Antibacterial and durable plastics and their manufacturing process

Abstract

This invention relates to antibacterial and durable plastics and their preparation process, belonging to the field of plastic preparation technology. The raw materials for the antibacterial and durable plastic provided by this invention include composite materials, maleic anhydride-grafted polypropylene, modified fillers, antibacterial agents, modified softeners, antioxidants, and UV stabilizers. Through the synergistic interaction of these components, an antibacterial and durable plastic is provided.

Description

Technical Field

[0001] This invention belongs to the field of plastic preparation technology, and relates to antibacterial and durable plastics and their preparation processes. Background Technology

[0002] In modern healthcare systems, plastic materials are widely used due to their lightweight, ease of processing, and cost-effectiveness. They not only reduce the burden of transportation and handling, but also provide quick and convenient services to patients, especially in cases of patient mobility impairment or emergencies, thereby improving the efficiency of clinical care. They are commonly found in medical kits, bedpans, urinals, medical casings, and medical gloves.

[0003] Although the widespread use of plastics in medical devices has brought many conveniences, its application still has shortcomings. First, plastic products have low strength and are easily damaged during use. After damage, they often become a large amount of medical waste, which can cause serious environmental pollution if not handled properly. In addition, bacteria can easily grow on plastic surfaces, especially in high-pathogen environments such as hospitals, which can pose a threat to patients' health. Summary of the Invention

[0004] The purpose of this invention is to provide an antibacterial and durable plastic and its preparation process. This invention provides an antibacterial and durable plastic through the synergistic interaction between its components.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] Antibacterial and durable plastic, wherein the antibacterial and durable plastic comprises the following raw materials in parts by weight: 90-110 parts composite material, 7-9 parts maleic anhydride grafted polypropylene, 23-27 parts modified filler, 3-4 parts antibacterial agent, 1.5-2.5 parts modified softener, 0.6-1 parts antioxidant and 1-2 parts UV stabilizer.

[0007] Furthermore, the composite material is composed of polypropylene, polyethylene and acrylonitrile-butadiene copolymer in a mass ratio of 2.8-3:1.9-2.1:0.8-1.

[0008] Furthermore, the modified filler is prepared by immersing glass fiber in coupling solution for 2-3 hours, then drying it in an oven at 90°C for 4 hours, and then subjecting it to plasma treatment to obtain the modified filler.

[0009] Furthermore, the raw materials of the coupling liquid include 3-7% KH-560 and the balance ethanol by mass percentage; the power and time of the plasma treatment are 80-120W and 5-15min, respectively.

[0010] Furthermore, the preparation method of the antibacterial agent is as follows: chitosan is added to the base solution at a ratio of 1:1.8-2.3 g / mL, ultrasonically treated for 2-8 min, soaked for 3-4 h, and then sodium hydroxide solution is added dropwise. After precipitation is complete, the addition is stopped to obtain the antibacterial agent.

[0011] Further, the raw materials of the base solution, by percentage, include 4-6 wt% garlic extract, 0.5-1.5 wt% tea tree extract, 1.8-3 wt% rose extract, 2.5-3.5 wt% vegetable glycerin, and the balance ethanol; the pH of the base solution is adjusted to 4-5 with 0.15-0.25 mol / L citric acid before use; the frequency and power of the ultrasonic treatment are 40-50 kHz and 200-400 W, respectively; the concentration of the sodium hydroxide solution is 0.1-0.3 mol / L.

[0012] Further, the modified softener is prepared by heating 90-110 parts by weight of epoxidized soybean oil to 120-130°C, adding 20-30 parts by weight of maleic anhydride and 1-2 parts by weight of dibutyltin dilaurate, stirring at 50-70 rpm, and when the stirring time reaches halfway, adding 0.8-1.2 wt% of nano-silica with an average particle size of 40-100 nm and 18-22 wt% of nano-titanium dioxide-supported glycyrrhizic acid, accounting for 18-22 wt% of the softener, and the total stirring time is 2-3 h. After stirring, the modified softener is obtained.

