A fresh fruit and vegetable preservation packaging material of composite stone-plastic box-nuclear pore membrane-graphene technology

Abstract

The application relates to the technical field of fruit and vegetable preservation, and discloses a fresh fruit and vegetable preservation packaging material based on a composite stone-plastic box-nuclear pore membrane-graphene technology, which is prepared by the following method: polyester resin, modified calcium carbonate and a plasticizer are mixed and stirred to form a mixture, the mixture is subjected to extrusion shaping to obtain a stone-plastic box base body; a PET polyester film is subjected to heavy ion irradiation to obtain a PET polyester nuclear pore membrane; a composite antibacterial material, tetraethyl orthosilicate, polyester resin, deionized water and ethanol are uniformly mixed and stirred to obtain a graphene antibacterial composite; an adhesive is applied to the stone-plastic box base body, the PET polyester nuclear pore membrane is attached, and the graphene antibacterial composite is sprayed after heat pressing, and the fresh-keeping packaging material is obtained after solidification. The fresh-keeping packaging material comprises a stone-plastic box base body formed by polyester and modified calcium carbonate, a PET polyester film as an air regulating layer, and a graphene antibacterial composite as an antibacterial layer, and has good antibacterial performance and compression strength.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of fruit and vegetable preservation, in particular to a fresh fruit and vegetable preservation packaging material based on a composite stone-plastic box-nuclear pore membrane-graphene technology. BACKGROUND

[0002] During the preservation and storage of fruits and vegetables, the fruits and vegetables are prone to yellowing and rotting due to high water content, tender and brittle organization, high field heat and respiration heat of postharvest fruits and vegetables, and fast water evaporation, and the shelf life is short, and the fruits and vegetables are prone to rotting during the logistics transportation process, therefore, the fruits and vegetables need to be preserved, and the preservation packaging materials on the market are mostly polyvinyl chloride, polypropylene and polyvinylidene fluoride packaging materials, and the fruits and vegetables are prone to rotting due to the condensation phenomenon during the storage and transportation of the packaging materials.

[0003] The PET polyester (polyethylene terephthalate) and calcium carbonate are mixed to form a stone-plastic box as the base of the fruit and vegetable preservation packaging material, and the stone-plastic box has heat resistance, moisture resistance and water resistance, and has good fruit and vegetable preservation effect, but the calcium carbonate is prone to agglomeration, stress concentration points are formed, the compression strength of the fruit and vegetable preservation packaging material is reduced, the antibacterial performance is poor, and the storage effect of the fruits and vegetables is affected, in addition, the existing technology lacks a solution of gas regulation-antibacterial-anti-vibration cooperation, and the loss rate of the fruits and vegetables during the storage process is high. SUMMARY

[0004] The application provides a fresh fruit and vegetable preservation packaging material based on a composite stone-plastic box-nuclear pore membrane-graphene technology, and solves the problems of poor antibacterial performance and compression strength of the existing fruit and vegetable preservation packaging materials.

[0005] The technical scheme of the application is as follows:

[0006] A preparation method of a fresh fruit and vegetable preservation packaging material based on a composite stone-plastic box-nuclear pore membrane-graphene technology, comprising the following preparation steps:

[0007] S1. mixing polyester resin, modified calcium carbonate and plasticizer, stirring to form a mixture, placing the mixture in a mold, and extruding and shaping to obtain a stone-plastic box base;

[0008] S2. irradiating a PET polyester film with heavy ions to obtain a PET polyester nuclear pore membrane;

[0009] S3. mixing a composite antibacterial material, tetraethyl orthosilicate, polyester resin, deionized water and ethanol, and stirring uniformly to obtain a graphene antibacterial composite;

[0010] S4. applying an adhesive on the stone-plastic box base, attaching the PET polyester nuclear pore membrane, heat pressing, then spraying the graphene antibacterial composite, and solidifying to obtain the preservation packaging material;

[0011] The modified calcium carbonate is obtained by depositing nano calcium carbonate on the surface of pretreated carbon fibers, and then mixing and reacting with ethylene glycol and terephthalic acid.

[0012] The composite antibacterial material is obtained by mixing and reacting modified graphene oxide, gum, carboxymethyl cellulose and sericin powder.

[0013] The modified graphene oxide is obtained by mixing and reacting copper sulfate pentahydrate, graphene oxide and L-ascorbic acid, and then reacting with naringin and a coupling agent.

[0014] Further, in step S1, the stirring temperature is 150-160℃, the stirring speed is 7000-8000r / min, and the stirring time is 10-15min; the mold temperature is 180-190℃.

[0015] Further, in step S1, the mass ratio of polyester resin, modified calcium carbonate and plasticizer is (50-60):(30-40):(1-2).

[0016] Further, in step S2, the heavy ion irradiation process: using the Lanzhou heavy ion research device, the energy of 129Xe ion beam is 80MeV / u, the irradiation dose is 1×10 11 ions / cm 2 .

[0017] Further, in step S3, the amount ratio of composite antibacterial material, tetraethyl orthosilicate, polyester resin, deionized water and ethanol is (2-3)g:(5-6)g:(45-55)g:(40-50)mL:(45-55)mL.

[0018] Further, in step S4, the hot pressing process: the hot pressing temperature is 165-175℃, the hot pressing pressure is 10-15MPa, and the hot pressing time is 10-20min.

[0019] Further, in step S4, the spraying pressure is 0.2-0.4MPa, the curing temperature is 100-120℃, and the curing time is 20-30min.

[0020] Further, the thickness of the stone plastic box base body is 2-3mm.

[0021] Further, the thickness of the PET polyester film is 45-55μm.

[0022] Further, the thickness of the graphene antibacterial compound coating is 45-55μm.

[0023] Further, the polyester resin is selected from any one of polyethylene terephthalate, polylactic acid and polybutylene terephthalate.

[0024] Further, the adhesive is a cyanoacrylate adhesive, brand ODAKE, Dongguan He Xuxinwang Adhesive Co., Ltd.

[0025] Further, the plasticizer is selected from any one of epoxidized soybean oil, triethyl citrate, glycerol and polyethylene glycol.

[0026] Further, the composite antibacterial material is specifically prepared by the following steps:

[0027] A1. The graphene oxide is added to the deionized water, stirred uniformly, copper sulfate is added, after ultrasonic treatment, L-ascorbic acid is added, and reacted at 30-40℃ for 1-2h, filtered, washed, dried, to obtain graphene oxide loaded with nano-copper;

[0028] A2. Naringin is added to ethanol and deionized water, stirred uniformly, coupling agent is added, stirred and reacted at 70-80℃ for 1-2h, graphene oxide loaded with nano-copper and hydrochloric acid are added, and continue to stir for 20-30min, filtered, washed, dried, to obtain modified graphene oxide;

[0029] A3. The modified graphene oxide is added to the deionized water, stirred uniformly, gum and glycerol are added, ultrasonic treatment is carried out at 40-60KHz for 10-20min, and dried to volatilize the water, to obtain a gum-modified graphene oxide composite material;

[0030] A4. The silk gum powder, gum-modified graphene oxide composite material and carboxymethyl cellulose are added to the deionized water, stirred and reacted at 45-50℃ for 40-50min, and freeze-dried, to obtain a composite antibacterial material.

[0031] Further, in the above A1 reaction process, the graphene oxide surface contains a large number of oxygen-containing functional groups, which can combine with copper ions in copper sulfate pentahydrate, so that the copper ions are deposited on the graphene oxide, and L-ascorbic acid as a reducing agent can reduce the copper ions to nano-copper particles, so that uniform distribution of nano-copper is formed on the surface of graphene oxide, and graphene oxide loaded with nano-copper is obtained.

[0032] Further, in the above A2 reaction process, the silicon hydroxyl produced by the hydrolysis of the coupling agent can react with the hydroxyl on the surface of the graphene oxide loaded with nano-copper, and the amino group carried by the coupling agent can combine with the oxygen-containing functional groups in naringin through chemical bonds, so that naringin is coated on the surface of graphene oxide loaded with nano-copper, and modified graphene oxide is obtained.

