High-barrier packaging material and preparation method thereof
By adding specific organic barrier fillers to polyethylene terephthalate and polylactic acid materials and graft modification, a crosslinking network structure is formed, which solves the problem of poor barrier properties of polyester materials for water and oxygen, and achieves efficient barrier effects and excellent mechanical properties.
Patent Information
- Application Number
- CN202411795628.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-02-28
AI Technical Summary
Polyethylene terephthalate has poor water and oxygen barrier properties as packaging materials, which makes the packaging susceptible to moisture, oxygen and microorganisms, limiting its application range.
Polyethylene terephthalate and polylactic acid are used as the main raw materials, and graft modification is made by adding specific organic barrier fillers and allyl tris(trimethylsiloxy)silane and perfluorodecyl ethylene to form a crosslinking network structure, which significantly improves the barrier properties of the material.
It realizes the excellent mechanical properties and barrier properties of polyester materials, effectively blocks moisture and oxygen, maintains the original excellent characteristics of the material, and is suitable for a wider range of packaging fields.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a high-barrier packaging material and a preparation method thereof. Background Art
[0002] Packaging materials play a vital role in modern society. They not only protect products from physical, chemical and biological factors, but also improve the market appeal of products, reduce losses during transportation, and extend the shelf life of food, medicine, daily chemicals and other products. Polyethylene terephthalate is a widely used plastic material. It has good transparency, strength and toughness. It is colorless and odorless, and easy to recycle, which makes polyester an ideal choice for packaging food and daily chemicals. Polyester materials are easy to shape and process, and can be recycled, which meets the requirements of sustainable development.
[0003] Although polyethylene terephthalate has many advantages as a packaging material, the barrier properties of polyester film to water and oxygen are relatively poor, which makes it easy for the packaged goods to change due to the influence of moisture, oxygen and microorganisms, limiting its wide application in certain fields. In order to overcome this defect, several methods have been adopted in the prior art to improve the barrier properties of polyester. One common method is to coat a layer of high barrier material, such as silicone coating or metal oxide, on the surface of the polyester material. These coatings can improve the moisture and oxygen resistance of the material. Another method is to blend polyester with other high barrier polymers through a co-extrusion process to form a composite material, thereby enhancing the overall barrier effect.
[0004] However, these methods also have some disadvantages. First, the additional coating will increase the production cost and make the process more complicated; second, the use of coating or inorganic filler will reduce the transparency of polyester, affecting its original advantages as a packaging material. Therefore, it is urgent to provide a high barrier packaging material that can maintain the original advantages of the material and effectively improve its barrier properties. Summary of the invention
[0005] The purpose of the present invention is to provide a high barrier packaging material, which uses polyethylene terephthalate and polylactic acid as main raw materials. By modifying polyethylene terephthalate and adding specific organic barrier fillers, the packaging material has excellent mechanical properties and barrier properties, and can effectively block the internal packaging from being affected by moisture and oxygen in the external environment.
[0006] In order to achieve the above object, the present invention provides the following technical solutions: The present invention provides a high barrier packaging material, comprising the following raw materials: 130-170 parts by weight of modified polyethylene terephthalate, 20-40 parts by weight of polylactic acid, 10-20 parts by weight of organic barrier filler, 1-2 parts by weight of lubricant, and 0.5-1 parts by weight of antioxidant.
[0007] Polyethylene terephthalate is very suitable for use as a packaging material due to its excellent toughness, moderate elongation, gloss and transparency. However, polyester materials have relatively poor barrier properties to moisture and oxygen in the external environment, which makes the packaging easily affected by moisture, oxygen and microorganisms, thereby affecting its quality. In order to solve this problem, the present invention provides an organic barrier filler specifically for PET matrix materials, which can not only effectively improve the barrier properties of PET materials, but also does not affect its original excellent properties.
