High-performance antibacterial PP plate and preparation method thereof

Abstract

The invention relates to a high-performance antibacterial PP plate and a preparation method thereof, and belongs to the technical field of high polymer materials. The high-performance antibacterial PP board comprises the following components in parts by weight: 60-80 parts of PP resin, 1-4 parts of a dispersing agent, 0.5-1.5 parts of a modified antibacterial agent, 2-6 parts of a modified flame retardant and 0.1-0.5 part of an antioxidant, nano-zinc oxide in the modified antibacterial agent is excited to have strong oxidizing property under ultraviolet light, destroys cell membranes, releases zinc ions to be combined with proteins and interferes bacterial enzyme activity, quaternary ammonium salt groups destroy cell membrane structures, and the quaternary ammonium salt groups and chitosan cooperate to destroy cell wall structures and permeate into the interior to inhibit bacterial activity; boron-based components in the modified flame retardant are heated to dehydrate, carbon formation is accelerated, a glassy protective layer is formed, a Si-O-B structure is constructed, incombustible gas is released, heat and oxygen are insulated, and the modified flame retardant and phosphorus-oxygen double bonds are synergistically flame-retardant; the high-performance antibacterial PP board prepared by the invention not only has a good antibacterial effect, but also has an excellent flame-retardant effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a high-performance antibacterial PP sheet and a preparation method thereof. Background Art

[0002] Polypropylene (PP material), as a semi-crystalline thermoplastic with wide sources and low prices, has been widely used in many fields such as food packaging, medical devices, and household appliances due to its excellent mechanical properties, chemical corrosion resistance, and thermal stability.

[0003] However, with the improvement of living quality and the enhancement of health and safety, people pay more and more attention to disease prevention and hygiene protection. Due to the lack of antibacterial properties, a large number of harmful pathogenic bacteria are likely to grow on the surface of traditional PP sheets during long-term use. This not only causes irritation to human skin and leads to various skin problems, but also makes it difficult to clean the products, shortens the service life, and increases the consumption of resources. At the same time, PP sheets are derived from petrochemical materials, and their characteristics of being composed of carbon and hydrogen elements make them flammable and prone to causing fires. These problems have restricted the wider application of PP sheets. Therefore, it is of great practical significance and application value to develop high-performance antibacterial PP sheets with excellent properties. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a high-performance antibacterial PP sheet and a preparation method thereof.

[0005] The object of the present invention can be achieved by the following technical solutions: A high-performance antibacterial PP sheet and a preparation method thereof, comprising the following raw materials in parts by weight: 60 - 80 parts of PP resin, 1 - 4 parts of dispersant, 0.5 - 1.5 parts of modified antibacterial agent, 2 - 6 parts of modified flame retardant, and 0.1 - 0.5 parts of antioxidant; The dispersant is polyvinylpyrrolidone; The antioxidant is antioxidant 1098.