[0033] Further, in the A3 reaction process, the naringin contained in the modified graphene oxide surface and the hydroxyl and carboxyl contained in the gum molecular chain are combined by hydrogen bond, so that the modified graphene oxide is uniformly dispersed in the gum, and the polysaccharide segment of the gum is inserted between the layers of the modified graphene oxide to form a layered gum-modified graphene oxide composite material.

[0034] Further, in the A4 reaction process, the sericin powder forms a sericin solution after heating, and the hydroxyl and carboxyl contained therein can be combined with carboxymethyl cellulose by chemical bond to form a cross-linked network structure of the gel, and the gum-modified graphene oxide composite material can also be embedded in the cross-linked network structure of the gel to obtain a composite antibacterial material.

[0035] Further, in step A1, the amount ratio of the graphene oxide, deionized water, copper sulfate and L-ascorbic acid is (1-2) g:(180-220) mL:(2-3) g:(1-1.2) g.

[0036] Further, in step A2, the amount ratio of the naringin, ethanol, deionized water, coupling agent, graphene oxide loaded with nano copper and hydrochloric acid is (1.3-1.5) g:(25-35) mL:(8-12) mL:(0.4-0.6) g:(2.5-2.9) g:(0.4-0.6) mL.

[0037] Further, in step A3, the amount ratio of the modified graphene oxide, deionized water, gum and glycerol is (2-3) g:(90-110) mL:(1.1-1.3) g:(0.4-1.6) g.

[0038] Further, in step A4, the amount ratio of the sericin powder, gum-modified graphene oxide composite material, carboxymethyl cellulose and deionized water is (8-9) g:(2-3) g:(1.2-1.4) g:(45-55) mL.

[0039] Further, the modified calcium carbonate is prepared by the following steps:

[0040] B1. The pretreated carbon fiber is added to deionized water, stirred uniformly, and then nano calcium carbonate is added. After ultrasonic treatment, filtration, washing and drying, the carbon fiber loaded with nano calcium carbonate is obtained.

[0041] B2. The carbon fiber loaded with nano calcium carbonate is added to ethylene glycol, stirred at 165-175℃ for 3-5h, and then terephthalic acid and antimony trioxide are added. After stirring uniformly, the reaction is carried out at 220-240℃, 0.4-0.6MPa for 30-40min, and then cooled to room temperature. After taking out, washing and drying, the modified nano calcium carbonate is obtained.

[0042] Further, in the above B1 reaction process, the pretreated carbon fiber has excellent adhesion and contains a large number of phenolic hydroxyl groups, so that the nano calcium carbonate is deposited on the surface of the pretreated carbon fiber to obtain the carbon fiber loaded with nano calcium carbonate.

[0043] Further, in the above B2 reaction process, the carbon fiber loaded with nano calcium carbonate is divided in ethylene glycol, and the ethylene glycol is subjected to polycondensation reaction with terephthalic acid with antimony trioxide as a catalyst, so that the polyethylene terephthalate is formed on the surface of the carbon fiber loaded with nano calcium carbonate to obtain the modified calcium carbonate.

[0044] Further, in step B1, the amount ratio of the pretreated carbon fiber, deionized water and nano calcium carbonate is (5-6) g:(90-110) mL:(1-2) g.

[0045] Further, in step B2, the mass ratio of the carbon fiber loaded with nano calcium carbonate, ethylene glycol, terephthalic acid and antimony trioxide is (2-3):(6-8):(15-17):(1.1-1.3).

[0046] Further, the nano particles are selected from any one of nano silicon dioxide, nano aluminum oxide and nano magnesium oxide.

[0047] The present application has the following beneficial effects:

[0048] (1) In the technical scheme of the present application, the nano copper is formed on the surface of the graphene oxide, the graphene oxide serves as a carrier of the nano copper, so that the nano copper is uniformly distributed on the surface of the graphene oxide, and the agglomeration of the nano copper is avoided, and the graphene oxide and the nano copper serve as inorganic antibacterial materials and have good antibacterial activity; the naringin is coated on the surface of the graphene oxide loaded with the nano copper through a coupling agent, on one hand, the naringin interacts with the microbial membrane, promotes the leakage of intracellular components, can prevent the bacteria from passing through the plastic-based thin film, has antibacterial activity, and the naringin and the graphene oxide loaded with the nano copper form organic-inorganic antibacterial materials, enhance the antibacterial activity of the fruit and vegetable preservation packaging material, on the other hand, the naringin forms a flexible protective film on the surface of the graphene oxide loaded with the nano copper, avoids the hardness of the graphene oxide loaded with the nano copper, prevents the antibacterial coating of the preservation packaging material from being damaged, and causes the antibacterial performance of the preservation packaging material to be reduced.

[0049] (2) In the technical scheme of the present application, the modified graphene oxide and the gum form a layered structure. On the one hand, the polysaccharide chain segments of the gum are inserted between the modified graphene oxide nanosheet layers to form an organic-inorganic alternating layered structure, which can reduce the water vapor transmission rate and improve the antibacterial activity. On the other hand, the organic-inorganic alternating layered structure can absorb external stress and enhance the compressive strength of the fresh-keeping packaging material. The gum-modified graphene oxide composite material, carboxymethyl cellulose, and silk gum powder are mixed to form an aerogel structure with a cross-linked network structure. On the one hand, the gum-modified graphene oxide composite material is dispersed in the silk gum gel system, enhancing the adsorption and fixation of the modified graphene oxide and preventing the inorganic antibacterial material from migrating and precipitating under external force, which affects the antibacterial activity. On the other hand, the gum-modified graphene oxide increases the cross-linking density of the silk gum gel, improving the mechanical strength of the silk gum gel and further enhancing the compressive strength of the fresh-keeping packaging material.

[0050] (3) In the technical scheme of the present application, nano calcium carbonate is deposited on the surface of pretreated carbon fiber. On the one hand, nano calcium carbonate forms a concave-convex structure on the surface of pretreated carbon fiber, increasing the contact area with the stone plastic box matrix, so that the carbon fiber loaded with nano calcium carbonate can better act in the polyester stone plastic box. On the other hand, the excellent aspect ratio of carbon fiber can form a transition layer that absorbs attraction in the stone plastic box matrix, thereby reducing the stress generated by external force and enhancing the compressive strength of the fruit and vegetable fresh-keeping packaging material. Polyethylene terephthalate is formed on the surface of the carbon fiber loaded with nano calcium carbonate to obtain modified calcium carbonate. The formed polyester structure has excellent compatibility with the polyester stone plastic box, and the modified calcium carbonate can strongly hydrogen bond with the polyester stone plastic box matrix, so that the modified calcium carbonate is uniformly dispersed in the polyester stone plastic box matrix to form a cross-linked network structure, enhancing the compressive strength of the polyester stone plastic box.

[0051] (4) In the technical scheme of the present application, the polyester stone plastic box formed by polyethylene terephthalate and modified calcium carbonate is used as the matrix of the fresh-keeping packaging material, which has excellent compressive strength. The PET polyester film with a nuclear pore structure is used as the modified atmosphere layer of the fresh-keeping packaging material, which significantly improves the CO2 / O2 exchange ratio of the fresh-keeping packaging material and has good storage effect on fruits and vegetables. The composite antibacterial material, tetraethyl orthosilicate, and polyethylene terephthalate are used as the graphene antibacterial layer of the fresh-keeping packaging material, which can significantly improve the antibacterial performance and compressive strength of the fresh-keeping packaging material, so that the fresh-keeping packaging material maintains the nuclear pore structure and improves the CO2 / O2 exchange ratio of the fresh-keeping packaging material. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be clearly and completely described below with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0053] The raw materials used in the embodiments of the present application are shown as follows, and all the reagents used are analytical grade.

[0054] The polyester resin is polyethylene terephthalate with a product number of P875573 and is purchased from Shanghai Macklin Biochemical Technology Co., Ltd. The plasticizer is epoxy soybean oil of industrial grade and is purchased from Shandong Kexing Chemical Co., Ltd.

