A durable antibacterial polypropylene filament nonwoven geotextile and a method of making the same

Abstract

The present application relates to a kind of long-lasting antibacterial polypropylene filament non-woven geotextile and its preparation method, the present application by the organic silicon quaternary ammonium salt containing double bond as antibacterial agent, with polypropylene master batch is carried out melt blending at a certain temperature, and appropriate initiator is added, promotes graft copolymerization reaction, makes antibacterial agent and polypropylene form covalent bond, ensure that antibacterial component is evenly distributed and not loss. Geotextile prepared by needle punching process has strong antibacterial performance and durability, effectively inhibits microbial growth, prolongs service life, and enhances the functional stability under a variety of environmental conditions. The geotextile of the present application meets the market demand of environmental protection and sustainable development, and is suitable for engineering that needs long-term exposure to high humidity and complex microbial environment, and provides reliable guarantee for wider engineering application.

Description

Technical Field

[0001] This invention relates to a durable antibacterial polypropylene filament nonwoven geotextile and its preparation method, belonging to the field of polymer materials technology. Background Technology

[0002] Polypropylene filament nonwoven geotextiles are widely used in various fields such as civil engineering, environmental protection, agriculture, and horticulture for functions such as reinforcement, isolation, filtration, and drainage. However, traditional polypropylene filament nonwoven geotextiles often face the challenge of microbial erosion during use. Because polypropylene itself lacks natural antibacterial properties due to its chemical structure, geotextiles easily become breeding grounds for bacteria, fungi, and other microorganisms in humid, organic-rich environments. This microbial proliferation not only leads to the biodegradation of the material, reducing its mechanical properties and toughness, but can also cause odors and pollution, severely impacting the material's service life and functionality. Furthermore, in certain applications, such as landfills or sewage treatment facilities, the accumulation of microorganisms can pose a threat to the environment and human health. Therefore, endowing polypropylene filament nonwoven geotextiles with antibacterial properties can effectively inhibit microbial growth, extend the material's service life, and maintain its structural strength and functional characteristics.

[0003] While addressing the aforementioned issues, the market demand for high-performance polypropylene geotextiles is increasing, especially in engineering projects requiring prolonged exposure to high humidity and complex microbial environments. Introducing antimicrobial agents into polypropylene materials can prevent microbial erosion at its source. However, the selection and addition method of the antimicrobial agent directly affects the material's antimicrobial efficacy and physical properties. Existing research involves attaching inorganic antimicrobial agents, such as nano-metals or metal oxides, and organic antimicrobial agents, such as chitosan and surfactants, to the surface of polypropylene filaments or geotextiles through spraying, casting, or coating methods to achieve antimicrobial effects. However, these methods suffer from the problem of antimicrobial agents easily detaching, affecting the longevity of the antimicrobial effect, and the types of antimicrobial agents are relatively limited, making it difficult to meet the needs of multiple industries. Therefore, it is necessary to develop a novel antimicrobial agent and introduce it into polypropylene filaments through melt graft copolymerization to prolong its antimicrobial effect.

[0004] Organosilicon quaternary ammonium salts are used in a variety of materials due to their chemical stability and safety as highly efficient and long-lasting antibacterial agents. However, how to effectively combine them into polypropylene masterbatch to ensure that the antibacterial components are evenly distributed in the material without loss, and without affecting its spinning performance and the mechanical properties of the final product, remains a technical challenge. Summary of the Invention

[0005] In view of the shortcomings of existing technologies, especially the problems of unstable antibacterial properties, easy shedding of antibacterial agents, short antibacterial duration, and limited types of antibacterial agents in existing antibacterial polypropylene filament geotextiles, this invention provides a long-lasting antibacterial polypropylene filament nonwoven geotextile and its preparation method.

[0006] This invention utilizes organosilicon quaternary ammonium salts with antibacterial properties and containing double bonds as antibacterial agents. These salts are melt-blended with polypropylene masterbatch at a specific temperature, and an appropriate amount of initiator is added to promote graft copolymerization of the double bonds of the organosilicon quaternary ammonium salt with polypropylene, thereby firmly binding the antibacterial agent to the polypropylene molecular chain. Antibacterial polypropylene filament nonwoven geotextiles are then prepared through a needle-punching process. The resulting geotextile exhibits strong and durable antibacterial properties, extending its service life and enhancing its functional stability under various environmental conditions.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] The first objective of this invention is to provide a durable antibacterial polypropylene filament nonwoven geotextile.