[0008] The present invention firstly utilizes cyclohexanediol isobutyl-POSS to react with 3-(triethoxysilyl)propyl succinic anhydride to obtain terminal carboxyl-POSS, and then converts the terminal carboxyl-POSS into a functional monomer by introducing a protective group. Next, the functional monomer undergoes a polymerization reaction with a (3-acryloxypropyl)methylbis(trimethylsiloxy)silane monomer to finally obtain an organic barrier filler. The organic barrier filler is centered on a cage-type skeleton structure and extends axially to eight branches to form an organic polymer. The structural design of the eight branches axially significantly increases the complexity of the path for water molecules and oxygen molecules to penetrate inward, making the penetration process of these molecules more difficult and tortuous; moreover, the hydrophobic and tightly structured polysiloxane units formed by the polymerization of the eight branches axially further increase the difficulty of the penetration path of water molecules and oxygen molecules, thereby effectively enhancing the barrier properties of the material.
[0009] In addition, after being embedded in the PET matrix material, the organic barrier filler can be firmly fixed in the matrix and will not migrate or precipitate over time, thereby ensuring the long-term stability of the comprehensive performance of the packaging material.
[0010] By adding the organic barrier filler, not only can the moisture and oxidation resistance of the polyester material be significantly improved, but also its original mechanical properties and appearance properties can be maintained, making its application in the packaging field more extensive and reliable.
[0011] Preferably, the method for preparing the organic barrier filler comprises the following steps: 5-8 parts by weight of trans-cyclohexanediol isobutyl-POSS and 2-3 parts by weight of 3-(triethoxysilyl)propyl succinic anhydride are added to isopropanol for reflux reaction, and distilled under reduced pressure to obtain carboxyl-terminated POSS; 3-5 parts by weight of carboxyl-terminated POSS are mixed with dimethyl sulfoxide, 1-2 parts by weight of tetramethylguanidine are added under an ice-water bath, and stirred, and then 1-3 parts by weight of 2-bromoterephthalic acid are added and stirred, and after the end, precipitation is performed, centrifugation is performed, and drying is performed to obtain a functional monomer; 0.3-0.6 parts by weight of functional monomers are added to dimethyl sulfoxide for ultrasonication, and then 20-30 parts by weight of (3-acryloxypropyl)methylbis(trimethylsiloxy)silane and 0.03-0.05 parts by weight of azobisisovaleronitrile are added for reaction, centrifuged and dried to obtain an organic barrier filler.
[0012] Furthermore, the method for preparing the organic barrier filler comprises the following steps: 5-8 parts by weight of trans-cyclohexanediol isobutyl-POSS and 2-3 parts by weight of 3-(triethoxysilyl)propyl succinic anhydride are added to 80-90 parts by weight of isopropanol, and the mixture is refluxed at 80-90° C. for 7-10 hours, and the solvent is recovered by reduced pressure distillation to obtain terminal carboxyl-POSS; 3-5 parts by weight of terminal carboxyl-POSS are mixed with 50-70 parts by weight of dimethyl sulfoxide, 1-2 parts by weight of tetramethylguanidine are added in an ice-water bath at 100-250 r / min, and stirred for 10-30 minutes, and then 1-3 parts by weight of 2-bromoterephthalic acid are added, and the mixture is stirred at 25-30° C. and 100-150 r / min for 10-20 hours. After the mixture is precipitated with methanol, the mixture is centrifuged, and dried to obtain a functional monomer; 0.3-0.6 parts by weight of functional monomers are added to 60-75 parts by weight of dimethyl sulfoxide, and ultrasonicated at 20-25kHz and 100-200W for 5-20 minutes, and then 20-30 parts by weight of (3-acryloxypropyl)methylbis(trimethylsiloxy)silane and 0.03-0.05 parts by weight of azobisisovaleronitrile are added, and the mixture is reacted at 60-70°C and in a nitrogen atmosphere for 20-30 hours, centrifuged, and dried to obtain an organic barrier filler.
[0013] Compared with directly using polyethylene terephthalate (PET), the present invention utilizes styrene-butadiene-styrene triblock copolymer (SBS), allyl tris(trimethylsiloxy)silane and perfluorodecylethylene under the action of initiator benzoyl peroxide to modify PET through a melt extrusion process, thereby further improving the barrier properties, heat resistance and chemical resistance of the material.