[0055] The PET polyester film is purchased from Tianjin Deli Film Co., Ltd.

[0056] The adhesive is a cyanoacrylate adhesive with a brand of ODAKE and is purchased from Dongguan He Xuxinwang Adhesive Co., Ltd.

[0057] The coupling agent is gamma-aminopropyl triethoxysilane, and the gum is gum arabic.

[0058] The silk powder is purchased from Wuhan Huaxiang Kejebio Technology Co., Ltd.

[0059] The particle size of the graphene oxide is 2.5 μm, the length of the carbon fiber is 5 μm, and the diameter of the carbon fiber is 100 nm; and the particle size of the nano calcium carbonate is 60 nm.

[0060] The pretreated carbon fiber is prepared by the following steps:

[0061] 2 g of carbon fiber is added into 100 mL of deionized water, stirred uniformly, 0.4 g of Tris-HCl buffer with a pH of 8.5 and 0.7 g of dopamine are added, and the mixture is stirred at 30℃ and 2000 r / min for 2 h, filtered, washed with ethanol for 2 times, and dried in a 70℃ oven for 10 min to obtain the pretreated carbon fiber.

[0062] Example 1

[0063] A preparation method of a fresh fruit and vegetable preservation packaging material of a composite stone-plastic box-nuclear pore membrane-graphene technology, comprising the following preparation steps:

[0064] S1. Polyethylene terephthalate, modified calcium carbonate and epoxy soybean oil are mixed to form a mixture, the mixture is placed in a mold, and is shaped by extrusion to obtain a stone-plastic box matrix; wherein the mass ratio of the polyester resin, the modified calcium carbonate and the epoxy soybean oil is 50:30:1.

[0065] S2. The PET polyester film is irradiated by heavy ions to obtain a PET polyester nuclear pore membrane; wherein the heavy ion irradiation process: using the Lanzhou heavy ion research device, the energy of the 129Xe ion beam is 80MeV / u, the irradiation dose is 1×10 11 ions / cm 2 ;

[0066] S3. The composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol are mixed and stirred uniformly to obtain a graphene antibacterial composite; wherein the amount ratio of the composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol is 2g:5g:45g:40mL:45mL;

[0067] S4. 10g of cyano acrylate adhesive is applied on the stone plastic box base body, the PET polyester nuclear pore membrane is attached, after hot pressing, the graphene antibacterial composite is sprayed, and after curing, a fresh-keeping packaging material is obtained; wherein the hot pressing process: the hot pressing temperature is 165℃, the hot pressing pressure is 10MPa, and the hot pressing time is 10min; the spraying pressure is 0.2MPa, the curing temperature is 100℃, and the curing time is 20min;

[0068] The thickness of the stone plastic box base body is 2mm; the thickness of the PET polyester film is 45μm; and the thickness of the graphene antibacterial composite coating is 45μm.

[0069] The composite antibacterial material is prepared by the following steps:

[0070] A1. 1g of graphene oxide is added to 180mL of deionized water, stirred uniformly, 2g of copper sulfate is added, ultrasonic mixing treatment is carried out at 50KHz for 30min, 1g of L-ascorbic acid is added, reaction is carried out at 30℃ for 1h, filtration is carried out, deionized water washing is carried out for 3 times, and drying is carried out in a 60℃ oven for 12h to obtain graphene oxide loaded with nano copper;

[0071] A2. 1.3g of naringin is added to 25mL of ethanol and 8mL of deionized water, stirred uniformly, 0.4g of γ-aminopropyl triethoxysilane is added, stirring reaction is carried out at 70℃ for 1h, 2.5g of graphene oxide loaded with nano copper and 0.4mL of hydrochloric acid with a concentration of 0.1mol / L are added, stirring is continued for 20min, filtration is carried out, deionized water washing is carried out for 3 times, and drying is carried out in a 60℃ oven for 15min to obtain modified graphene oxide;

[0072] A3. 2g of modified graphene oxide is added to 90mL of deionized water, stirred uniformly, 1.1g of gum arabic and 0.4g of glycerol are added, ultrasonic treatment is carried out at 40KHz for 10min, and drying is carried out at 100℃ until the water volatilizes to obtain a gum-modified graphene oxide composite material;

[0073] A4. 8 g of silk powder, 2 g of gum-modified graphene oxide composite material and 1.2 g of carboxymethyl cellulose were added to 45 mL of deionized water, stirred at 45°C for 40 min, placed in a freezer, frozen and dried at -20°C for 20 h to obtain a composite antibacterial material.

[0074] The modified calcium carbonate was prepared by the following steps:

[0075] B1. 5 g of pretreated carbon fiber was added to 90 mL of deionized water, stirred uniformly, 1 g of nano calcium carbonate was added, ultrasonically treated at 50 KHz for 1.5 h, filtered, washed with deionized water for 3 times, and dried in an oven at 80°C for 10 min to obtain carbon fiber loaded with nano calcium carbonate;

[0076] B2. 2 g of carbon fiber loaded with nano calcium carbonate was added to 6 g of ethylene glycol, stirred at 165°C for 3 h, 15 g of terephthalic acid and 1.1 g of antimony trioxide were added, stirred uniformly, reacted at 220°C and 0.4 MPa for 30 min, cooled to room temperature, taken out, washed with deionized water for 3 times, and dried in an oven at 70°C for 10 min to obtain modified nano calcium carbonate.

[0077] Example 2

[0078] A preparation method of a fresh fruit and vegetable preservation packaging material of a composite stone plastic box-nanopore membrane-graphene technology, comprising the following preparation steps:

[0079] S1. Polyethylene terephthalate, modified calcium carbonate and epoxy soybean oil were mixed to form a mixture, the mixture was placed in a mold and extruded to shape to obtain a stone plastic box matrix; wherein the mass ratio of polyester resin, modified calcium carbonate and epoxy soybean oil was 55:35:1.5;

[0080] S2. The PET polyester film was irradiated by heavy ions to obtain a PET polyester nanopore membrane; wherein the heavy ion irradiation process: using a 80 MeV / u 129Xe ion beam of Lanzhou Heavy Ion Research Device, the irradiation dose was 1×10 11 ions / cm 2 ;

[0081] S3. The composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol were mixed and stirred uniformly to obtain a graphene antibacterial composite; wherein the amount ratio of the composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol was 2.5 g:5.5 g:50 g:45 mL:50 mL;

[0082] S4. 10 g of cyanoacrylate adhesive is applied on the stone plastic box base body, and a PET polyester microporous film is attached. After hot pressing, a graphene antibacterial compound is sprayed, and after curing, a fresh-keeping packaging material is obtained. The hot pressing process is as follows: hot pressing temperature is 170℃, hot pressing pressure is 13 MPa, hot pressing time is 15 min; the spraying pressure is 0.3 MPa, the curing temperature is 110℃, and the curing time is 25 min;

[0083] The thickness of the stone plastic box base body is 2.5 mm; the thickness of the PET polyester film is 50 μm; and the thickness of the graphene antibacterial compound coating is 50 μm.

[0084] The composite antibacterial material is prepared by the following steps:

[0085] A1. 1.5 g of graphene oxide is added to 200 mL of deionized water, stirred uniformly, 2.5 g of copper sulfate is added, ultrasonic mixing treatment is carried out at 50 KHz for 30 min, 1.1 g of L-ascorbic acid is added, and reaction is carried out at 35℃ for 1.5 h. After filtration, deionized water washing is carried out for 3 times, and drying is carried out in a 60℃ oven for 12 h to obtain graphene oxide loaded with nano copper;

[0086] A2. 1.4 g of naringin is added to 30 mL of ethanol and 10 mL of deionized water, stirred uniformly, 0.5 g of γ-aminopropyl triethoxysilane is added, stirring reaction is carried out at 75℃ for 1.5 h, 2.7 g of graphene oxide loaded with nano copper and 0.5 mL of hydrochloric acid with a concentration of 0.1 mol / L are added, and stirring is continued for 25 min. After filtration, deionized water washing is carried out for 3 times, and drying is carried out in a 60℃ oven for 15 min to obtain modified graphene oxide;

[0087] A3. 2.5 g of modified graphene oxide is added to 100 mL of deionized water, stirred uniformly, 1.2 g of gum arabic and 0.5 g of glycerol are added, ultrasonic treatment is carried out at 50 KHz for 15 min, and drying is carried out at 100℃ until the water volatilizes to obtain a gum-modified graphene oxide composite material;

[0088] A4. 8.5 g of silk gum powder, 2.5 g of gum-modified graphene oxide composite material and 1.3 g of carboxymethyl cellulose are added to 50 mL of deionized water, stirring reaction is carried out at 48℃ for 45 min, and freezing drying is carried out in a freezer at -20℃ for 20 h to obtain a composite antibacterial material.

