Degradable antibacterial plastic packaging bag and preparation method thereof

Abstract

The application belongs to the technical field of plastics, and particularly relates to a degradable antibacterial plastic packaging bag and a preparation method thereof. The degradable antibacterial plastic packaging bag comprises the following raw materials in parts by weight: polycaprolactone 70-90 parts; polybutylene adipate terephthalate 20-40 parts; Cr and Cu co-modified ZIF-8 5-20 parts; and cerium oxide tannic acid material 2-6 parts. The Cr and Cu co-modified ZIF-8 synergistically improves the antibacterial performance of the packaging bag, and the addition of the cerium oxide tannic acid material further improves the antibacterial performance of the packaging bag. Moreover, the degradable antibacterial plastic packaging bag prepared by the application has excellent mechanical properties.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of plastics. More particularly, it relates to a degradable antibacterial plastic packaging bag and a preparation method thereof. BACKGROUND

[0002] Food is easily contaminated by microorganisms, leading to spoilage. Food packaging is an effective means to ensure food safety, and commercialized packaging such as polyethylene (PE), polyvinyl chloride (PVC), and polyvinylidene chloride (PVDC) has problems such as not being easily degradable, poor antibacterial performance, and large environmental pollution. Therefore, developing degradable antibacterial fresh-keeping materials has become a research hotspot in the field of food packaging.

[0003] Biodegradable materials can undergo chemical or physical changes under the action of natural microorganisms, decompose from polymers into small molecules, and eventually decompose into carbon dioxide and water. Such materials have no pressure on the environment during use, and using this type of plastic product is a powerful measure to solve white pollution. Commonly used degradable polymer materials in research can be broadly divided into two categories: natural polymer materials and artificially synthesized polymer materials. Natural polymer materials include polysaccharides, proteins, lipids, and other types of materials. Artificially synthesized biodegradable plastics have developed rapidly, and related materials such as poly-beta-hydroxybutyric acid (PHB), polybutylene adipate terephthalate (PBAT), and polybutylene succinate (PBS) have been favored by people and are expected to replace traditional plastics.

[0004] The physical puncture mechanism of MOF and MOF-based composite materials refers to the contact between the sharp edges of the nanostructure of MOF and MOF-based composite materials and the bacterial cell membrane through van der Waals forces, electrostatic interaction forces, and other non-covalent forces, causing the cell membrane to rupture and leading to the death of the bacteria.

[0005] Metal ions are coordinated with tannic acid (TA) to prepare a variety of different metal polyphenol-based nanometer antibacterial materials through a one-step blending method. The combination of the polyphenol on the surface of tannic acid and the coordination of metal ions achieves common antibacterial properties and has excellent antibacterial performance.

[0006] CN119307078A discloses a high sealing property packaging bag and a preparation process thereof, belonging to the technical field of packaging materials. The packaging bag comprises the following raw materials: polylactic acid, polycaprolactone, nano-silver filler composite antibacterial agent and epoxy-based compatibilizer. The nano-silver filler composite antibacterial agent is nano-silver loaded after a hybrid modified coating is deposited on the surface of a nano two-dimensional filler. The hybrid modified coating comprises polydopamine and hyperbranched polyethyleneimine. Polylactic acid and polycaprolactone are used as main substrates to give the packaging bag good mechanical properties due to the high mechanical strength of polylactic acid and the excellent flexibility of polycaprolactone. Nano-silver filler composite antibacterial agent and epoxy-based compatibilizer are also added. The nano-silver filler composite antibacterial agent is prepared from nano two-dimensional filler. The nano two-dimensional filler has a high aspect ratio to block the transmission of gas molecules. The dispersion performance is improved by combining with the epoxy-based compatibilizer, further improving the barrier property and mechanical property of the packaging bag.

[0007] CN119019826A discloses a biodegradable milk tea packaging bag and a preparation method thereof. The biodegradable milk tea packaging bag comprises the following raw materials by weight: polybutylene adipate terephthalate 40-60 parts, polylactic acid 20-30 parts, modified starch 5-15 parts, diatom shell 5-8 parts, inorganic filler 5-8 parts, hydrolysis-resistant agent 1-3 parts, chain extender 0.5-1 part, lubricant 1-3 parts, toughening plasticizer 1-3 parts, hydroxy silicone oil 0.4-0.8 parts, and antibacterial agent 0.5-1.5 parts. The packaging bag prepared by the present application is prepared by compounding polybutylene adipate terephthalate and polylactic acid to improve the tensile strength and thermal stability of the packaging bag, and reduce the deformation and damage of the packaging bag.