[0014] The present invention obtains a grafted modified masterbatch by grafting allyl tris(trimethylsiloxy)silane and perfluorodecylethylene onto PET and SBS using free radical initiation. In this process, the introduction of allyl tris(trimethylsiloxy)silane forms silicon-oxygen bonds on the modified masterbatch, and these silicon-oxygen bonds can interact with organic barrier fillers in subsequent processing to form a cross-linked network structure. This cross-linked network structure not only improves the mechanical properties of the material, but also further enhances its barrier properties. This is because the cross-linked network structure can effectively reduce the pores and defects inside the material, thereby reducing the permeation path of water molecules and oxygen molecules and improving the barrier effect. At the same time, the introduction of perfluorodecylethylene forms perfluorodecyl groups on the main chain of the PET molecule. These perfluorodecyl groups have good chemical stability and thermal stability, and can protect the PET main chain from damage under high temperature conditions, thereby improving the heat resistance of the packaging material.
[0015] In addition, the grafted modified masterbatch can also effectively solve the problem of large gaps between PET molecules. Due to the introduction of SBS, the styrene segment in the modified masterbatch can form physical crosslinking points with the PET molecular chain, while the butadiene segment can fill the gaps between PET molecules, thereby improving the density of the material; this dense structure not only further improves the barrier properties of the material from another aspect, but also helps to improve its heat resistance.
[0016] Preferably, the method for preparing the modified polyethylene terephthalate comprises the following steps: 80-100 parts by weight of polyethylene terephthalate, 8-12 parts by weight of styrene-butadiene-styrene triblock copolymer, 1-4 parts by weight of allyl tris(trimethylsiloxy)silane, 1-2 parts by weight of perfluorodecylethylene, and 0.08-0.12 parts by weight of benzoyl peroxide are added into a high-speed mixer for premixing, and then put into an extruder for melt extrusion and granulation to obtain modified polyethylene terephthalate.
[0017] Furthermore, the preparation method of the modified polyethylene terephthalate comprises the following steps: 80-100 parts by weight of polyethylene terephthalate, 8-12 parts by weight of styrene-butadiene-styrene triblock copolymer, 1-4 parts by weight of allyl tris(trimethylsiloxy)silane, 1-2 parts by weight of perfluorodecylethylene and 0.08-0.12 parts by weight of benzoyl peroxide are added into a high-speed mixer and pre-mixed for 5-8 minutes at a stirring speed of 100-200 r / min. The mixture is then put into a twin-screw extruder for melt extrusion and granulation at a screw extrusion temperature of 250-270°C and a screw speed of 150-300 r / min to obtain modified polyethylene terephthalate.
[0018] Preferably, the lubricant is at least one of polyethylene wax, pentaerythritol stearate, N,N′-ethylene bisstearamide, stearic acid amide, and silicone powder.
[0019] Furthermore, the lubricant is a mixture of polyethylene wax and pentaerythritol stearate in a weight ratio of 1:1-3.
[0020] Preferably, the antioxidant is at least one of antioxidant 1010, antioxidant DSTDP, antioxidant 168, antioxidant 2246, and antioxidant 264.
[0021] Furthermore, the antioxidant is a mixture of antioxidant 1010 and antioxidant DSTDP in a weight ratio of 3:1-3.
[0022] The present invention provides a method for preparing a high barrier packaging material, comprising the following steps: The weighed modified polyethylene terephthalate, polylactic acid, organic barrier filler, lubricant and antioxidant are added to a high-speed mixer for premixing for 2-5 minutes at a stirring speed of 200-300 r / min, and then put into a twin-screw extruder for melt extrusion and granulation. The screw extrusion temperature is 245-260°C and the screw speed is 200-350 r / min to obtain the high barrier packaging material.
[0023] Compared with the prior art, the advantages and beneficial effects of the present invention are: 1. The present invention provides a method for preparing a high barrier packaging material, which uses polyethylene terephthalate and polylactic acid as main raw materials, and adopts specific organic barrier fillers to effectively improve the barrier properties of polyester materials without affecting the original excellent properties of polyester, so that the packaging material has excellent mechanical properties and barrier properties, and can effectively block the internal packaging from being affected by moisture and oxygen in the external environment.