[0089] The modified calcium carbonate is prepared by the following steps:

[0090] B1. 5.6 g of pretreated carbon fiber was added to 100 mL of deionized water, stirred uniformly, 1.5 g of nano calcium carbonate was added, ultrasonic treatment was carried out for 1.5 h at 50 KHz, filtered, washed with deionized water for 3 times, dried in an oven at 80℃ for 10 min, to obtain carbon fiber loaded with nano calcium carbonate;

[0091] B2. 2.6 g of carbon fiber loaded with nano calcium carbonate was added to 7 g of ethylene glycol, stirred at 170℃ for 4 h, 16 g of terephthalic acid and 1.2 g of antimony trioxide were added, stirred uniformly, reacted at 230℃, 0.5 MPa for 35 min, cooled to room temperature, taken out, washed with deionized water for 3 times, dried in an oven at 70℃ for 10 min, to obtain modified nano calcium carbonate.

[0092] Example 3

[0093] A preparation method of a fresh fruit and vegetable preservation packaging material based on a composite stone-plastic box-nanopore membrane-graphene technology, comprising the following preparation steps:

[0094] S1. Polyethylene terephthalate, modified calcium carbonate and epoxy soybean oil were mixed to form a mixture, the mixture was placed in a mold and extruded to shape, to obtain a stone-plastic box matrix; wherein the mass ratio of polyester resin, modified calcium carbonate and epoxy soybean oil was 60:40:2;

[0095] S2. The PET polyester film was irradiated by heavy ions to obtain a PET polyester nanopore membrane; wherein the heavy ion irradiation process: using the Lanzhou Heavy Ion Research Device, 129Xe ion beam with an energy of 80 MeV / u, the irradiation dose was 1×10 11 ions / cm 2 ;

[0096] S3. The composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol were mixed and stirred uniformly to obtain a graphene antibacterial composite; wherein the amount ratio of the composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol was 3 g:6 g:55 g:50 mL:55 mL;

[0097] S4. 12 g of cyanoacrylate adhesive was applied on the stone-plastic box matrix, the PET polyester nanopore membrane was attached, and then the graphene antibacterial composite was sprayed, and after curing, a preservation packaging material was obtained; wherein the hot pressing process: the hot pressing temperature was 175℃, the hot pressing pressure was 15 MPa, and the hot pressing time was 20 min; the spraying pressure was 0.4 MPa, the curing temperature was 120℃, and the curing time was 30 min;

[0098] The thickness of the stone-plastic box matrix was 3 mm; the thickness of the PET polyester film was 55 μm; the thickness of the graphene antibacterial composite coating was 55 μm.

[0099] The composite antibacterial material is prepared by the following steps:

[0100] A1. 2 g of graphene oxide was added into 220 mL of deionized water, stirred uniformly, 3 g of copper sulfate was added, ultrasonic mixing treatment was carried out at 50 KHz for 30 min, 1.2 g of L-ascorbic acid was added, reaction was carried out at 40°C for 2 h, filtration was carried out, deionized water washing was carried out for 3 times, drying was carried out in an oven at 60°C for 12 h, and graphene oxide loaded with nano copper was obtained;

[0101] A2. 1.5 g of naringin was added into 35 mL of ethanol and 12 mL of deionized water, stirred uniformly, 0.6 g of γ-aminopropyl triethoxysilane was added, stirring reaction was carried out at 80°C for 2 h, 2.9 g of graphene oxide loaded with nano copper and 0.6 mL of hydrochloric acid with a concentration of 0.1 mol / L were added, stirring was continued for 30 min, filtration was carried out, deionized water washing was carried out for 3 times, drying was carried out in an oven at 60°C for 15 min, and modified graphene oxide was obtained;

[0102] A3. 3 g of modified graphene oxide was added into 110 mL of deionized water, stirred uniformly, 1.3 g of gum arabic and 0.6 g of glycerol were added, ultrasonic treatment was carried out at 60 KHz for 20 min, drying was carried out at 100°C until water volatilization, and gum-modified graphene oxide composite material was obtained;

[0103] A4. 9 g of silk gum powder, 3 g of gum-modified graphene oxide composite material and 1.4 g of carboxymethyl cellulose were added into 55 mL of deionized water, stirring reaction was carried out at 50°C for 50 min, freezing drying was carried out in a freezer at -20°C for 20 h, and the composite antibacterial material was obtained.

[0104] The modified calcium carbonate is prepared by the following steps:

[0105] B1. 6 g of pretreated carbon fiber was added into 110 mL of deionized water, stirred uniformly, 2 g of nano calcium carbonate was added, ultrasonic treatment was carried out at 50 KHz for 1.5 h, filtration was carried out, deionized water washing was carried out for 3 times, drying was carried out in an oven at 80°C for 10 min, and carbon fiber loaded with nano calcium carbonate was obtained;

[0106] B2. 3 g of carbon fiber loaded with nano calcium carbonate was added into 8 g of ethylene glycol, stirring was carried out at 175°C for 5 h, 17 g of terephthalic acid and 1.3 g of antimony trioxide were added, stirring was carried out uniformly, reaction was carried out at 240°C, 0.6 MPa for 40 min, cooling was carried out to room temperature, taken out, deionized water washing was carried out for 3 times, drying was carried out in an oven at 70°C for 10 min, and modified nano calcium carbonate was obtained.

[0107] Comparative Example 1

[0108] The application discloses a preparation method of a fresh fruit and vegetable preservation packaging material based on a composite stone-plastic box-nuclear pore membrane-graphene technology.

[0109] S1. Polyethylene terephthalate, modified calcium carbonate and epoxy soybean oil are mixed to form a mixture, the mixture is placed in a mold, and is shaped by extrusion to obtain a stone-plastic box base body; wherein the mass ratio of the polyester resin, the modified calcium carbonate and the epoxy soybean oil is 60:40:2;

[0110] S2. The PET polyester film is irradiated by heavy ions to obtain a PET polyester nuclear pore membrane; wherein the heavy ion irradiation process is as follows: a 129Xe ion beam with an energy of 80 MeV / u is adopted by using a Lanzhou heavy ion research device, and the irradiation dose is 1x10 11 ions / cm 2 ;

[0111] S3. The composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol are mixed and stirred uniformly to obtain a graphene antibacterial composite; wherein the dosage ratio of the composite antibacterial material, the tetraethyl orthosilicate, the polyethylene terephthalate, the deionized water and the ethanol is 3g:6g:55g:50mL:55mL;

[0112] S4. 12g of cyano acrylate adhesive is applied on the stone-plastic box base body, the PET polyester nuclear pore membrane is attached, and then the graphene antibacterial composite is sprayed after hot pressing, and the preservation packaging material is obtained after solidification; wherein the hot pressing process is as follows: the hot pressing temperature is 175 DEG C, the hot pressing pressure is 15 MPa, and the hot pressing time is 20 min; the spraying pressure is 0.4 MPa, the solidification temperature is 120 DEG C, and the solidification time is 30 min;

[0113] The thickness of the stone-plastic box base body is 3mm; the thickness of the PET polyester film is 55um; and the coating thickness of the graphene antibacterial composite is 55um.

