Antibacterial modified PP material and preparation method thereof

Abstract

The application discloses an antibacterial modified PP material and a preparation method thereof and belongs to the technical field of antibacterial PP materials. The antibacterial modified PP material is prepared from the following components: 65-70 parts of polypropylene, 15-20 parts of a ternary ethylene-propylene rubber, 5-10 parts of an antibacterial agent, 3-5 parts of inorganic modified fillers, 1-3 parts of zinc stearate, 0.5-1.5 parts of an antioxidant 2,6-di-tert-butyl-p-cresol and 0.5-0.8 parts of an initiator dicumyl peroxide. The self-prepared antibacterial agent is used to effectively improve the antibacterial performance of the PP material; the inorganic modified fillers are prepared by modifying natural rubber with talcum powder, and the mechanical properties of the PP material are greatly improved, so that the antibacterial modified PP material has important application value in the technical field of PP materials.

Description

Technical Field

[0001] This invention belongs to the field of PP material technology, specifically, it relates to an antibacterial modified PP material and its preparation method. Background Technology

[0002] Polypropylene (PP) is an important general-purpose plastic with excellent comprehensive properties, good chemical stability and processability, and relatively low cost. It is widely used in home appliance manufacturing, daily necessities, films, and pipes. In recent years, with the improvement of living standards and health awareness, the market demand for product diversification has been increasing. Antibacterial modified PP materials can not only significantly improve the hygiene and safety level of products and effectively protect user health, but also extend the service life of products and enhance market competitiveness. However, PP materials themselves have inherent defects such as low strength and poor antibacterial properties, which to some extent limit the further expansion of its application range. To overcome these shortcomings, polypropylene needs to be modified accordingly. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an antibacterial modified PP material and its preparation method.

[0004] The objective of this invention can be achieved through the following technical solutions: An antibacterial modified PP material and its preparation method, comprising the following steps: Step A1: Weigh each ingredient according to the specified weight proportions and set aside. In step A2, polypropylene, EPDM rubber, antibacterial agent, inorganic modified filler, zinc stearate, and antioxidant 2,6-di-tert-butyl-p-cresol are added to a high-speed mixer and mechanically mixed evenly. The mixture is then fed into a twin-screw extruder through a feed hopper. The temperatures of each zone of the extruder are controlled sequentially as follows: 200±5℃, 210±5℃, 220±5℃, 220±5℃, 210±5℃, and 210±5℃. The screw speed is 50-60 rpm. After melt extrusion, the antibacterial modified PP material can be obtained.

[0005] Furthermore, the antibacterial modified PP material is prepared from the following components in parts by weight: 65-70 parts of polypropylene, 15-20 parts of EPDM rubber, 5-10 parts of antibacterial agent, 3-5 parts of inorganic modified filler, 1-3 parts of zinc stearate, 0.5-1.5 parts of antioxidant 2,6-di-tert-butyl-p-cresol, and 0.5-0.8 parts of initiator dicumyl peroxide.

[0006] Furthermore, the inorganic modified filler is prepared through the following steps: Talc powder was ultrasonically dispersed in N,N-dimethylformamide to form a uniform dispersion. Then, epoxidized natural rubber was added to the dispersion, along with stannous chloride. Heating was started and the temperature was controlled at 130-140℃. The mixture was kept warm and stirred for 6-9 hours. Heating was then stopped, the material was cooled and discharged, and the solid material was centrifuged. After washing and vacuum drying, the inorganic modified filler was obtained.

[0007] Furthermore, the antibacterial agent is prepared through the following steps: Step B1: In a three-necked flask equipped with a stirrer, condenser, and thermometer, add triclosan and carbon tetrachloride, and cool the reactants to 0-5°C using an ice-water bath; add chlorosulfonic acid dropwise with stirring, remove the ice-water bath, raise the temperature to 20-30°C and react for 2-4 hours, then heat the reactants under reflux for 1 hour; cool the reaction product to 20-30°C, dilute with distilled water, and separate the carbon tetrachloride layer and the aqueous layer; neutralize the organic layer with 30% sodium hydroxide solution and wash with water to remove the solvent, obtaining intermediate product A; The specific reaction process is as follows:

