High-toughness antibacterial PVDC composite film and preparation method thereof

Abstract

The invention relates to the technical field of films, and discloses a high-toughness antibacterial PVDC composite film and a preparation method thereof.The high-toughness antibacterial PVDC composite film is prepared from, by weight, 100 parts of 1, 1-dichloroethylene, 10-15 parts of methyl acrylate, 10-15 parts of 2-ethylhexyl acrylate, 5-10 parts of a modified mesoporous silica-based cardanol product, 1-3 parts of an emulsifier and 2-5 parts of an initiator. According to the present invention, the main raw materials are all from biomass, such that the raw materials have characteristics of no toxicity and green, and can be used in the field of packaging films, and the prepared composite film has excellent antibacterial property and excellent mechanical property.

Description

Technical Field

[0001] The present invention relates to the technical field of thin films, and particularly to a high-toughness antibacterial PVDC composite film and a preparation method thereof. Background Art

[0002] Polyvinylidene chloride (PVDC) is a copolymer mainly composed of vinylidene chloride monomer. The film prepared therefrom has good oxygen barrier and moisture barrier properties and is widely used in the fields of food and drug packaging, which can extend the storage life of packaged products, and has a quite broad market development prospect. However, traditional polyvinylidene chloride can no longer meet the requirements of high toughness and antibacterial properties of existing films.

[0003] Cardanol is a natural phenolic compound extracted from waste cashew nut shell liquid, which has properties such as antioxidant, antibacterial, and corrosion resistance. It is rich in resources and low in price, and is widely used in fields such as coatings and adhesives. Mesoporous silica is a porous silica inorganic material with a pore diameter between 2 - 15 nm, which has characteristics such as a large specific surface area, a single and adjustable pore diameter, and high stability. Ginger essential oil is an extract of ginger, which has functions such as antioxidant, antibacterial, and anti-cancer, and is widely used in fields such as daily products and food. However, the stability of ginger essential oil is poor, that is, it is easy to volatilize, which limits the development of ginger essential oil, affects the overall applicability of ginger essential oil, and has a low utilization rate. Summary of the Invention

[0004] (I) Technical Problems to be Solved

[0005] Aiming at the deficiencies of the prior art, the present invention provides a high-toughness antibacterial PVDC composite film and a preparation method thereof. The prepared PVDC composite film has the advantages of long-term antibacterial property and high toughness.

[0006] (II) Technical Solutions

[0007] A high-toughness antibacterial PVDC composite film, the high-toughness antibacterial PVDC composite film comprises the following raw materials in parts by weight: 100 parts by weight of 1,1-dichloroethylene, 10 - 15 parts of methyl acrylate, 10 - 15 parts of isooctyl acrylate, 5 - 10 parts of a modified mesoporous silica-based cardanol product, 1 - 3 parts of an emulsifier, and 2 - 5 parts of an initiator;

[0008] The preparation method of the high-toughness antibacterial PVDC composite film comprises the following steps:

[0009] Add 1,1-dichloroethylene, methyl acrylate, isooctyl acrylate, modified mesoporous silica-based cardanol product, and emulsifier to deionized water. At room temperature, stir and emulsify for 20 - 30 min. Then add an initiator. Under the initiation of the initiator, the alkenyl structure contained in the modified mesoporous silica-based cardanol product reacts with 1,1-dichloroethylene, methyl acrylate, and isooctyl acrylate at 55 - 65 °C for 4 - 6 h. After the reaction, raise the temperature to 70 - 75 °C and cure for 1 h. Coating on a glass plate, control the coating thickness to be 150 μm, and dry to obtain a high-toughness antibacterial PVDC composite film. The mesoporous silica therein is modified to be evenly dispersed in the matrix material. When subjected to external impact, it can absorb the impact energy and improve the mechanical properties of the material.

[0010] Preferably, the emulsifier is one of dodecyl diphenyl ether and sodium styrene sulfonate; the initiator is one of potassium persulfate and sodium bisulfite.