[0114] The composite antibacterial material is prepared by the following steps:

[0115] A1. 1.5g of naringin is added into 35mL of ethanol and 12mL of deionized water, and is stirred uniformly, 0.6g of γ-aminopropyl triethoxysilane is added, and stirring reaction is carried out at 80 DEG C for 2h, 2.9g of graphene oxide and 0.6mL of hydrochloric acid with a concentration of 0.1mol / L are added, and stirring is continued for 30min, filtration is carried out, deionized water washing is carried out for 3 times, and drying is carried out in a 60 DEG C oven for 15min to obtain modified graphene oxide;

[0116] A2. 3 g of modified graphene oxide was added to 110 mL of deionized water, stirred uniformly, 1.3 g of gum arabic and 0.6 g of glycerol were added, ultrasonic treatment was carried out at 60 KHz for 20 min, and drying was carried out at 100℃ until the water was volatilized to obtain a gum-modified graphene oxide composite material;

[0117] A3. 9 g of gum powder, 3 g of gum-modified graphene oxide composite material and 1.4 g of carboxymethyl cellulose were added to 55 mL of deionized water, stirred and reacted at 50℃ for 50 min, and freeze-dried at -20℃ for 20 h in a refrigerator to obtain a composite antibacterial material.

[0118] The modified calcium carbonate was prepared by the following steps:

[0119] B1. 6 g of pretreated carbon fiber was added to 110 mL of deionized water, stirred uniformly, 2 g of nano calcium carbonate was added, ultrasonic treatment was carried out at 50 KHz for 1.5 h, filtered, washed with deionized water for 3 times, and dried in an oven at 80℃ for 10 min to obtain nano calcium carbonate loaded carbon fiber;

[0120] B2. 3 g of nano calcium carbonate loaded carbon fiber was added to 8 g of ethylene glycol, stirred at 175℃ for 5 h, 17 g of terephthalic acid and 1.3 g of antimony trioxide were added, stirred uniformly, reacted at 240℃ and 0.6 MPa for 40 min, cooled to room temperature, taken out, washed with deionized water for 3 times, and dried in an oven at 70℃ for 10 min to obtain modified nano calcium carbonate.

[0121] Comparative Example 2

[0122] A preparation method of a fresh fruit and vegetable preservation packaging material of a composite stone plastic box-nanopore membrane-graphene technology, comprising the following preparation steps:

[0123] S1. Polyethylene terephthalate, modified calcium carbonate and epoxy soybean oil were mixed to form a mixture, the mixture was placed in a mold and extruded to be shaped to obtain a stone plastic box matrix; wherein the mass ratio of polyester resin, modified calcium carbonate and epoxy soybean oil is 60:40:2;

[0124] S2. The PET polyester film was irradiated by heavy ions to obtain a PET polyester nanopore membrane; wherein the heavy ion irradiation process: using a 80 MeV / u 129Xe ion beam of a Lanzhou heavy ion research device, the irradiation dose is 1×10 11 ions / cm 2 ;

[0125] S3. Mix the composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol, stir uniformly to obtain a graphene antibacterial compound; wherein the amount ratio of the composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol is 3g:6g:55g:50mL:55mL;

[0126] S4. Apply 12g of cyano acrylate adhesive on the stone plastic box base, adhere the PET polyester microporous film, after hot pressing, spray the graphene antibacterial compound, and after curing, obtain a fresh-keeping packaging material; wherein the hot pressing process is: hot pressing temperature is 175℃, hot pressing pressure is 15MPa, hot pressing time is 20min; the spraying pressure is 0.4MPa, the curing temperature is 120℃, and the curing time is 30min;

[0127] The thickness of the stone plastic box base is 3mm; the thickness of the PET polyester film is 55μm; the thickness of the graphene antibacterial compound coating is 55μm.

[0128] The composite antibacterial material is specifically prepared by the following steps:

[0129] A1. Add 2g of graphene oxide to 220mL of deionized water, stir uniformly, add 3g of copper sulfate, ultrasonic mixing treatment at 50KHz for 30min, add 1.2g of L-ascorbic acid, react at 40℃ for 2h, filter, wash with deionized water for 3 times, dry in a 60℃ oven for 12h to obtain graphene oxide loaded with nano copper;

[0130] A2. Add 3g of graphene oxide loaded with nano copper to 110mL of deionized water, stir uniformly, add 1.3g of gum arabic and 0.6g of glycerol, ultrasonic treatment at 60KHz for 20min, dry at 100℃ until the water volatilizes to obtain a gum-graphene oxide composite material;

[0131] A3. Add 9g of silk gum powder, 3g of gum-graphene oxide composite material and 1.4g of carboxymethyl cellulose to 55mL of deionized water, stir and react at 50℃ for 50min, freeze dry at-20℃ for 20h in a freezer to obtain a composite antibacterial material.

[0132] The modified calcium carbonate is specifically prepared by the following steps:

[0133] B1. Add 6g of pretreated carbon fiber to 110mL of deionized water, stir uniformly, add 2g of nano calcium carbonate, ultrasonic treatment at 50KHz for 1.5h, filter, wash with deionized water for 3 times, dry in an 80℃ oven for 10min to obtain carbon fiber loaded with nano calcium carbonate;

[0134] B2. 3 g of carbon nanometer calcium-loaded carbon fiber was added to 8 g of ethylene glycol, stirred at 175℃ for 5 h, 17 g of terephthalic acid and 1.3 g of antimony trioxide were added, stirred uniformly, reacted at 240℃, 0.6 MPa for 40 min, cooled to room temperature, taken out, washed with deionized water for 3 times, dried in an oven at 70℃ for 10 min, to obtain modified nanometer calcium carbonate.

[0135] Comparative Example 3

[0136] The preparation method of the fresh fruit and vegetable preservation packaging material of the composite stone-plastic box-nanopore membrane-graphene technology comprises the following preparation steps:

[0137] S1. Polyethylene terephthalate, modified calcium carbonate and epoxy soybean oil were mixed and stirred to form a mixture, the mixture was placed in a mold and extruded to shape, to obtain a stone-plastic box matrix; wherein the mass ratio of polyester resin, modified calcium carbonate and epoxy soybean oil is 60:40:2;

[0138] S2. The PET polyester film was irradiated by heavy ions to obtain a PET polyester nanopore membrane; wherein the heavy ion irradiation process: using the Lanzhou Heavy Ion Research Device, the energy of the 129Xe ion beam is 80 MeV / u, the irradiation dose is 1×10 11 ions / cm 2 ;

[0139] S3. The composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol were mixed and stirred uniformly to obtain a graphene antibacterial composite; wherein the amount ratio of the composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol is 3g:6g:55g:50mL:55mL;

[0140] S4. 12 g of cyanoacrylate adhesive was applied on the stone-plastic box matrix, the PET polyester nanopore membrane was attached, and then the graphene antibacterial composite was sprayed after hot pressing, and the preservation packaging material was obtained after curing; wherein the hot pressing process: the hot pressing temperature is 175℃, the hot pressing pressure is 15 MPa, and the hot pressing time is 20 min; the spraying pressure is 0.4 MPa, the curing temperature is 120℃, and the curing time is 30 min;

[0141] The thickness of the stone-plastic box matrix is 3 mm; the thickness of the PET polyester film is 55 μm; and the thickness of the graphene antibacterial composite coating is 55 μm.