[0013] Furthermore, the preparation method of the nano-titanium dioxide loaded with glycyrrhizic acid is as follows:

[0014] In a reaction vessel, nano-titanium dioxide with an average particle size of 60-80 nm and anhydrous ethanol are mixed and stirred at 250-350 rpm for 20-30 min to obtain a nano-titanium dioxide suspension with a concentration of 9-11 wt%. Glycyrrhizic acid (8-12% by mass of nano-titanium dioxide) and ethyl silicate (4-5% by mass of nano-titanium dioxide) are added to the suspension. The ultrasonic frequency and power are set to 30-50 kHz and 300-500 W, respectively. After ultrasonication for 10-20 min, the reaction vessel is placed in a 60℃ constant temperature water bath and stirred continuously at 300-500 rpm until a gel-like product is obtained. The gel-like product is dried in an 80℃ oven for 5-6 h. After removal, it is ground into powder at 800-1200 rpm to obtain nano-titanium dioxide loaded with glycyrrhizic acid.

[0015] Furthermore, the preparation method includes the following steps:

[0016] (1) After drying the composite material, add it into a high-speed mixer, set the machine temperature to 90℃, stir at 450-550 rpm for 6-10 min, add maleic anhydride-grafted polypropylene, and stir at the same temperature and speed for 6-10 min to obtain material one.

[0017] (2) Add modified filler, antibacterial agent, modified softener, antioxidant and anti-ultraviolet agent to material 1, heat to 105-115℃, stir at 700-900rpm for 10-14min, melt and extrude, granulate to obtain antibacterial durable plastic.

[0018] Further, the drying in step (1) is to use a hot air dryer at 60-80℃ for 4-6 hours; the melting temperature in step (2) is 175-185℃; and the extrusion speed and temperature are 100-200 rpm and 195-205℃, respectively.

[0019] The beneficial effects of this invention are:

[0020] (1) This invention comprises a composite material composed of polypropylene, polyethylene, and acrylonitrile-butadiene copolymer, wherein polypropylene has high strength and heat resistance; polyethylene has good flexibility and chemical corrosion resistance; and acrylonitrile-butadiene copolymer imparts certain elasticity and toughness to the material. The three are combined in a specific mass ratio to complement each other, giving the plastic comprehensive properties.

[0021] (2) The modified filler in this invention is treated with coupling liquid and plasma to improve the interfacial compatibility of glass fiber with other materials, promote its uniform distribution, and at the same time improve the surface activity of glass fiber and enhance the bonding force, which helps to further improve the stiffness and strength of plastic. When plastic is subjected to external force, it shares part of the stress and improves the plastic's resistance to deformation and durability.

[0022] (3) The antibacterial agent of the present invention is made by soaking chitosan in a base liquid and promoting its uniform dispersion by ultrasound. Chitosan has good biocompatibility and antibacterial properties. Garlic extract contains active ingredients such as allicin, tea tree extract is rich in polyphenols and other substances, and terpenoids in rose extract have strong antibacterial effects. The combination of chitosan and various natural extracts provides a broad-spectrum antibacterial effect for plastics. Finally, the addition of sodium hydroxide solution causes chitosan to precipitate into particles, which helps to combine with other matrix materials, improves the dispersibility and uniformity of the antibacterial agent in plastics, and thus enhances the antibacterial effect.

[0023] (4) The present invention also adds a modified softener. By adding maleic anhydride, the plastic is given good flexibility, making it less prone to cracking during use. At the same time, a small amount of nano silica is introduced to improve the stability and durability of the softener. Nano titanium dioxide loaded with glycyrrhizic acid is also added. Glycyrrhizic acid has good anti-allergic and anti-inflammatory effects. Nano titanium dioxide itself has certain antibacterial properties, which can synergistically enhance the antibacterial effect while reducing the overall irritation of the material to the user.

[0024] (5) The present invention provides an antibacterial and durable plastic through the synergistic interaction between its components. Detailed Implementation

[0025] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0026] Example 1

[0027] The antibacterial and durable plastic of this embodiment comprises the following raw materials in parts by weight: 90 parts composite material, 7 parts maleic anhydride grafted polypropylene, 23 parts modified filler, 3 parts antibacterial agent, 1.5 parts modified softener, 0.6 parts antioxidant and 1 part UV stabilizer.