[0008] In documents CN118755242A, CN118620367A, CN118496634A, etc., the antibacterial performance of the packaging bag is endowed by adding an antibacterial component in the packaging bag. Based on the above, the present application provides a new degradable antibacterial plastic packaging bag with excellent antibacterial performance and mechanical properties. SUMMARY

[0009] The technical problem to be solved by the present application is to overcome the defects and deficiencies in the prior art and provide a degradable antibacterial plastic packaging bag and a preparation method thereof. The degradable antibacterial plastic packaging bag of the present application comprises the following raw materials by weight: polycaprolactone 70-90 parts; polybutylene adipate terephthalate 20-40 parts; Cr and Cu co-modified ZIF-8 1-5 parts; and cerium oxide tannic acid material 2-6 parts. The antibacterial performance of the packaging bag is improved by Cr and Cu co-modified ZIF-8, and the antibacterial performance of the packaging bag is further improved by adding the cerium oxide tannic acid material. Moreover, the degradable antibacterial plastic packaging bag prepared by the present application has excellent mechanical properties.

[0010] The application aims to provide a degradable antibacterial plastic packaging bag.

[0011] Another object of the application is to provide a preparation method of the degradable antibacterial plastic packaging bag.

[0012] The above objects of the application are achieved by the following technical scheme.

[0013] The degradable antibacterial plastic packaging bag comprises the following raw materials in parts by weight: polycaprolactone 70-90 parts; polybutylene adipate terephthalate 20-40 parts; Cr and Cu co-modified ZIF-8 1-5 parts; and cerium oxide tannic acid material 2-6 parts.

[0014] In the application, preferably, the preparation method of the Cr and Cu co-modified ZIF-8 comprises the following steps.

[0015] The chromium salt, copper salt, zinc salt and 2-methyl imidazole are ultrasonically dispersed in ethanol, stirred, then subjected to hydrothermal treatment, filtered, washed, and vacuum dried to obtain the Cr and Cu co-modified ZIF-8.

[0016] Preferably, the chromium salt is one of chromium nitrate, chromium acetate and chromium chloride; the copper salt is one of copper nitrate, copper acetate and copper chloride; the zinc salt is one of zinc nitrate, zinc acetate and zinc chloride; and the molar ratio of the chromium salt, copper salt, zinc salt and 2-methyl imidazole is 0.02-0.06:0.01-0.05:1.5:3-4.

[0017] Preferably, the stirring time is 20-40 min.

[0018] Further preferably, the hydrothermal treatment is performed at 140-180 DEG C for 10-20 h, and the vacuum drying is performed at 60-90 DEG C for 14-20 h.

[0019] In the application, further preferably, the preparation method of the cerium oxide tannic acid material comprises the following steps.

[0020] The tannic acid and sodium periodate are ultrasonically dispersed in deionized water, stirred and reacted; then an appropriate amount of ethylene glycol is added to remove unreacted sodium periodate, and then a cerium salt is added, stirred for 20-40 min to obtain a mixed solution, then a 0.1 mol / L sodium hydroxide solution is added dropwise to adjust the pH of the mixed solution to 7-9, then the mixed solution is stirred at room temperature for 2-4 h, filtered, washed, and vacuum dried at 70-90 DEG C for 10-14 h to obtain the cerium oxide tannic acid material; the molar ratio of the tannic acid and cerium salt is 1:2-4; and the cerium salt is at least one of cerium nitrate, cerium chloride and cerium acetate.

[0021] Preferably, the stirring reaction time is 3-7h, and the molar ratio of tannic acid to sodium periodate is 1:2-4.

[0022] Preferably, the concentration of the sodium hydroxide solution is 0.1mol / L, the pH is 7-9, and the vacuum drying is performed at 70-90℃ for 10-14h.