[0011] Preferably, the preparation method of the modified mesoporous silica-based cardanol product includes the following steps:

[0012] Step 1: Add cardanol and formaldehyde to a toluene dispersion medium, and then add p-aminostyrene thereto. The dosage ratio of cardanol, formaldehyde, and p-aminostyrene is 1 mol:(2 - 2.5) mol:(1 - 1.2) mol. Control the reaction temperature to be 75 - 85 °C and continue the reaction for 6 - 10 h. After the reaction, let it stand and separate the layers. Use a separating funnel to separate the lower layer, wash it with a 10% sodium hydroxide solution by mass, rotary evaporate, and dry to obtain a vinyl cardanol product. In this reaction, using cardanol, formaldehyde, and p-aminostyrene as raw materials, through the Mannich reaction, a vinyl cardanol product is obtained, that is, an active alkenyl group is introduced into the product. The reaction equation is:

[0013] ;

[0014] Step 2: Disperse 3-mercaptopropyltriethoxysilane and the vinyl cardanol product in an ethanol dispersion medium. The dosage ratio of 3-mercaptopropyltriethoxysilane to the vinyl cardanol product is 1 mol:(0.8 - 1) mol. Then add an initiator, and the initiator is 2,2-dimethoxy-2-phenylacetophenone, and its dosage is 10 - 20% of the molar dosage of 3-mercaptopropyltriethoxysilane. Stir under ultraviolet light irradiation for 10 - 14 h. After the reaction, wash with deionized water and dry to obtain a silyl cardanol product. In this reaction, under the initiation of 2,2-dimethoxy-2-phenylacetophenone and the condition of ultraviolet light, the alkenyl group contained in the vinyl cardanol product and the mercapto group structure contained in 3-mercaptopropyltriethoxysilane undergo a click reaction to obtain a silyl cardanol product. The reaction equation is:

[0015] ;

[0016] Step 3: Disperse mesoporous silica and ginger essential oil into n-hexane solvent. The dosage ratio of mesoporous silica to ginger essential oil is 1 g : (10 - 15) g. Stir at room temperature for 20 - 24 h, then perform suction filtration and drying to obtain the product of mesoporous silica loaded with ginger essential oil. Ginger essential oil is a natural bacteriostatic agent. However, due to the special volatility of the essential oil, the bacteriostatic effect of ginger essential oil is not ideal. Therefore, in the present invention, mesoporous silica is selected to construct the carrier of ginger essential oil. By utilizing the mesoporous distribution of mesoporous silica, an effective controlled release system can be achieved to reduce the evaporation rate of the loaded ginger essential oil. Moreover, the modified mesoporous silica contains more chemical bonds, enabling mesoporous silica to be tightly combined with the organic structure, and further physically hindering the evaporation of ginger essential oil through the closed effect of molecular chains, thereby improving the physical and chemical stability of ginger essential oil.

[0017] Step 4: Add the product of mesoporous silica loaded with ginger essential oil and the product of silylated cardanol to toluene dispersion medium. The dosage ratio of the product of mesoporous silica loaded with ginger essential oil to the product of silylated cardanol is 1 g : (0.04 - 0.1) mol. React at 75 - 80 °C for 10 - 14 h. After the reaction, filter, wash with ethanol, and dry to obtain the modified mesoporous silica-based cardanol product. The hydroxyl groups on the surface of mesoporous silica and the siloxane structure in the product of silylated cardanol undergo hydrolysis to obtain the modified mesoporous silica-based cardanol product. The reaction route is as follows:

[0018] 。

[0019] (III) Beneficial technical effects

[0020] The PVDC film prepared in the present invention contains antibacterial cardanol structure and antibacterial ginger essential oil. By using modified mesoporous silica to physically adsorb and form a physical barrier to ginger essential oil, the evaporation effect of ginger essential oil is reduced, and the antibacterial persistence of the PVDC composite film is improved.