[0028] In this embodiment, maleic anhydride-grafted polypropylene was purchased from Shanghai Juyilong Plastics Co., Ltd.; the antioxidant was antioxidant 1010, purchased from Shandong Xinyida Chemical Technology Co., Ltd.; and the UV absorber was benzophenone-based UV absorber, purchased from Zhangjiagang Free Trade Zone Xinyou Chemical Additives Co., Ltd.

[0029] The composite material in this embodiment is composed of polypropylene, polyethylene and acrylonitrile-butadiene copolymer in a mass ratio of 2.8:1.9:0.8. The polypropylene, polyethylene and acrylonitrile-butadiene copolymer are all from Jieyang Jiachun Medical Device Co., Ltd.

[0030] The modified filler in this embodiment is prepared by immersing glass fiber in coupling solution for 2 hours, drying it in an oven at 90°C for 4 hours, and then performing plasma treatment to obtain the modified filler. The glass fiber was purchased from Dongguan Wanshixin Plastic Raw Materials Co., Ltd.

[0031] The coupling solution in this embodiment comprises 3% KH-560 and the balance ethanol by mass percentage; the plasma treatment power and time are 80W and 5min, respectively; KH-560 was purchased from Jinan Rongguang Chemical Co., Ltd.

[0032] The preparation method of the antibacterial agent in this embodiment is as follows: chitosan is added to the base solution at a ratio of 1:1.8 g / mL, ultrasonically treated for 2 min, soaked for 3 h, and then sodium hydroxide solution is added dropwise. After precipitation is complete, the addition is stopped to obtain the antibacterial agent. The chitosan was purchased from Shandong Guante Biotechnology Co., Ltd.

[0033] The base solution in this embodiment comprises, by percentage, 4 wt% garlic extract, 0.5 wt% tea tree extract, 1.8 wt% rose extract, 2.5 wt% vegetable glycerin, and the balance ethanol. The garlic extract was purchased from Jiangsu Caiwei Biotechnology Co., Ltd., the tea tree extract from Jiangsu Jufeng Chemical Technology Co., Ltd., and the rose extract from Lanzhou Waterles Biotechnology Co., Ltd. Before use, the pH of the base solution was adjusted to 4 with 0.15 mol / L citric acid. The frequency and power of the ultrasonic treatment were 40 kHz and 200 W, respectively. The concentration of the sodium hydroxide solution was 0.1 mol / L.

[0034] The modified softener in this embodiment is prepared as follows: 90 parts by weight of epoxidized soybean oil are heated to 120°C, then 20 parts by weight of maleic anhydride and 1 part by weight of dibutyltin dilaurate are added. The mixture is stirred at 50 rpm. When the stirring time reaches halfway, 0.8 wt% of nano-silica with an average particle size of 40 nm and 18 wt% of nano-titanium dioxide loaded with glycyrrhizic acid are added. The total stirring time is 2 hours. The modified softener is obtained after stirring. The epoxidized soybean oil was purchased from Shandong Hongyunchang Chemical Technology Co., Ltd., the maleic anhydride was purchased from Nanjing Qiangren Plastics Co., Ltd., the dibutyltin dilaurate was purchased from Jilin Huaxin Chemical Co., Ltd., the nano-silica was purchased from Shanghai Yingfeng Ruihuang Metal Materials Co., Ltd., the nano-titanium dioxide was purchased from Shanghai Yingfeng Ruihuang Metal Materials Co., Ltd., and the glycyrrhizic acid was purchased from Lanzhou Waterles Biotechnology Co., Ltd.

[0035] The preparation method of glycyrrhizic acid supported on nano-titanium dioxide in this embodiment is as follows:

[0036] In a reaction vessel, nano-titanium dioxide with an average particle size of 60 nm and anhydrous ethanol were mixed and stirred at 250 rpm for 20 min to obtain a nano-titanium dioxide suspension with a concentration of 9 wt%. Glycyrrhizic acid (8% by mass of nano-titanium dioxide) and ethyl silicate (4% by mass of nano-titanium dioxide) were added to the suspension. The ultrasonic frequency and power were set to 30 kHz and 300 W, respectively. After ultrasonication for 10 min, the reaction vessel was placed in a 60°C constant temperature water bath and stirred continuously at 300 rpm until a gel-like product was obtained. The gel-like product was dried in an 80°C oven for 5 h. After removal, it was ground into powder at 800 rpm to obtain nano-titanium dioxide loaded with glycyrrhizic acid.

