Degradable bamboo-fiber-based polymer material and preparation method therefor

Abstract

The present invention relates to the technical field of degradable materials. Particularly disclosed are a degradable bamboo-fiber-based polymer material and a preparation method therefor. The degradable bamboo-fiber-based polymer material comprises, in parts by weight: 30-45 parts of a bamboo fiber raw material, 17-40 parts of PBAT, 30-40 parts of PE, 1-3 parts of a silane coupling agent, 1-3 parts of polyethylene wax, 3-5 parts of maleic anhydride, 1-3 parts of calcium stearate, 2-5 parts of a talcum powder and 1-5 parts of an ECO organic degrading agent. In the degradable bamboo-fiber-based polymer material of the present invention, the silane coupling agent is added into the bamboo fiber raw material to perform a surface treatment, such that bamboo fibers, PBAT and PE can have a bridging effect, and the modified polymer material can obtain better processability and mechanical properties. In the degradable bamboo-fiber-based polymer material of the present invention, a polyethylene-grafted maleic anhydride master batch improves the compatibility of the bamboo fibers, the talcum powder and other additives in a formulation, thereby improving various physical properties of the whole system.

Description

A degradable bamboo fiber-based polymer material and preparation method thereof Technical Field

[0001] The invention relates to a degradable bamboo fiber-based polymer material and a preparation method thereof, belonging to the technical field of degradable materials. Background Art

[0002] Bamboo fiber is a common natural polymer material. The development of this most abundant renewable resource in nature, particularly its modification, has attracted increasing attention in recent years. Common methods for modifying bamboo fiber include surface modification, graft copolymerization, and blending. While surface modification and graft copolymerization offer relatively good results, they require stringent process conditions, making large-scale industrialization difficult. Blending, on the other hand, offers a simpler process and is readily adaptable to industrial production. This is particularly true when blended with biodegradable polymers such as polylactic acid (PLA), PBAT, and PCL, resulting in fully renewable and biodegradable polymer materials, which are of significant significance for reducing environmental pollution. In addition to excellent biological properties, biodegradable polymers also require good molecular chain flexibility and chemical stability. While bamboo fiber exhibits good moisture resistance, it is not heat-resistant and exhibits low strength and toughness. Similarly, PBAT combines the properties of PBA and PBT, offering excellent ductility and elongation at break, as well as good heat resistance and impact resistance. Furthermore, it exhibits excellent biodegradability, making it a highly sought-after biodegradable material in biodegradable plastics research and one of the most widely used biodegradable materials in the market. The importance of blending and modifying the fibers to achieve biodegradability while also improving the hydrophilicity, stability, and processing properties of bamboo fibers is paramount.

[0003] Summary of the Invention

[0004] The present invention provides a degradable bamboo fiber-based polymer material and a preparation method thereof, which solves the problems of poor processing performance, mechanical properties and degradability of existing bamboo fiber-based polymer materials.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A degradable bamboo fiber-based polymer material comprises, by weight, 30-45 parts of bamboo fiber raw material, 17-40 parts of PBAT, 30-40 parts of PE, 1-3 parts of silane coupling agent, 1-3 parts of polyethylene wax, 3-5 parts of maleic anhydride, 1-3 parts of calcium stearate, 2-5 parts of talc and 1-5 parts of ECO organic degradation agent.

[0007] Furthermore, preferably: the bamboo fiber raw material is selected from plant-derived bamboo fiber, with a particle size of 400-1000 mesh.

[0008] Furthermore, preferably, the talcum powder is 1000-3000 mesh talcum powder.

[0009] Furthermore, preferably: the number average molecular weight of the PBAT is greater than 100, and the melt index is 3-10 g / 10 min.

[0010] Furthermore, preferably: the PE is linear low-density polyethylene.

[0011] Furthermore, preferably: the silane coupling agent is γ-aminopropyltriethoxysilane.

[0012] Furthermore, preferably: the molecular weight of the polyethylene wax is 1500-5000.