[0006] The modified antibacterial agent is prepared by the following method: Step A1: Chitosan and NaOH solution are stirred at room temperature for 3 h, frozen at -10°C for 24 h, thawed, dried, 2,3-epoxypropyltrimethylammonium chloride and ethanol are added, heated to 60°C, and reacted for 6 h, and then filtered to obtain a compound; Furthermore, the dosage ratio of chitosan, NaOH solution, 2,3-epoxypropyltrimethylammonium chloride, and ethanol is 0.01 - 0.02 mol: 15 mL: 0.01 - 0.02 mol: 20 mL, and the mass fraction of the NaOH solution is 50%; Secondly, the compound is prepared by reacting the hydroxyl group of chitosan with the epoxy group of 2,3-epoxypropyltrimethylammonium chloride; Step A2: Pre-dry the nano-zinc oxide in a vacuum drying oven, add an ethanol-water mixed solution and mix, perform ultrasonic fragmentation treatment for 30 min, stir at 1000 r / min for 1 h, then slowly add 3-(methacryloyloxy)propyltrimethoxysilane and absolute ethanol, and react at 60 °C for 2 h. Wash, centrifuge, and vacuum dry to obtain a pre-product; Furthermore, the dosage ratio of nano-zinc oxide, ethanol-water mixed solution, 3-(methacryloyloxy)propyltrimethoxysilane, and absolute ethanol is 0.03 - 0.06 mol: 15 mL: 0.08 - 0.16 mol: 20 mL, and the volume ratio of ethanol to deionized water in the ethanol-water mixed solution is 4:1; Secondly, the pre-product is prepared by hydrolyzing the siloxy group of 3-(methacryloyloxy)propyltrimethoxysilane into silanol groups and reacting with the hydroxyl groups on the surface of nano-zinc oxide; Step A3: Mix the compound and acetic acid ethanol, stir for 30 min, then add ammonium cerium nitrate, stir at 60 °C for 30 min, then add the pre-product, and react for 24 h. Wash and dry to obtain the modified antibacterial agent; Furthermore, the dosage ratio of the compound, acetic acid ethanol, ammonium cerium nitrate, and pre-product is 0.01 - 0.02 mol: 7 mL: 0.2 g: 0.01 - 0.02 mol, and the mass fraction of acetic acid ethanol is 1%; Finally, the modified antibacterial agent is prepared by reacting the amino group of the compound with the carbon-carbon double bond of the pre-product.

[0007] The modified flame retardant is prepared by the following method: Step B1: Mix 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and tetrahydrofuran evenly, then add azobisisobutyronitrile and methylvinyldimethoxysilane, and react at 65 °C for 24 h under nitrogen protection. Perform vacuum distillation and vacuum dry for 8 h to obtain an intermediate; Furthermore, the dosage ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tetrahydrofuran, azobisisobutyronitrile, and methylvinyldimethoxysilane is 0.01 - 0.03 mol: 20 - 50 mL: 0.16 g: 0.01 - 0.03 mol; First, an intermediate is synthesized by reacting the carbon-carbon double bond of methylvinyldimethoxysilane with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; Step B2: Mix the intermediate, phenylboronic acid, and tetrahydrofuran, and add hydrochloric acid with pH = 1. React at 70 °C for 12 h, then perform vacuum distillation, wash, and vacuum dry to obtain the modified flame retardant; Furthermore, the dosage ratio of the intermediate, phenylboronic acid, tetrahydrofuran, and hydrochloric acid is 0.01 - 0.02 mol : 0.01 - 0.02 mol : 5 - 10 mL : 2 mL; Finally, the modified flame retardant is prepared by reacting the hydrolyzed silanol groups of the intermediate with the hydroxyl groups of phenylboronic acid.

[0008] A preparation method of a high - performance antibacterial PP sheet specifically includes the following steps: S1. Mix the PP resin, dispersant, modified antibacterial agent, modified flame retardant, and antioxidant evenly to obtain a mixed material; S2: Extrude and pelletize the mixed material through a twin - screw extruder, control the screw speed at 200 - 500 r / min, and injection - mold it through an injection - molding machine to obtain a high - performance antibacterial PP sheet.

[0009] The beneficial effects of the present invention: The high - performance antibacterial PP sheet of the present invention has a good antibacterial effect, and at the same time, has excellent flame - retardant effect, which prolongs the service life.

