolysis temperature is 400 ° C, the compressive strength of the sand fixation sample is 4 MPa, and the permeability coefficient is 5.5 x 10 -4 In Example 2, the high temperature thermal stability, the final pyrolysis temperature is 450°C, the compressive strength of the sand-fixing sample is 5 MPa, and the permeability coefficient is 7.5 x 10 -4 In Example 3, the high temperature thermal stability, the final pyrolysis temperature is 500°C, the compressive strength of the sand fixation sample is 5.5MPa, and the permeability coefficient is 1x10 -3 cm / s.

[0041] Example 4

[0042] 20 g of cellulose acetate (degree of substitution: 2.76-3.03) was added to a 3-aminopropyldiethoxymethylsilane solution (ethanol / water: 80 / 20, w / w), the molar ratio of silane coupling agent to cellulose acetate was 2:1, HCl was added, pH was adjusted to 4, stirred for 3 h, and vacuum heat treated at 105 ° C for 1 hour. The reaction process is as follows: Figure 1 As shown. Then, distilled water was added to the obtained reaction system to adjust the pH value to neutral, and a silane coupling agent modified cellulose acetate (SCA-CA) high temperature and drought resistant sand fixation agent was obtained. The sand fixation sample was 7.07mx7.07mx7.07m in size, with at least 3 samples in each group.

[0043] Example 5

[0044] 20 g of cellulose acetate (degree of substitution: 2.76-3.03) was added to a γ-aminopropyltriethoxysilane solution (ethanol / water: 80 / 20, w / w), the molar ratio of silane coupling agent to cellulose acetate was 2:1, HCl was added, pH was adjusted to 4, stirred for 3 h, and vacuum heat treated at 125 ° C for 2 h. The reaction process is as follows: Figure 1 As shown. Then, distilled water was added to the obtained reaction system to adjust the pH value to neutral, and a silane coupling agent modified cellulose acetate (SCA-CA) high temperature and drought resistant sand fixation agent was obtained. The sand fixation sample was 7.07mx7.07mx7.07m in size, with at least 3 samples in each group.

[0045] Example 6

[0046] 20 g of cellulose acetate (degree of substitution: 2.76-3.03) was added to N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (N-2-aminoethyl-3-aminopropyltrimethoxysilane) solution (ethanol / water: 80 / 40, w / w), the molar ratio of silane coupling agent to cellulose acetate was 2:1, HCl was added, pH was adjusted to 4, stirred for 3 h, and vacuum heat treated at 150°C for 0.5 h. The reaction process was as follows: Figure 1 As shown. Then, distilled water was added to the obtained reaction system to adjust the pH value to neutral, and a silane coupling agent modified cellulose acetate (SCA-CA) high temperature and drought resistant sand fixation agent was obtained. The sand fixation sample was 7.07mx7.07mx7.07m in size, with at least 3 samples in each group.

[0047] The inventors of this case also tested the high temperature thermal stability, mechanical strength, water solubility and other properties of the sand-fixing agent obtained in the above examples, and the results are as follows:

[0048] In Example 4, the high temperature thermal stability, the final pyrolysis temperature is 400 ° C, the compressive strength of the sand fixation sample is 4 MPa, and the permeability coefficient is 5.5x10 -4In Example 5, the high temperature thermal stability, the final pyrolysis temperature is 450°C, the compressive strength of the sand fixation sample is 5MPa, and the permeability coefficient is 7.5x10 -4 In Example 6, the high temperature thermal stability, the final pyrolysis temperature is 500°C, the compressive strength of the sand fixation sample is 5.5MPa, and the permeability coefficient is 1x10 -3 cm / s.

[0049] Comparative Example 1

[0050] Weigh 20g CA and dissolve it in 150g methyl acetate to prepare CA solution. Compared with Example 1, this comparative example differs in that no aminosilane coupling agent is added. The sand fixation sample adopts the specification of 7.07mx7.07mx7.07m, and each group of samples has at least 3. The final pyrolysis temperature of the obtained sand fixation agent is 350℃, the compressive strength of the sand fixation sample is 2MPa, and the permeability coefficient is 2x10 -4 cm / s.

[0051] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0052] It should be understood that the above examples are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a high temperature and drought resistant sand fixation agent of cellulose acetate modified by a silane coupling agent, characterized in that: include: Cellulose acetate, a silane coupling agent, a solvent and hydrochloric acid are mixed to make the pH value of the formed mixed reaction system be 4, the mixed reaction system is subjected to vacuum heat treatment, and the pH value of the mixed reaction system is adjusted to be neutral, so as to obtain a silane coupling agent modified cellulose acetate high temperature and drought resistant sand fixation agent, wherein the silane coupling agent is an aminosilane coupling agent, and the aminosilane coupling agent is selected from any one or a combination of two or more of 3-aminopropyldiethoxymethylsilane, γ-aminopropyltriethoxysilane and N-2-aminoethyl-3-aminopropyltrimethoxysilane, the degree of substitution of the cellulose acetate is 1.72-3.03, the molar ratio of the silane coupling agent to the cellulose acetate is 0.5-2:1, the solvent is a combination of ethanol and water, wherein the mass ratio of ethanol to water is 80:20-80:40 w / w, the temperature of the vacuum heat treatment is 105°C-150°C, and the time is 0.5-2h.

2. A high temperature and drought resistant sand fixation agent prepared by the preparation method of claim 1.

3. Use of the silane coupling agent modified cellulose acetate high temperature and drought resistant sand fixation agent according to claim 2 in the field of sand fixation.

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