A fully degradable low-carbon biological sheet and preparation method thereof

Abstract

The present invention discloses a fully degradable low-carbon bio-sheet, comprising the following components in weight percentage: 80%-88% polylactic acid; 2%-8% PBAT; 2%-12% inorganic filler; 0.2%-1% soybean oil; 0.4%-1.2% oil-soluble plasticizer. The present invention also discloses a method for preparing a fully degradable low-carbon bio-sheet. Compared with the prior art, the present invention solves the problem that cutting scratches and debris are easily left on the cutting surface during the chip processing of the existing degradable packaging material.

Description

Technical Field

[0001] The invention relates to the technical field of degradable sheets, and in particular to a fully degradable low-carbon biological sheet and a preparation method thereof. Background Art

[0002] Polylactic acid (PLA) is derived from biomass and can be completely degraded into CO2 and H2O under composting conditions without causing pollution to the environment. Existing degradable materials are usually prepared by blending PBAT, polylactic acid and starch. For example, Chinese patent CN109135203B discloses a ground covering film for planting southern sand pear trees and a preparation method thereof. The raw materials of the ground covering film include: PBAT, polylactic acid, ethylene-vinyl acetate copolymer, cellulose, modified starch, calcium carbonate, nano-sized titanium dioxide, polycarbonate, brassinolide, micro-powder silica gel and plasticizer.

[0003] The biodegradable material is mainly made by blending PBAT, polylactic acid and starch. When cutting, it is easy to leave cutting scratches and debris on the cutting surface, which leads to safety hazards when used as food packaging materials. In addition, the components of existing biodegradable materials are complex, which makes it difficult to control the stability of the biodegradable materials and easy to degrade incompletely. Summary of the invention

[0004] The purpose of the present invention is to provide a fully degradable low-carbon bio-sheet and a preparation method thereof, so as to solve the problem that cutting scratches and debris are easily left on the cutting surface during the chip processing of the existing degradable packaging material.

[0005] In order to achieve the above object, on the one hand, the present invention discloses a fully degradable low-carbon bio-sheet, comprising the following components in weight percentage:

[0006] Polylactic acid 80%-88%;

[0007] PBAT 7%-8%;

[0008] Inorganic fillers 2%-12%;

[0009] Soybean oil 0.2%-1%;

[0010] Oil-soluble plasticizer 0.4%-1.2%.

[0011] As a further description of the above technical solution:

[0012] The inorganic filler includes one or more of talc, nano calcium carbonate and nano zinc oxide.

[0013] On the other hand, the present invention also discloses a method for preparing a fully degradable low-carbon bio-sheet, comprising the following steps:

[0014] S1. Take the sheet components in the above formula ratio, add polylactic acid, PBAT, inorganic filler, soybean oil, and oil-soluble plasticizer into a high-speed mixer in sequence and mix them evenly;

[0015] S2, sending the uniformly mixed sheet components into a twin-screw extruder for melt blending;

[0016] S3. The blend extruded by the twin-screw extruder is pressed into a sheet with a thickness of 1 mm to 5 mm by a flat vulcanizer.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0018] 1. In the present invention, starch is not included in the sheet component, which is mainly composed of PLA biodegradable material. The PBAT material added in the sheet component has excellent biodegradability, ensuring the degradable performance. A small amount of PBAT material also makes the sheet excellent in ductility, elongation at break, heat resistance and impact resistance.

[0019] 2. In the present invention, the addition of inorganic fillers improves the crystallinity and strength of PLA. At the same time, in order to avoid the poor compatibility between PLA and inorganic fillers, soybean oil and oil-soluble plasticizers are added, thereby effectively improving the toughness of the sheet, further improving the ductility and elongation at break of the sheet, so that the cut surface of the sheet is free of cutting scratches and debris during chip processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 The present invention is a flow chart of a method for preparing a fully degradable low-carbon bio-sheet. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0024] Example 1

[0025] The fully degradable low-carbon bio-sheet comprises the following components in percentage by weight:

[0026] Polylactic acid 82%;

[0027] PBAT 5%;

[0028] Inorganic filler 12%;

[0029] Soybean oil 0.4%;

[0030] Oil-soluble plasticizer 0.6%.

[0031] See also Figure 1 The method for preparing a fully degradable low-carbon bio-sheet comprises the following steps:

[0032] S1. Take the sheet components in the above formula ratio, add polylactic acid, PBAT, inorganic filler, soybean oil, and oil-soluble plasticizer into a high-speed mixer in sequence and mix them evenly, and add soybean oil and oil-soluble plasticizer in sequence by spraying;

[0033] S2, sending the uniformly mixed sheet components into a twin-screw extruder for melt blending;

[0034] S3. The blend is extruded by a twin-screw extruder, the screw speed of the twin-screw extruder is 50 to 500 rpm, and is pressed into a sheet with a thickness of 1 mm to 5 mm by a flat vulcanizer.

[0035] The polylactic acid is PLA particles with the brand name FY804 manufactured by Anhui Fengyuan. The inorganic filler includes one or more of talc, nano calcium carbonate, and nano zinc oxide. The specific type of addition can be flexibly selected according to the performance requirements of the product to be prepared by the sheet.

