Bio-based composite acrylic acid aid for improving tear resistance of geotechnical cloth and preparation method and application of bio-based composite acrylic acid aid

Abstract

The invention relates to a bio-based composite acrylic acid aid for improving the tear resistance of geotechnical cloth as well as a preparation method and application of the bio-based composite acrylic acid aid. The bio-based composite acrylic acid aid is prepared from the following raw materials in parts by mass: 5 to 10 parts of maleic anhydride, 2 to 5 parts of carboxymethyl cellulose, 2 to 5 parts of methacrylic acid, 30 to 45 parts of methyl methacrylate, 20 to 30 parts of butyl acrylate, 2 to 5 parts of hydroxyethyl acrylate, 2 to 5 parts of urea methacrylate, 5 to 8 parts of tween-80, 15 to 25 parts of dipropylene glycol monomethyl ether, 0.5 to 2 parts of initiator and 450 to 550 parts of water. According to the composite acrylic acid auxiliary agent, bio-based carboxymethyl cellulose is added on the basis of multiple acrylic acid monomers, the characteristic that carboxymethyl cellulose has negative electricity is used for resisting static electricity, it is avoided that in the needling process of geotechnical cloth, due to the electrostatic interaction, the tear resistance is reduced, and meanwhile carboxymethyl cellulose has the moisture absorption and lubrication effects; stress concentration of the geotechnical layout part is avoided, and the tearing risk is reduced.

Description

Technical Field

[0001] The invention relates to a bio-based composite acrylic acid additive for improving the tear resistance of geotextiles, a preparation method and application thereof, and belongs to the technical field of geotextile preparation and improvement. Background Art

[0002] As an indispensable basic material in modern civil engineering, the tear resistance of geotextiles is directly related to the stability and service life of engineering structures. With the rapid advancement of infrastructure construction in my country, the demand for high-performance geotechnical materials in major projects such as water conservancy projects, highways, and airport runways has surged, and the shortcomings of traditional geotextiles in terms of tear resistance have become increasingly prominent. This article will systematically analyze the background needs for improving the tear resistance of geotextiles, deeply explore the current mainstream and cutting-edge improvement methods, compare the advantages and disadvantages of different technologies, and look forward to future development trends. From raw material selection, structural design, process optimization, to functional composites, improving the tear resistance of geotextiles has become an important research direction in the intersection of materials science and civil engineering, and is of great significance to ensuring the safety of major projects and extending the life of structures.

[0003] In actual engineering environments, geotextiles may face a variety of risk scenarios that may lead to tearing. For example, during the laying process, the geotextile may come into contact with sharp stones or construction equipment, causing initial cracks; in long-term use, uneven settlement or local stress concentration may cause crack expansion; in water conservancy projects, debris carried by high-speed water flow may impact and tear the geotextile. Once the geotextile is torn and damaged, it may lose some functions (such as decreased filtration performance) at the least, or cause the entire engineering structure to fail (such as dam leakage and roadbed mixing) at worst. Especially in environmental protection projects such as landfills and hazardous waste disposal sites, the tearing of geotextiles may cause the leakage of harmful substances and cause serious environmental pollution, which makes improving tear resistance the key to the research and development and application of geotextiles.

[0004] Currently, the main approaches to improving fiber strength and toughness are selecting polypropylene with a narrow molecular weight distribution and a high melt index, or adding elastomers to enhance the toughness of the matrix. Alternatively, oriented spinning or stretching can be used to align the fibers along the direction of force, improving longitudinal and transverse tear strength. Alternatively, improvements can be made to the needle punching process, increasing the density and depth of needle punches to enhance fiber entanglement. Hot calendering or hot air consolidation can be used to improve interfiber bonding.

