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CN-119591980-B - Antibacterial plastic and preparation method thereof

CN119591980BCN 119591980 BCN119591980 BCN 119591980BCN-119591980-B

Abstract

The invention provides an antibacterial polypropylene plastic, which aims to obtain a composite antibacterial agent with the advantages of an inorganic antibacterial agent and an organic antibacterial agent by compositing the inorganic antibacterial agent and the organic antibacterial agent, and the obtained composite antibacterial agent is added into the polypropylene plastic to obtain the antibacterial polypropylene plastic with good antibacterial performance, good migration resistance and long-acting antibacterial property.

Inventors

  • XIAO ZHONGWEI
  • Lin Chongpu
  • Zheng Guiwu

Assignees

  • 江西米娅新材料有限公司

Dates

Publication Date
20260508
Application Date
20250108

Claims (7)

  1. 1. The antibacterial plastic material is characterized by comprising, by weight, 100 parts of polypropylene resin, 3-5 parts of a composite antibacterial agent, 1-2 parts of a dispersing agent, 2-3 parts of an antioxidant and 0.1-0.3 part of an initiator; The composite antibacterial agent is quaternary ammonium salt chitosan modified nano TiO 2 composite particles, and the preparation process is as follows: Adding nano TiO 2 with the median particle diameter D50 of 10-50nm into 100-300mL of ethanol water solution with the mass fraction of 95% for ultrasonic dispersion, adding an aminosilane coupling agent and triethylamine under magnetic stirring after ultrasonic dispersion is finished, stirring at 70-80 ℃, carrying out reflux reaction for 7-8h, cooling to room temperature after the reaction is finished, sequentially carrying out suction filtration, repeatedly washing with toluene and ethanol, and then drying in an oven to obtain modified nano TiO 2 ; Step 2, dissolving chitosan in 100-200mL of acetic acid aqueous solution with mass fraction of 2%, adding sodium hydroxide solution to adjust pH to 8-9, heating to 80 ℃, adding isopropanol solution of 2, 3-epoxypropyl trimethyl ammonium chloride, stirring for reaction for 3-5h, adding absolute ethyl alcohol for precipitation, carrying out suction filtration, and drying a filter cake to obtain quaternary ammonium salt chitosan; Step 3, preparing 200-500 mL of mixed solution of N, N-dimethylformamide and water, wherein the volume percentage of water is not more than 50% of the total volume of the solution; Step 4, adding the modified nano TiO 2 prepared in the step 1 and the quaternary ammonium salt chitosan prepared in the step 2 into the mixed solution prepared in the step 3, dripping 10-30mL of N, N-dimethylformamide solution containing maleic anhydride into the mixed solution, continuously stirring and refluxing for reaction for 4-6 hours, wherein the reaction temperature is not more than 45 ℃, and centrifuging, washing and drying after the reaction is finished to obtain the quaternary ammonium salt chitosan modified nano TiO 2 composite particles; In the step 2, the mass ratio of the chitosan to the 2, 3-epoxypropyl trimethyl ammonium chloride is 5-6:1-3; in the step 4, the mass ratio of the modified nano TiO 2 to the quaternary ammonium salt chitosan to the maleic anhydride is 7-8:2-3:1.
  2. 2. An antibacterial plastic material according to claim 1 wherein the dispersing agent is selected from one or a combination of two or more of stearic acid, polyethylene wax, liquid paraffin.
  3. 3. An antimicrobial plastic material according to claim 1, wherein the antioxidant is selected from the group consisting of antioxidant 1010 and antioxidant 168 in a 1:1 ratio.
  4. 4. An antimicrobial plastic material according to claim 1, wherein the initiator is selected from one or a combination of dibenzoyl peroxide and methyl ethyl ketone peroxide.
  5. 5. The antibacterial plastic material according to claim 1, wherein in the step 1, the mass ratio of the nano TiO 2 , the aminosilane coupling agent and the triethylamine is 3-6:5-10:1.
  6. 6. The preparation process of the antibacterial plastic material according to any one of claims 1 to 5, wherein the preparation process of the antibacterial plastic material is characterized in that 100 parts of polypropylene resin, 3 to 5 parts of composite antibacterial agent, 1 to 2 parts of dispersing agent, 2 to 3 parts of antioxidant and 0.1 to 0.3 part of initiator are put into a high-speed mixer according to the proportion, mixed for 10 to 30 minutes at the rotating speed of 600 to 800rpm, the materials are uniformly dispersed, discharged and cooled after uniform mixing, the cooled mixed materials are fed into a double-screw extruder for melt extrusion, so that strip-shaped materials are obtained, and the extruded strip-shaped materials are cooled by a water tank, pulled into a granulator for granulation and dried, so that the polypropylene antibacterial plastic is obtained.
  7. 7. The process for preparing an antibacterial plastic material according to claim 6, wherein the twin-screw extruder has a first zone temperature of 155-165 ℃, a second zone temperature of 175-185 ℃, a third zone temperature of 185-195 ℃, a fourth zone temperature of 205-215 ℃, a fifth zone temperature of 205-215 ℃ and a sixth zone temperature of 195-205 ℃.