[0008] Step B2: In a three-necked flask equipped with a stirrer, condenser, and thermometer, air interference is eliminated by passing an argon gas through the flask. Intermediate product A and 4-dimethylaminopyridine are dissolved in anhydrous dichloromethane and cooled to 0°C in an ice bath. Triethylamine is slowly added, and under stirring, an anhydrous dichloromethane solution of 10-undecenoyl chloride is slowly added dropwise while maintaining the temperature below 5°C. After the addition is complete, the mixture is brought to room temperature and reacted overnight to obtain intermediate product B. The specific reaction process is as follows:

[0009] Step B3: In a three-necked flask equipped with a stirrer, condenser, and thermometer, add intermediate product B and anhydrous ethanol, and add a small amount of sodium hydroxide; under stirring, slowly add 40% dimethylamine aqueous solution to the reaction flask, heat to 70-80℃ and reflux, and react for 12 hours under stirring; after the reaction is complete, cool to room temperature, pour the reaction solution into ice water, precipitate solid, filter, and wash thoroughly with water to obtain intermediate product C; The specific reaction process is as follows:

[0010] Step B4: In a three-necked flask equipped with a stirrer, condenser, and thermometer, add intermediate product C and anhydrous ethanol. Place the apparatus in an ice-water bath and add bromoethane dropwise while stirring. After the addition is complete, remove the ice-water bath, raise the temperature to room temperature, and continue stirring for 10-12 hours. After the reaction is complete, filter the solid and wash it with diethyl ether. Place the solid product in a vacuum drying oven and dry it at 40-50°C for 12 hours to obtain the final product, the antibacterial agent. The specific reaction process is as follows:

[0011] Furthermore, in step B1, the ratio of triclosan to chlorosulfonic acid is 60g:15ml.

[0012] Furthermore, in step B2, the ratio of intermediate product A, 4-dimethylaminopyridine, triethylamine, and 10-undecenoyl chloride is 15g:0.5g:6g:10g.

[0013] Furthermore, in step B3, the ratio of intermediate product B, sodium hydroxide, and 40% dimethylamine aqueous solution is 10g:1.5g:5ml.

[0014] Furthermore, in step B4, the ratio of intermediate product C to bromoethane is 5g:5ml.

[0015] The antibacterial agent prepared by this invention possesses hydrophilic properties due to the condensation of sodium sulfonate groups and cyanuric chloride. Unmodified PP material is strongly hydrophobic, while the hydrophilic antibacterial agent adsorbs moisture from the environment, forming conductive channels that help dissipate accumulated static charge on the surface and improve the antistatic properties of the PP material. Simultaneously, it combines with a positively charged quaternary ammonium salt, which strongly adsorbs onto the negatively charged bacterial cell membrane through electrostatic interactions. The hydrophobic tail inserts and disrupts the integrity of the lipid bilayer. Triclosan more easily penetrates the cell interior, disrupting cell wall permeability, leading to significant leakage of cell contents or infiltration of harmful substances, ultimately causing microbial death. Furthermore, the unsaturated double bonds graft this synergistic antibacterial agent onto the polypropylene material through a copolymerization reaction, giving the material good and long-lasting antibacterial properties.

[0016] The beneficial effects of this invention are: 1. The antibacterial agent prepared by this invention contains water-soluble groups, which facilitates storage; it also contains quaternary ammonium salt groups and triclosan structure, which can disrupt the permeability of bacterial cell membranes, leading to bacterial death; and it contains unsaturated double bond structure, which can copolymerize and graft the antibacterial agent onto polypropylene materials, giving the materials better durable antibacterial properties.

[0017] 2. This invention modifies natural rubber on the surface of talc to obtain an inorganic modified filler. Natural rubber forms a transitional structure between talc and polypropylene, effectively improving their interfacial compatibility and allowing talc to fully exert its reinforcing effect as an inorganic filler, achieving stress dispersion and load transfer. Simultaneously, the high flexibility of the natural rubber molecular chains significantly toughens the polypropylene matrix, further enhancing the mechanical strength of the composite material. Detailed Implementation