[0142] The composite antibacterial material is prepared by the following steps:

[0143] A1. 2 g of graphene oxide was added to 220 mL of deionized water, stirred uniformly, 3 g of copper sulfate was added, ultrasonic mixing treatment was carried out at 50 KHz for 30 min, 1.2 g of L-ascorbic acid was added, and reaction was carried out at 40℃ for 2 h, filtration was carried out, deionized water washing was carried out 3 times, and drying was carried out in an oven at 60℃ for 12 h to obtain graphene oxide loaded with nano copper;

[0144] A2. 1.5 g of naringin was added to 35 mL of ethanol and 12 mL of deionized water, stirred uniformly, 0.6 g of γ-aminopropyl triethoxysilane was added, and stirring reaction was carried out at 80℃ for 2 h, 2.9 g of graphene oxide loaded with nano copper and 0.6 mL of hydrochloric acid with a concentration of 0.1 mol / L were added, and stirring was continued for 30 min, filtration was carried out, deionized water washing was carried out 3 times, and drying was carried out in an oven at 60℃ for 15 min to obtain modified graphene oxide;

[0145] A3. 9 g of gum silk powder, 3 g of modified graphene oxide and 1.4 g of carboxymethyl cellulose were added to 55 mL of deionized water, stirring reaction was carried out at 50℃ for 50 min, freezing drying was carried out in a freezer at-20℃ for 20 h to obtain a composite antibacterial material.

[0146] The modified calcium carbonate is specifically prepared by the following steps:

[0147] B1. 6 g of pretreated carbon fiber was added to 110 mL of deionized water, stirred uniformly, 2 g of nano calcium carbonate was added, ultrasonic treatment was carried out at 50 KHz for 1.5 h, filtration was carried out, deionized water washing was carried out 3 times, and drying was carried out in an oven at 80℃ for 10 min to obtain carbon fiber loaded with nano calcium carbonate;

[0148] B2. 3 g of carbon fiber loaded with nano calcium carbonate was added to 8 g of ethylene glycol, stirring was carried out at 175℃ for 5 h, 17 g of terephthalic acid and 1.3 g of antimony trioxide were added, stirring was carried out uniformly, reaction was carried out at 240℃ and 0.6 MPa for 40 min, cooling was carried out to room temperature, and the product was taken out, deionized water washing was carried out 3 times, and drying was carried out in an oven at 70℃ for 10 min to obtain modified nano calcium carbonate.

[0149] Comparative Example 4

[0150] A preparation method of a fresh fruit and vegetable preservation packaging material of a composite stone-plastic box-nuclear pore membrane-graphene technology, comprising the following preparation steps:

[0151] S1. Polyethylene terephthalate, modified calcium carbonate and epoxy soybean oil were mixed to form a mixture, the mixture was placed in a mold, and extrusion molding was carried out to obtain a stone-plastic box matrix; wherein the mass ratio of polyester resin, modified calcium carbonate and epoxy soybean oil was 60:40:2;

[0152] S2. Irradiating the PET polyester film with heavy ions to obtain a PET polyester nuclear pore membrane; wherein the heavy ion irradiation process: using the Lanzhou Heavy Ion Research Device, an ion beam of 129Xe with an energy of 80 MeV / u, and an irradiation dose of 1 x 10 11 ions / cm 2 ;

[0153] S3. Mixing the composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol, and stirring uniformly to obtain a graphene antibacterial compound; wherein the amount ratio of the composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol is 3g:6g:55g:50mL:55mL;

[0154] S4. Applying 12g of cyano acrylate adhesive on the stone plastic box base body, attaching the PET polyester nuclear pore membrane, and then spraying the graphene antibacterial compound after heat pressing, and solidifying to obtain a fresh-keeping packaging material; wherein the heat pressing process: heat pressing temperature is 175℃, heat pressing pressure is 15MPa, and heat pressing time is 20min; the spraying pressure is 0.4MPa, the solidification temperature is 120℃, and the solidification time is 30min;

[0155] The thickness of the stone plastic box base body is 3mm; the thickness of the PET polyester film is 55μm; and the thickness of the graphene antibacterial compound coating is 55μm.

[0156] The composite antibacterial material is prepared by the following steps:

[0157] A1. Adding 2g of graphene oxide into 220mL of deionized water, stirring uniformly, adding 3g of copper sulfate, ultrasonic mixing treatment at 50KHz for 30min, adding 1.2g of L-ascorbic acid, reacting at 40℃ for 2h, filtering, washing with deionized water for 3 times, and drying in a 60℃ oven for 12h to obtain graphene oxide loaded with nano copper;

[0158] A2. Adding 1.5g of naringin into 35mL of ethanol and 12mL of deionized water, stirring uniformly, adding 0.6g of γ-aminopropyl triethoxysilane, stirring and reacting at 80℃ for 2h, adding 2.9g of graphene oxide loaded with nano copper and 0.6mL of hydrochloric acid with a concentration of 0.1mol / L, continuing to stir for 30min, filtering, washing with deionized water for 3 times, and drying in a 60℃ oven for 15min to obtain modified graphene oxide;

[0159] A3. Adding 3g of modified graphene oxide into 110mL of deionized water, stirring uniformly, adding 1.3g of gum arabic and 0.6g of glycerol, ultrasonic treatment at 60KHz for 20min, and drying at 100℃ until the water volatilizes to obtain a composite antibacterial material.

[0160] The modified calcium carbonate is prepared by the following steps:

[0161] B1. 6g of pretreated carbon fiber was added to 110mL of deionized water, stirred uniformly, 2g of nano calcium carbonate was added, ultrasonic treatment was carried out at 50KHz for 1.5h, filtration was carried out, deionized water washing was carried out for 3 times, drying was carried out in an oven at 80℃ for 10min, and the carbon fiber loaded with nano calcium carbonate was obtained;

[0162] B2. 3g of the carbon fiber loaded with nano calcium carbonate was added to 8g of ethylene glycol, stirring was carried out at 175℃ for 5h, 17g of terephthalic acid and 1.3g of antimony trioxide were added, stirring was carried out uniformly, reaction was carried out at 240℃, 0.6MPa for 40min, cooling was carried out to room temperature, the product was taken out, deionized water washing was carried out for 3 times, drying was carried out in an oven at 70℃ for 10min, and the modified nano calcium carbonate was obtained.

[0163] Comparative example 5

[0164] A preparation method of a fresh fruit and vegetable preservation packaging material based on a composite stone-plastic box-nuclear pore membrane-graphene technology, comprising the following preparation steps:

[0165] S1. Polyethylene terephthalate, modified calcium carbonate and epoxy soybean oil were mixed to form a mixture, the mixture was placed in a mold and extruded to form a stone-plastic box matrix; wherein the mass ratio of polyester resin, modified calcium carbonate and epoxy soybean oil is 60:40:2;

[0166] S2. The PET polyester film was irradiated by heavy ions to obtain a PET polyester nuclear pore membrane; wherein the heavy ion irradiation process: using the 129Xe ion beam with an energy of 80MeV / u of the Lanzhou Heavy Ion Research Device, the irradiation dose is 1×10 11 ions / cm 2 ;

[0167] S3. The composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol were mixed and stirred uniformly to obtain a graphene antibacterial composite; wherein the amount ratio of the composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol is 3g:6g:55g:50mL:55mL;

[0168] S4. 12g of cyanoacrylate adhesive was applied on the stone-plastic box matrix, the PET polyester nuclear pore membrane was attached, and then the graphene antibacterial composite was sprayed, and after curing, a preservation packaging material was obtained; wherein the hot pressing process: the hot pressing temperature is 175℃, the hot pressing pressure is 15MPa, and the hot pressing time is 20min; the spraying pressure is 0.4MPa, the curing temperature is 120℃, and the curing time is 30min;

[0169] The thickness of the stone plastic box base body is 3 mm; the thickness of the PET polyester film is 55 μm; and the thickness of the graphene antibacterial compound coating is 55 μm.