[0005] Therefore, there is an urgent need to develop a new type of bio-based composite acrylic additive that can improve the tear resistance of geotextiles. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides a bio-based composite acrylic additive for improving the tear resistance of geotextiles, as well as its preparation method and application. The main component of the additive is a bio-based composite acrylic emulsion, which is mainly prepared by free radical polymerization of monomers such as maleic anhydride, carboxymethyl cellulose, methacrylic acid, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate and methacrylate urea. The prepared emulsion is electronegative, and the film is soft and transparent. It can be well composited with polypropylene filaments to improve the tear resistance and antistatic properties of polypropylene filaments and meet production needs. When in use, by spraying a surface treatment agent on the polypropylene filaments before needling, a flexible antistatic coating is formed on the fiber surface, which not only protects the antistatic damage of the fiber during the needling process but also improves the tear resistance of the geotextile.

[0007] The technical solutions of the present invention are as follows:

[0008] A bio-based composite acrylic additive for improving the tear resistance of geotextiles is prepared from the following raw materials in parts by weight:

[0009] 5-10 parts of maleic anhydride, 2-5 parts of carboxymethyl cellulose, 2-5 parts of methacrylic acid, 30-45 parts of methyl methacrylate, 20-30 parts of butyl acrylate, 2-5 parts of hydroxyethyl acrylate, 2-5 parts of urea methacrylate, 5-8 parts of Tween-80, 15-25 parts of dipropylene glycol monomethyl ether, 0.5-2 parts of initiator, and 450-550 parts of water.

[0010] According to the preferred embodiment of the present invention, the bio-based composite acrylic additive for improving the tear resistance of geotextile is prepared from the following raw materials in parts by mass:

[0011] 10 parts of maleic anhydride, 5 parts of carboxymethyl cellulose, 5 parts of methacrylic acid, 45 parts of methyl methacrylate, 20 parts of butyl acrylate, 5 parts of hydroxyethyl acrylate, 2 parts of urea methacrylate, 8 parts of Tween-80, 20 parts of dipropylene glycol monomethyl ether, 0.5 parts of initiator, and 500 parts of water.

[0012] According to the present invention, the initiator is preferably ammonium persulfate or 2,2'-azobisisobutylamidine dihydrochloride (V-50).

[0013] The method for preparing the bio-based composite acrylic additive for improving the tear resistance of geotextiles comprises the following steps:

[0014] According to the proportion, maleic anhydride, carboxymethyl cellulose, methacrylic acid, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, urea methacrylate, Tween-80, dipropylene glycol monomethyl ether and water are added to a reaction vessel, stirred and homogenized to obtain a reaction liquid; then, under nitrogen protection, the reaction liquid is heated at 75-85°C for 8-12 minutes, an initiator is added, and the reaction is kept warm for 1.5-2.5 hours. After cooling and filtration, a bio-based composite acrylic additive for improving the tear resistance of geotextile is obtained.

[0015] Preferably, according to the present invention, the homogenizing after stirring means: stirring at 55-65° C. for 2-8 minutes, and then homogenizing at 800-1000 bar and 20-50 ml / min for 5-15 minutes, with stirring-homogenizing being considered as one time, and stirring-homogenizing 3-5 times in total.

[0016] The application of the above-mentioned bio-based composite acrylic additive in the production of geotextiles.

[0017] According to the preferred embodiment of the present invention, the specific steps of the application method are as follows:

[0018] The polypropylene masterbatch and the antioxidant 1010 are melt-blended, dispersed, and extruded in a screw extruder to obtain a copolymer; the copolymer is then made into polypropylene filament fibers by a melt-blowing method or a spun-bonding method, and then a bio-based composite acrylic additive is sprayed on the surface of the polypropylene filament fibers. Finally, the sprayed polypropylene filament fibers are woven by a needle-punching or hydroentanglement method to obtain an anti-static and high-tear-strength polypropylene filament geotextile.

[0019] More preferably, the mass ratio of the polypropylene masterbatch to the antioxidant 1010 is (99-95): (1-5).