[0018] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] Example 1 The antibacterial agent is prepared through the following steps: Step B1: In a three-necked flask equipped with a stirrer, condenser, and thermometer, add 60g of triclosan and 150ml of carbon tetrachloride. Cool the reactants to 0°C using an ice-water bath. Add 15ml of chlorosulfonic acid dropwise while stirring. Remove the ice-water bath and heat to 20°C for 2-4 hours. Reheat the reactants under reflux for 1 hour. Cool the reaction product to 20°C, dilute with distilled water, and separate the carbon tetrachloride layer and the aqueous layer. Neutralize the organic layer with 30% sodium hydroxide solution and wash with water to remove the solvent, obtaining intermediate product A. Step B2: In a three-necked flask equipped with a stirrer, condenser, and thermometer, and with argon gas purging to remove air interference, 15g of intermediate product A and 0.5g of 4-dimethylaminopyridine are dissolved in 30ml of anhydrous dichloromethane and cooled to 0°C in an ice bath. 6g of triethylamine is slowly added, and while stirring, 10ml of anhydrous dichloromethane solution containing 10g of 10-undecenoyl chloride is slowly added dropwise, maintaining the temperature below 5°C. After the addition is complete, the mixture is brought to room temperature and reacted overnight to obtain intermediate product B. Step B3: In a three-necked flask equipped with a stirrer, condenser, and thermometer, add 10g of intermediate product B and 60ml of anhydrous ethanol, and add 1.5g of sodium hydroxide; under stirring, slowly add 5ml of 40% dimethylamine aqueous solution to the reaction flask, heat to 70℃ and reflux, and react for 12h under stirring; after the reaction is complete, cool to room temperature, pour the reaction solution into ice water, precipitate the solid, filter, and wash thoroughly with water to obtain intermediate product C; Step B4: In a three-necked flask equipped with a stirrer, condenser, and thermometer, add 5g of intermediate product C and 20ml of anhydrous ethanol. Place the apparatus in an ice-water bath and add 5ml of bromoethane dropwise while stirring. After the addition is complete, remove the ice-water bath, raise the temperature to room temperature, and continue stirring for 10 hours. After the reaction is complete, filter the solid and wash it with diethyl ether. Place the solid product in a vacuum drying oven and dry it at 40°C for 12 hours to obtain the final product, the antibacterial agent.

[0020] Example 2 The antibacterial agent is prepared through the following steps: Step B1: In a three-necked flask equipped with a stirrer, condenser, and thermometer, add 120g of triclosan and 300ml of carbon tetrachloride. Cool the reactants to 0°C using an ice-water bath. Add 30ml of chlorosulfonic acid dropwise while stirring. Remove the ice-water bath and heat to 20°C for 2-4 hours. Reheat the reactants under reflux for 1 hour. Cool the reaction product to 20°C, dilute with distilled water, and separate the carbon tetrachloride layer and the aqueous layer. Neutralize the organic layer with 30% sodium hydroxide solution and wash with water to remove the solvent, obtaining intermediate product A. Step B2: In a three-necked flask equipped with a stirrer, condenser, and thermometer, and with argon gas purging to remove air interference, dissolve 30g of intermediate product A and 1g of 4-dimethylaminopyridine in 60ml of anhydrous dichloromethane and cool to 0°C in an ice bath. Slowly add 12g of triethylamine, and while stirring, slowly add 20ml of anhydrous dichloromethane solution containing 20g of 10-undecenoyl chloride, keeping the temperature below 5°C. After the addition is complete, raise the temperature to room temperature and react overnight to obtain intermediate product B. Step B3: In a three-necked flask equipped with a stirrer, condenser, and thermometer, add 20g of intermediate product B and 120ml of anhydrous ethanol, and add 3g of sodium hydroxide; under stirring, slowly add 10ml of 40% dimethylamine aqueous solution to the reaction flask, heat to 70℃ and reflux, and react for 12h under stirring; after the reaction is complete, cool to room temperature, pour the reaction solution into ice water, precipitate the solid, filter, and wash thoroughly with water to obtain intermediate product C; Step B4: In a three-necked flask equipped with a stirrer, condenser, and thermometer, add 10g of intermediate product C and 40ml of anhydrous ethanol. Place the apparatus in an ice-water bath and add 10ml of bromoethane dropwise while stirring. After the addition is complete, remove the ice-water bath, raise the temperature to room temperature, and continue stirring for 10 hours. After the reaction is complete, filter the solid and wash it with diethyl ether. Place the solid product in a vacuum drying oven and dry it at 40°C for 12 hours to obtain the final product, the antibacterial agent.

