Modified polylactic acid high-barrier packaging material and preparation method thereof
By combining modified graphene with polylactic acid resin and polyvinylidene fluoride-hexafluoropropylene copolymer, a modified polylactic acid packaging material with high barrier and high elongation of break was prepared, which solved the insufficient barrier performance of traditional polylactic acid materials. The problem has achieved widespread application in the field of high-end packaging.
Patent Information
- Application Number
- CN202411407361.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-02-18
AI Technical Summary
Traditional petroleum-based polymer packaging materials put huge pressure on the environment, and polylactic acid is difficult to replace traditional materials due to insufficient barrier properties in the high-end packaging field.
Preparation was prepared by placing graphene in an aqueous solution containing cocamide monoethanolamide and lauryl sulfonated succinate monoester and in combination with polylactic acid resin and polyvinylidene fluoride-hexafluoropropylene copolymer with a copolymer of polyvinylidene fluoride-hexafluoropropylene Modified polylactic acid packaging materials with high barrier and high elongation of break.
It significantly improves the barrier properties and elongation of breaking materials, making them suitable for food packaging, pharmaceutical packaging and electronic product packaging.
Smart Images
Figure BDA0005077019850000061
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of polymer materials, and in particular to a modified polylactic acid high-barrier packaging material and a preparation method thereof. Background Art
[0002] In the rapidly developing packaging industry, polymer materials have become indispensable materials due to their unique advantages, such as light weight, high cost-effectiveness, easy processing and functionalization. However, traditional packaging polymers, such as polyethylene and polypropylene, rely on non-renewable fossil resources, and their production and waste disposal processes have caused tremendous pressure on the environment, including resource depletion and environmental pollution. Therefore, exploring and developing biodegradable polymer materials to replace traditional petroleum-based polymers has become a key way to solve this global challenge.
[0003] Among many biodegradable polymers, polylactic acid (PLA) has become one of the most promising candidate materials due to its abundant monomer sources, relatively low cost, excellent mechanical properties and processing properties, and excellent transparency. However, despite PLA's excellent performance in many aspects, its relatively moderate barrier properties have become a bottleneck limiting its widespread application in the field of high-end packaging. Especially for those application scenarios that require high barrier properties, such as food packaging, pharmaceutical packaging, and electronic product packaging, the barrier properties of PLA are far from meeting actual needs. Summary of the invention
[0004] In order to overcome at least one of the technical problems existing in the prior art, the present invention provides a modified polylactic acid high barrier packaging material and a preparation method thereof.
[0005] The technical solution of the present invention is as follows:
[0006] A modified polylactic acid high-barrier packaging material comprises the following components in parts by weight: 60 to 100 parts of polylactic acid resin, 20 to 40 parts of polyvinylidene fluoride-hexafluoropropylene copolymer, and 10 to 20 parts of graphene.
[0007] Preferably, the graphene is modified graphene, and the modified graphene is prepared by the following steps:
[0008] (1) Mixing methanol and hydrogen peroxide, and then adding pyrrole and mixing evenly to obtain a mixed solution;
[0009] (2) adding graphene to the mixed solution prepared in step (1) and stirring evenly;
[0010] (3) After the stirring treatment is completed, the graphene is separated, and then added to the modified liquid and stirred evenly. After the stirring is completed, the solid is separated and dried to obtain the modified graphene.
[0011] Preferably, the usage ratio of the methanol, hydrogen peroxide and pyrrole is 1L:1L:30g, and the usage ratio of the graphene to the mixed solution is 1kg:5L.
[0012] Preferably, the modified liquid is an aqueous solution containing cocamide monoethanolamide and disodium lauryl sulfosuccinate.
[0013] Preferably, the mass concentration of cocamide monoethanolamide in the modified liquid is 5-10%.
[0014] Preferably, the mass concentration of disodium lauryl sulfosuccinate in the modified solution is 5-10%.
[0015] The method for preparing the above-mentioned modified polylactic acid high barrier packaging material comprises the following steps:
[0016] The polylactic acid resin, polyvinylidene fluoride-hexafluoropropylene copolymer and graphene are mixed evenly and then melt-extruded through a twin-screw extruder to obtain the modified polylactic acid high-barrier packaging material.
