Bio-based degradable plastic packaging material

Abstract

The invention provides a bio-based degradable plastic packaging material, and relates to the technical field of plastic packaging materials. The bio-based degradable plastic packaging material is prepared from the following components in parts by weight: 50 to 70 parts of bio-based polymer, 20 to 40 parts of natural filler, 5 to 10 parts of cellulose nanofibril, 10 to 20 parts of chitosan, 5 to 15 parts of plasticizer, 1 to 5 parts of stabilizer and 4 to 12 parts of additive. By adjusting the content and proportion of the bio-based polymer, the natural filler, the plasticizer, the stabilizer and the auxiliaries, the purpose of optimizing the performance of the material is achieved. Particularly, due to the combined use of polylactic acid and polyhydroxyalkanoate, the biodegradability of the material is improved, and the material is endowed with good mechanical properties. Meanwhile, due to the addition of natural fillers such as starch and cellulose, the cost is reduced, and the biodegradability and sustainability of the material are further enhanced. In addition, due to the addition of the plasticizer, the stabilizer and the auxiliaries, the processing performance and the physical performance of the material are also remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of plastic packaging materials, in particular to bio-based degradable plastic packaging materials. Background Art

[0002] Biodegradable plastics refer to a type of plastic that meets the requirements of use during the storage period and can be degraded into environmentally friendly substances under natural environmental conditions after use. They are considered to be one of the effective ways to solve the problem of plastic pollution. With the rapid development of social economy, plastic products are widely used due to their lightness and durability, but they also bring serious environmental pollution problems. In particular, disposable plastic packaging materials, whose difficult-to-degrade characteristics pose a long-term threat to the natural ecosystem.

[0003] The existing patent CN202210899712.6 provides a degradable plastic packaging material and its preparation process, which uses 80-120 parts of aliphatic polymers, 10-20 parts of plant starch, 15-25 parts of inorganic powder fillers, 1-5 parts of chitosan and its derivatives, and 1-5 parts of functional additives, so that the provided product has excellent antibacterial properties, flame retardant properties, barrier properties and degradable properties, and can be effectively used in the packaging of products in the fields of sanitary products, food, electronic products, etc.

[0004] However, the above-mentioned packaging materials are difficult to degrade and will accumulate over a long period of time to form "white pollution", posing a serious threat to the ecosystem. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the shortcomings of the prior art, the present invention provides a bio-based degradable plastic packaging material, which solves the problem of being difficult to degrade and posing a serious threat to the ecosystem.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical scheme: bio-based degradable plastic packaging material, including the following components by weight: 50-70 parts of bio-based polymer, 20-40 parts of natural filler, 5-10 parts of cellulose nanofibrils, 10-20 parts of chitosan, 5-15 parts of plasticizer, 1-5 parts of stabilizer, and 4-12 parts of additives.

[0009] Preferably, the following components are included in weight: 60 parts of bio-based polymer, 30 parts of natural filler, 8 parts of cellulose nanofibrils, 15 parts of chitosan, 10 parts of plasticizer, 3 parts of stabilizer, and 8 parts of auxiliary agent.

[0010] Preferably, the bio-based polymer comprises the following components in parts by weight: 25-35 parts of polylactic acid and 25-35 parts of polyhydroxyalkanoate.

[0011] Preferably, the natural filler comprises the following components in parts by weight: 10-20 parts of starch and 10-20 parts of cellulose.

[0012] Preferably, the plasticizer comprises the following components in parts by weight: 1-5 parts of citrate, 2-5 parts of epoxidized soybean oil, and 2-5 parts of tributyl citrate.

[0013] Preferably, the stabilizer comprises the following components in parts by weight: 1-2 parts of antioxidant, 1-2 parts of light stabilizer, and 1-2 parts of ultraviolet absorber.

[0014] Preferably, the antioxidant is plant active selenium, the light stabilizer is GW-480, and the ultraviolet absorber is phenyl o-hydroxybenzoate.