[0013] Furthermore, preferably, the maleic anhydride is polyethylene grafted maleic anhydride.

[0014] Furthermore, preferably: it also includes 0.1-0.5 parts of a degradation aid, which includes 30 parts of Aspergillus niger, 18 parts of Bacillus cereus, 1 part of Coptis chinensis extract, and 1 part of PLA, according to weight parts.

[0015] The preparation method comprises the following steps: firstly preparing PLA solution with a solvent and setting aside, uniformly mixing Aspergillus niger and Bacillus cereus, and setting aside; then spraying 1 / 3 of the PLA solution into the mixture of Aspergillus niger and Bacillus cereus, stirring while spraying, and adding a coptis root extract and mixing evenly; finally spraying the remaining PLA solution onto the mixture, stirring while spraying, and drying at 60-70°C after spraying to remove the solvent.

[0016] The degradation aid of the present invention can be added simultaneously with the bamboo fiber raw material in the preparation step 1.

[0017] The method for preparing the degradable bamboo fiber-based polymer material of the present invention comprises the following steps:

[0018] (1) Bamboo fiber raw materials were dried in a hot mixer at 100° C. for 30 minutes, talcum powder was added, and then the atomized silane coupling agent was added. The bamboo fiber raw materials and talcum powder were surface treated under the treatment conditions of 50-100 r / min and 90-110° C.;

[0019] (2) adding polyethylene wax, calcium stearate, maleic anhydride and ECO organic degradation agent into a hot mixer, mixing with the surface-treated bamboo fiber raw material and talcum powder, and melt-processing at 110-120° C. and 50-100 r / min;

[0020] (3) Add PBAT and PE (polyethylene) to a hot mixer, heat to 130°C, 150-200 r / min for 30 minutes, mix well in a hot mixer, and then process into a premix in a cold mixer at 40°C and 50-100 r / min;

[0021] (4) The premix is ​​placed in a feeder and quantitatively added from the first feed port of a twin-screw extruder, and the biodegradable bamboo fiber-based polymer material is obtained through twin-screw blending, extrusion, cooling, and pelletizing.

[0022] The extrusion temperature of the twin-screw extruder is 140-160°C and the screw speed is 50-100r / min. Compared with the prior art, the present invention has the following advantages:

[0023] 1) The biodegradable bamboo fiber-based polymer material of the present invention is surface treated by adding a silane coupling agent to the bamboo fiber raw material, which can bridge the bamboo fiber with PBAT and PE, so that the modified polymer material can obtain better processing performance and mechanical properties.

[0024] 2) In the biodegradable bamboo fiber-based polymer material of the present invention, the polyethylene grafted maleic anhydride masterbatch solves the compatibility of bamboo fiber, talc and other additives in the formula, thereby improving the physical properties of the entire system.

[0025] 3) In the degradable bamboo fiber-based polymer material of the present invention, the ECO organic degradation agent is a fully biodegradable material - a plastic-eating agent. ECO (plastic-eating agent) is an organic additive made by injecting anaerobic organic additives into traditional plastics. The additive introduces the plastic into the biodegradation stage through chemical activity caused by bacteria, leaving only natural gases and bioenergy. After adding ECO (plastic-eating agent), the plastic can be biodegraded in landfills through anaerobic digestion, and can decompose naturally in marine environments and industrial composting.

[0026] PBAT has good ductility and elongation at break, as well as good heat resistance and impact resistance. It also exhibits excellent biodegradability. Polyethylene grafted maleic anhydride is a degradable polymer that can enhance the material's degradability and biocompatibility. The combination of PBAT, polyethylene grafted maleic anhydride, and ECO organic degrader effectively improves not only the performance of the biodegradable bamboo fiber-based polymer material but also its biodegradation efficiency.