[0017] The beneficial effects of the present invention are:
[0018] The invention provides a new modified polylactic acid high-barrier packaging material; research shows that the packaging material prepared by using polylactic acid resin, polyvinylidene fluoride-hexafluoropropylene copolymer and graphene as raw materials has high barrier performance; in addition, the inventor creatively finds that only after the graphene is placed in an aqueous solution containing cocamide monoethanolamide and disodium lauryl sulfosuccinate for modification, the modified graphene can further significantly improve the elongation at break of the packaging material through the compatibility with polylactic acid resin and polyvinylidene fluoride-hexafluoropropylene copolymer; therefore, the packaging material with high barrier and high elongation at break provided by the invention can be applied to the fields of food packaging, drug packaging, electronic product packaging and the like. DETAILED DESCRIPTION
[0019] The present invention is further explained below in conjunction with specific examples, but the examples do not limit the present invention in any form.
[0020] The polylactic acid resin used in the following examples is polylactic acid resin with a brand number of 2002D produced by NatureWorks, USA; the polyvinylidene fluoride-hexafluoropropylene copolymer used is polyvinylidene fluoride-hexafluoropropylene copolymer with a brand number of 21216 produced by Solvay, USA; and the remaining raw materials are conventional raw materials that can be purchased by those skilled in the art.
[0021] Example 1: Modified polylactic acid high barrier packaging material
[0022] The raw materials are composed by weight: 70 parts of polylactic acid resin; 30 parts of polyvinylidene fluoride-hexafluoropropylene copolymer; and 15 parts of graphene.
[0023] Preparation method: polylactic acid resin, polyvinylidene fluoride-hexafluoropropylene copolymer and graphene are mixed evenly and then melt-extruded through a twin-screw extruder to obtain the modified polylactic acid high-barrier packaging material.
[0024] Example 2: Modified polylactic acid high barrier packaging material
[0025] The raw materials are composed by weight: 70 parts of polylactic acid resin; 30 parts of polyvinylidene fluoride-hexafluoropropylene copolymer; and 15 parts of modified graphene.
[0026] The modified graphene is prepared by the following method:
[0027] (1) Mixing methanol and hydrogen peroxide, and then adding pyrrole to mix evenly to obtain a mixed solution; wherein the amount ratio of methanol, hydrogen peroxide and pyrrole is 1L:1L:30g;
[0028] (2) adding graphene to the mixed solution prepared in step (1), and stirring for 6 hours; wherein the amount ratio of graphene to the mixed solution is 1 kg:5 L;
[0029] (3) After the stirring treatment is completed, the graphene is separated and dried to obtain the modified graphene.
[0030] Preparation method: polylactic acid resin, polyvinylidene fluoride-hexafluoropropylene copolymer and modified graphene are mixed evenly and then melt-extruded through a twin-screw extruder to obtain the modified polylactic acid high-barrier packaging material.
[0031] Example 3: Modified polylactic acid high barrier packaging material
[0032] The raw materials are composed by weight: 70 parts of polylactic acid resin; 30 parts of polyvinylidene fluoride-hexafluoropropylene copolymer; and 15 parts of modified graphene.
[0033] The modified graphene is prepared by the following method:
[0034] (1) Mixing methanol and hydrogen peroxide, and then adding pyrrole to mix evenly to obtain a mixed solution; wherein the amount ratio of methanol, hydrogen peroxide and pyrrole is 1L:1L:30g;
[0035] (2) adding graphene to the mixed solution prepared in step (1), and stirring for 6 hours; wherein the amount ratio of graphene to the mixed solution is 1 kg:5 L;
[0036] (3) separating the graphene after the stirring treatment, and then adding it to the modified liquid and stirring for 6 hours, separating the solid after the stirring and drying to obtain the modified graphene;
[0037] Wherein, in step (3), the usage ratio of graphene to modifying liquid is 1kg:5L; the modifying liquid is an aqueous solution containing cocamide monoethanolamide and disodium lauryl sulfosuccinate; the mass concentration of cocamide monoethanolamide in the modifying liquid is 6%; the mass concentration of disodium lauryl sulfosuccinate in the modifying liquid is 9%.