[0037] The preparation method of this embodiment includes the following steps:

[0038] (1) After the composite material is dried, it is added to a high-speed mixer. The mixer temperature is set to 90℃ and the mixture is stirred at 450 rpm for 6 minutes. Then, maleic anhydride-grafted polypropylene is added and stirred at the same temperature and speed for 6 minutes to obtain material one.

[0039] (2) Add modified filler, antibacterial agent, modified softener, antioxidant and anti-ultraviolet agent to material 1, heat to 105°C, stir at 700 rpm for 10 min, melt and extrude, granulate to obtain antibacterial durable plastic.

[0040] In this embodiment, the drying in step (1) is to use a hot air dryer at 60°C for 4 hours; the melting temperature in step (2) is 175°C; and the extrusion speed and temperature are 100 rpm and 195°C, respectively.

[0041] Example 2

[0042] The antibacterial and durable plastic of this embodiment comprises the following raw materials in parts by weight: 110 parts composite material, 9 parts maleic anhydride grafted polypropylene, 27 parts modified filler, 4 parts antibacterial agent, 2.5 parts modified softener, 1 part antioxidant and 2 parts UV stabilizer.

[0043] In this embodiment, maleic anhydride-grafted polypropylene was purchased from Shanghai Juyilong Plastics Co., Ltd.; the antioxidant was antioxidant 1010, purchased from Shandong Xinyida Chemical Technology Co., Ltd.; and the UV absorber was benzophenone-based UV absorber, purchased from Zhangjiagang Free Trade Zone Xinyou Chemical Additives Co., Ltd.

[0044] The composite material in this embodiment is composed of polypropylene, polyethylene and acrylonitrile-butadiene copolymer in a mass ratio of 3:2.1:1. The polypropylene, polyethylene and acrylonitrile-butadiene copolymer are all from Jieyang Jiachun Medical Device Co., Ltd.

[0045] The modified filler in this embodiment is prepared by immersing glass fiber in coupling solution for 3 hours, then drying it in an oven at 90°C for 4 hours, and then subjecting it to plasma treatment to obtain the modified filler. The glass fiber was purchased from Dongguan Wanshixin Plastic Raw Materials Co., Ltd.

[0046] The coupling solution in this embodiment comprises 7% KH-560 and the balance ethanol by mass percentage; the plasma treatment power and time are 120W and 15min, respectively; KH-560 was purchased from Jinan Rongguang Chemical Co., Ltd.

[0047] The preparation method of the antibacterial agent in this embodiment is as follows: chitosan is added to the base solution at a ratio of 1:2.3 g / mL, ultrasonically treated for 8 min, soaked for 4 h, and then sodium hydroxide solution is added dropwise. After precipitation is complete, the addition is stopped to obtain the antibacterial agent. The chitosan was purchased from Shandong Guante Biotechnology Co., Ltd.

[0048] The base solution in this embodiment comprises, by percentage, 6 wt% garlic extract, 1.5 wt% tea tree extract, 3 wt% rose extract, 3.5 wt% vegetable glycerin, and the balance ethanol. The garlic extract was purchased from Jiangsu Caiwei Biotechnology Co., Ltd., the tea tree extract from Jiangsu Jufeng Chemical Technology Co., Ltd., and the rose extract from Lanzhou Waterles Biotechnology Co., Ltd. Before use, the pH of the base solution was adjusted to 5 with 0.25 mol / L citric acid. The frequency and power of the ultrasonic treatment were 50 kHz and 400 W, respectively. The concentration of the sodium hydroxide solution was 0.3 mol / L.