[0021] The present invention uses mesoporous silica as a raw material. The mesoporous silica has poor compatibility with the PVDC matrix and weak interfacial bonding. After modification in the present invention, the mesoporous silica has an organic-philic end, has good compatibility with the PVDC matrix, and the modified mesoporous silica can be uniformly dispersed in the film substrate to form an interpenetrating interfacial transition layer and chemical bonds, improving the bonding state of the two-phase interface and thus enhancing the mechanical properties of the film material. The PVDC composite film prepared in the present invention contains more branched-chain structures, which can interpenetrate with other branched-chain structures and the main-chain structure, generate chemical bonds, and form physical and chemical crosslinked structures, further enhancing the mechanical properties of the film.

[0022] In addition, due to the poor thermal stability of the PVDC material, it is prone to decomposition when heated. However, the PVDC composite film prepared in the present invention contains heat-resistant rigid benzene ring structures, mesoporous silica inorganic materials, and benzoxazine structures (the benzoxazine structure can absorb heat when heated, open-ring crosslink to form a huge crosslinked network structure, thereby enhancing the heat resistance of the material), which can enhance the heat resistance of the PVDC film and has good application prospects in the field of heat-resistant PVDC. Specific embodiments

[0023] The following further describes in detail a high-toughness antibacterial PVDC composite film and its preparation method in combination with specific embodiments. These embodiments are only for comparison and explanation purposes, and the present invention is not limited to these embodiments.

[0024] Preparation method of mesoporous silica: Add 175 mL of 25% by mass ammonia water and 2.5 g of cetyltrimethylammonium bromide to 250 mL of deionized water, stir at 60 °C for 2 h, then add 12.5 g of tetraethyl orthosilicate thereto, stir vigorously for 8 h, crystallize at room temperature for 24 h, filter, wash, dry, bake at 550 °C for 5 h, and cool to obtain mesoporous silica.

[0025] Example 1

[0026] (1) Add 30 mmol of cardanol and 60 mmol of formaldehyde to a toluene dispersion medium, then add 36 mmol of p-aminostyrene thereto, control the reaction temperature at 80 °C, continue the reaction for 10 h. After the reaction is completed, let it stand and layer, separate the lower layer with a separatory funnel, wash with a 10% by mass sodium hydroxide solution, rotary evaporate, and dry to obtain a vinyl cardanol product.

[0027] (2) 20 mmol of mercaptopropyltriethoxysilane and 19 mmol of vinyl cardanol product were dispersed in an ethanol dispersion medium, and then 3 mmol of 2-dimethoxy-2-phenylacetophenone initiator was added thereto. The mixture was stirred for 12 h under ultraviolet lamp irradiation. After the reaction was completed, it was washed with deionized water and dried to obtain a silyl cardanol product.

[0028] (3) 1 g of mesoporous silica and 10 g of ginger essential oil were dispersed in a n-hexane solvent, stirred at room temperature for 24 h, filtered by suction, and dried to obtain a mesoporous silica-supported ginger essential oil product.

[0029] (4) 0.5 g of the mesoporous silica-supported ginger essential oil product and 0.02 mol of the silyl cardanol product were added to a toluene dispersion medium, and the reaction was carried out at 75 °C for 14 h. After the reaction was completed, it was filtered, washed with ethanol, and dried to obtain a modified mesoporous silica-based cardanol product.

[0030] (5) By weight, 100 parts by weight of 1,1-dichloroethylene, 10 parts of methyl acrylate, 15 parts of isooctyl acrylate, 5 parts of the modified mesoporous silica-based cardanol product, and 2 parts of dodecyl diphenyl ether emulsifier were added to deionized water. At room temperature, it was stirred for 30 min, and then 4 parts of potassium persulfate initiator was added thereto. The temperature was raised to 65 °C and the reaction was carried out for 5 h. After the reaction was completed, the temperature was raised to 75 °C and cured for 1 h. It was coated on a glass plate, and the coating thickness was controlled to be 150 μm, and then dried to obtain a high-toughness antibacterial PVDC composite film.