[0015] Preferably, the auxiliary agent includes the following components in parts by weight: 1-3 parts of dispersant, 1-3 parts of lubricant, 1-3 parts of coupling agent, and 1-3 parts of flame retardant.

[0016] Preferably, the dispersant is any one or more mixtures of triethylhexyl phosphoric acid, sodium lauryl sulfate, and methyl amyl alcohol, the lubricant is ethylene bisstearamide, the coupling agent is 3-aminopropyl triethoxysilane, and the flame retardant is dimethyl methyl phosphate.

[0017] The present invention further discloses a method for preparing a bio-based degradable plastic packaging material, comprising the following steps:

[0018] Step 1: Preliminary mixing:

[0019] Dissolve the bio-based polymer, natural filler and chitosan in a suitable solvent and mix well;

[0020] Step 2: Ultrasonic dispersion:

[0021] The cellulose nanofibrils are uniformly dispersed in the solution by ultrasonic dispersion technology;

[0022] Step 3: Mix again:

[0023] Gradually add plasticizer, stabilizer and additives, and continue stirring until the mixture is evenly mixed;

[0024] Step 4: Cooling and forming:

[0025] The mixed solution is quickly cooled and shaped through a cooling system to be made into films, sheets or injection-molded products according to demand;

[0026] Step 5: Post-processing:

[0027] The molded products are moderately stretched or heat treated to further optimize the physical properties and appearance quality of the materials.

[0028] (III) Beneficial effects

[0029] The present invention provides a bio-based degradable plastic packaging material, which has the following beneficial effects:

[0030] 1. The present invention uses bio-based polymers and natural fillers as main components, ensuring that the packaging material has good biodegradability, thereby greatly reducing long-term pollution to the environment.

[0031] 2. The cellulose nanofibrils added in the present invention significantly improve the mechanical strength and heat resistance of the packaging material, making it more suitable for packaging in the fields of food, electronic products, etc.

[0032] 3. The present invention not only enhances the antibacterial property of the packaging material by adding chitosan, but also improves its biocompatibility, making it safer and more environmentally friendly.

[0033] 4. Through the carefully selected plasticizers, stabilizers and additives, the packaging material of the present invention has excellent physical properties and stability, and can meet the requirements of packaging materials in different fields.

[0034] 5. The preparation method of the present invention is simple and efficient, and the ultrasonic dispersion technology is used to ensure the uniform dispersion of cellulose nanofibrils in the solution, thereby further improving the performance of the packaging material.

[0035] In summary, the bio-based degradable plastic packaging material provided by the present invention not only solves the problem of difficult degradation in the prior art, but also improves the performance and quality of the packaging material, providing new ideas and methods for the development of environmentally friendly packaging materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic flow chart of the preparation method of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0038] Embodiment 1:

[0039] The embodiment of the present invention provides a bio-based degradable plastic packaging material, comprising the following components in parts by weight: 50 parts of a bio-based polymer, 20 parts of a natural filler, 5 parts of cellulose nanofibrils, 10 parts of chitosan, 5 parts of a plasticizer, 3 parts of a stabilizer, and 4 parts of an additive.

[0040] The bio-based polymer includes the following components in parts by weight: 25 parts of polylactic acid and 25 parts of polyhydroxyalkanoate.

[0041] Secondly, the natural filler comprises the following components in parts by weight: 10 parts of starch and 10 parts of cellulose.

[0042] Secondly, the plasticizer includes the following components in parts by weight: 1 part of citrate ester, 2 parts of epoxy soybean oil, and 2 parts of tributyl citrate.

[0043] Secondly, the stabilizer includes the following components in parts by weight: 1 part of antioxidant, 1 part of light stabilizer, and 1 part of ultraviolet absorber. Specifically, the antioxidant is plant active selenium, the light stabilizer is GW-480, and the ultraviolet absorber is phenyl o-hydroxybenzoate.