[0049] The modified softener in this embodiment is prepared as follows: 110 parts by weight of epoxidized soybean oil is heated to 130°C, then 30 parts by weight of maleic anhydride and 2 parts by weight of dibutyltin dilaurate are added. The mixture is stirred at 70 rpm. When the stirring time reaches halfway, 1.2 wt% of nano-silica with an average particle size of 100 nm and 22 wt% of nano-titanium dioxide loaded with glycyrrhizic acid are added. The total stirring time is 3 hours. The modified softener is obtained after stirring. The epoxidized soybean oil was purchased from Shandong Hongyunchang Chemical Technology Co., Ltd., the maleic anhydride was purchased from Nanjing Qiangren Plastics Co., Ltd., the dibutyltin dilaurate was purchased from Jilin Huaxin Chemical Co., Ltd., the nano-silica was purchased from Shanghai Yingfeng Ruihuang Metal Materials Co., Ltd., the nano-titanium dioxide was purchased from Shanghai Yingfeng Ruihuang Metal Materials Co., Ltd., and the glycyrrhizic acid was purchased from Lanzhou Waterles Biotechnology Co., Ltd.

[0050] The preparation method of glycyrrhizic acid supported on nano-titanium dioxide in this embodiment is as follows:

[0051] In a reaction vessel, nano-titanium dioxide with an average particle size of 80 nm and anhydrous ethanol were mixed and stirred at 350 rpm for 30 min to obtain a nano-titanium dioxide suspension with a concentration of 11 wt%. Glycyrrhizic acid (12% of the mass of nano-titanium dioxide) and ethyl silicate (5% of the mass of nano-titanium dioxide) were added to the suspension. The ultrasonic frequency and power were set to 50 kHz and 500 W, respectively. After ultrasonication for 20 min, the reaction vessel was placed in a 60°C constant temperature water bath and stirred continuously at 500 rpm until a gel-like product was obtained. The gel-like product was dried in an 80°C oven for 6 h. After removal, it was ground into powder at 1200 rpm to obtain nano-titanium dioxide loaded with glycyrrhizic acid.

[0052] The preparation method of this embodiment includes the following steps:

[0053] (1) After drying the composite material, add it into a high-speed mixer, set the machine temperature to 90℃, stir at 550rpm for 10min, add maleic anhydride grafted polypropylene, stir at the same temperature and speed for 10min to obtain material one.

[0054] (2) Add modified filler, antibacterial agent, modified softener, antioxidant and anti-ultraviolet agent to material 1, heat to 115℃, stir at 900rpm for 14min, melt and extrude, granulate to obtain antibacterial durable plastic.

[0055] In this embodiment, the drying in step (1) is to use a hot air dryer at 80°C for 6 hours; the melting temperature in step (2) is 185°C; and the extrusion speed and temperature are 200 rpm and 205°C, respectively.

[0056] Example 3

[0057] The antibacterial and durable plastic of this embodiment comprises the following raw materials in parts by weight: 100 parts composite material, 8 parts maleic anhydride grafted polypropylene, 25 parts modified filler, 3.5 parts antibacterial agent, 2 parts modified softener, 0.8 parts antioxidant and 1.5 parts UV stabilizer.

[0058] In this embodiment, maleic anhydride-grafted polypropylene was purchased from Shanghai Juyilong Plastics Co., Ltd.; the antioxidant was antioxidant 1010, purchased from Shandong Xinyida Chemical Technology Co., Ltd.; and the UV absorber was benzophenone-based UV absorber, purchased from Zhangjiagang Free Trade Zone Xinyou Chemical Additives Co., Ltd.

[0059] The composite material in this embodiment is composed of polypropylene, polyethylene and acrylonitrile-butadiene copolymer in a mass ratio of 2.9:2:0.9. The polypropylene, polyethylene and acrylonitrile-butadiene copolymer are all from Jieyang Jiachun Medical Device Co., Ltd.

[0060] The modified filler in this embodiment is prepared by immersing glass fiber in coupling solution for 2.5 hours, drying it in an oven at 90°C for 4 hours, and then subjecting it to plasma treatment to obtain the modified filler. The glass fiber was purchased from Dongguan Wanshixin Plastic Raw Materials Co., Ltd.