[0009] A durable antibacterial polypropylene filament nonwoven geotextile is prepared by melt blending polypropylene masterbatch containing double-bonded organosilicon quaternary ammonium salt and polypropylene masterbatch in a mass ratio of (1-3):(200-1500), grafting copolymerization under an initiator, and then needle punching the resulting graft copolymer.

[0010] The organosilicon quaternary ammonium salt containing double bonds has the structure shown in Formula I:

[0011]

[0012] According to a preferred embodiment of the present invention, the number-average molecular weight Mn of the organosilicon quaternary ammonium salt containing double bonds is 4000-30000.

[0013] According to a preferred embodiment of the present invention, the organosilicon quaternary ammonium salt containing double bonds is prepared by a nucleophilic substitution reaction of terminal chloromethyl epoxy silicone oil II and dimethylaminoethyl methacrylate III under certain temperature and solvent conditions;

[0014]

[0015] According to a preferred embodiment of the present invention, the solvent for the preparation reaction of organosilicon quaternary ammonium salts containing double bonds is one or a mixture of two or more of 1,4-dioxane, toluene, xylene, 1,2-dichloroethane, tetrahydrofuran, and water.

[0016] According to a preferred embodiment of the present invention, the reaction temperature for preparing organosilicon quaternary ammonium salts containing double bonds is 50-150°C.

[0017] The most preferred temperature for the preparation reaction of organosilicon quaternary ammonium salts containing double bonds is 80-120℃.

[0018] According to a preferred embodiment of the present invention, the nucleophilic substitution reaction time is 10-20 h.

[0019] According to a preferred embodiment of the present invention, the mass ratio of terminal chloromethyl epoxy silicone oil II to dimethylaminoethyl methacrylate III is (50-1000):1.

[0020] The most preferred ratio of terminal chloromethyl epoxy silicone oil II to dimethylaminoethyl methacrylate III is (100-800):1.

[0021] According to a preferred embodiment of the present invention, the total mass ratio of terminal chloromethyl epoxy silicone oil II and dimethylaminoethyl methacrylate III to the solvent is 1:(1-9).

[0022] Most preferably, the ratio of the total mass of terminal chloromethyl epoxy silicone oil II and dimethylaminoethyl methacrylate III to the mass of solvent is 1:(2-6).

[0023] A second objective of this invention is to provide a method for preparing the aforementioned durable antibacterial polypropylene filament nonwoven geotextile.

[0024] A preferred method for preparing a durable antibacterial polypropylene filament nonwoven geotextile according to the present invention includes the following steps:

[0025] 1) The above-mentioned organosilicon quaternary ammonium salt containing double bonds is melt-blended with polypropylene masterbatch in a screw extruder. The blending temperature is controlled between the melting point of polypropylene and the thermal decomposition temperature of organosilicon quaternary ammonium salt to ensure that the two are mixed uniformly.

[0026] 2) During the melt blending process, an initiator is added to promote the graft copolymerization reaction between the double bonds of organosilicon quaternary ammonium salt and polypropylene molecular chains, forming a stable graft copolymer.

[0027] 3) The graft copolymer obtained in step 2) is made into filaments by spinning process to obtain a uniform filament structure;

[0028] 4) Lay the filaments into a web to form the initial structure of the geotextile, and then reinforce the structure of the geotextile through needle punching to improve its strength and stability;

[0029] 5) The needle-punched geotextile is heat-set to obtain a durable antibacterial polypropylene filament nonwoven geotextile.

[0030] According to a preferred embodiment of the present invention, in step 1), the mass ratio of the double-bonded organosilicon quaternary ammonium salt to the polypropylene masterbatch is (1-3):(200-1500).