[0024] 2. The present invention provides an organic barrier filler specifically for polyester materials, which is centered on a cage-type skeleton structure and extends axially to eight branches to form an organic polymer. This structure increases the complexity of the path for water molecules and oxygen molecules to penetrate inward, making the penetration process of these molecules more difficult and tortuous; moreover, the hydrophobic and tightly structured polysiloxane units formed by the axial polymerization of the eight branches further increase the difficulty of the penetration path for water molecules and oxygen molecules, thereby effectively enhancing the barrier properties of the material.
[0025] 3. The present invention adds allyl tris(trimethylsiloxy)silane and perfluorodecylethylene, and utilizes free radical initiation to graft onto polyethylene terephthalate and styrene-butadiene-styrene triblock copolymer to obtain grafted modified polyethylene terephthalate masterbatch, wherein the introduction of allyl tris(trimethylsiloxy)silane forms silicon-oxygen bonds on the modified masterbatch, which can interact with organic barrier fillers in subsequent processing to form a cross-linked network structure, which not only improves the mechanical properties of the material, but also further enhances its barrier properties; the introduction of perfluorodecylethylene forms perfluorodecyl groups on the main chain of the PET molecule, and these perfluorodecyl groups have good chemical stability and thermal stability, and can protect the PET main chain from damage in a high temperature environment, thereby improving the heat resistance of the packaging material. DETAILED DESCRIPTION
[0026] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0027] Polyethylene terephthalate, brand: PET 4210M3, melt index (190°C, 2.16kg, ASTM D1238) is 60g / 10min, manufacturer: Nan Ya.
[0028] Styrene-butadiene-styrene triblock copolymer, brand: SBS YH-792, melt index is 5g / 10min (190℃, 2.16kg, ASTM D1238), manufacturer: Yueyang Baling Petrochemical.
[0029] Polylactic acid, brand: PLA V554X51, melt index is 6g / 10min (190℃, 2.16kg, ISO1133), manufacturer: Toray, Japan.
[0030] Example 1 This embodiment provides a high barrier packaging material, comprising the following raw materials in parts by weight: 150 parts by weight of modified polyethylene terephthalate, 30 parts by weight of polylactic acid, 15 parts by weight of organic barrier filler, 1.2 parts by weight of lubricant, and 0.8 parts by weight of antioxidant.
[0031] The lubricant is a mixture of polyethylene wax and pentaerythritol stearate in a weight ratio of 1:2.
[0032] The antioxidant is a mixture of antioxidant 1010 and antioxidant DSTDP in a weight ratio of 3:2.
[0033] The preparation method of the modified polyethylene terephthalate comprises the following steps: 90 parts by weight of polyethylene terephthalate, 10 parts by weight of styrene-butadiene-styrene triblock copolymer, 2.5 parts by weight of allyl tri(trimethylsiloxy)silane, 1.5 parts by weight of perfluorodecylethylene, and 0.1 parts by weight of benzoyl peroxide were added to a high-speed mixer and pre-mixed for 6 minutes at a stirring speed of 150 r / min. The mixture was then put into a twin-screw extruder for melt extrusion and granulation at a screw extrusion temperature of 260°C and a screw speed of 200 r / min to obtain modified polyethylene terephthalate.
[0034] The method for preparing the organic barrier filler comprises the following steps: 6 parts by weight of trans-cyclohexanediol isobutyl-POSS (CAS: 480439-48-3) and 2.5 parts by weight of 3-(triethoxysilyl)propyl succinic anhydride (CAS: 93642-68-3) are added to 85 parts by weight of isopropanol, and the mixture is refluxed at 85° C. for 8 hours, and the solvent is recovered by reduced pressure distillation to obtain carboxyl-terminated POSS; 4.5 parts by weight of carboxyl-terminated POSS is mixed with 60 parts by weight of dimethyl sulfoxide, 1.2 parts by weight of tetramethylguanidine is added in an ice-water bath at 200 r / min and stirred for 20 minutes, and then 2 parts by weight of 2-bromoterephthalic acid are added, and the mixture is stirred at 27° C. and 120 r / min for 15 hours. After the mixture is precipitated with methanol, the mixture is centrifuged and dried to obtain a functional monomer; 0.5 parts by weight of functional monomers were added to 70 parts by weight of dimethyl sulfoxide, and ultrasonicated at 20 kHz and 150 W for 10 min. Then, 25 parts by weight of (3-acryloxypropyl)methylbis(trimethylsiloxy)silane (CAS: 177617-17-3) and 0.04 parts by weight of azobisisovaleronitrile were added, and the mixture was reacted at 65° C. and in a nitrogen atmosphere for 24 h. The mixture was centrifuged and dried to obtain an organic barrier filler.