[0061] The coupling solution in this embodiment comprises 5% KH-560 and the balance ethanol by mass percentage; the power and time of plasma treatment are 100W and 10min, respectively; KH-560 was purchased from Jinan Rongguang Chemical Co., Ltd.

[0062] The preparation method of the antibacterial agent in this embodiment is as follows: chitosan is added to the base solution at a ratio of 1:2.05 g / mL, ultrasonically treated for 5 min, soaked for 3.5 h, and then sodium hydroxide solution is added dropwise. After precipitation is complete, the addition is stopped to obtain the antibacterial agent. The chitosan was purchased from Shandong Guante Biotechnology Co., Ltd.

[0063] The base solution in this embodiment comprises, by percentage, 5 wt% garlic extract, 1 wt% tea tree extract, 2.4 wt% rose extract, 3 wt% vegetable glycerin, and the balance ethanol. The garlic extract was purchased from Jiangsu Caiwei Biotechnology Co., Ltd., the tea tree extract from Jiangsu Jufeng Chemical Technology Co., Ltd., and the rose extract from Lanzhou Waterles Biotechnology Co., Ltd. Before use, the pH of the base solution was adjusted to 4.5 with 0.2 mol / L citric acid. The frequency and power of the ultrasonic treatment were 45 kHz and 300 W, respectively. The concentration of the sodium hydroxide solution was 0.2 mol / L.

[0064] The modified softener in this embodiment is prepared as follows: 100 parts by weight of epoxidized soybean oil is heated to 125°C, then 25 parts by weight of maleic anhydride and 1.5 parts by weight of dibutyltin dilaurate are added. The mixture is stirred at 60 rpm. When the stirring time reaches halfway, 1 wt% of nano-silica with an average particle size of 70 nm and 20 wt% of nano-titanium dioxide loaded with glycyrrhizic acid are added. The total stirring time is 2.5 h. The modified softener is obtained after stirring. The epoxidized soybean oil was purchased from Shandong Hongyunchang Chemical Technology Co., Ltd., the maleic anhydride was purchased from Nanjing Qiangren Plastics Co., Ltd., the dibutyltin dilaurate was purchased from Jilin Huaxin Chemical Co., Ltd., the nano-silica was purchased from Shanghai Yingfeng Ruihuang Metal Materials Co., Ltd., the nano-titanium dioxide was purchased from Shanghai Yingfeng Ruihuang Metal Materials Co., Ltd., and the glycyrrhizic acid was purchased from Lanzhou Waterles Biotechnology Co., Ltd.

[0065] The preparation method of glycyrrhizic acid supported on nano-titanium dioxide in this embodiment is as follows:

[0066] In a reaction vessel, nano-titanium dioxide with an average particle size of 70 nm and anhydrous ethanol were mixed and stirred at 300 rpm for 25 min to obtain a nano-titanium dioxide suspension with a concentration of 10 wt%. Glycyrrhizic acid (10% of the mass of nano-titanium dioxide) and ethyl silicate (4.5 wt% of the mass of nano-titanium dioxide) were added to the suspension. The ultrasonic frequency and power were set to 40 kHz and 400 W, respectively. After ultrasonication for 15 min, the reaction vessel was placed in a 60°C constant temperature water bath and stirred continuously at 400 rpm until a gel-like product was obtained. The gel-like product was dried in an 80°C oven for 5.5 h. After removal, it was ground into powder at 1000 rpm to obtain nano-titanium dioxide loaded with glycyrrhizic acid.

[0067] The preparation method of this embodiment includes the following steps:

[0068] (1) After the composite material is dried, it is added to a high-speed mixer. The mixer temperature is set to 90℃ and stirred at 500 rpm for 8 minutes. Then, maleic anhydride-grafted polypropylene is added and stirred at the same temperature and speed for 8 minutes to obtain material one.

[0069] (2) Add modified filler, antibacterial agent, modified softener, antioxidant and anti-ultraviolet agent to material 1, heat to 110°C, stir at 800 rpm for 12 minutes, melt and extrude, granulate to obtain antibacterial durable plastic.