[0023] Preferably, the molar ratio of tannic acid to cerium salt is 1:2-4, and the cerium salt is at least one of cerium nitrate, cerium chloride and cerium acetate.

[0024] Based on the above-mentioned preparation method of the degradable antibacterial plastic packaging bag, the preparation method comprises the following steps: uniformly mixing polycaprolactone, polybutylene adipate terephthalate, Cr and Cu co-modified ZIF-8 and oxidized tannic acid cerium material, then feeding the mixture into a double screw extruder, and setting the parameters as follows: screw rotation speed 200-250rpm, and 1-5 zone heating temperature as follows: 140-150℃, 150-160℃, 160-170℃, 160-170℃, 170-175℃; then drying the granules at 50-70℃ for 8-12h to obtain a film blowing material, then feeding the film blowing material into a film blowing machine to blow a film, and setting the parameters as follows: screw rotation speed 220-260rpm, 1-5 zone heating temperature as follows: 135-140℃, 145-150℃, 150-160℃, 160-170℃, 170-175℃, and traction speed 8-10m / min, to manufacture a plastic film, and then cutting and bag making the plastic film to obtain the degradable antibacterial plastic packaging bag.

[0025] The present application has the following beneficial effects:

[0026] The present application co-modifies ZIF-8 by Cr and Cu, utilizes the synergistic effect between Cr and Cu, improves the antibacterial performance of ZIF-8 itself, and further improves the antibacterial performance of the packaging bag, adds the oxidized tannic acid cerium material, utilizes the polyphenol on the surface of tannic acid and the antibacterial ion cerium, and the two together make the packaging bag have excellent antibacterial performance, and the degradable antibacterial plastic packaging bag prepared by the present application has excellent mechanical properties, therefore, the degradable antibacterial plastic packaging bag prepared by the present application has excellent antibacterial performance and good mechanical properties. DETAILED DESCRIPTION

[0027] The present application will be further described below in combination with specific examples, but the examples do not limit the present application in any form. Unless otherwise specified, the reagents, methods and equipment used in the present application are conventional reagents, methods and equipment in the technical field.

[0028] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0029] Example 1

[0030] A degradable antibacterial plastic packaging bag, comprising the following raw materials in parts by weight: polycaprolactone 80 parts; polybutylene adipate terephthalate 30 parts; Cr and Cu co-modified ZIF-8 3 parts; cerium oxidized tannic acid material 4 parts;

[0031] The preparation method of the Cr and Cu co-modified ZIF-8 comprises the following steps:

[0032] 0.04 mol of chromium nitrate, 0.03 mol of copper acetate, 1.5 mol of zinc chloride and 3.5 mol of 2-methylimidazole are ultrasonically dispersed in 200 mL of ethanol, stirred for 30 min, then hydrothermally treated at 160°C for 15h, filtered, washed, and vacuum dried at 80°C for 18h to obtain the Cr and Cu co-modified ZIF-8;

[0033] The preparation method of the cerium oxidized tannic acid material comprises the following steps:

[0034] (1) 1 mol of tannic acid and 3 mol of sodium periodate are ultrasonically dispersed in 200 mL of deionized water, stirred for 5h, then an appropriate amount of ethylene glycol is added to remove unreacted sodium periodate, then 3 mol of cerium nitrate is added, stirred for 30 min to obtain a mixed solution, then a 0.1 mol / L sodium hydroxide solution is added dropwise, the pH of the mixed solution is adjusted to 8, then stirred at room temperature for 3h, filtered, washed, and vacuum dried at 80°C for 12h to obtain the cerium oxidized tannic acid material.

[0035] A preparation method of a degradable antibacterial plastic packaging bag, the preparation method comprising the following steps: mixing polycaprolactone, polybutylene adipate terephthalate, Cr and Cu co-modified ZIF-8, and cerium oxidized tannic acid material uniformly, then feeding into a twin-screw extruder, setting the parameters as follows: screw rotation speed 240 rpm, 1-5 zone heating temperature as follows: 145°C, 155°C, 165°C, 165°C, 170°C; then drying the granules at 60°C for 10h to obtain a film blowing material, then feeding into a film blowing machine to blow a film, setting the parameters as follows: screw rotation speed 240 rpm, 1-5 zone heating temperature as follows: 140°C, 150°C, 155°C, 165°C, 175°C, pulling speed 9 m / min, to make a plastic film, and then cutting and bag making to obtain the degradable antibacterial plastic packaging bag.