[0035] This embodiment provides a method for preparing a high barrier packaging material, comprising the following steps: The weighed modified polyethylene terephthalate, polylactic acid, organic barrier filler, lubricant and antioxidant were added to a high-speed mixer for premixing for 3 minutes at a stirring speed of 250 r / min, and then put into a twin-screw extruder for melt extrusion and granulation. The screw extrusion temperature was 250°C and the screw speed was 300 r / min to obtain the high barrier packaging material.
[0036] Example 2 This embodiment provides a high barrier packaging material, comprising the following raw materials in parts by weight: 130 parts by weight of modified polyethylene terephthalate, 20 parts by weight of polylactic acid, 10 parts by weight of organic barrier filler, 1 part by weight of lubricant, and 0.5 parts by weight of antioxidant.
[0037] The lubricant is a mixture of polyethylene wax and pentaerythritol stearate in a weight ratio of 1:1.
[0038] The antioxidant is a mixture of antioxidant 1010 and antioxidant DSTDP in a weight ratio of 3:1.
[0039] The preparation method of the modified polyethylene terephthalate is the same as that of Example 1.
[0040] The preparation method of the organic barrier filler is the same as that of Example 1.
[0041] This embodiment provides a method for preparing a high barrier packaging material, comprising the following steps: The weighed modified polyethylene terephthalate, polylactic acid, organic barrier filler, lubricant and antioxidant were added into a high-speed mixer for premixing for 2 minutes at a stirring speed of 200 r / min, and then put into a twin-screw extruder for melt extrusion and granulation. The screw extrusion temperature was 245°C and the screw speed was 200 r / min to obtain the high barrier packaging material.
[0042] Example 3 This embodiment provides a high barrier packaging material, comprising the following raw materials in parts by weight: 170 parts by weight of modified polyethylene terephthalate, 40 parts by weight of polylactic acid, 20 parts by weight of organic barrier filler, 2 parts by weight of lubricant, and 1 part by weight of antioxidant.
[0043] The lubricant is a mixture of polyethylene wax and pentaerythritol stearate in a weight ratio of 1:3.
[0044] The antioxidant is a mixture of antioxidant 1010 and antioxidant DSTDP in a weight ratio of 3:3.
[0045] The preparation method of the modified polyethylene terephthalate is the same as that of Example 1.
[0046] The preparation method of the organic barrier filler is the same as that of Example 1.
[0047] This embodiment provides a method for preparing a high barrier packaging material, comprising the following steps: The weighed modified polyethylene terephthalate, polylactic acid, organic barrier filler, lubricant and antioxidant were added to a high-speed mixer for premixing for 5 minutes at a stirring speed of 300 r / min, and then put into a twin-screw extruder for melt extrusion and granulation. The screw extrusion temperature was 260°C and the screw speed was 350 r / min to obtain the high barrier packaging material.
[0048] Comparative Example 1 The difference between this comparative example and Example 1 is that the preparation method of the modified polyethylene terephthalate is different, specifically as follows: the preparation method of the modified polyethylene terephthalate comprises the following steps: 90 parts by weight of polyethylene terephthalate, 10 parts by weight of styrene-butadiene-styrene triblock copolymer, 1.5 parts by weight of perfluorodecylethylene, and 0.1 parts by weight of benzoyl peroxide are added to a high-speed mixer and pre-mixed for 6 minutes at a stirring speed of 150 r / min, and then put into a twin-screw extruder for melt extrusion and granulation. The screw extrusion temperature is 260°C and the screw speed is 200 r / min to obtain modified polyethylene terephthalate.