[0070] In this embodiment, the drying in step (1) is to use a hot air dryer at 70°C for 5 hours; the melting temperature in step (2) is 180°C; and the extrusion speed and temperature are 150 rpm and 200°C, respectively.

[0071] Comparative Example 1

[0072] Based on Example 3, the polypropylene in the composite material was removed and replaced with an equal weight of polyethylene, while other conditions remained the same as in Example 3.

[0073] Comparative Example 2

[0074] Based on Example 3, the polyethylene in the composite material was removed and replaced with an equal weight of acrylonitrile-butadiene copolymer, while other conditions remained the same as in Example 3.

[0075] Comparative Example 3

[0076] Based on Example 3, the acrylonitrile-butadiene copolymer in the composite material was removed and replaced with an equal weight of polypropylene, while other conditions remained the same as in Example 3.

[0077] Comparative Example 4

[0078] Based on Example 3, the modified filler was removed and replaced with an equal weight of glass fiber, while other conditions remained the same as in Example 3.

[0079] Comparative Example 5

[0080] Based on Example 3, the garlic extract in the base liquid was removed and replaced with an equal weight of tea tree extract, while other conditions remained the same as in Example 3.

[0081] Comparative Example 6

[0082] Based on Example 3, the tea tree extract in the base liquid was removed and replaced with an equal weight of rose extract, while other conditions remained the same as in Example 3.

[0083] Comparative Example 7

[0084] Based on Example 3, the rose extract in the base solution was removed and replaced with an equal weight of garlic extract, while other conditions remained the same as in Example 3.

[0085] Comparative Example 8

[0086] Based on Example 3, the preparation method of the antibacterial agent was changed as follows: chitosan was added to the base solution at a ratio of 1:2.05 g / mL, ultrasonically treated for 5 min, and then soaked for 3.5 h to obtain the antibacterial agent. Other conditions were the same as in Example 3.

[0087] Comparative Example 9

[0088] Based on Example 3, the modified softener was removed, while other conditions remained the same as in Example 3.

[0089] Comparative Example 10

[0090] Based on Example 3, the nano-titanium dioxide-loaded glycyrrhizic acid in the modified softener was removed and replaced with an equal weight of epoxidized soybean oil, while other conditions remained the same as in Example 3.

[0091] The plastics prepared in Example 3 and Comparative Examples 1-10 were used as samples. The load-bearing strength of the samples was determined according to GB / T14484-2008, and the tensile properties of the samples were determined according to GB / T 1040.1-2018. The average values ​​of each sample were recorded in Table 1 below after making 3 parallel tests.

[0092] According to QB / T 2591-2003, the antibacterial effects of the samples against Staphylococcus aureus and Escherichia coli were tested. The samples were prepared into discs with a diameter of 1 cm and a thickness of 1 mm, sterilized, and dried. A 0.2% solution of Escherichia coli and a 2% solution of Staphylococcus aureus were prepared using physiological saline solution. The pH was adjusted to 7.2 after sterilization using 0.1 mol / L sodium hydroxide solution. The samples were sterilized at 121℃ for 30 min, followed by a 6 × 10⁻⁶... 5 A concentration of CFU / mL was added dropwise to the sample, and a sterilized polyethylene covering film (40mm × 40mm, 0.05mm thick) was placed over the sample. The sample was then incubated at 37℃ and relative humidity greater than 90% for 24 hours. After incubation, the sample was inoculated onto agar medium (purchased from Nantong Kaiheng Biotechnology Development Co., Ltd.) at an inoculation density of 10... 5 CFU was cultured at 37℃ for 24 hours, and the viable count was determined according to GB / T 4789.2. Five replicates were performed for each sample, and the average test results were recorded as shown in Table 1 below.