[0036] During the preparation process, in step S1, soybean oil and oil-soluble plasticizer are added in sequence by spraying, which effectively improves the mixing effect and improves the compatibility of the subsequent melt blending of the sheet components.

[0037] During the preparation process, in step S3, the screw speed of the twin-screw extruder is 50 to 500 rpm, which effectively controls the extrusion speed.

[0038] Working principle: The sheet components do not include starch, and are mainly composed of PLA biodegradable materials. The PBAT material added to the sheet components has excellent biodegradability, ensuring degradable performance. A small amount of PBAT material also makes the sheet excellent in ductility, elongation at break, heat resistance, and impact resistance. The addition of inorganic fillers improves the crystallinity and strength of PLA. At the same time, in order to avoid the poor compatibility between PLA and inorganic fillers, soybean oil and oil-soluble plasticizers are added to effectively improve the toughness of the sheet, further improve the ductility and elongation at break of the sheet, and make the cutting surface free of cutting scratches and debris during the chip processing of the sheet. The sheet components are simple, and the physical properties of the obtained sheet are easy to control and stabilize.

[0039] Example 2

[0040] The fully degradable low-carbon bio-sheet comprises the following components in percentage by weight:

[0041] Polylactic acid 86%;

[0042] PBAT 4%;

[0043] Inorganic filler 9%;

[0044] Soybean oil 0.2%;

[0045] Oil-soluble plasticizer 0.8%.

[0046] See also Figure 1 The method for preparing a fully degradable low-carbon bio-sheet comprises the following steps:

[0047] S1. Take the sheet components in the above formula ratio, add polylactic acid, PBAT, inorganic filler, soybean oil, and oil-soluble plasticizer into a high-speed mixer in sequence and mix them evenly, and add soybean oil and oil-soluble plasticizer in sequence by spraying;

[0048] S2, sending the uniformly mixed sheet components into a twin-screw extruder for melt blending;

[0049] S3. The blend is extruded by a twin-screw extruder, the screw speed of the twin-screw extruder is 50 to 500 rpm, and is pressed into a sheet with a thickness of 1 mm to 5 mm by a flat vulcanizer.

[0050] Example 3

[0051] The fully degradable low-carbon bio-sheet comprises the following components in percentage by weight:

[0052] Polylactic acid 85%;

[0053] PBAT 4%;

[0054] Inorganic filler 10%;

[0055] Soybean oil 0.3%;

[0056] Oil-soluble plasticizer 0.7%.

[0057] See also Figure 1 The method for preparing a fully degradable low-carbon bio-sheet comprises the following steps:

[0058] S1. Take the sheet components in the above formula ratio, add polylactic acid, PBAT, inorganic filler, soybean oil, and oil-soluble plasticizer into a high-speed mixer in sequence and mix them evenly, and add soybean oil and oil-soluble plasticizer in sequence by spraying;

[0059] S2, sending the uniformly mixed sheet components into a twin-screw extruder for melt blending;

[0060] S3. The blend is extruded by a twin-screw extruder, the screw speed of the twin-screw extruder is 50 to 500 rpm, and is pressed into a sheet with a thickness of 1 mm to 5 mm by a flat vulcanizer.

[0061] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A fully degradable low-carbon bio-sheet, characterized in that: The composition includes the following weight percentages: Polylactic acid 80%-88%; PBAT 2%-8%; Inorganic fillers 2%-12%; Soybean oil 0.2%-1%; Oil-soluble plasticizer 0.4%-1.2%.

2. A fully degradable low-carbon bio-sheet according to claim 1, characterized in that: The invention comprises the following components in weight percentage: 82%-88% of polylactic acid; 2%-6% of PBAT; 4%-10% of inorganic filler; 0.2%-0.6% of soybean oil; and 0.4%-0.8% of oil-soluble plasticizer.

3. A fully degradable low-carbon bio-sheet according to claim 2, characterized in that: The composition includes the following weight percentages: The invention comprises the following components in weight percentage: polylactic acid 85%; PBAT 4%; Inorganic filler 10%; Soybean oil 0.3%; Oil-soluble plasticizer 0.7%.

4. The fully degradable low-carbon bio-sheet according to claim 1, characterized in that: The inorganic filler includes one or more of talc, nano calcium carbonate and nano zinc oxide.

5. The fully degradable low-carbon bio-sheet according to claim 1, characterized in that: The polylactic acid is PLA particles with the brand number FY804 manufactured by Anhui Fengyuan.

6. A method for preparing a fully degradable low-carbon bio-sheet as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Take the sheet material components according to any one of the formula ratios of claims 1 to 5, add polylactic acid, PBAT, inorganic filler, soybean oil, and oil-soluble plasticizer into a high-speed mixer in sequence and mix evenly; S2, sending the uniformly mixed sheet components into a twin-screw extruder for melt blending; S3. The blend extruded by the twin-screw extruder is pressed into a sheet with a thickness of 1 mm to 5 mm by a flat vulcanizer.

7. The method for preparing a fully degradable low-carbon bio-sheet according to claim 6, characterized in that: In the step S1, soybean oil and oil-soluble plasticizer are added in sequence by spraying.

8. The method for preparing a fully degradable low-carbon bio-sheet according to claim 6, characterized in that: In step S3, the screw speed of the twin-screw extruder is 50 to 500 rpm.

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