[0027] PBAT, PE and polyethylene grafted maleic anhydride can be fully combined with bamboo fiber, with the following advantages: enhancing the mechanical properties of the material, improving the tensile strength and stiffness of the material; having good thermal stability, which can improve the high temperature resistance of the composite material and reduce the thermal decomposition and oxidative degradation of the material; increasing the impact resistance of the degradable bamboo fiber-based polymer material, making it more suitable for applications requiring high impact resistance; improving the flame retardant properties of the material and reducing the risk of fire; improving the interface compatibility of the composite material, reducing interface peeling and enhancing the interface bonding strength of the material; having good plasticity and processability, which is conducive to the molding and processing of the degradable bamboo fiber-based polymer material and the preparation of products of various shapes and sizes. DETAILED DESCRIPTION

[0028] The technical solutions of the present invention are described below in conjunction with specific embodiments. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0029] Example 1

[0030] A degradable bamboo fiber-based polymer material comprises, by weight, 35 parts of bamboo fiber raw material, 27 parts of PBAT, 38 parts of PE, 1 part of silane coupling agent, 1 part of polyethylene wax, 3 parts of maleic anhydride, 1 part of calcium stearate, 5 parts of talc and 1 part of ECO organic degradation agent.

[0031] The bamboo fiber raw material is selected from plant-derived bamboo fiber with a mesh size of 400-1000. In this embodiment, the 400-mesh bamboo fiber powder produced by Jiangxi Polysilicon Mining Co., Ltd. is used.

[0032] The talc powder is 1000-3000 mesh talc powder. This embodiment uses 1000 mesh talc powder from Yuyao Jushi New Materials Co., Ltd.

[0033] The number average molecular weight of PBAT is >100, and the melt index is 3-10 g / 10 min. This embodiment uses PBAT produced by Kanghui New Material Technology Co., Ltd.

[0034] PE is linear low-density polyethylene, and DFDA-7042 from Sinopec Yangzi Petrochemical Co., Ltd. is used.

[0035] The silane coupling agent was γ-aminopropyltriethoxysilane, purchased from Zhengzhou Hanshuo Chemical Materials Co., Ltd.

[0036] The molecular weight of the polyethylene wax is 1500-5000, and H116 from Shanghai Panren International Trade Co., Ltd. is used.

[0037] Maleic anhydride is polyethylene grafted maleic anhydride, and W1L is used from Cozhis Chemical Co., Ltd. ECO organic degradation agent is ECO-E1000 (general type) purchased from Suzhou Yinrui Environmental Protection Materials Co., Ltd.

[0038] The preparation method thereof comprises the following steps:

[0039] (1) Bamboo fiber raw materials were dried in a hot mixer at 100°C for 30 minutes, talcum powder was added, and then the atomized silane coupling agent was added. The bamboo fiber raw materials and talcum powder were surface treated under the treatment conditions of 100 r / min and 110°C;

[0040] (2) Polyethylene wax, calcium stearate, maleic anhydride and ECO organic degradation agent were added to a hot mixer, mixed with the surface-treated bamboo fiber raw material and talcum powder, and melt-processed at 120°C and 100 r / min;

[0041] (3) Add PBAT and PE (polyethylene) into a hot mixer, heat to 130 ° C, 200 r / min, 30 minutes, mix in the hot mixer high-speed mixer, and then process into a premix in a cold mixer at 40 ° C, 100 r / min;

[0042] (4) The premix was placed in a feeder and quantitatively added through the first feed port of a twin-screw extruder. After twin-screw blending, extrusion, cooling, and pelletizing, a biodegradable bamboo fiber-based polymer material was obtained. The film was then blown into a 0.1 mm film using a film blowing machine for performance testing. The extrusion temperature of the twin-screw extruder was 160°C and the screw speed was 100 r / min.

[0043] Example 2

[0044] A degradable bamboo fiber-based polymer material comprises, by weight, 45 parts of bamboo fiber raw material, 17 parts of PBAT, 38 parts of PE, 1 part of silane coupling agent, 1 part of polyethylene wax, 3 parts of maleic anhydride, 1 part of calcium stearate, 5 parts of talc and 1 part of ECO organic degradation agent.