[0093] Table 1

[0094]

[0095]

[0096] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any indirect modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. Antibacterial and durable plastic, characterized in that: The antibacterial durable plastic comprises the following raw materials in parts by weight: 90-110 parts composite material, 7-9 parts maleic anhydride grafted polypropylene, 23-27 parts modified filler, 3-4 parts antibacterial agent, 1.5-2.5 parts modified softener, 0.6-1 part antioxidant and 1-2 parts UV stabilizer; The composite material is composed of polypropylene, polyethylene, and acrylonitrile-butadiene copolymer in a mass ratio of 2.8-3:1.9-2.1:0.8-1; The method for preparing the antibacterial agent is as follows: chitosan is added to the base solution at a ratio of 1:1.8-2.3 g / mL, ultrasonically treated for 2-8 min, soaked for 3-4 h, and then sodium hydroxide solution is added dropwise. After precipitation is complete, the addition is stopped to obtain the antibacterial agent. The raw materials of the base solution, by percentage, include 4-6 wt% garlic extract, 0.5-1.5 wt% tea tree extract, 1.8-3 wt% rose extract, 2.5-3.5 wt% vegetable glycerin, and the balance ethanol; the pH of the base solution is adjusted to 4-5 with 0.15-0.25 mol / L citric acid before use. The modified softener is prepared as follows: 90-110 parts by weight of epoxidized soybean oil are heated to 120-130°C, and then 20-30 parts by weight of maleic anhydride and 1-2 parts by weight of dibutyltin dilaurate are added. The mixture is stirred at 50-70 rpm. When the stirring time reaches halfway, 0.8-1.2 wt% of nano-silica with an average particle size of 40-100 nm and 18-22 wt% of nano-titanium dioxide-supported glycyrrhizic acid are added. The total stirring time is 2-3 hours. The modified softener is obtained after stirring is completed.

2. The antibacterial and durable plastic according to claim 1, characterized in that, The modified filler is prepared by immersing glass fiber in coupling solution for 2-3 hours, then drying it in an oven at 90°C for 4 hours, and then subjecting it to plasma treatment to obtain the modified filler.

3. The antibacterial and durable plastic according to claim 2, characterized in that, The coupling solution comprises 3-7% KH-560 and the balance ethanol by mass percentage; the power and time of the plasma treatment are 80-120W and 5-15min, respectively.

4. The antibacterial and durable plastic according to claim 1, characterized in that, The frequency and power of the ultrasonic treatment are 40-50kHz and 200-400W, respectively; the concentration of the sodium hydroxide solution is 0.1-0.3mol / L.

5. The antibacterial and durable plastic according to claim 1, characterized in that, The preparation method of the nano-titanium dioxide loaded with glycyrrhizic acid is as follows: In a reaction vessel, nano-titanium dioxide with an average particle size of 60-80 nm and anhydrous ethanol are mixed and stirred at 250-350 rpm for 20-30 min to obtain a nano-titanium dioxide suspension with a concentration of 9-11 wt%. Glycyrrhizic acid (8-12% by mass of nano-titanium dioxide) and ethyl silicate (4-5 wt% by mass of nano-titanium dioxide) are added to the suspension. The ultrasonic frequency and power are set to 30-50 kHz and 300-500 W, respectively. After ultrasonication for 10-20 min, the reaction vessel is placed in a 60℃ constant temperature water bath and stirred continuously at 300-500 rpm until a gel-like product is obtained. The gel-like product is dried in an 80℃ oven for 5-6 h. After removal, it is ground into powder at 800-1200 rpm to obtain nano-titanium dioxide loaded with glycyrrhizic acid.

6. A method for preparing an antibacterial and durable plastic as described in any one of claims 1-5, characterized in that, The preparation method includes the following steps: (1) After the composite material is dried, it is added to a high-speed mixer. The machine temperature is set to 90℃ and stirred at 450-550 rpm for 6-10 minutes. Then, maleic anhydride-grafted polypropylene is added and stirred at the same temperature and speed for 6-10 minutes to obtain material one. (2) Add modified filler, antibacterial agent, modified softener, antioxidant and anti-ultraviolet agent to material 1, heat to 105-115℃, stir at 700-900rpm for 10-14min, melt and extrude, granulate, and obtain antibacterial durable plastic.

7. The method for preparing antibacterial and durable plastic according to claim 6, characterized in that, The drying in step (1) is to use a hot air dryer at 60-80℃ for 4-6 hours; the melting temperature in step (2) is 175-185℃; the extrusion speed and temperature are 100-200 rpm and 195-205℃, respectively.

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