[0010] In the modified antibacterial agent prepared by the present invention, nano - zinc oxide is excited under ultraviolet light to generate strong oxidizing properties, producing H2O2 and reactive oxygen species, which destroy the bacterial cell membrane and inhibit its growth and reproduction. At the same time, the released zinc ions can bind to the proteins on the bacterial cell membrane, destroy the cell membrane structure, cause the outflow of cell contents, and interfere with the metabolic enzyme activity of bacteria, leading to protein denaturation in bacteria and further inhibiting bacterial growth. In addition, nano - zinc oxide has good compatibility with the PP matrix, which can improve the tensile strength of the material and increase the heat distortion temperature of the PP sheet, delaying the degradation of the material at high temperatures; furthermore, 2,3 - epoxypropyltrimethylammonium chloride introduces quaternary ammonium cationic groups, which can destroy the structure of the bacterial cell membrane, resulting in protein leakage, accelerating bacterial death, and enhancing the antibacterial effect. And it synergistically acts with chitosan, can firmly adsorb on the negatively charged bacterial cell wall, destroy the cell wall structure and penetrate into the interior, causing the cell wall to rupture or form pores, thereby inhibiting bacterial activities and significantly enhancing the bactericidal effect. The modified flame retardant prepared by the present invention, through the synergistic effect of boron and phosphorus, not only improves the stability but also effectively reduces the generation of smoke. In the initial stage of combustion, the boron-based component is dehydrated by heat, accelerating carbonization and forming a glassy protective layer to prevent the spread of combustion. An Si-O-B vitreous structure is constructed on the surface of the carbon layer to further enhance the flame retardancy. At the same time, non-combustible gases are released to expand the carbon layer, forming a heat-insulating and oxygen-barrier, significantly improving the flame retardant performance. In addition, the phosphorus-nitrogen flame retardant 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, as a phosphaphenanthrene compound with high thermal stability, promotes the formation of a dense and continuous carbon layer during combustion, further isolating oxygen and heat exchange, and synergistically retarding fire with the phosphorus-oxygen double bond to extend its service life. Moreover, the modified flame retardant prepared by the present invention is halogen-free, which helps to reduce environmental pollution and damage to the ecosystem, is harmless to human health, and achieves sustainable development. Detailed implementation manners

[0011] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without any creative work shall fall within the protection scope of the present invention.

[0012] Example 1: A preparation method of a high-performance antibacterial PP sheet, specifically including the following steps: S1. Weigh the raw materials by weight: 60 parts of PP resin, 1 part of dispersant, 0.5 part of modified antibacterial agent (prepared in this example), 2 parts of modified flame retardant (prepared in this example), and 0.1 part of antioxidant; mix the PP resin, polyvinylpyrrolidone, modified antibacterial agent, modified flame retardant, and antioxidant evenly to obtain a mixed material. S2: Extrude and pelletize the mixed material through a twin-screw extruder, control the screw speed at 200 r / min, and inject and mold it through an injection molding machine to obtain a high-performance antibacterial PP sheet. The modified antibacterial agent is prepared by the following method: Step A1: Mix 0.01 mol of chitosan and 15 mL of NaOH solution, stir at room temperature for 3 h, freeze at -10 °C for 24 h, thaw, dry, add 0.01 mol of 2,3-epoxypropyltrimethylammonium chloride and 20 mL of ethanol, heat to 60 °C, react for 6 h, and filter to obtain a compound. The mass fraction of the NaOH solution is 50%. Step A2: Pre-dry 0.03 mol of nano-zinc oxide in a vacuum drying oven, add 15 mL of ethanol-water mixed solution and mix. Perform ultrasonic fragmentation treatment for 30 min, stir at 1000 r / min for 1 h, then slowly add 0.08 mol of 3-(methacryloyloxy)propyltrimethoxysilane and 20 mL of absolute ethanol, and react at 60 °C for 2 h. Wash, centrifuge, and vacuum dry to obtain a pre-product. The volume ratio of ethanol to deionized water in the ethanol-water mixed solution is 4:1; Step A3: Mix 0.01 mol of the compound with 7 mL of acetic acid ethanol and stir for 30 min. Then add 0.2 g of ammonium cerium nitrate, stir at 60 °C for 30 min, and then add 0.01 mol of the pre-product and react for 24 h. Wash and dry to obtain the modified antibacterial agent. The mass fraction of acetic acid ethanol is 1%; The modified flame retardant is prepared by the following method: Step B1: Mix 0.01 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with 20 mL of tetrahydrofuran uniformly, then add 0.16 g of azobisisobutyronitrile and 0.01 mol of methylvinyldimethoxysilane. Under nitrogen protection, react at 65 °C for 24 h, perform reduced pressure distillation, and vacuum dry for 8 h to obtain an intermediate; Step B2: Mix 0.01 mol of the intermediate, 0.01 mol of phenylboronic acid and 5 mL of tetrahydrofuran, and add 2 mL of hydrochloric acid with pH = 1. React at 70 °C for 12 h, then perform reduced pressure distillation, wash, and vacuum dry to obtain the modified flame retardant.