[0020] Further preferably, the amount of the bio-based composite acrylic acid additive is 1 to 5% of the mass of the polypropylene filament fiber.

[0021] The melt blending, dispersion, extrusion, melt blowing, spunbonding, needle punching and hydroentanglement in the present invention are all conventional processes and can be carried out according to existing technologies.

[0022] The technical features and beneficial effects of the present invention are as follows:

[0023] 1. The composite acrylic acid additive provided by the present invention is an innovative addition of bio-based carboxymethyl cellulose to a variety of acrylic acid monomers. The anti-static property of carboxymethyl cellulose is utilized to avoid the reduction of tear resistance due to electrostatic effects during the needle punching process of geotextiles. At the same time, carboxymethyl cellulose has a hygroscopic and lubricating effect. In a humid environment, CMC forms a gel layer after absorbing moisture, which lubricates the fiber to slide, avoids local stress concentration in the geotextile, and reduces the risk of tearing. The composite acrylic acid additive utilizes hydrogen bond interactions and covalent bonding to adjust the softness and hardness of the emulsion, and at the same time utilizes in-situ blending and the introduction of anionic monomers to prepare anionic emulsions. In-situ blending can evenly disperse carboxymethyl cellulose in the acrylic emulsion, and the prepared emulsion is more uniform. Emulsion polymerization effectively reduces the use of organic solvents and is more environmentally friendly.

[0024] 2. The composite acrylic additive provided by the present invention can effectively improve the tear resistance of geotextiles. It can give polypropylene filament fiber geotextiles the advantages of antistatic and high tear strength by surface spraying without damaging the original properties of polypropylene filament fibers. It effectively avoids the problem of poor compatibility of different raw materials caused by masterbatch blending modification, thereby affecting the fiber spinning, stretching and traction properties. As a result, the geotextile prepared by the present invention has a gram weight between 151 and 152, and a tear strength of 0.54 kN, which is much higher than conventional acrylic additives. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a demonstration diagram of the sample in the tear resistance test of the experimental example. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be further described below in conjunction with the examples, but the protection scope of the present invention is not limited thereto. The reagents and materials involved in the examples are all common commercial products unless otherwise specified.

[0027] Example 1

[0028] A bio-based composite acrylic additive for improving the tear resistance of geotextiles is prepared from the following raw materials in parts by weight:

[0029] 10 parts of maleic anhydride, 5 parts of carboxymethyl cellulose, 5 parts of methacrylic acid, 45 parts of methyl methacrylate, 20 parts of butyl acrylate, 5 parts of hydroxyethyl acrylate, 2 parts of urea methacrylate, 8 parts of Tween-80, 20 parts of dipropylene glycol monomethyl ether, 0.5 parts of 2,2'-azobisisobutylamidine dihydrochloride, and 500 parts of water.

[0030] The method for preparing the bio-based composite acrylic additive for improving the tear resistance of geotextiles comprises the following steps:

[0031] According to the ratio, maleic anhydride, carboxymethyl cellulose, methacrylic acid, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, urea methacrylate, Tween-80, dipropylene glycol monomethyl ether and water were added to a reaction vessel, stirred at 60°C for 5 minutes, and then homogenized at 900 bar and 30 ml / min for 10 minutes, with stirring and homogenization as one time, and stirring and homogenization were performed three times in total to obtain a reaction solution; after nitrogen was passed through room temperature (25°C) for 30 minutes, the reaction solution was heated at 80°C for 10 minutes under nitrogen protection, 2,2'-azobisisobutylamidine dihydrochloride was added, the reaction was kept warm for 2 hours, and after cooling and filtration, a bio-based composite acrylic additive for improving the tear resistance of geotextile was obtained.