[0038] Preparation method: polylactic acid resin, polyvinylidene fluoride-hexafluoropropylene copolymer and modified graphene are mixed evenly and then melt-extruded through a twin-screw extruder to obtain the modified polylactic acid high-barrier packaging material.
[0039] Comparative Example 1: Modified polylactic acid high barrier packaging material
[0040] The raw materials are composed by weight: 70 parts of polylactic acid resin; 30 parts of polyvinylidene fluoride-hexafluoropropylene copolymer; and 15 parts of modified graphene.
[0041] The modified graphene is prepared by the following method:
[0042] (1) Mixing methanol and hydrogen peroxide, and then adding pyrrole to mix evenly to obtain a mixed solution; wherein the amount ratio of methanol, hydrogen peroxide and pyrrole is 1L:1L:30g;
[0043] (2) adding graphene to the mixed solution prepared in step (1), and stirring for 6 hours; wherein the amount ratio of graphene to the mixed solution is 1 kg:5 L;
[0044] (3) separating the graphene after the stirring treatment, and then adding it to the modified liquid and stirring for 6 hours, separating the solid after the stirring and drying to obtain the modified graphene;
[0045] Wherein, in step (3), the usage ratio of graphene to modifying liquid is 1kg:5L; the modifying liquid is an aqueous solution containing disodium lauryl sulfosuccinate; and the mass concentration of disodium lauryl sulfosuccinate in the modifying liquid is 15%.
[0046] Preparation method: polylactic acid resin, polyvinylidene fluoride-hexafluoropropylene copolymer and modified graphene are mixed evenly and then melt-extruded through a twin-screw extruder to obtain the modified polylactic acid high-barrier packaging material.
[0047] Comparative Example 2: Modified polylactic acid high barrier packaging material
[0048] The raw materials are composed by weight: 70 parts of polylactic acid resin; 30 parts of polyvinylidene fluoride-hexafluoropropylene copolymer; and 15 parts of modified graphene.
[0049] The modified graphene is prepared by the following method:
[0050] (1) Mixing methanol and hydrogen peroxide, and then adding pyrrole to mix evenly to obtain a mixed solution; wherein the amount ratio of methanol, hydrogen peroxide and pyrrole is 1L:1L:30g;
[0051] (2) adding graphene to the mixed solution prepared in step (1), and stirring for 6 hours; wherein the amount ratio of graphene to the mixed solution is 1 kg:5 L;
[0052] (3) separating the graphene after the stirring treatment, and then adding it to the modified liquid and stirring for 6 hours, separating the solid after the stirring and drying to obtain the modified graphene;
[0053] Wherein, in step (3), the usage ratio of graphene to modifying liquid is 1kg:5L; the modifying liquid is an aqueous solution containing cocamide monoethanolamide; and the mass concentration of cocamide monoethanolamide in the modifying liquid is 15%.
[0054] Preparation method: polylactic acid resin, polyvinylidene fluoride-hexafluoropropylene copolymer and modified graphene are mixed evenly and then melt-extruded through a twin-screw extruder to obtain the modified polylactic acid high-barrier packaging material.
[0055] The modified polylactic acid high barrier packaging materials prepared in Examples 1 to 3 and Comparative Examples 1 to 2 were made into sheets and then calendered into films with a thickness of 15 μm; then, the water vapor permeability coefficient was tested according to the method in GB / T 1037-2021, and the elongation at break was tested according to the method in GB / T 1040.3-2006; the test results are shown in Table 1.
[0056] Table 1. Test results of properties of modified polylactic acid high barrier packaging materials
[0057]
[0058] It can be seen from the experimental results in Table 1 that the modified polylactic acid high barrier packaging material in Example 1 has a smaller water vapor permeability coefficient; this shows that the packaging material prepared with polylactic acid resin, polyvinylidene fluoride-hexafluoropropylene copolymer and graphene as raw materials has higher barrier properties.