[0013] Example 2: A preparation method of a high-performance antibacterial PP sheet, specifically including the following steps: S1. Weigh the raw materials by weight parts: 70 parts of PP resin, 2.5 parts of dispersant, 1 part of modified antibacterial agent (prepared in this example), 4 parts of modified flame retardant (prepared in this example), and 0.4 part of antioxidant; Mix the PP resin, polyvinylpyrrolidone, modified antibacterial agent, modified flame retardant, and antioxidant 1098 uniformly to obtain a mixed material; S2: Extrude and pelletize the mixed material through a twin-screw extruder, control the screw speed at 350 r / min, and inject and mold through an injection molding machine to obtain a high-performance antibacterial PP sheet; The modified antibacterial agent is prepared by the following method: Step A1: Mix 0.015 mol of chitosan with 15 mL of NaOH solution, stir at room temperature for 3 h, freeze at -10 °C for 24 h, thaw, dry, add 0.015 mol of 2,3-epoxypropyltrimethylammonium chloride and 20 mL of ethanol, heat to 60 °C, react for 6 h, and filter to obtain a compound. The mass fraction of the NaOH solution is 50%; Step A2: Pre-dry 0.045 mol of nano-zinc oxide in a vacuum drying oven, add 15 mL of ethanol-water mixed solution and mix. Perform ultrasonic fragmentation treatment for 30 min, stir at 1000 r / min for 1 h, then slowly add 0.12 mol of 3-(methacryloyloxy)propyltrimethoxysilane and 20 mL of absolute ethanol, and react at 60 °C for 2 h. Wash, centrifuge, and vacuum dry to obtain a pre-product. The volume ratio of ethanol to deionized water in the ethanol-water mixed solution is 4:1; Step A3: Mix 0.015 mol of the compound with 7 mL of acetic acid ethanol and stir for 30 min. Then add 0.2 g of ammonium cerium nitrate, stir at 60 °C for 30 min, and then add 0.015 mol of the pre-product and react for 24 h. Wash and dry to obtain the modified antibacterial agent. The mass fraction of acetic acid ethanol is 1%; The modified flame retardant is prepared by the following method: Step B1: Mix 0.02 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with 35 mL of tetrahydrofuran evenly, then add 0.16 g of azobisisobutyronitrile and 0.02 mol of methylvinyldimethoxysilane. Under nitrogen protection, react at 65 °C for 24 h, perform reduced pressure distillation, and vacuum dry for 8 h to obtain an intermediate; Step B2: Mix 0.015 mol of the intermediate, 0.015 mol of phenylboronic acid and 7.5 mL of tetrahydrofuran, and add 2 mL of hydrochloric acid with pH = 1. React at 70 °C for 12 h, then perform reduced pressure distillation, wash, and vacuum dry to obtain the modified flame retardant.