[0021] Example 3 Modified inorganic fillers are prepared through the following steps: 3.5g of talc powder was ultrasonically dispersed in 20ml of N,N-dimethylformamide to form a uniform dispersion. Then, 5g of epoxidized natural rubber was added to the dispersion, along with 0.01g of stannous chloride. Heating was started and the temperature was controlled at 130℃. After continuous stirring and maintaining the temperature for 6 hours, heating was stopped, the material was cooled and discharged, and the solid material was centrifuged. After washing and vacuum drying, the inorganic modified filler was obtained.

[0022] Example 4 65 parts of polypropylene, 15 parts of EPDM rubber, 5 parts of the antibacterial agent prepared in Example 1, 3 parts of the inorganic modified filler prepared in Example 3, 1 part of zinc stearate, 0.5 parts of antioxidant 2,6-di-tert-butyl-p-cresol, and 0.5 parts of initiator dicumyl peroxide were added to a high-speed mixer and mechanically mixed evenly. The mixture was then fed into a twin-screw extruder through a feed hopper. The temperatures of each zone of the extruder were controlled sequentially as follows: 200±5℃, 210±5℃, 220±5℃, 220±5℃, 210±5℃, and 210±5℃. The screw speed was 50-60 rpm. The antibacterial modified PP material was obtained through melt extrusion.

[0023] Example 5 68 parts of polypropylene, 18 parts of EPDM rubber, 8 parts of the antibacterial agent prepared in Example 1, 4 parts of the inorganic modified filler prepared in Example 3, 2 parts of zinc stearate, 0.75 parts of antioxidant 2,6-di-tert-butyl-p-cresol, and 0.6 parts of initiator dicumyl peroxide were added to a high-speed mixer and mechanically mixed evenly. The mixture was then fed into a twin-screw extruder through a feed hopper. The temperatures of each zone of the extruder were controlled sequentially as 200±5℃, 210±5℃, 220±5℃, 220±5℃, 210±5℃, and 210±5℃, and the screw speed was 50-60 rpm. The antibacterial modified PP material was obtained through melt extrusion.

[0024] Example 6 70 parts of polypropylene, 20 parts of EPDM rubber, 10 parts of the antibacterial agent prepared in Example 1, 5 parts of the inorganic modified filler prepared in Example 3, 3 parts of zinc stearate, 1.5 parts of antioxidant 2,6-di-tert-butyl-p-cresol, and 0.8 parts of initiator dicumyl peroxide were added to a high-speed mixer and mechanically mixed evenly. The mixture was then fed into a twin-screw extruder through a feed hopper. The temperatures of each zone of the extruder were controlled sequentially as 200±5℃, 210±5℃, 220±5℃, 220±5℃, 210±5℃, and 210±5℃, and the screw speed was 50-60 rpm. The antibacterial modified PP material was obtained through melt extrusion.

[0025] Comparative Example 1 The multi-effect antibacterial agent in Example 6 was replaced with a commercially available antibacterial agent of equal quality, and the remaining steps were the same as in Example 5.

[0026] Comparative Example 2 No antibacterial agent was added; the remaining steps were the same as in Example 6.

[0027] Comparative Example 3 Without adding inorganic modified fillers, the remaining steps are the same as in Example 6.

[0028] The tensile properties of the samples were determined by placing them in an environment of 180℃ in accordance with the national standard GB / T 1040-2006 "Determination of tensile properties of plastics". The antibacterial properties of plastic surfaces were tested using the national standard GB / T 31402-2015 "Test Method for Antibacterial Properties of Plastic Surfaces" and the film coating method. The method is as follows: Escherichia coli or Staphylococcus aureus bacteria were inoculated onto agar plates, covered and preserved for 24 hours, and then viable bacteria were cultured. The results of parallel experiments with empty samples were compared to obtain the antibacterial rate of the samples. Using the same testing standards, the antibacterial rate of the samples was determined after being placed at room temperature for 180 days.