[0032] Example 2

[0033] A bio-based composite acrylic additive for improving the tear resistance of geotextiles is prepared from the following raw materials in parts by weight:

[0034] 10 parts of maleic anhydride, 5 parts of carboxymethyl cellulose, 5 parts of methacrylic acid, 35 parts of methyl methacrylate, 30 parts of butyl acrylate, 5 parts of hydroxyethyl acrylate, 2 parts of urea methacrylate, 8 parts of Tween-80, 20 parts of dipropylene glycol monomethyl ether, 0.5 parts of 2,2'-azobisisobutylamidine dihydrochloride, and 500 parts of water.

[0035] The specific preparation method is the same as that in Example 1.

[0036] Example 3

[0037] A bio-based composite acrylic additive for improving the tear resistance of geotextiles is prepared from the following raw materials in parts by weight:

[0038] 10 parts of maleic anhydride, 2 parts of carboxymethyl cellulose, 3 parts of methacrylic acid, 45 parts of methyl methacrylate, 25 parts of butyl acrylate, 5 parts of hydroxyethyl acrylate, 2 parts of urea methacrylate, 8 parts of Tween-80, 20 parts of dipropylene glycol monomethyl ether, 0.5 parts of ammonium persulfate, and 500 parts of water.

[0039] The specific preparation method is the same as that in Example 1.

[0040] Example 4

[0041] A method for preparing an anti-static and high-tear strength polypropylene filament geotextile comprises the following steps:

[0042] The polypropylene masterbatch and the antioxidant 1010 are melt-blended, dispersed, and extruded in a screw extruder to obtain a copolymer; the copolymer is then formed into polypropylene filament fibers by a melt-blowing method; the bio-based composite acrylic acid additive described in Example 1 is then sprayed onto the surface of the polypropylene filament fibers; and finally, the sprayed polypropylene filament fibers are woven by a needle punching process to obtain an antistatic and high-tear-strength polypropylene filament geotextile.

[0043] The mass ratio of the polypropylene masterbatch to the antioxidant 1010 is 95:5, and the amount of the bio-based composite acrylic acid additive is 3% of the mass of the polypropylene filament fiber.

[0044] Example 5

[0045] A method for preparing an antistatic and high-tear strength polypropylene filament geotextile, wherein the specific steps are the same as those of Example 4, except that the bio-based composite acrylic acid additive prepared in Example 2 is used.

[0046] Example 6

[0047] A method for preparing an antistatic and high-tear strength polypropylene filament geotextile, wherein the specific steps are the same as those of Example 4, except that the bio-based composite acrylic acid additive prepared in Example 3 is used.

[0048] Comparative Example 1

[0049] An acrylic acid additive is prepared from the following raw materials in parts by weight:

[0050] 10 parts of maleic anhydride, 5 parts of methacrylic acid, 45 parts of methyl methacrylate, 25 parts of butyl acrylate, 5 parts of hydroxyethyl acrylate, 2 parts of urea methacrylate, 8 parts of Tween-80, 20 parts of dipropylene glycol monomethyl ether, 0.5 parts of 2,2'-azobisisobutylamidine dihydrochloride, and 500 parts of water.

[0051] The specific preparation method is the same as that in Example 1.

[0052] Using the acrylic acid additive prepared in this comparative example, a polypropylene filament geotextile was prepared according to the method described in Example 4.

[0053] Test example

[0054] The polypropylene filament geotextiles prepared in Examples 4 to 6 and Comparative Example 1 were weighed and tested for tear resistance according to the national standard GB / T13763. The results are shown in Table 1.

[0055] The specific method is as follows: cut the polypropylene filament geotextiles prepared in Examples 4 to 6 and Comparative Example 1 into samples of the same size (200mm×75mm), then use a trapezoidal template to draw an isosceles trapezoid (upper base 25mm, lower base 100mm, height 75mm) on each sample, and then cut a 15mm long incision in the center of the short side of the trapezoid. Set the distance between the two clamps to 25±1mm and the stretching speed to 50mm / min. Clamp the sample along the non-parallel sides of the trapezoid (specifically as Figure 1 (As shown by the center clamping line) so that the cut is located between the two clamps and the long side is wrinkled. Start the tensile testing machine, stretch, and record the maximum tear strength in Newtons (N).