[0031] According to a preferred embodiment of the present invention, in step 2), the amount of initiator is 1-10% of the mass of the organosilicon quaternary ammonium salt containing double bonds;

[0032] According to a preferred embodiment of the present invention, in step 2), the initiator is one or two of benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, Ziegler-Natta catalyst, and metallocene catalyst.

[0033] The spinning process for producing filaments, web laying, needle punching, and heat setting are carried out according to existing technologies.

[0034] The double-bonded organosilicon quaternary ammonium salt of this invention has highly efficient and long-lasting antibacterial properties. The double bonds of the organosilicon quaternary ammonium salt undergo a graft copolymerization reaction with polypropylene to form strong covalent bonds, thereby firmly binding the antibacterial agent to the polypropylene molecular chain. This effectively improves the problem of loss or failure of antibacterial polypropylene filament geotextile during long-term use. Furthermore, the long-chain silicon-oxygen bonds of the double-bonded organosilicon quaternary ammonium salt have low thermal conductivity and resistance to high temperatures up to 300°C. The low thermal conductivity can delay heat transfer, while the stable silicon-oxygen bonds of organosilicon partially lock the creep of polymer bonds, further improving the temperature resistance of the geotextile. Thus, the overall antibacterial and high-temperature resistance of polypropylene filament geotextile are synergistically improved.

[0035] Technical features and superior effects of the present invention:

[0036] 1. Highly Effective Antibacterial Properties: This invention utilizes organosilicon quaternary ammonium salts containing double bonds as antibacterial agents. These agents possess broad-spectrum antibacterial activity, effectively inhibiting the growth of various microorganisms, including bacteria, molds, and fungi. This invention achieves strong covalent bonds through a graft copolymerization reaction between the double bonds of the organosilicon quaternary ammonium salt and polypropylene, thus firmly binding the antibacterial agent to the polypropylene molecular chain. This strong bond ensures uniform distribution of the antibacterial components within the material without loss, and does not affect its spinning properties or the mechanical properties of the final product.

[0037] 2. Enhanced Durability: This invention utilizes melt blending and graft copolymerization techniques to uniformly disperse the antibacterial agent within a polypropylene matrix, forming a stable antibacterial layer. This structure not only improves the antibacterial properties of the geotextile but also enhances its durability under harsh environmental conditions, extending its service life and ensuring long-term stability of the geotextile's antibacterial performance. It avoids the problems of easy antibacterial agent shedding and short-lived antibacterial effects.

[0038] 3. Excellent environmental adaptability: The organosilicon quaternary ammonium salt of this invention exhibits high chemical and thermal stability, ensuring that the antibacterial polypropylene filament nonwoven geotextile can maintain its function under various environmental conditions, including high humidity, high temperature, and acid / alkali environments. This makes the geotextile more widely applicable in various engineering applications.

[0039] 4. Environmental friendliness and safety: The organosilicon quaternary ammonium salt antibacterial agent of this invention has low toxicity and biodegradability, making it environmentally friendly. Furthermore, due to its highly efficient antibacterial properties, it can reduce the use of chemical disinfectants, lowering potential risks to the environment and human health.

[0040] 5. Physical properties are maintained: While imparting antibacterial properties to the geotextile, the method of the present invention does not affect the original physical properties of the polypropylene filament nonwoven geotextile, such as strength, aging resistance and chemical resistance, thus ensuring the reliability of the geotextile in various engineering applications. Attached Figure Description

[0041] Figure 1 The images show the antibacterial effect of the antibacterial polypropylene filament geotextiles obtained in Examples 1-9 and Comparative Example 1. Detailed Implementation

[0042] The present invention will be further described in detail below with reference to the embodiments, but this does not limit the scope of the present invention.

[0043] Example 1

[0044] The preparation method of organosilicon quaternary ammonium salts containing double bonds is as follows:

[0045] One part of dimethylaminoethyl methacrylate, 200 parts of chloromethyl epoxy silicone oil (Mn = 10000) and 469 parts of toluene were mixed evenly, heated to 80°C, stirred and reacted for 12 h, and toluene was removed under reduced pressure to obtain a double-bonded organosilicon quaternary ammonium salt.