[0029] As can be seen from the table above, the PP materials prepared in Examples 4, 5, and 6 of this invention have better mechanical strength and excellent antibacterial properties compared with those prepared in Comparative Examples 1, 2, and 3, and have important application value in the field of antibacterial PP materials technology.

[0030] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] The above description is merely an example and illustration of the present invention. Any modifications or additions made by those skilled in the art to the specific embodiments described, or any substitutions made in a similar manner, should fall within the protection scope of the present invention.

Claims

1. A method for preparing an antibacterial modified PP material, characterized in that, Includes the following steps: Polypropylene, EPDM rubber, antibacterial agent, inorganic modified filler, zinc stearate, antioxidant 2,6-di-tert-butyl-p-cresol, and initiator dicumyl peroxide are added to a high-speed mixer and mechanically mixed evenly. The mixture is then fed into a twin-screw extruder through a feed hopper and melt extruded to obtain antibacterial modified PP material.

2. The method for preparing an antibacterial modified PP material according to claim 1, characterized in that, The temperatures of each zone of the extruder are controlled sequentially as follows: 200±5℃, 210±5℃, 220±5℃, 220±5℃, 210±5℃, and 210±5℃, with the screw speed at 50-60 rpm.

3. The method for preparing an antibacterial modified PP material according to claim 1, characterized in that, The antibacterial modified PP material is prepared from the following components in parts by weight: 65-70 parts polypropylene, 15-20 parts EPDM rubber, 5-10 parts antibacterial agent, 3-5 parts inorganic modified filler, 1-3 parts zinc stearate, 0.5-1.5 parts antioxidant 2,6-di-tert-butyl-p-cresol, and 0.5-0.8 parts initiator dicumyl peroxide.

4. The method for preparing an antibacterial modified PP material according to claim 1, characterized in that, The antibacterial agent is prepared by the following steps: Step B1: Add triclosan and carbon tetrachloride to a three-necked flask and cool to 0-5°C; add chlorosulfonic acid dropwise with stirring, heat to react for 2-4 hours, and then heat under reflux for 1 hour; after cooling the reaction, dilute and separate the layers; neutralize the organic layer with 30% sodium hydroxide solution and wash with water to obtain intermediate product A; Step B2: In a three-necked flask, argon gas is passed through to eliminate air interference. Intermediate product A and 4-dimethylaminopyridine are dissolved in anhydrous dichloromethane and cooled to 0°C in an ice bath. Triethylamine is added, and a solution of 10-undecenoyl chloride in anhydrous dichloromethane is added dropwise with stirring. After the addition is complete, the mixture is brought to room temperature and reacted overnight to obtain intermediate product B. Step B3: Add intermediate product B and anhydrous ethanol to a three-necked flask, and add a small amount of sodium hydroxide; slowly add 40% dimethylamine aqueous solution to the reaction flask under stirring, heat to reflux, and react for 12 hours under stirring; after the reaction is completed, cool to room temperature, precipitate solid with ice water, filter, and wash with water to obtain intermediate product C. Step B4: Add intermediate product C and anhydrous ethanol to a three-necked flask, place the apparatus in an ice-water bath, and add bromoethane dropwise while stirring. After the addition is complete, raise the temperature to room temperature and stir for 10-12 hours. After the reaction is complete, filter, wash, and vacuum dry to obtain the final product, the antibacterial agent.

5. The method for preparing an antibacterial modified PP material according to claim 4, characterized in that, In step B1, the ratio of triclosan to chlorosulfonic acid is 60g:15ml.

6. The method for preparing an antibacterial modified PP material according to claim 4, characterized in that, In step B2, the ratio of intermediate product A, 4-dimethylaminopyridine, triethylamine, and 10-undecenoyl chloride is 15g:0.5g:6g:10g.

7. The method for preparing an antibacterial modified PP material according to claim 4, characterized in that, In step B3, the ratio of intermediate product B, sodium hydroxide, and 40% dimethylamine aqueous solution is 10g:1.5g:5ml.

8. The method for preparing an antibacterial modified PP material according to claim 4, characterized in that, In step B4, the ratio of intermediate product C to bromoethane is 5g:5ml.

9. An antibacterial modified PP material, characterized in that, Prepared according to the method according to any one of claims 1-8.

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