[0049] Comparative Example 2 The difference between this comparative example and Example 1 is that the preparation method of the modified polyethylene terephthalate is different, specifically as follows: the preparation method of the modified polyethylene terephthalate comprises the following steps: 90 parts by weight of polyethylene terephthalate, 10 parts by weight of styrene-butadiene-styrene triblock copolymer, 2.5 parts by weight of allyl tris(trimethylsiloxy)silane, and 0.1 parts by weight of benzoyl peroxide are added to a high-speed mixer and pre-mixed for 6 minutes at a stirring speed of 150 r / min, and then put into a twin-screw extruder for melt extrusion and granulation. The screw extrusion temperature is 260°C and the screw speed is 200 r / min to obtain modified polyethylene terephthalate.
[0050] Comparative Example 3 The difference between this comparative example and Example 1 is that the modified polyethylene terephthalate is replaced by polyethylene terephthalate.
[0051] Comparative Example 4 The difference between this comparative example and Example 1 is that the preparation method of the organic barrier filler is different, specifically as follows: the preparation method of the organic barrier filler comprises the following steps: 0.5 parts by weight of trans-cyclohexanediol isobutyl-POSS (CAS: 480439-48-3) was added to 70 parts by weight of dimethyl sulfoxide, and ultrasonicated at 20kHz and 150W for 10 minutes. Then, 25 parts by weight of (3-acryloxypropyl)methylbis(trimethylsiloxy)silane (CAS: 177617-17-3) and 0.04 parts by weight of azobisisovaleronitrile were added, and the mixture was reacted at 65°C and in a nitrogen atmosphere for 24 hours. The mixture was centrifuged and dried to obtain an organic barrier filler.
[0052] Comparative Example 5 The difference between this comparative example and Example 1 is that the preparation method of the organic barrier filler is different, specifically as follows: the preparation method of the organic barrier filler comprises the following steps: 6 parts by weight of trans-cyclohexanediol isobutyl-POSS (CAS: 480439-48-3) and 2.5 parts by weight of 3-(triethoxysilyl)propyl succinic anhydride (CAS: 93642-68-3) were added to 85 parts by weight of isopropanol, and the mixture was refluxed at 85° C. for 8 h, and the solvent was recovered by distillation under reduced pressure to obtain carboxyl-terminated POSS; 0.5 parts by weight of terminal carboxyl-POSS was added to 70 parts by weight of dimethyl sulfoxide, and ultrasonicated at 20 kHz and 150 W for 10 min. Then, 25 parts by weight of (3-acryloxypropyl)methylbis(trimethylsiloxy)silane (CAS: 177617-17-3) and 0.04 parts by weight of azobisisovaleronitrile were added, and the mixture was reacted at 65° C. in a nitrogen atmosphere for 24 h. The mixture was centrifuged and dried to obtain an organic barrier filler.
[0053] Comparative Example 6 The difference between this comparative example and Example 1 is that the preparation method of the organic barrier filler is different, specifically as follows: the preparation method of the organic barrier filler comprises the following steps: 6 parts by weight of trans-cyclohexanediol isobutyl-POSS (CAS: 480439-48-3) and 2.5 parts by weight of 3-(triethoxysilyl)propyl succinic anhydride (CAS: 93642-68-3) are added to 85 parts by weight of isopropanol, and the mixture is refluxed at 85° C. for 8 hours, and the solvent is recovered by reduced pressure distillation to obtain carboxyl-terminated POSS; 4.5 parts by weight of carboxyl-terminated POSS is mixed with 60 parts by weight of dimethyl sulfoxide, 1.2 parts by weight of tetramethylguanidine is added in an ice-water bath at 200 r / min and stirred for 20 minutes, and then 2 parts by weight of 2-bromoterephthalic acid are added, and the mixture is stirred at 27° C. and 120 r / min for 15 hours. After the mixture is precipitated with methanol, the mixture is centrifuged and dried to obtain a functional monomer; 0.5 parts by weight of functional monomers were added to 70 parts by weight of dimethyl sulfoxide, and ultrasonicated at 20 kHz and 150 W for 10 min. Then, 25 parts by weight of acryloxypropyltrimethoxysilane (CAS: 21134-38-3) and 0.04 parts by weight of azobisisovaleronitrile were added, and the mixture was reacted at 65° C. and in a nitrogen atmosphere for 24 h. The mixture was centrifuged and dried to obtain an organic barrier filler.