[0059] It can be seen from the experimental results in Table 1 that the water vapor permeability coefficient of the modified polylactic acid high barrier packaging material in Example 2 is smaller than that in Example 1; this indicates that adding the modified graphene prepared by the method of the present invention to the modified polylactic acid high barrier packaging material of the present invention can improve the barrier properties of the packaging material compared to adding unmodified graphene.
[0060] It can be seen from the experimental results in Table 1 that the elongation at break of the modified polylactic acid high barrier packaging material in Example 2 is further significantly higher than that in Example 1; this indicates that adding the modified graphene prepared by the above method to the modified polylactic acid high barrier packaging material of the present invention can significantly improve the elongation at break of the packaging material compared to adding unmodified graphene.
[0061] It can be seen from the experimental results in Table 1 that the water vapor permeability coefficient of the modified polylactic acid high barrier packaging material in Example 3 is further smaller than that in Example 2; this indicates that the modified graphene obtained by further placing the graphene in an aqueous solution containing cocamide monoethanolamide and disodium lauryl sulfosuccinate for modification can further improve the barrier properties of the packaging material compared with the modified graphene prepared without this step.
[0062] It can be seen from the experimental results in Table 1 that the elongation at break of the modified polylactic acid high barrier packaging material of Example 3 is further significantly higher than that of Example 2; this indicates that the modified graphene obtained by further placing the graphene in an aqueous solution containing cocamide monoethanolamide and disodium lauryl sulfosuccinate for modification can further significantly improve the elongation at break of the packaging material compared with the modified graphene prepared without this step.
[0063] It can be seen from the experimental results in Table 1 that the elongation at break of the modified polylactic acid high barrier packaging materials of Comparative Examples 1 and 2 is improved compared with that of Example 2, but the improvement is not large; this shows that the elongation at break of the packaging material can be further significantly improved by further placing the graphene in an aqueous solution containing both cocamide monoethanolamide and disodium lauryl sulfosuccinate for modification; however, the elongation at break of the packaging material cannot be further significantly improved by placing the graphene in an aqueous solution containing only cocamide monoethanolamide or only disodium lauryl sulfosuccinate for modification.
Claims
1. A modified polylactic acid high barrier packaging material, characterized in that: The invention comprises the following components in parts by weight: 60 to 100 parts of polylactic acid resin, 20 to 40 parts of polyvinylidene fluoride-hexafluoropropylene copolymer, and 10 to 20 parts of graphene.
2. The modified polylactic acid high barrier packaging material according to claim 1, characterized in that: The graphene is modified graphene, and the modified graphene is prepared by the following steps: (1) Mixing methanol and hydrogen peroxide, and then adding pyrrole and mixing evenly to obtain a mixed solution; (2) adding graphene to the mixed solution prepared in step (1) and stirring evenly; (3) After the stirring treatment is completed, the graphene is separated, and then added to the modified liquid and stirred evenly. After the stirring is completed, the solid is separated and dried to obtain the modified graphene.
3. The modified polylactic acid high barrier packaging material according to claim 2, characterized in that: The usage ratio of the methanol, hydrogen peroxide and pyrrole is 1L:1L:30g, and the usage ratio of the graphene to the mixed solution is 1kg:5L.
4. The modified polylactic acid high barrier packaging material according to claim 2, characterized in that: The modified liquid is an aqueous solution containing cocamide monoethanolamide and disodium lauryl sulfosuccinate.
5. The modified polylactic acid high barrier packaging material according to claim 4, characterized in that: The mass concentration of cocamide monoethanolamide in the modified liquid is 5-10%.
6. The modified polylactic acid high barrier packaging material according to claim 4, characterized in that: The mass concentration of disodium lauryl sulfosuccinate in the modified solution is 5-10%.
7. A method for preparing a modified polylactic acid high barrier packaging material as claimed in claim 1, characterized in that: The following steps are included: The polylactic acid resin, polyvinylidene fluoride-hexafluoropropylene copolymer and graphene are mixed evenly and then melt-extruded through a twin-screw extruder to obtain the modified polylactic acid high-barrier packaging material.