[0046] Preparation of antibacterial polypropylene filament nonwoven geotextile:

[0047] 1) Melt-blend 1 part of double-bonded organosilicon quaternary ammonium salt with 500 parts of polypropylene masterbatch in a screw extruder. The blending temperature is controlled between the melting point of polypropylene and the thermal decomposition temperature of organosilicon quaternary ammonium salt to ensure that the two are mixed uniformly.

[0048] 2) Add 0.05 parts of benzoyl peroxide during melt blending and retain for 1 hour to promote the graft copolymerization reaction between the double bonds of organosilicon quaternary ammonium salt and polypropylene molecular chains, and then extrude and granulate to obtain modified polypropylene masterbatch.

[0049] 3) The modified polypropylene masterbatch obtained in step 2) is made into filaments by spinning process to obtain a uniform filament structure.

[0050] 4) Lay the filaments into a web to form the initial structure of the geotextile, and then reinforce the structure of the geotextile through needle punching to improve its strength and stability;

[0051] 5) The needle-punched geotextile is heat-set to obtain a durable antibacterial polypropylene filament nonwoven geotextile.

[0052] Example 2

[0053] The preparation method of organosilicon quaternary ammonium salts containing double bonds is as follows:

[0054] One part of dimethylaminoethyl methacrylate, 500 parts of chloromethyl epoxy silicone oil (Mn=10000) and 1169 parts of toluene were mixed evenly, heated to 80°C, stirred and reacted for 12 h, and toluene was removed under reduced pressure to obtain a double-bonded organosilicon quaternary ammonium salt.

[0055] The preparation of antibacterial polypropylene filament nonwoven geotextile was carried out according to Example 1.

[0056] Example 3

[0057] The preparation method of organosilicon quaternary ammonium salts containing double bonds is as follows:

[0058] One part of dimethylaminoethyl methacrylate, 800 parts of chloromethyl epoxy silicone oil (Mn = 10000) and 1869 parts of toluene were mixed evenly, heated to 80°C, stirred and reacted for 12 h, and toluene was removed under reduced pressure to obtain a double-bonded organosilicon quaternary ammonium salt.

[0059] The preparation of antibacterial polypropylene filament nonwoven geotextile was carried out according to Example 1.

[0060] Example 4

[0061] The preparation method of organosilicon quaternary ammonium salts containing double bonds is as follows:

[0062] One part of dimethylaminoethyl methacrylate, 200 parts of chloromethyl epoxy silicone oil (Mn = 10000) and 469 parts of toluene were mixed evenly, heated to 100°C, stirred and reacted for 12 h, and toluene was removed under reduced pressure to obtain a double-bonded organosilicon quaternary ammonium salt.

[0063] The preparation of antibacterial polypropylene filament nonwoven geotextile was carried out according to Example 1.

[0064] Example 5

[0065] The preparation method of organosilicon quaternary ammonium salts containing double bonds is as follows:

[0066] One part of dimethylaminoethyl methacrylate, 200 parts of chloromethyl epoxy silicone oil (Mn = 10000) and 469 parts of xylene were mixed evenly, heated to 80°C, stirred and reacted for 12 h, and xylene was removed under reduced pressure to obtain an organosilicon quaternary ammonium salt containing double bonds.

[0067] The preparation of antibacterial polypropylene filament nonwoven geotextile was carried out according to Example 1.

[0068] Example 6

[0069] The preparation of organosilicon quaternary ammonium salts containing double bonds was carried out according to Example 1.

[0070] Preparation of antibacterial polypropylene filament nonwoven geotextile:

[0071] 1) Melt-blend 1 part of double-bonded organosilicon quaternary ammonium salt with 1000 parts of polypropylene masterbatch in a screw extruder. The blending temperature is controlled between the melting point of polypropylene and the thermal decomposition temperature of organosilicon quaternary ammonium salt to ensure uniform mixing of the two.

[0072] 2) Add 0.05 parts of benzoyl peroxide during melt blending and retain for 1 hour to promote the graft copolymerization reaction between the double bonds of organosilicon quaternary ammonium salt and polypropylene molecular chains, and then extrude and granulate to obtain modified polypropylene masterbatch.

[0073] 3) The modified polypropylene masterbatch obtained in step 2) is made into filaments by spinning process to obtain a uniform filament structure.