[0044] Secondly, the auxiliary agent includes the following components in parts by weight: 1 part of dispersant, 1 part of lubricant, 1 part of coupling agent, and 1 part of flame retardant. Specifically, the dispersant is triethylhexyl phosphoric acid, the lubricant is ethylene bisstearamide, the coupling agent is 3-aminopropyl triethoxysilane, and the flame retardant is dimethyl methyl phosphate.

[0045] like Figure 1 As shown, the embodiment of the present invention also provides a method for preparing a bio-based degradable plastic packaging material, comprising the following steps:

[0046] Step 1: Preliminary mixing:

[0047] Dissolve the bio-based polymer, natural filler and chitosan in a suitable solvent and mix well;

[0048] Step 2: Ultrasonic dispersion:

[0049] The cellulose nanofibrils are uniformly dispersed in the solution by ultrasonic dispersion technology;

[0050] Step 3: Mix again:

[0051] Gradually add plasticizer, stabilizer and additives, stirring continuously until the mixture is evenly mixed;

[0052] Step 4: Cooling and forming:

[0053] The mixed solution is quickly cooled and shaped through a cooling system to be made into films, sheets or injection-molded products according to demand;

[0054] Step 5: Post-processing:

[0055] The molded products are moderately stretched or heat treated to further optimize the physical properties and appearance quality of the materials.

[0056] Embodiment 2:

[0057] The embodiment of the present invention provides a bio-based degradable plastic packaging material, comprising the following components in parts by weight: 60 parts of a bio-based polymer, 30 parts of a natural filler, 8 parts of cellulose nanofibrils, 15 parts of chitosan, 10 parts of a plasticizer, 3 parts of a stabilizer, and 8 parts of an additive.

[0058] The bio-based polymer includes the following components in parts by weight: 30 parts of polylactic acid and 30 parts of polyhydroxyalkanoate.

[0059] Secondly, the natural filler comprises the following components in parts by weight: 15 parts of starch and 15 parts of cellulose.

[0060] Secondly, the plasticizer includes the following components in parts by weight: 2 parts of citrate ester, 4 parts of epoxy soybean oil, and 4 parts of tributyl citrate.

[0061] Secondly, the stabilizer includes the following components in parts by weight: 1 part of antioxidant, 1 part of light stabilizer, and 1 part of ultraviolet absorber. Specifically, the antioxidant is plant active selenium, the light stabilizer is GW-480, and the ultraviolet absorber is phenyl o-hydroxybenzoate.

[0062] Secondly, the auxiliary agent includes the following components in parts by weight: 2 parts of dispersant, 2 parts of lubricant, 2 parts of coupling agent, and 2 parts of flame retardant. Specifically, the dispersant is sodium dodecyl sulfate, the lubricant is ethylene bisstearamide, the coupling agent is 3-aminopropyl triethoxysilane, and the flame retardant is dimethyl methyl phosphate.

[0063] like Figure 1 As shown, the embodiment of the present invention also provides a method for preparing a bio-based degradable plastic packaging material, comprising the following steps:

[0064] Step 1: Preliminary mixing:

[0065] Dissolve the bio-based polymer, natural filler and chitosan in a suitable solvent and mix well;

[0066] Step 2: Ultrasonic dispersion:

[0067] The cellulose nanofibrils are uniformly dispersed in the solution by ultrasonic dispersion technology;

[0068] Step 3: Mix again:

[0069] Gradually add plasticizer, stabilizer and additives, and continue stirring until the mixture is evenly mixed;

[0070] Step 4: Cooling and forming:

[0071] The mixed solution is quickly cooled and shaped through a cooling system to be made into films, sheets or injection-molded products according to demand;

[0072] Step 5: Post-processing:

[0073] The molded products are moderately stretched or heat treated to further optimize the physical properties and appearance quality of the materials.