[0014] Example 3: A preparation method of a high-performance antibacterial PP sheet, specifically including the following steps: S1. Weigh the raw materials by weight parts: 80 parts of PP resin, 4 parts of dispersant, 1.5 parts of modified antibacterial agent (prepared in this example), 6 parts of modified flame retardant (prepared in this example), and 0.5 part of antioxidant; Mix the PP resin, polyvinylpyrrolidone, modified antibacterial agent, modified flame retardant, and antioxidant 1098 evenly to obtain a mixed material; S2: Extrude and pelletize the mixed material through a twin-screw extruder, control the screw speed at 500 r / min, and inject and mold through an injection molding machine to obtain a high-performance antibacterial PP sheet; The modified antibacterial agent is prepared by the following method: Step A1: Mix 0.02 mol of chitosan with 15 mL of NaOH solution, stir at room temperature for 3 h, freeze at -10 °C for 24 h, thaw, dry, add 0.02 mol of 2,3-epoxypropyltrimethylammonium chloride and 20 mL of ethanol, heat to 60 °C, react for 6 h, and filter to obtain a compound. The mass fraction of the NaOH solution is 50%; Step A2: Pre-dry 0.06 mol of nano-zinc oxide in a vacuum drying oven, add 15 mL of ethanol-water mixed solution and mix, perform ultrasonic fragmentation treatment for 30 min, stir at 1000 r / min for 1 h, then slowly dropwise add 0.16 mol of 3-(methacryloyloxy)propyltrimethoxysilane and 20 mL of absolute ethanol, react at 60 °C for 2 h, wash, centrifuge, and vacuum dry to obtain a pre-product. The volume ratio of ethanol to deionized water in the ethanol-water mixed solution is 4:1; Step A3: Mix 0.02 mol of the compound with 7 mL of acetic acid ethanol and stir for 30 min, then add 0.2 g of ammonium cerium nitrate, stir at 60 °C for 30 min, then add 0.02 mol of the pre-product, react for 24 h, wash, and dry to obtain the modified antibacterial agent. The mass fraction of acetic acid ethanol is 1%; The modified flame retardant is prepared by the following method: Step B1: Mix 0.03 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with 50 mL of tetrahydrofuran evenly, then add 0.16 g of azobisisobutyronitrile and 0.03 mol of methylvinyldimethoxysilane, react at 65 °C for 24 h under nitrogen protection, perform vacuum distillation, and vacuum dry for 8 h to obtain an intermediate; Step B2: Mix 0.02 mol of the intermediate, 0.02 mol of phenylboronic acid and 10 mL of tetrahydrofuran, add 2 mL of hydrochloric acid with pH = 1, react at 70 °C for 12 h, then perform vacuum distillation, wash, and vacuum dry to obtain the modified flame retardant.

[0015] Comparative Example 1: This comparative example is a high-performance antibacterial PP sheet. The difference from Example 3 is that an equal amount of silver ion antibacterial agent is used instead of the modified antibacterial agent prepared in Example 3, and the rest are the same.

[0016] Comparative Example 2: This comparative example is a high-performance antibacterial PP sheet. The difference from Example 3 is that an equal amount of magnesium hydroxide is used instead of the modified flame retardant prepared in Example 3, and the rest are the same.

[0017] Performance test: Cut the high-performance antibacterial PP sheets prepared in Examples 1-3 and Comparative Examples 1-2 into standard test sizes, use the film pasting method according to the standard QB / T2591-2008, and measure the total number of colonies according to the standard GB / T4789.2-2003. Make the high-performance antibacterial PP sheets into 50 mm x 50 mm. The calculation formula for the antibacterial rate is as follows: R(%)=(B - C) / B x 100 Where: R - antibacterial rate, %: B - average number of recovered bacteria in the blank control sample, cfu / sheet; C - average number of recovered bacteria in the antibacterial plastic sample, cfu / sheet; The vertical burning performance was tested by the test method for burning performance of plastics in GB / T 2048-1996; the tensile strength was tested in accordance with ASTM D-638; the test results are shown in Table 1 below: Table 1

[0018] It can be seen from the data tested in Table 1 that the high-performance antibacterial PP sheet prepared by the present invention has good antibacterial effects. It can also be seen from Table 1 that the high-performance antibacterial PP sheet prepared by the present invention has good flame retardant and tensile strength effects, and the service life is extended.

[0019] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they should fall within the protection scope of the present invention.