[0056] Table 1

[0057]

[0058] As can be seen from Table 1, the geotextiles prepared in Examples 4 to 6 have a gram weight between 151 and 152, and a tear strength of 0.44 to 0.54 kN, which is much higher than the 0.36 kN of the conventional acrylic acid additive in Comparative Example 1. There is a significant improvement, which can meet the requirements for the tear resistance of geotextiles in actual engineering.

[0059] The above-described embodiments are only preferred specific implementation plans of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A bio-based composite acrylic additive for improving the tear resistance of geotextiles, characterized in that: It is prepared from the following raw materials in parts by weight: 5-10 parts of maleic anhydride, 2-5 parts of carboxymethyl cellulose, 2-5 parts of methacrylic acid, 30-45 parts of methyl methacrylate, 20-30 parts of butyl acrylate, 2-5 parts of hydroxyethyl acrylate, 2-5 parts of urea methacrylate, 5-8 parts of Tween-80, 15-25 parts of dipropylene glycol monomethyl ether, 0.5-2 parts of initiator, and 450-550 parts of water.

2. The bio-based composite acrylic acid additive according to claim 1, characterized in that: It is prepared from the following raw materials in parts by weight: 10 parts of maleic anhydride, 5 parts of carboxymethyl cellulose, 5 parts of methacrylic acid, 45 parts of methyl methacrylate, 20 parts of butyl acrylate, 5 parts of hydroxyethyl acrylate, 2 parts of urea methacrylate, 8 parts of Tween-80, 20 parts of dipropylene glycol monomethyl ether, 0.5 parts of initiator, and 500 parts of water.

3. The bio-based composite acrylic acid additive according to claim 1, characterized in that: The initiator is ammonium persulfate or 2,2'-azobisisobutylamidine dihydrochloride (V-50).

4. The method for preparing the bio-based composite acrylic acid additive for improving the tear resistance of geotextiles according to claim 1, characterized in that: The steps are as follows: According to the proportion, maleic anhydride, carboxymethyl cellulose, methacrylic acid, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, urea methacrylate, Tween-80, dipropylene glycol monomethyl ether and water are added to a reaction vessel, stirred and homogenized to obtain a reaction liquid; then, under nitrogen protection, the reaction liquid is heated at 75-85°C for 8-12 minutes, an initiator is added, and the reaction is kept warm for 1.5-2.5 hours. After cooling and filtration, a bio-based composite acrylic additive for improving the tear resistance of geotextile is obtained.

5. The preparation method according to claim 4, wherein The homogenization after stirring means: stirring at 55-65° C. for 2-8 minutes, and then homogenizing at 800-1000 bar and 20-50 ml / min for 5-15 minutes, with stirring-homogenizing being considered as one time, and stirring-homogenizing being performed 3-5 times in total.

6. Use of the bio-based composite acrylic acid additive according to any one of claims 1 to 3 in the production of geotextiles.

7. The use according to claim 6, characterized in that The specific steps are as follows: The polypropylene masterbatch and the antioxidant 1010 are melt-blended, dispersed, and extruded in a screw extruder to obtain a copolymer; the copolymer is then made into polypropylene filament fibers by a melt-blowing method or a spun-bonding method, and then a bio-based composite acrylic additive is sprayed on the surface of the polypropylene filament fibers. Finally, the sprayed polypropylene filament fibers are woven by a needle-punching or hydroentanglement method to obtain an anti-static and high-tear-strength polypropylene filament geotextile.

8. The use according to claim 7, characterized in that The mass ratio of the polypropylene masterbatch to the antioxidant 1010 is (99-95): (1-5).

9. The use according to claim 7, characterized in that The usage of the bio-based composite acrylic acid additive is 1-5% of the mass of the polypropylene filament fiber.

Images