[0170] The composite antibacterial material is prepared by the following steps:

[0171] A1. 2 g of graphene oxide is added to 220 mL of deionized water, stirred uniformly, 3 g of copper sulfate is added, ultrasonic mixing treatment is performed at 50 KHz for 30 min, 1.2 g of L-ascorbic acid is added, reaction is performed at 40°C for 2 h, filtration is performed, deionized water is used for washing 3 times, and drying is performed in a 60°C oven for 12 h to obtain graphene oxide loaded with nano copper;

[0172] A2. 1.5 g of naringin is added to 35 mL of ethanol and 12 mL of deionized water, stirred uniformly, 0.6 g of γ-aminopropyltriethoxysilane is added, stirring reaction is performed at 80°C for 2 h, 2.9 g of graphene oxide loaded with nano copper and 0.6 mL of hydrochloric acid with a concentration of 0.1 mol / L are added, stirring is continuously performed for 30 min, filtration is performed, deionized water is used for washing 3 times, and drying is performed in a 60°C oven for 15 min to obtain modified graphene oxide;

[0173] A3. 3 g of modified graphene oxide is added to 110 mL of deionized water, stirred uniformly, 1.3 g of gum arabic and 0.6 g of glycerol are added, ultrasonic treatment is performed at 60 KHz for 20 min, and drying is performed at 100°C until the water volatilizes to obtain a gum-modified graphene oxide composite material;

[0174] A4. 9 g of silk gum powder, 3 g of the gum-modified graphene oxide composite material, and 1.4 g of carboxymethyl cellulose are added to 55 mL of deionized water, stirring reaction is performed at 50°C for 50 min, freezing drying is performed in a freezer at -20°C for 20 h to obtain a composite antibacterial material.

[0175] The modified calcium carbonate is prepared by the following steps:

[0176] 3 g of nano calcium carbonate is added to 8 g of ethylene glycol, stirring is performed at 175°C for 5 h, 17 g of terephthalic acid and 1.3 g of antimony trioxide are added, stirring is uniformly performed, reaction is performed at 240°C and 0.6 MPa for 40 min, cooling is performed to room temperature, the product is taken out, deionized water is used for washing 3 times, and drying is performed in a 70°C oven for 10 min to obtain modified nano calcium carbonate.

[0177] Comparative Example 6

[0178] A preparation method of a fresh fruit and vegetable preservation packaging material of a composite stone plastic box-nuclear pore membrane-graphene technology, comprising the following preparation steps:

[0179] S1. Polyethylene terephthalate, carbon fiber loaded with nano calcium carbonate and epoxy soybean oil are mixed, stirred to form a mixture, the mixture is placed in a mold, and the stone plastic box matrix is obtained by extrusion molding; wherein the mass ratio of polyester resin, carbon fiber loaded with nano calcium carbonate and epoxy soybean oil is 60:40:2;

[0180] S2. The PET polyester film is irradiated by heavy ions to obtain a PET polyester nuclear pore membrane; wherein the heavy ion irradiation process: using Lanzhou heavy ion research device, 129Xe ion beam with energy of 80MeV / u, irradiation dose is 1×10 11 ions / cm 2 ;

[0181] S3. The composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol are mixed and stirred uniformly to obtain a graphene antibacterial compound; wherein the amount ratio of the composite antibacterial material, tetraethyl orthosilicate, polyethylene terephthalate, deionized water and ethanol is 3g:6g:55g:50mL:55mL;

[0182] S4. 12g of cyano acrylate adhesive is applied on the stone plastic box matrix, the PET polyester nuclear pore membrane is attached, and after hot pressing, the graphene antibacterial compound is sprayed, and after curing, the fresh-keeping packaging material is obtained; wherein the hot pressing process: hot pressing temperature is 175℃, hot pressing pressure is 15MPa, hot pressing time is 20min; the spraying pressure is 0.4MPa, the curing temperature is 120℃, and the curing time is 30min;

[0183] The thickness of the stone plastic box matrix is 3mm; the thickness of the PET polyester film is 55μm; the coating thickness of the graphene antibacterial compound is 55μm.

[0184] The composite antibacterial material is prepared by the following steps:

[0185] A1. 2g of graphene oxide is added to 220mL of deionized water, stirred uniformly, 3g of copper sulfate is added, ultrasonic mixing treatment is carried out at 50KHz for 30min, 1.2g of L-ascorbic acid is added, and reaction is carried out at 40℃ for 2h, filtration is carried out, deionized water is washed for 3 times, and drying is carried out in a 60℃ oven for 12h to obtain graphene oxide loaded with nano copper;

[0186] A2. 1.5g of naringin is added to 35mL of ethanol and 12mL of deionized water, stirred uniformly, 0.6g of γ-aminopropyl triethoxysilane is added, stirring reaction is carried out at 80℃ for 2h, 2.9g of graphene oxide loaded with nano copper and 0.6mL of hydrochloric acid with a concentration of 0.1mol / L are added, and stirring is continued for 30min, filtration is carried out, deionized water is washed for 3 times, and drying is carried out in a 60℃ oven for 15min to obtain modified graphene oxide;

[0187] A3. 3 g of modified graphene oxide was added to 110 mL of deionized water, stirred uniformly, 1.3 g of gum arabic and 0.6 g of glycerol were added, ultrasonic treatment was carried out at 60 KHz for 20 min, and drying was carried out at 100℃ until the water volatilized to obtain a gum-modified graphene oxide composite;

[0188] A4. 9 g of silk gum powder, 3 g of gum-modified graphene oxide composite and 1.4 g of carboxymethyl cellulose were added to 55 mL of deionized water, stirred and reacted at 50℃ for 50 min, and freeze-dried at -20℃ for 20 h in a freezer to obtain a composite antibacterial material.

[0189] The carbon fiber loaded with nano calcium carbonate was prepared by the following steps:

[0190] 6 g of pretreated carbon fiber was added to 110 mL of deionized water, stirred uniformly, 2 g of nano calcium carbonate was added, ultrasonic treatment was carried out at 50 KHz for 1.5 h, filtered, washed with deionized water for 3 times, and dried in an oven at 80℃ for 10 min to obtain carbon fiber loaded with nano calcium carbonate.

[0191] The performance of the fresh-keeping packaging materials prepared in Examples 1-3 and Comparative Examples 1-6 was detected.

[0192] The fresh-keeping packaging materials prepared above were cut into a pattern of 250 mm x 250 mm x 250 mm.

[0193] Compression strength test: tested according to ISTA 3A standard, using ASTM D642 pressure testing machine.

[0194] Antibacterial performance test: tested according to GB / T31402-2015 standard.

[0195] CO2 / O2 exchange ratio test: the CO2 and O2 permeability of the fresh-keeping packaging material was determined according to GB / T1038.1-2022 standard, the temperature was 25℃, the relative humidity was 50%, and the CO2 / O2 exchange ratio = CO2 permeability / O2 permeability.

[0196] Fresh-keeping storage experiment: perfect blueberries (mass m0) and litchi (mass M0) were selected and loaded into the cut fresh-keeping packaging materials, the blueberry storage conditions were: transportation distance 1200 km, temperature 0℃, humidity 85%; the litchi storage conditions were: transportation time 6 h, temperature 30℃, the blueberry weight loss rate (%) = (m0-m1) / m0, the litchi weight loss rate (%) = (M0-M1) / M0, m1 was the weight of blueberries after storage, and M1 was the weight of litchi after storage.

[0197] The test results are shown in Table 1 below.

[0198] Table 1 Performance detection of fresh-keeping packaging materials of Examples 1-3 and Comparative Examples 1-6

[0199]

[0200] As can be seen from the data in Table 1, the fresh-keeping packaging materials prepared in Examples 1-3 have good compression strength and antibacterial performance, and good fresh-keeping storage performance for fruits and vegetables.

[0201] In Comparative Example 1, the graphene antibacterial composite prepared by replacing the graphene oxide loaded with nano-copper with graphene oxide is used as the antibacterial layer of the fresh-keeping packaging material, and the antibacterial performance and fresh-keeping storage performance thereof decrease, which proves that the nano-copper is formed on the surface of the graphene oxide, the agglomeration of the nano-copper is avoided, and the graphene oxide and the nano-copper have good antibacterial activity as inorganic antibacterial materials.

[0202] In Comparative Example 2, the graphene antibacterial composite prepared by replacing the modified graphene oxide with the graphene oxide loaded with nano-copper is used as the antibacterial layer of the fresh-keeping packaging material, and the antibacterial performance and fresh-keeping storage performance thereof decrease, which proves that the naringin is coated on the surface of the graphene oxide loaded with nano-copper to form an organic-inorganic antibacterial material, the antibacterial activity of the fresh-keeping packaging material for fruits and vegetables is enhanced, and the naringin forms a flexible protective film on the surface of the graphene oxide loaded with nano-copper to protect the antibacterial coating of the fresh-keeping packaging material.