[0074] Embodiment three:

[0075] The embodiment of the present invention provides a bio-based degradable plastic packaging material, comprising the following components in parts by weight: 70 parts of a bio-based polymer, 40 parts of a natural filler, 10 parts of cellulose nanofibrils, 20 parts of chitosan, 15 parts of a plasticizer, 5 parts of a stabilizer, and 12 parts of an additive.

[0076] The bio-based polymer includes the following components in parts by weight: 35 parts of polylactic acid and 35 parts of polyhydroxyalkanoate.

[0077] Secondly, the natural filler comprises the following components in parts by weight: 20 parts of starch and 20 parts of cellulose.

[0078] Secondly, the plasticizer includes the following components in parts by weight: 5 parts of citrate ester, 5 parts of epoxy soybean oil, and 5 parts of tributyl citrate.

[0079] Secondly, the stabilizer includes the following components in parts by weight: 1 part of antioxidant, 2 parts of light stabilizer, and 2 parts of ultraviolet absorber. Specifically, the antioxidant is plant active selenium, the light stabilizer is GW-480, and the ultraviolet absorber is phenyl o-hydroxybenzoate.

[0080] Secondly, the auxiliary agent includes the following components in parts by weight: 3 parts of dispersant, 3 parts of lubricant, 3 parts of coupling agent, and 3 parts of flame retardant. Specifically, the dispersant is methyl pentanol, the lubricant is ethylene bisstearamide, the coupling agent is 3-aminopropyl triethoxysilane, and the flame retardant is dimethyl methyl phosphate.

[0081] like Figure 1 As shown, the embodiment of the present invention also provides a method for preparing a bio-based degradable plastic packaging material, comprising the following steps:

[0082] Step 1: Preliminary mixing:

[0083] Dissolve the bio-based polymer, natural filler and chitosan in a suitable solvent and mix well;

[0084] Step 2: Ultrasonic dispersion:

[0085] The cellulose nanofibrils are uniformly dispersed in the solution by ultrasonic dispersion technology;

[0086] Step 3: Mix again:

[0087] Gradually add plasticizer, stabilizer and additives, and continue stirring until the mixture is evenly mixed;

[0088] Step 4: Cooling and forming:

[0089] The mixed solution is quickly cooled and shaped through a cooling system to be made into films, sheets or injection-molded products according to demand;

[0090] Step 5: Post-processing:

[0091] The molded products are moderately stretched or heat treated to further optimize the physical properties and appearance quality of the materials.

[0092] Comparative Example 1:

[0093] The bio-based degradable plastic packaging material comprises the following components in parts by weight: 50 parts of bio-based polymer, 20 parts of natural filler, 5 parts of plasticizer, 3 parts of stabilizer and 4 parts of auxiliary agent.

[0094] The bio-based polymer includes the following components in parts by weight: 25 parts of polylactic acid and 25 parts of polyhydroxyalkanoate.

[0095] Secondly, the natural filler comprises the following components in parts by weight: 10 parts of starch and 10 parts of cellulose.

[0096] Secondly, the plasticizer includes the following components in parts by weight: 1 part of citrate ester, 2 parts of epoxy soybean oil, and 2 parts of tributyl citrate.

[0097] Secondly, the stabilizer includes the following components in parts by weight: 1 part of antioxidant, 1 part of light stabilizer, and 1 part of ultraviolet absorber. Specifically, the antioxidant is plant active selenium, the light stabilizer is GW-480, and the ultraviolet absorber is phenyl o-hydroxybenzoate.

[0098] Secondly, the auxiliary agent includes the following components in parts by weight: 1 part of dispersant, 1 part of lubricant, 1 part of coupling agent, and 1 part of flame retardant. Specifically, the dispersant is triethylhexyl phosphoric acid, the lubricant is ethylene bisstearamide, the coupling agent is 3-aminopropyl triethoxysilane, and the flame retardant is dimethyl methyl phosphate.