[0074] 4) Lay the filaments into a web to form the initial structure of the geotextile, and then reinforce the structure of the geotextile through needle punching to improve its strength and stability;

[0075] 5) The needle-punched geotextile is heat-set to obtain a durable antibacterial polypropylene filament nonwoven geotextile.

[0076] Example 7

[0077] The preparation method of the organosilicon quaternary ammonium salt containing double bonds was carried out according to Example 1.

[0078] Preparation of antibacterial polypropylene filament nonwoven geotextile:

[0079] 1) Melt-blend 1 part of double-bonded organosilicon quaternary ammonium salt with 800 parts of polypropylene masterbatch in a screw extruder. The blending temperature is controlled between the melting point of polypropylene and the thermal decomposition temperature of organosilicon quaternary ammonium salt to ensure that the two are mixed uniformly.

[0080] 2) Add 0.05 parts of benzoyl peroxide during melt blending and retain for 1 hour to promote the graft copolymerization reaction between the double bonds of organosilicon quaternary ammonium salt and polypropylene molecular chains, and then extrude and granulate to obtain modified polypropylene masterbatch.

[0081] 3) The modified polypropylene masterbatch obtained in step 2) is made into filaments by spinning process to obtain a uniform filament structure.

[0082] 4) Lay the filaments into a web to form the initial structure of the geotextile, and then reinforce the structure of the geotextile through needle punching to improve its strength and stability;

[0083] 5) The needle-punched geotextile is heat-set to obtain a durable antibacterial polypropylene filament nonwoven geotextile.

[0084] Example 8

[0085] The preparation method of the organosilicon quaternary ammonium salt containing double bonds was carried out according to Example 1.

[0086] Preparation of antibacterial polypropylene filament nonwoven geotextile:

[0087] 1) Melt-blend 1 part of double-bonded organosilicon quaternary ammonium salt with 500 parts of polypropylene masterbatch in a screw extruder. The blending temperature is controlled between the melting point of polypropylene and the thermal decomposition temperature of organosilicon quaternary ammonium salt to ensure that the two are mixed uniformly.

[0088] 2) During the melt blending process, 0.05 parts of lauroyl peroxide were added and retained for 1 hour to promote the graft copolymerization reaction between the double bonds of organosilicon quaternary ammonium salt and polypropylene molecular chains. The modified polypropylene masterbatch was then obtained by extrusion granulation.

[0089] 3) The modified polypropylene masterbatch obtained in step 2) is made into filaments by spinning process to obtain a uniform filament structure.

[0090] 4) Lay the filaments into a web to form the initial structure of the geotextile, and then reinforce the structure of the geotextile through needle punching to improve its strength and stability;

[0091] 5) The needle-punched geotextile is heat-set to obtain a durable antibacterial polypropylene filament nonwoven geotextile.

[0092] Example 9

[0093] The preparation method of the organosilicon quaternary ammonium salt containing double bonds was carried out according to Example 1.

[0094] Preparation of antibacterial polypropylene filament nonwoven geotextile:

[0095] 1) Melt-blend 1 part of double-bonded organosilicon quaternary ammonium salt with 500 parts of polypropylene masterbatch in a screw extruder. The blending temperature is controlled between the melting point of polypropylene and the thermal decomposition temperature of organosilicon quaternary ammonium salt to ensure that the two are mixed uniformly.

[0096] 2) Add 0.1 parts of benzoyl peroxide during the melt blending process and retain for 1 hour to promote the graft copolymerization reaction between the double bonds of organosilicon quaternary ammonium salt and polypropylene molecular chains, and then extrude and granulate to obtain modified polypropylene masterbatch.

[0097] 3) The modified polypropylene masterbatch obtained in step 2) is made into filaments by spinning process to obtain a uniform filament structure.

[0098] 4) Lay the filaments into a web to form the initial structure of the geotextile, and then reinforce the structure of the geotextile through needle punching to improve its strength and stability;

[0099] 5) The needle-punched geotextile is heat-set to obtain a durable antibacterial polypropylene filament nonwoven geotextile.