[0054] Performance Testing 1. The mechanical properties and heat resistance of the high barrier packaging materials prepared in Examples 1-3 and Comparative Examples 1-6 were evaluated. The tensile strength was measured according to the standard GB / T 1040-2006, and the heat deformation temperature (0.45 MPa) was measured according to the standard ASTM D648-16. The results are shown in Table 1.
[0055] Table 1: Mechanical properties and heat resistance test results
[0056] 2. Evaluate the barrier properties of the high barrier packaging materials prepared in Examples 1-3 and Comparative Examples 1-6. The water vapor permeability coefficient was determined according to the standard GB / T 1037-2021 (sample thickness 20 μm, film test area 35 cm 2 ; 23°C, relative humidity 50%), oxygen permeability coefficient was determined according to standard GB / T 1038-2022 (sample thickness 20 μm, film test area 35 cm 2 ; 37°C, relative humidity 90%), the results are shown in Table 2.
[0057] Table 2: Barrier performance test results
[0058] It can be seen from the above performance test results that the high barrier packaging materials prepared in Examples 1-3 have excellent mechanical properties, barrier properties and heat resistance, especially the comprehensive performance of the packaging material in Example 1 is the most outstanding. This is because the present invention significantly improves the barrier properties of the material by adding specific organic barrier fillers, and further realizes the modification of polyester through melt extrusion. The introduced silicon-oxygen bonds can form a cross-linked network structure with the organic barrier filler in subsequent processing, which not only improves the mechanical properties of the material, but also further enhances its barrier properties, so that the packaging material has stable mechanical properties and barrier properties.
[0059] In comparison, since Comparative Examples 1-6 do not adopt the necessary technical solutions, their corresponding performance tests are significantly worse than those of Examples 1-3. In Comparative Examples 1-3, modified polyethylene terephthalate is not used, and in Comparative Examples 4-6, organic barrier fillers prepared by a specific method are not used. It can be seen from the results that the barrier properties and heat resistance of the packaging materials are reduced. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.
[0060] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A high barrier packaging material, characterized in that: It includes the following raw materials in parts by weight: 130-170 parts by weight of modified polyethylene terephthalate, 20-40 parts by weight of polylactic acid, 10-20 parts by weight of organic barrier filler, 1-2 parts by weight of lubricant, and 0.5-1 parts by weight of antioxidant; The modified polyethylene terephthalate is prepared by melt extrusion of polyethylene terephthalate, styrene-butadiene-styrene triblock copolymer, allyl tris(trimethylsiloxy)silane and perfluorodecylethylene.
2. The high barrier packaging material according to claim 1, characterized in that: The preparation method of the modified polyethylene terephthalate comprises the following steps: 80-100 parts by weight of polyethylene terephthalate, 8-12 parts by weight of styrene-butadiene-styrene triblock copolymer, 1-4 parts by weight of allyl tris(trimethylsiloxy)silane, 1-2 parts by weight of perfluorodecylethylene, and 0.08-0.12 parts by weight of benzoyl peroxide are added into a high-speed mixer for premixing, and then put into an extruder for melt extrusion and granulation to obtain modified polyethylene terephthalate.