[0099] Furthermore, the preparation method of the bio-based degradable plastic packaging material comprises the following steps:

[0100] Step 1: Preliminary mixing:

[0101] Dissolve the bio-based polymer and natural filler in a suitable solvent and mix well;

[0102] Step 2: Mix again:

[0103] Gradually add plasticizer, stabilizer and additives, and continue stirring until the mixture is evenly mixed;

[0104] Step 3: Cooling and forming:

[0105] The mixed solution is quickly cooled and shaped through a cooling system to be made into films, sheets or injection-molded products according to demand;

[0106] Step 4: Post-processing:

[0107] The molded products are moderately stretched or heat treated to further optimize the physical properties and appearance quality of the materials.

[0108] Comparative Example 2:

[0109] The bio-based degradable plastic packaging material comprises the following components in parts by weight: 50 parts of bio-based polymer, 20 parts of natural filler, 10 parts of chitosan, 3 parts of stabilizer and 4 parts of auxiliary agent.

[0110] The bio-based polymer includes the following components in parts by weight: 25 parts of polylactic acid and 25 parts of polyhydroxyalkanoate.

[0111] Secondly, the natural filler comprises the following components in parts by weight: 10 parts of starch and 10 parts of cellulose.

[0112] Secondly, the stabilizer includes the following components in parts by weight: 1 part of antioxidant, 1 part of light stabilizer, and 1 part of ultraviolet absorber. Specifically, the antioxidant is plant active selenium, the light stabilizer is GW-480, and the ultraviolet absorber is phenyl o-hydroxybenzoate.

[0113] Secondly, the auxiliary agent includes the following components in parts by weight: 1 part of dispersant, 1 part of lubricant, 1 part of coupling agent, and 1 part of flame retardant. Specifically, the dispersant is triethylhexyl phosphoric acid, the lubricant is ethylene bisstearamide, the coupling agent is 3-aminopropyl triethoxysilane, and the flame retardant is dimethyl methyl phosphate.

[0114] Furthermore, the preparation method of the bio-based degradable plastic packaging material comprises the following steps:

[0115] Step 1: Preliminary mixing:

[0116] Dissolve the bio-based polymer, natural filler and chitosan in a suitable solvent and mix well;

[0117] Step 2: Mix again:

[0118] Gradually add stabilizer and additives, and continue stirring until the mixture is evenly mixed;

[0119] Step 3: Cooling and forming:

[0120] The mixed solution is quickly cooled and shaped through a cooling system to be made into films, sheets or injection-molded products according to demand;

[0121] Step 4: Post-processing:

[0122] The molded products are moderately stretched or heat treated to further optimize the physical properties and appearance quality of the materials.

[0123] Experimental example:

[0124] The performance of the bio-based degradable plastic packaging materials prepared in Examples 1, 2, 3 and Comparative Examples 1 and 2 was tested, and the results are shown in the following table:

[0125] Example Biodegradability (%) Tensile strength(MPa) Antibacterial rate (%) Embodiment 1 98.8 48 99.9 Embodiment 2 99.1 50 99.9 Embodiment 3 98.9 49 99.9 Comparative Example 1 76.6 39 93.6 Comparative Example 2 72.9 40 91.8

[0126] In summary, the bio-based degradable plastic packaging material prepared by the present invention has excellent biodegradability, tensile strength and antibacterial properties, which are significantly better than the materials prepared by Comparative Examples 1 and 2. This result is mainly attributed to the carefully designed formula and unique preparation method in the present invention.

[0127] In terms of formulation, the present invention achieves the purpose of optimizing material properties by adjusting the content and ratio of bio-based polymers, natural fillers, plasticizers, stabilizers and additives. In particular, the combined use of polylactic acid and polyhydroxyalkanoates not only improves the biodegradability of the material, but also gives the material good mechanical properties. At the same time, the addition of natural fillers such as starch and cellulose not only reduces costs, but also further enhances the biodegradability and sustainability of the material. In addition, the addition of plasticizers, stabilizers and additives also significantly improves the processing performance and physical properties of the material.