[0045] The bamboo fiber raw material is selected from plant-derived bamboo fiber, 400-1000 mesh. This embodiment uses 400-mesh bamboo fiber powder produced by Jiangxi Polysilicon Mining Co., Ltd.

[0046] The talc powder is 1000-3000 mesh talc powder. This embodiment uses 1000 mesh talc powder from Yuyao Jushi New Materials Co., Ltd.

[0047] The number average molecular weight of PBAT is >100, and the melt index is 3-10 g / 10 min. This embodiment uses PBAT produced by Kanghui New Material Technology Co., Ltd.

[0048] PE is linear low-density polyethylene, and DFDA-7042 from Sinopec Yangzi Petrochemical Co., Ltd. is used.

[0049] The silane coupling agent was γ-aminopropyltriethoxysilane, purchased from Zhengzhou Hanshuo Chemical Materials Co., Ltd.

[0050] The molecular weight of the polyethylene wax is 1500-5000, and H116 from Shanghai Panren International Trade Co., Ltd. is used.

[0051] Maleic anhydride is polyethylene grafted maleic anhydride, and W1L is used from Cozhis Chemical Co., Ltd. ECO organic degradation agent is ECO-E1000 (general type) purchased from Suzhou Yinrui Environmental Protection Materials Co., Ltd.

[0052] The preparation method thereof comprises the following steps:

[0053] (1) Bamboo fiber raw materials were dried in a hot mixer at 100°C for 30 minutes, talcum powder was added, and then the atomized silane coupling agent was added. The bamboo fiber raw materials and talcum powder were surface treated under the treatment conditions of 50 r / min and 90°C;

[0054] (2) Polyethylene wax, calcium stearate, maleic anhydride and ECO organic degradation agent were added to a hot mixer, mixed with the surface-treated bamboo fiber raw material and talcum powder, and melt-processed at 110°C and 50 r / min;

[0055] (3) Add PBAT and PE (polyethylene) into a hot mixer, heat to 130 ° C, 150 r / min, 30 minutes, mix in a hot mixer high-speed mixer, and then process into a premix in a cold mixer at 40 ° C, 50 r / min;

[0056] (4) The premix was placed in a feeder and quantitatively added through the first feed port of a twin-screw extruder. After twin-screw blending, extrusion, cooling, and pelletizing, a biodegradable bamboo fiber-based polymer material was obtained. The material was then blown into a 0.1 mm film using a film blowing machine for performance testing. The extrusion temperature of the twin-screw extruder was 140°C and the screw speed was 50 r / min.

[0057] Example 3

[0058] A degradable bamboo fiber-based polymer material comprises, by weight, 30 parts of bamboo fiber raw material, 30 parts of PBAT, 40 parts of PE, 3 parts of silane coupling agent, 2 parts of polyethylene wax, 5 parts of maleic anhydride, 2 parts of calcium stearate, 3 parts of talc and 3 parts of ECO organic degradation agent.

[0059] The bamboo fiber raw material is selected from plant-derived bamboo fiber, 400-1000 mesh. This embodiment uses 400-mesh bamboo fiber powder produced by Jiangxi Polysilicon Mining Co., Ltd.

[0060] The talc powder is 1000-3000 mesh talc powder. This embodiment uses 1000 mesh talc powder from Yuyao Jushi New Materials Co., Ltd.

[0061] The number average molecular weight of PBAT is >100, and the melt index is 3-10 g / 10 min. This embodiment uses PBAT produced by Kanghui New Material Technology Co., Ltd.

[0062] PE is linear low-density polyethylene, and DFDA-7042 from Sinopec Yangzi Petrochemical Co., Ltd. is used.

[0063] The silane coupling agent was γ-aminopropyltriethoxysilane, purchased from Zhengzhou Hanshuo Chemical Materials Co., Ltd.

[0064] The molecular weight of the polyethylene wax is 1500-5000, and H116 from Shanghai Panren International Trade Co., Ltd. is used.

[0065] Maleic anhydride is polyethylene grafted maleic anhydride, and W1L is used from Cozhis Chemical Co., Ltd. ECO organic degradation agent is ECO-E1000 (general type) purchased from Suzhou Yinrui Environmental Protection Materials Co., Ltd.