[0100] Comparative Example 1

[0101] Nonwoven geotextile made of polypropylene filament without any emulsion modification.

[0102] Experimental Example

[0103] Antibacterial performance test:

[0104] The antibacterial performance test method is as follows: First, the *S. aureus* bacterial suspension was incubated in a constant temperature incubator for 18 hours (37℃, 150 rpm / min) to obtain a bacterial solution with an initial concentration of (1-5)×10⁸ CFU / ml. Then, 2×2 cm pieces of polypropylene filament geotextile material were cut and irradiated under a UV lamp for 1 hour to kill the original bacteria on the material. The prepared bacterial solution was diluted 10 times, and 100 μL of the solution was dropped onto the material. After 2 hours, the material was transferred to a test tube containing 10 mL of PBS solution, sonicated for 2 minutes, and the diluted PBS solution was inoculated onto agar plates. After incubation at 37℃ for 24 hours, the number of bacteria on each plate was recorded. Finally, the antibacterial activity of the polypropylene filament geotextile material sample was calculated using the following formula:

[0105]

[0106] Where N and N0 are the colony counts of the samples treated with geotextile material and the untreated samples, respectively. The results are as follows: Figure 1 As shown.

[0107] The results of the above antibacterial experiments show that polypropylene filament geotextile modified with double-bonded organosilicon quaternary ammonium salt has a significant antibacterial effect.

Claims

1. A durable antibacterial polypropylene filament nonwoven geotextile, comprising a melt blend of double-bonded organosilicon quaternary ammonium salt and polypropylene masterbatch in a mass ratio of (1-3):(200-1500), a graft copolymerization reaction under an initiator, the graft copolymer being spun into filaments, the filaments being laid into a web, and then prepared by needle punching and heat setting. The amount of initiator is 1-10% of the mass of the organosilicon quaternary ammonium salt containing double bonds. The initiator is one or two of the following: benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, Ziegler-Natta catalyst, and metallocene catalyst. The organosilicon quaternary ammonium salt containing double bonds has the structure shown in Formula I: ； The number-average molecular weight (Mn) of organosilicon quaternary ammonium salts containing double bonds is 4000-30000. The organosilicon quaternary ammonium salt containing double bonds is prepared by nucleophilic substitution reaction of terminal chloromethyl epoxy silicone oil II and dimethylaminoethyl methacrylate III under certain temperature and solvent conditions; ； The mass ratio of terminal chloromethyl epoxy silicone oil II to dimethylaminoethyl methacrylate III is (50-1000):1, and the mass ratio of the total mass of terminal chloromethyl epoxy silicone oil II and dimethylaminoethyl methacrylate III to the mass of solvent is 1:(1-9).

2. The durable antibacterial polypropylene filament nonwoven geotextile according to claim 1, characterized in that, The solvent for the preparation reaction of organosilicon quaternary ammonium salts containing double bonds is one or two of 1,4-dioxane, toluene, xylene, 1,2-dichloroethane, tetrahydrofuran, and water.

3. The durable antibacterial polypropylene filament nonwoven geotextile according to claim 1, characterized in that, The reaction temperature for preparing organosilicon quaternary ammonium salts containing double bonds is 50-150℃.

4. A method for preparing the durable antibacterial polypropylene filament nonwoven geotextile according to any one of claims 1-3, comprising the following steps: 1) The above-mentioned organosilicon quaternary ammonium salt containing double bonds is melt-blended with polypropylene masterbatch in a screw extruder. The blending temperature is controlled between the melting point of polypropylene and the thermal decomposition temperature of organosilicon quaternary ammonium salt to ensure that the two are mixed uniformly. 2) During the melt blending process, an initiator is added to promote the graft copolymerization reaction between the double bonds of organosilicon quaternary ammonium salt and polypropylene molecular chains, forming a stable graft copolymer. 3) The graft copolymer obtained in step 2) is made into filaments by spinning process to obtain a uniform filament structure; 4) Lay the filaments into a web to form the initial structure of the geotextile, and then reinforce the structure of the geotextile through needle punching to improve its strength and stability; 5) The needle-punched geotextile is heat-set to obtain a durable antibacterial polypropylene filament nonwoven geotextile.

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