[0036] Example 2

[0037] A degradable antibacterial plastic packaging bag, comprising the following raw materials in parts by weight: polycaprolactone 90 parts; said polybutylene terephthalate-adipate 20 parts; Cr and Cu co-modified ZIF-8 5 parts; cerium oxidation tannic acid material 2 parts;

[0038] The preparation method of the Cr and Cu co-modified ZIF-8 comprises the following steps:

[0039] 0.06 mol of chromium acetate, 0.01 mol of copper chloride, 1.5 mol of zinc nitrate and 4 mol of 2-methylimidazole are ultrasonically dispersed in 200 mL of ethanol, stirred for 40 min, then hydrothermally treated at 180℃ for 10 h, filtered, washed, and vacuum dried at 90℃ for 14 h to obtain the Cr and Cu co-modified ZIF-8;

[0040] The preparation method of the cerium oxidation tannic acid material is the same as that in Embodiment 1.

[0041] A preparation method of a degradable antibacterial plastic packaging bag is the same as that in Embodiment 1.

[0042] Embodiment 3

[0043] A degradable antibacterial plastic packaging bag, comprising the following raw materials in parts by weight: polycaprolactone 70 parts; said polybutylene terephthalate-adipate 40 parts; Cr and Cu co-modified ZIF-8 1 part; cerium oxidation tannic acid material 6 parts;

[0044] The preparation method of the Cr and Cu co-modified ZIF-8 comprises the following steps:

[0045] 0.02 mol of chromium chloride, 0.05 mol of copper nitrate, 1.5 mol of zinc acetate and 3 mol of 2-methylimidazole are ultrasonically dispersed in 200 mL of ethanol, stirred for 20 min, then hydrothermally treated at 140℃ for 20 h, filtered, washed, and vacuum dried at 60℃ for 20 h to obtain the Cr and Cu co-modified ZIF-8;

[0046] The preparation method of the cerium oxidation tannic acid material is the same as that in Embodiment 1.

[0047] A preparation method of a degradable antibacterial plastic packaging bag is the same as that in Embodiment 1.

[0048] Comparative Example 1

[0049] Comparative Example 1 is basically the same as Embodiment 1, except that no Cr and Cu are added in the preparation process of ZIF-8.

[0050] Comparative Example 2

[0051] Comparative Example 2 is basically the same as Example 1, except that an equal amount of Cu-modified ZIF-8 is used to replace the Cr and Cu co-modified ZIF-8. The preparation method of the Cu-modified ZIF-8 comprises the following steps:

[0052] 0.07 mol of copper acetate, 1.5 mol of zinc chloride and 3.5 mol of 2-methylimidazole are ultrasonically dispersed in 200 mL of ethanol, stirred for 30 min, then hydrothermally treated at 160℃ for 15 h, filtered, washed, and vacuum dried at 80℃ for 18 h to obtain Cu-modified ZIF-8.

[0053] Comparative Example 3

[0054] Comparative Example 3 is basically the same as Example 1, except that an equal amount of tannic acid is used to replace the cerium-oxidized tannic acid material.

[0055] Comparative Example 4

[0056] Comparative Example 4 is basically the same as Example 1, except that the cerium-oxidized tannic acid material is used to replace the Cr and Cu co-modified ZIF-8.

[0057] The performance of the degradable antibacterial plastic packaging bag of Examples 1-3 and Comparative Examples 1-4 is tested, and the specific test results are shown in Table 1:

[0058] Among them, the tensile strength is tested according to the national standard GB / T 1040.3-2006;

[0059] The antibacterial rate is tested according to the standard QB / T 2591-2003, and the test strain is Staphylococcus aureus.

[0060] Table 1

[0061]

[0062] As can be seen from 1, the degradable antibacterial plastic packaging bag prepared by the application has excellent antibacterial performance. As can be seen from the comparison of the examples and comparative examples, the antibacterial material selected by the application can significantly improve the antibacterial performance of the packaging bag, and the mechanical properties are better.