[0031] Example 2

[0032] (1) 30 mmol of cardanol and 75 mmol of formaldehyde were added to a toluene dispersion medium, and then 35 mmol of p-aminostyrene was added thereto. The reaction temperature was controlled at 85 °C and the reaction was continued for 6 h. After the reaction was completed, it was allowed to stand and layer-separated. The lower layer was separated with a separatory funnel, washed with a 10% by mass sodium hydroxide solution, rotary evaporated, and dried to obtain a vinyl cardanol product.

[0033] (2) 20 mmol of mercaptopropyltriethoxysilane and 20 mmol of vinyl cardanol product were dispersed in an ethanol dispersion medium, and then 3 mmol of 2-dimethoxy-2-phenylacetophenone initiator was added thereto. The mixture was stirred for 14 h under ultraviolet lamp irradiation. After the reaction was completed, it was washed with deionized water and dried to obtain a silyl cardanol product.

[0034] (3) 1 g of mesoporous silica and 12 g of ginger essential oil were dispersed in a n-hexane solvent, stirred at room temperature for 20 h, filtered by suction, and dried to obtain a mesoporous silica-supported ginger essential oil product.

[0035] (4) Add 0.5 g of the mesoporous silica-supported ginger essential oil product and 0.03 mol of the silylated cardanol product into a toluene dispersion medium, react at 80 °C for 10 h. After the reaction, filter, wash with ethanol, and dry to obtain the modified mesoporous silica-based cardanol product.

[0036] (5) By weight, add 100 parts by weight of 1,1-dichloroethylene, 10 parts of methyl acrylate, 10 parts of isooctyl acrylate, 6 parts of the modified mesoporous silica-based cardanol product, and 3 parts of dodecyl diphenyl ether emulsifier into deionized water, stir and emulsify at room temperature for 20 min, then add 2 parts of potassium persulfate initiator thereto, raise the temperature to 60 °C, react for 6 h. After the reaction, raise the temperature to 70 °C and cure for 1 h, coat on a glass plate, control the coating thickness to be 150 μm, and dry to obtain the high-toughness antibacterial PVDC composite film.

[0037] Example 3

[0038] (1) Add 30 mmol of cardanol and 65 mmol of formaldehyde into a toluene dispersion medium, then add 30 mmol of p-aminostyrene thereto, control the reaction temperature to be 75 °C, continue to react for 10 h. After the reaction, let it stand and separate layers, separate the lower layer with a separatory funnel, wash with a 10% by mass sodium hydroxide solution, rotary evaporate, and dry to obtain the vinyl cardanol product.

[0039] (2) Disperse 20 mmol of mercaptopropyltriethoxysilane and 18 mmol of the vinyl cardanol product into an ethanol dispersion medium, then add 2 mmol of 2-dimethoxy-2-phenylacetophenone initiator thereto, stir under ultraviolet lamp irradiation for 10 h. After the reaction, wash with deionized water and dry to obtain the silylated cardanol product.

[0040] (3) Disperse 1 g of mesoporous silica and 14 g of ginger essential oil into a n-hexane solvent, stir at room temperature for 22 h, filter by suction, and dry to obtain the mesoporous silica-supported ginger essential oil product.

[0041] (4) Add 0.5 g of the mesoporous silica-supported ginger essential oil product and 0.04 mol of the silylated cardanol product into a toluene dispersion medium, react at 75 °C for 14 h. After the reaction, filter, wash with ethanol, and dry to obtain the modified mesoporous silica-based cardanol product.

[0042] (5) By weight parts, add 100 parts by weight of 1,1-dichloroethylene, 15 parts of methyl acrylate, 12 parts of isooctyl acrylate, 8 parts of modified mesoporous silica-based cardanol product, and 1 part of sodium p-styrenesulfonate emulsifier to deionized water. At room temperature, stir and emulsify for 30 min, then add 5 parts of sodium bisulfite initiator thereto, raise the temperature to 55 °C, react for 6 h. After the reaction is completed, raise the temperature to 70 °C, cure for 1 h, coat on a glass plate, control the coating thickness to be 150 μm, and dry to obtain a high-toughness antibacterial PVDC composite film.