[0128] In terms of preparation method, the present invention adopts ultrasonic dispersion technology to evenly disperse cellulose nanofibrils in the solution, thereby improving the uniformity and performance of the material. At the same time, by gradually adding additives and continuously stirring, the full mixing and uniform distribution of the components are ensured. In addition, the introduction of cooling molding and post-processing steps also further optimizes the physical properties and appearance quality of the material.

[0129] In summary, the present invention provides a bio-based degradable plastic packaging material with excellent performance, environmental protection and sustainability and a preparation method thereof. The material has broad application prospects in the packaging field and is of great significance for promoting green packaging and sustainable development.

[0130] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Bio-based degradable plastic packaging material, characterized by: The invention comprises the following components in parts by weight: 50-70 parts of bio-based polymer, 20-40 parts of natural filler, 5-10 parts of cellulose nanofibrils, 10-20 parts of chitosan, 5-15 parts of plasticizer, 1-5 parts of stabilizer and 4-12 parts of auxiliary agent.

2. The bio-based degradable plastic packaging material according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 60 parts of bio-based polymer, 30 parts of natural filler, 8 parts of cellulose nanofibrils, 15 parts of chitosan, 10 parts of plasticizer, 3 parts of stabilizer and 8 parts of auxiliary agent.

3. The bio-based degradable plastic packaging material according to claim 1, characterized in that: The bio-based polymer comprises the following components in parts by weight: 25-35 parts of polylactic acid and 25-35 parts of polyhydroxyalkanoate.

4. The bio-based degradable plastic packaging material according to claim 1, characterized in that: The natural filler comprises the following components in parts by weight: 10-20 parts of starch and 10-20 parts of cellulose.

5. The bio-based degradable plastic packaging material according to claim 1, characterized in that: The plasticizer comprises the following components in parts by weight: 1-5 parts of citric acid ester, 2-5 parts of epoxy soybean oil, and 2-5 parts of tributyl citrate.

6. The bio-based degradable plastic packaging material according to claim 1, characterized in that: The stabilizer comprises the following components in parts by weight: 1-2 parts of antioxidant, 1-2 parts of light stabilizer, and 1-2 parts of ultraviolet absorber.

7. The bio-based degradable plastic packaging material according to claim 6, characterized in that: The antioxidant is plant active selenium, the light stabilizer is GW-480, and the ultraviolet absorber is phenyl o-hydroxybenzoate.

8. The bio-based degradable plastic packaging material according to claim 1, characterized in that: The auxiliary agent comprises the following components in parts by weight: 1-3 parts of a dispersant, 1-3 parts of a lubricant, 1-3 parts of a coupling agent, and 1-3 parts of a flame retardant.

9. The bio-based degradable plastic packaging material according to claim 8, characterized in that: The dispersant is any one or more mixtures of triethylhexyl phosphoric acid, sodium dodecyl sulfate, and methyl amyl alcohol; the lubricant is ethylene bisstearamide; the coupling agent is 3-aminopropyl triethoxysilane; and the flame retardant is dimethyl methyl phosphate.

10. The method for preparing the bio-based degradable plastic packaging material according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Preliminary mixing: Dissolve the bio-based polymer, natural filler and chitosan in a suitable solvent and mix well; Step 2: Ultrasonic dispersion: The cellulose nanofibrils are uniformly dispersed in the solution by ultrasonic dispersion technology; Step 3: Mix again: Gradually add plasticizer, stabilizer and additives, and continue stirring until the mixture is evenly mixed; Step 4: Cooling and forming: The mixed solution is quickly cooled and shaped through a cooling system to be made into films, sheets or injection-molded products according to demand; Step 5: Post-processing: The molded products are moderately stretched or heat treated to further optimize the physical properties and appearance quality of the materials.

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