Claims

1. A preparation method of a high-performance antibacterial PP sheet, characterized in that, Specifically, it includes the following steps: S1. Weigh the raw materials by weight parts: 60 - 80 parts of PP resin, 1 - 4 parts of dispersant, 0.5 - 1.5 parts of modified antibacterial agent, 2 - 6 parts of modified flame retardant, and 0.1 - 0.5 parts of antioxidant; mix the PP resin, dispersant, modified antibacterial agent, modified flame retardant, and antioxidant evenly to obtain a mixed material; S2: Extrude and pelletize the mixed material through a twin - screw extruder, control the screw speed at 200 - 500 r / min, and inject - mold it through an injection - molding machine to obtain a high - performance antibacterial PP sheet; The modified antibacterial agent is prepared by the following method: Step A1: Mix chitosan and NaOH solution, stir at room temperature for 3 h, freeze at - 10 °C for 24 h, thaw, dry, add 2,3 - epoxypropyltrimethylammonium chloride and ethanol, heat to 60 °C, react for 6 h, filter to obtain a compound; Step A2: Pre - dry nano - zinc oxide in a vacuum drying oven, add an ethanol - water mixed solution to mix, perform ultrasonic fragmentation treatment for 30 min, stir at 1000 r / min for 1 h, then slowly dropwise add 3 - (methacryloyloxy)propyltrimethoxysilane and absolute ethanol, react at 60 °C for 2 h, wash, centrifuge, and vacuum - dry to obtain a pre - product; Step A3: Mix the compound and acetic acid ethanol, stir for 30 min, then add ammonium cerium(IV) nitrate, stir at 60 °C for 30 min, then add the pre - product, react for 24 h, wash, and dry to obtain the modified antibacterial agent.

2. The preparation method of a high-performance antibacterial PP sheet according to claim 1, characterized in that, In Step A1, the dosage ratio of chitosan, NaOH solution, 2,3 - epoxypropyltrimethylammonium chloride, and ethanol is 0.01 - 0.02 mol: 15 mL: 0.01 - 0.02 mol: 20 mL, and the mass fraction of the NaOH solution is 50%.

3. The preparation method of a high-performance antibacterial PP sheet according to claim 1, characterized in that, In Step A2, the dosage ratio of nano - zinc oxide, ethanol - water mixed solution, 3 - (methacryloyloxy)propyltrimethoxysilane, and absolute ethanol is 0.03 - 0.06 mol: 15 mL: 0.08 - 0.16 mol: 20 mL, and the volume ratio of ethanol to deionized water in the ethanol - water mixed solution is 4:

1.

4. The preparation method of a high-performance antibacterial PP sheet according to claim 1, characterized in that, In Step A3, the dosage ratio of the compound, acetic acid ethanol, ammonium cerium(IV) nitrate, and pre - product is 0.01 - 0.02 mol: 7 mL: 0.2 g: 0.01 - 0.02 mol, and the mass fraction of acetic acid ethanol is 1%.

5. The preparation method of a high-performance antibacterial PP sheet according to claim 1, characterized in that The modified flame retardant is prepared by the following method: Step B1: Mix 9,10 - dihydro - 9 - oxa - 10 - phosphaphenanthrene - 10 - oxide and tetrahydrofuran evenly, then add azobisisobutyronitrile and methylvinyldimethoxysilane, react at 65 °C for 24 h under nitrogen protection, perform vacuum distillation, and vacuum - dry for 8 h to obtain an intermediate; Step B2: Mix the intermediate, phenylboronic acid, and tetrahydrofuran, and add hydrochloric acid with pH = 1, react at 70 °C for 12 h, then perform vacuum distillation, wash, and vacuum - dry to obtain the modified flame retardant.

6. The preparation method of a high-performance antibacterial PP sheet according to claim 5, characterized in that, In step B1, the dosage ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tetrahydrofuran, azobisisobutyronitrile, and methylvinyldimethoxysilane is 0.01 - 0.03 mol : 20 - 50 mL : 0.16 g : 0.01 - 0.03 mol.

7. The preparation method of a high-performance antibacterial PP sheet according to claim 5, characterized in that, In step B2, the dosage ratio of the intermediate, phenylboronic acid, tetrahydrofuran, and hydrochloric acid is 0.01 - 0.02 mol : 0.01 - 0.02 mol : 5 - 10 mL : 2 mL.

8. The preparation method of a high-performance antibacterial PP sheet according to claim 1, characterized in that, The dispersant is polyvinylpyrrolidone, and the antioxidant is antioxidant 1098.

9. A high-performance antibacterial PP sheet, characterized in that, Prepared according to the preparation method described in any one of claims 1 - 8.

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