3. The high barrier packaging material according to claim 1, characterized in that: The method for preparing the organic barrier filler comprises the following steps: 5-8 parts by weight of trans-cyclohexanediol isobutyl-POSS and 2-3 parts by weight of 3-(triethoxysilyl)propyl succinic anhydride are added to isopropanol for reflux reaction, and distilled under reduced pressure to obtain carboxyl-terminated POSS; 3-5 parts by weight of carboxyl-terminated POSS are mixed with dimethyl sulfoxide, 1-2 parts by weight of tetramethylguanidine are added under an ice-water bath, and stirred, and then 1-3 parts by weight of 2-bromoterephthalic acid are added and stirred, and after the end, precipitation is performed, centrifugation is performed, and drying is performed to obtain a functional monomer; 0.3-0.6 parts by weight of functional monomers are added to dimethyl sulfoxide for ultrasonication, and then 20-30 parts by weight of (3-acryloxypropyl)methylbis(trimethylsiloxy)silane and 0.03-0.05 parts by weight of azobisisovaleronitrile are added for reaction, centrifuged and dried to obtain an organic barrier filler.
4. The high barrier packaging material according to claim 2, characterized in that: The preparation method of the modified polyethylene terephthalate comprises the following steps: 80-100 parts by weight of polyethylene terephthalate, 8-12 parts by weight of styrene-butadiene-styrene triblock copolymer, 1-4 parts by weight of allyl tris(trimethylsiloxy)silane, 1-2 parts by weight of perfluorodecylethylene and 0.08-0.12 parts by weight of benzoyl peroxide are added into a high-speed mixer and pre-mixed for 5-8 minutes at a stirring speed of 100-200 r / min. The mixture is then put into a twin-screw extruder for melt extrusion and granulation at a screw extrusion temperature of 250-270°C and a screw speed of 150-300 r / min to obtain modified polyethylene terephthalate.
5. The high barrier packaging material according to claim 3, characterized in that: The method for preparing the organic barrier filler comprises the following steps: 5-8 parts by weight of trans-cyclohexanediol isobutyl-POSS and 2-3 parts by weight of 3-(triethoxysilyl)propyl succinic anhydride are added to 80-90 parts by weight of isopropanol, and the mixture is refluxed at 80-90° C. for 7-10 hours, and the solvent is recovered by reduced pressure distillation to obtain terminal carboxyl-POSS; 3-5 parts by weight of terminal carboxyl-POSS are mixed with 50-70 parts by weight of dimethyl sulfoxide, 1-2 parts by weight of tetramethylguanidine are added in an ice-water bath at 100-250 r / min, and stirred for 10-30 minutes, and then 1-3 parts by weight of 2-bromoterephthalic acid are added, and the mixture is stirred at 25-30° C. and 100-150 r / min for 10-20 hours. After the mixture is precipitated with methanol, the mixture is centrifuged, and dried to obtain a functional monomer; 0.3-0.6 parts by weight of functional monomers are added to 60-75 parts by weight of dimethyl sulfoxide, and ultrasonicated at 20-25kHz and 100-200W for 5-20 minutes, and then 20-30 parts by weight of (3-acryloxypropyl)methylbis(trimethylsiloxy)silane and 0.03-0.05 parts by weight of azobisisovaleronitrile are added, and the mixture is reacted at 60-70°C and in a nitrogen atmosphere for 20-30 hours, centrifuged, and dried to obtain an organic barrier filler.
6. The high barrier packaging material according to claim 1, characterized in that: The lubricant is at least one of polyethylene wax, pentaerythritol stearate, N,N′-ethylene bisstearamide, stearic acid amide and silicone powder.
7. The high barrier packaging material according to claim 6, characterized in that: The lubricant is a mixture of polyethylene wax and pentaerythritol stearate in a weight ratio of 1:1-3.
8. The high barrier packaging material according to claim 1, characterized in that: The antioxidant is at least one of antioxidant 1010, antioxidant DSTDP, antioxidant 168, antioxidant 2246, and antioxidant 264.
9. The high barrier packaging material according to claim 8, characterized in that: The antioxidant is a mixture of antioxidant 1010 and antioxidant DSTDP in a weight ratio of 3:1-3.
10. The method for preparing a high barrier packaging material according to any one of claims 1 to 9, characterized in that: The following steps are involved: The weighed modified polyethylene terephthalate, polylactic acid, organic barrier filler, lubricant and antioxidant are added into a high-speed mixer for premixing, and then put into a twin-screw extruder for melt extrusion and granulation to obtain the high barrier packaging material.