Description

Antibacterial plastic and preparation method thereof Technical Field The invention relates to an antibacterial plastic, in particular to an antibacterial polypropylene plastic. Background With the sustainable development of the economy and society, plastic products are increasingly penetrated into the lives of people. Plastic is a material which is mainly composed of a polymer, is processed into a certain shape under certain conditions, and can keep its shape unchanged at normal temperature. There are many kinds of plastics, and polyethylene, polypropylene, polyvinyl chloride, polystyrene, etc. are commonly used. By adding additives such as filler, plasticizer, colorant and the like into the matrix, the light weight, high strength, corrosion resistance, heat resistance, impact resistance, stretching resistance and the like can be endowed. Polypropylene (PP) is a general plastic, has excellent mechanical properties and low cost, and is widely applied to the fields of automobile parts, home appliances, toys, kitchen appliances, medical treatment and the like, the products are often contacted with human skin, a large amount of bacteria are often attached to the surfaces of the products, the harmful bacteria can be continuously spread and transferred, the health of people who are contacted is threatened, and the addition of an antibacterial agent into the plastic is an effective measure for improving the antibacterial performance of the plastic. The antibacterial agents are of various types and comprise inorganic antibacterial agents, organic antibacterial agents and natural antibacterial agents. The inorganic antibacterial agent includes silver ion, copper ion, zinc oxide, titanium dioxide, etc. The inorganic antibacterial agent has higher safety, heat resistance and durability, is more applied in the fields of fiber and plastic box building materials, has the defects of higher price, slow effect, incapability of killing bacteria as fast as an organic antibacterial agent and almost no inhibition effect on fungi and moulds. The organic antibacterial agent mainly comprises quaternary ammonium salts, biguanides, alcohols, chlorine-containing hydrochloric acid, organic halides, organic metal compounds, phenols, pyridines, imidazoles, iodides and the like as main components. The organic antibacterial agent has the advantages of high sterilization speed, high efficiency and low price, but the organic antibacterial agent has poor heat resistance generally and is easy to generate drug resistance. The natural antibacterial agent is an extract from animals and plants, belongs to an organic antibacterial agent, and has the characteristics of natural environment protection, no toxicity, no harm, good biocompatibility and the like. The natural antibacterial agent comprises chitosan, chitin, mugwort, aloe, etc. At present, research on antibacterial performance of polypropylene mainly focuses on single use or physical mixing of antibacterial agents, for example, a small roquette et al prepare antibacterial materials by respectively using silver-series, zinc-series and organic polymer antibacterial agents and polypropylene (PP) through a double-screw extruder, so that influence of different types of antibacterial agents on PP performance is researched, and antibacterial activity, high-temperature yellowing resistance effect, timeliness and the like of the antibacterial materials are evaluated. The results show that the silver-based, zinc-based and organic polymer antibacterial agents have little influence on the mechanical properties of materials, and the organic antibacterial agents are better than the silver-based antibacterial agents and the zinc-based antibacterial agents in terms of antibacterial efficiency, but the organic antibacterial agents are obviously worse than the silver-based and the zinc-based antibacterial agents in terms of high Wen Kanghuang denaturation. Li Jie et al studied the effects of granulation temperature, injection temperature, ultraviolet light aging, discoloration inhibitor and the like on the yellow index and color difference of antibacterial polypropylene by developing antibacterial polypropylene using isothiazolinone antibacterial agent, and analyzed the thermal stability of isothiazolinone by a thermal weightlessness/infrared synchronous thermal analyzer. The result shows that when the content of 4, 5-dichloro-2-n-octyl-4-isothiazolin-3-ketone in the color-changing-resistant antibacterial polypropylene reaches 0.25% (w), the antibacterial rate of the sample on escherichia coli and staphylococcus aureus is more than 99% after the sample is boiled in water at 50 ℃ for 16 h. On the basis of the existing research work, the application combines the advantages and disadvantages of the organic antibacterial agent and the inorganic antibacterial agent, and organically combines the inorganic antibacterial agent and the organic antibacterial agent through chemical modification. The prepared composite