[0063] The above examples are preferred embodiments of the application, but the embodiments of the application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the application are equivalent replacement methods, and are all included in the protection scope of the application.

Claims

1. A biodegradable antibacterial plastic packaging bag, characterized in that: By weight, it includes the following raw materials: 70-90 parts of polycaprolactone; 20-40 parts of polybutylene terephthalate-adipate; 1-5 parts of Cr and Cu co-modified ZIF-8; and 2-6 parts of cerium tannin oxide material. The preparation method of the Cr and Cu co-modified ZIF-8 includes the following steps: ultrasonically dispersing chromium salt, copper salt, zinc salt and 2-methylimidazole in ethanol, stirring, then performing hydrothermal treatment, filtering, washing, and vacuum drying to obtain Cr and Cu co-modified ZIF-8; the molar ratio of chromium salt, copper salt, zinc salt and 2-methylimidazole is 0.02~0.06:0.01~0.05:1.5:3~4; The preparation method of the cerium tannate oxide material includes the following steps: tannic acid and sodium periodate are ultrasonically dispersed in deionized water and stirred to react; then an appropriate amount of ethylene glycol is added to remove unreacted sodium periodate, followed by the addition of cerium salt, and the mixture is stirred for 20-40 minutes to obtain a mixed solution; then sodium hydroxide solution is added dropwise to adjust the pH of the mixed solution, and the mixture is stirred at room temperature for 2-4 hours; the solution is then filtered, washed, and vacuum dried to obtain the cerium tannate oxide material; the molar ratio of tannic acid to sodium periodate is 1:2-4; the molar ratio of tannic acid to cerium salt is 1:2-4.

2. The biodegradable antibacterial plastic packaging bag according to claim 1, characterized in that: The chromium salt is one of chromium nitrate, chromium acetate, and chromium chloride; the copper salt is one of copper nitrate, copper acetate, and copper chloride; and the zinc salt is one of zinc nitrate, zinc acetate, and zinc chloride.

3. The biodegradable antibacterial plastic packaging bag according to claim 1, wherein: In the preparation method of Cr and Cu co-modified ZIF-8, the stirring time is 20 to 40 minutes.

4. The biodegradable antibacterial plastic packaging bag according to claim 1, characterized in that: In the preparation method of Cr and Cu co-modified ZIF-8, the hydrothermal treatment conditions are 140-180℃ for 10-20h; the vacuum drying is 60-90℃ for 14-20h.

5. The degradable antibacterial plastic packaging bag according to claim 1, wherein: In the preparation method of the cerium tannin oxide material, the stirring reaction time is 3 to 7 hours.

6. The biodegradable antibacterial plastic packaging bag according to claim 5, characterized in that: In the preparation method of the cerium tannin oxide material, the concentration of the sodium hydroxide solution is 0.1 mol / L, the pH is 7-9, and the vacuum drying is performed at 70-90℃ for 10-14 hours.

7. A biodegradable antibacterial plastic packaging bag according to any one of claims 5-6, characterized in that: The cerium salt is at least one of cerium nitrate, cerium chloride, and cerium acetate.

8. A method for preparing a biodegradable antibacterial plastic packaging bag according to any one of claims 1-7, characterized in that: The preparation method includes the following steps: Polycaprolactone, polybutylene terephthalate-adipate, Cr and Cu co-modified ZIF-8, and cerium tannin oxide are mixed evenly, and then fed into a twin-screw extruder. The parameters are set as follows: screw speed 200-250 rpm, heating temperatures in zones 1-5 as follows: 140-150℃, 150-160℃, 160-170℃, 160-170℃, 170-175℃; then the resulting material... The granules are dried at 50-70℃ for 8-12 hours to obtain blown film material, which is then fed into a blown film machine to form a film. The parameters are set as follows: screw speed 220-260 rpm, heating temperatures of zones 1-5 as follows: 135-140℃, 145-150℃, 150-160℃, 160-170℃, 170-175℃, and traction speed 8-10 m / min. The resulting plastic film is then slit and bagged to obtain biodegradable antibacterial plastic packaging bags.

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