[0043] Example 4

[0044] (1) Add 30 mmol of cardanol and 70 mmol of formaldehyde to a toluene dispersion medium, then add 34 mmol of p-aminostyrene thereto, control the reaction temperature to be 85 °C, continue to react for 8 h. After the reaction is completed, let it stand and separate layers. Use a separatory funnel to separate the lower layer, wash it with a 10% sodium hydroxide solution by mass fraction, rotary evaporate, and dry to obtain a vinyl cardanol product.

[0045] (2) Disperse 20 mmol of mercaptopropyltriethoxysilane and 16 mmol of vinyl cardanol product in an ethanol dispersion medium, then add 4 mmol of 2,2-dimethoxy-2-phenylacetophenone initiator thereto, stir for 12 h under ultraviolet light irradiation. After the reaction is completed, wash with deionized water and dry to obtain a silyl cardanol product.

[0046] (3) Disperse 1 g of mesoporous silica and 15 g of ginger essential oil in a n-hexane solvent, stir at room temperature for 24 h, filter by suction, and dry to obtain a mesoporous silica-supported ginger essential oil product.

[0047] (4) Add 0.5 g of the mesoporous silica-supported ginger essential oil product and 0.05 mol of the silyl cardanol product to a toluene dispersion medium, react at 80 °C for 12 h. After the reaction is completed, filter, wash with ethanol, and dry to obtain a modified mesoporous silica-based cardanol product.

[0048] (5) By weight parts, add 100 parts by weight of 1,1-dichloroethylene, 12 parts of methyl acrylate, 14 parts of isooctyl acrylate, 10 parts of the modified mesoporous silica-based cardanol product, and 3 parts of sodium p-styrenesulfonate emulsifier to deionized water. At room temperature, stir and emulsify for 25 min, then add 4 parts of sodium bisulfite initiator thereto, raise the temperature to 65 °C, react for 4 h. After the reaction is completed, raise the temperature to 75 °C, cure for 1 h, coat on a glass plate, control the coating thickness to be 150 μm, and dry to obtain a high-toughness antibacterial PVDC composite film.

[0049] Comparative Example 1

[0050] The difference between this comparative example and Example 1 lies in that in step (5), cardanol is used instead of the modified mesoporous silica-based cardanol product.

[0051] Comparative Example 2

[0052] The difference between this comparative example and Example 1 lies in that in step (5), the mesoporous silica-supported ginger essential oil product is used instead of the modified mesoporous silica-based cardanol product.

[0053] Referring to GB / T1040-2006, the tensile properties of the film were tested at a tensile rate of 50 mm / min.

[0054] Referring to GB / T16578.1-2008, the film samples were made into strips 150 mm long and 50 mm wide to test the tear strength.

[0055] Table 1: Mechanical property tests of each example and comparative example

[0056]

[0057] As can be seen from the table, the mechanical properties of Examples 1-4 are better than those of Comparative Examples 1-2. In Comparative Example 2, the mesoporous silica-supported ginger essential oil product is used, and its mechanical properties are the worst. This is because the unmodified mesoporous silica has poor compatibility with the film substrate when added to the film substrate, while the modified mesoporous silica has good compatibility with the film substrate and is more likely to improve the mechanical properties of the material. The greater the tear strength, the better the toughness. It can be seen from Examples 1-4 and Comparative Examples 1-2 that the film prepared by the present invention has good toughness.

[0058] Referring to QB / T2591-2003, the antibacterial properties of the film were tested, and the antibacterial rate after being placed at room temperature for one week was tested. The test bacteria were Escherichia coli and Staphylococcus aureus.

[0059] Table 2: Antibacterial property tests of each example and comparative example

[0060]

[0061] As can be seen from the table, after being placed for one week, the film prepared by the present invention still has good long-term antibacterial properties, and the antibacterial rate can reach up to 99.9%.