[0203] In Comparative Example 3, the graphene antibacterial composite prepared by replacing the gum-modified graphene oxide composite material with the modified graphene oxide is used as the antibacterial layer of the fresh-keeping packaging material, and the antibacterial performance, mechanical performance and fresh-keeping storage performance thereof decrease, which proves that the polysaccharide segments of the gum are inserted between the nanosheets of the modified graphene oxide to form a layered structure with organic-inorganic alternating phase connection, which can reduce the water vapor transmission rate and improve the antibacterial activity, and the layered structure can absorb external stress to enhance the compression strength of the fresh-keeping packaging material.

[0204] In Comparative Example 4, the graphene antibacterial composite prepared without adding silk gum powder and carboxymethyl cellulose is used as the antibacterial layer of the fresh-keeping packaging material, and the antibacterial performance, mechanical performance and fresh-keeping storage performance thereof decrease, which proves that the gum-modified graphene oxide composite material is dispersed in the silk gum gel system to enhance the adsorption and fixation of the modified graphene oxide, avoid the easy migration and precipitation of the inorganic antibacterial material under external force, and affect the antibacterial activity, and the gum-modified graphene oxide increases the crosslinking density of the silk gum gel, improves the mechanical strength of the silk gum gel, and further enhances the compression strength of the fresh-keeping packaging material.

[0205] The modified calcium carbonate prepared by replacing the carbon fiber loaded with nano calcium carbonate with nano calcium carbonate is added to the fresh-keeping packaging material formed by the stone plastic box base body, and the mechanical properties and fresh-keeping storage performance decrease, which proves that the nano calcium carbonate is deposited on the surface of the pretreated carbon fiber to form a concave-convex structure, the contact area with the stone plastic box base body is increased, and the polyester stone plastic box is better acted on, and the carbon fiber can form an absorption attractive transition layer in the stone plastic box base body, and the compression strength of the fruit and vegetable fresh-keeping packaging material is enhanced.

[0206] The modified calcium carbonate prepared by replacing the carbon fiber loaded with nano calcium carbonate with nano calcium carbonate is added to the fresh-keeping packaging material formed by the stone plastic box base body, and the mechanical properties and fresh-keeping storage performance decrease, which proves that the nano calcium carbonate is deposited on the surface of the pretreated carbon fiber to form a concave-convex structure, the contact area with the stone plastic box base body is increased, and the polyester stone plastic box is better acted on, and the carbon fiber can form an absorption attractive transition layer in the stone plastic box base body, and the compression strength of the fruit and vegetable fresh-keeping packaging material is enhanced.

[0207] In the description of the specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0208] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace, as long as the modifications or supplements do not deviate from the invention or exceed the scope defined by the present claims, and should belong to the protection scope of the present application.

Claims

1. A composite stone plastic box-nuclear pore membrane-graphene technology fresh fruit and vegetable preservation packaging material, characterized in that, It is prepared by the following method: S1. The polyester resin, modified calcium carbonate and plasticizer are mixed, stirred to form a mixture, the mixture is placed in a mold, and the stone plastic box matrix is obtained by extrusion setting; S2. The PET polyester film is irradiated by heavy ions to obtain a PET polyester nuclear pore membrane; S3. The composite antibacterial material, tetraethyl orthosilicate, polyester resin, deionized water and ethanol are mixed and stirred uniformly to obtain a graphene antibacterial composite; S4. The adhesive is applied on the stone plastic box matrix, the PET polyester nuclear pore membrane is attached, and then the graphene antibacterial composite is sprayed after hot pressing, and the fresh-keeping packaging material is obtained after curing; The composite antibacterial material is obtained by mixing and reacting modified graphene oxide, deionized water, gum, glycerol, carboxymethyl cellulose and sericin powder; The modified graphene oxide is obtained by mixing and reacting copper sulfate, deionized water, graphene oxide and L-ascorbic acid, and then reacting with naringin, ethanol, deionized water and coupling agent; The composite antibacterial material is prepared by the following steps: A1. The graphene oxide is added to the deionized water, stirred uniformly, copper sulfate is added, ultrasonic treated, L-ascorbic acid is added, reacted at 30-40℃ for 1-2h, filtered, washed and dried to obtain graphene oxide loaded with nano copper; A2. The naringin is added to the ethanol and deionized water, stirred uniformly, the coupling agent is added, stirred and reacted at 70-80℃ for 1-2h, the graphene oxide loaded with nano copper and hydrochloric acid are added, continue to stir for 20-30min, filter, wash and dry to obtain modified graphene oxide; A3. The modified graphene oxide is added to the deionized water, stirred uniformly, the gum and glycerol are added, ultrasonic treated at 40-60kHz for 10-20min, and dried to volatilize water to obtain a gum-modified graphene oxide composite material; A4. The sericin powder, gum-modified graphene oxide composite material and carboxymethyl cellulose are added to the deionized water, stirred and reacted at 45-50℃ for 40-50min, and freeze-dried to obtain a composite antibacterial material; The modified calcium carbonate is obtained by depositing nano calcium carbonate on the surface of pretreated carbon fiber, and then mixing and reacting with ethylene glycol, antimony trioxide and terephthalic acid; The modified calcium carbonate is prepared by the following steps: B1. The pretreated carbon fiber is added to the deionized water, stirred uniformly, nano calcium carbonate is added, ultrasonic treated, filtered, washed and dried to obtain carbon fiber loaded with nano calcium carbonate; B2. The carbon fiber loaded with nano calcium carbonate is added to the ethylene glycol, stirred at 165-175℃ for 3-5h, terephthalic acid and antimony trioxide are added, stirred uniformly, reacted at 220-240℃, 0.4-0.6MPa for 30-40min, cooled to room temperature, taken out, washed and dried to obtain modified calcium carbonate.

2. A composite stone-plastic box-nanopore membrane-graphene technology fresh fruit and vegetable preservation packaging material according to claim 1, characterized in that, In step A1, the amount ratio of graphene oxide, deionized water, copper sulfate and L-ascorbic acid is (1-2)g:(180-220)mL:(2-3)g:(1-1.2)g.

3. A composite stone-plastic box-nanopore membrane-graphene technology fresh fruit and vegetable preservation packaging material according to claim 1, characterized in that, In step A2, the naringin, ethanol, deionized water, coupling agent, graphene oxide loaded with nano-copper and hydrochloric acid are used in a ratio of (1.3-1.5) g:(25-35) mL:(8-12) mL:(0.4-0.6) g:(2.5-2.9) g:(0.4-0.6) mL.

4. A composite stone-plastic box-nanopore membrane-graphene technology fresh fruit and vegetable preservation packaging material according to claim 1, characterized in that, In step A3, the modified graphene oxide, deionized water, gum and glycerol are used in a ratio of (2-3) g:(90-110) mL:(1.1-1.3) g:(0.4-1.6) g.

5. A composite stone-plastic box-nanopore membrane-graphene technology fresh fruit and vegetable preservation packaging material according to claim 1, characterized in that, In step A4, the silk powder, gum-modified graphene oxide composite material, carboxymethyl cellulose and deionized water are used in a ratio of (8-9) g:(2-3) g:(1.2-1.4) g:(45-55) mL.

6. A composite stone-plastic box-nanopore membrane-graphene technology fresh fruit and vegetable preservation packaging material according to claim 1, characterized in that, In step B1, the pretreated carbon fiber, deionized water and nano-calcium carbonate are used in a ratio of (5-6) g:(90-110) mL:(1-2) g.

7. A composite stone-plastic box-nanopore membrane-graphene technology fresh fruit and vegetable preservation packaging material according to claim 1, characterized in that, In step B2, the carbon fiber loaded with nano-calcium carbonate, ethylene glycol, terephthalic acid and antimony trioxide are used in a ratio of (2-3):(6-8):(15-17):(1.1-1.3).

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