[0062] The present invention illustrates a high-toughness antibacterial PVDC composite film and its preparation method through the above examples, but the present invention is not limited to the above examples, that is, it does not mean that the present invention must rely on the above examples to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A high-toughness antibacterial PVDC composite film, characterized in that, The high-toughness antibacterial PVDC composite film comprises the following raw materials in parts by weight: 100 parts by weight of 1,1-dichloroethylene, 10-15 parts of methyl acrylate, 10-15 parts of isooctyl acrylate, 5-10 parts of a modified mesoporous silica-based cardanol product, 1-3 parts of an emulsifier, and 2-5 parts of an initiator; The preparation method of the high-toughness antibacterial PVDC composite film comprises the following steps: Add 1,1-dichloroethylene, methyl acrylate, isooctyl acrylate, the modified mesoporous silica-based cardanol product, and the emulsifier into deionized water, stir and emulsify at room temperature for 20-30 min, then add the initiator thereto, raise the temperature to 55-65 °C, react for 4-6 h, after the reaction is completed, raise the temperature to 70-75 °C, cure for 1 h, coat on a glass plate, control the coating thickness to be 150 μm, and dry to obtain the high-toughness antibacterial PVDC composite film.

2. The high-toughness antibacterial PVDC composite film according to claim 1, wherein The emulsifier is one of dodecyl diphenyl ether and sodium styrene sulfonate; the initiator is one of potassium persulfate and sodium bisulfite.

3. The high-toughness antibacterial PVDC composite film according to claim 1, characterized in that The preparation method of the modified mesoporous silica-based cardanol product comprises the following steps: Step 1: Add cardanol and formaldehyde into a toluene dispersion medium, then add p-aminostyrene thereto, control the reaction temperature to be 75-85 °C, continue to react for 6-10 h, after the reaction is completed, let it stand and separate layers, separate the lower layer with a separating funnel, wash with a 10% sodium hydroxide solution by mass fraction, rotary evaporate and dry to obtain a vinyl cardanol product; Step 2: Disperse 3-mercaptopropyltriethoxysilane and the vinyl cardanol product into an ethanol dispersion medium, then add the initiator thereto, stir under ultraviolet lamp irradiation for 10-14 h, after the reaction is completed, wash with deionized water and dry to obtain a silyl cardanol product; Step 3: Disperse mesoporous silica and ginger essential oil into a n-hexane solvent, stir at room temperature for 20-24 h, filter by suction and dry to obtain a mesoporous silica-supported ginger essential oil product; Step 4: Add the mesoporous silica-supported ginger essential oil product and the silyl cardanol product into a toluene dispersion medium, react at 75-80 °C for 10-14 h, after the reaction is completed, filter, wash with ethanol and dry to obtain the modified mesoporous silica-based cardanol product.

4. The high-toughness antibacterial PVDC composite film according to claim 3, wherein In the step 1, the dosage ratio of cardanol, formaldehyde, and p-aminostyrene is 1 mol:(2-2.5) mol:(1-1.2) mol.

5. The high-toughness antibacterial PVDC composite film according to claim 3, wherein In the step 2, the dosage ratio of 3-mercaptopropyltriethoxysilane and the vinyl cardanol product is 1 mol:(0.8-1) mol.

6. The high-toughness antibacterial PVDC composite film according to claim 3, wherein, In the step 2, the initiator is 2,2-dimethoxy-2-phenylacetophenone, and its dosage is 10-20% of the molar dosage of 3-mercaptopropyltriethoxysilane.

7. The high-toughness antibacterial PVDC composite film according to claim 3, wherein, In the step 3, the dosage ratio of mesoporous silica and ginger essential oil is 1 g:(10-15) g.

8. The high-toughness antibacterial PVDC composite film according to claim 3, wherein In the step 4, the dosage ratio of the mesoporous silica-supported ginger essential oil product and the silyl cardanol product is 1 g:(0.04-0.1) mol.

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