[0066] The preparation method thereof comprises the following steps:

[0067] (1) Bamboo fiber raw materials were dried in a hot mixer at 100°C for 30 minutes, talcum powder was added, and then atomized silane coupling agent was added. The bamboo fiber raw materials and talcum powder were surface treated under the treatment conditions of 80 r / min and temperature of 100°C;

[0068] (2) adding polyethylene wax, calcium stearate, maleic anhydride and ECO organic degradation agent into a hot mixer, mixing with the surface-treated bamboo fiber raw material and talcum powder, and melt-processing at 110-120° C. and 80 r / min;

[0069] (3) Add PBAT and PE (polyethylene) into a hot mixer, heat to 130 ° C, 200 r / min, 30 minutes, mix in the hot mixer high-speed mixer, and then process into a premix in a cold mixer at 40 ° C, 80 r / min;

[0070] (4) The premix was placed in a feeder and quantitatively added through the first feed port of a twin-screw extruder. After twin-screw blending, extrusion, cooling, and pelletizing, a biodegradable bamboo fiber-based polymer material was obtained. The material was then blown into a 0.1 mm film using a film blowing machine for performance testing. The extrusion temperature of the twin-screw extruder was 150°C and the screw speed was 80 r / min.

[0071] Example 4

[0072] Basically the same as Example 1, except that: a degradable bamboo fiber-based polymer material, calculated by weight, includes 30 parts of bamboo fiber raw material, 40 parts of PBAT, 30 parts of PE, 2 parts of silane coupling agent, 3 parts of polyethylene wax, 3 parts of maleic anhydride, 3 parts of calcium stearate, 5 parts of talc and 5 parts of ECO organic degradation agent.

[0073] Example 5

[0074] Basically the same as Example 1, except that: a degradable bamboo fiber-based polymer material, calculated by weight, includes 35 parts of bamboo fiber raw material, 25 parts of PBAT, 40 parts of PE, 2 parts of silane coupling agent, 2 parts of polyethylene wax, 4 parts of maleic anhydride, 1 part of calcium stearate, 3 parts of talc and 1 part of ECO organic degradation agent.

[0075] Example 6

[0076] The invention is basically the same as Example 1, except that: in parts by weight, it includes 35 parts of bamboo fiber raw material, 27 parts of PBAT, 38 parts of PE, 1 part of silane coupling agent, 1 part of polyethylene wax, 3 parts of maleic anhydride, 1 part of calcium stearate, 5 parts of talc, 1 part of ECO organic degradation agent and 0.1 part of degradation aid. The degradation aid includes, in parts by weight, 30 parts of Aspergillus niger powder, 18 parts of Bacillus cereus powder, 1 part of Coptis chinensis extract, 1 part of PLA,

[0077] The active viable spore content of Aspergillus niger powder was ≥ 10 billion / g, and the active viable bacterial content of Bacillus cereus powder was ≥ 5 × 109 CFU / g. Coptis chinensis extract was purchased from Shaanxi Sinuote Biotechnology Co., Ltd., with a content of 98 parts. PLA was produced using Zhejiang Hisun's REVODE190.

[0078] The preparation method comprises the following steps: firstly preparing a PLA solution using a solvent (dichloromethane) for standby use, and uniformly mixing Aspergillus niger and Bacillus cereus for standby use; then spraying 1 / 3 of the PLA solution into the mixture of Aspergillus niger and Bacillus cereus, stirring while spraying, and adding a coptis root extract to mix uniformly after the spraying is completed; finally, spraying the remaining PLA solution onto the mixture, stirring while spraying, and drying at 65°C for 4 hours after the spraying is completed, and then removing the solvent.

[0079] Example 7

[0080] The method is basically the same as Example 6, except that: the degradation aid comprises, by weight, 30 parts of Aspergillus niger, 18 parts of Bacillus cereus, 1 part of Coptis chinensis extract, 0.5 parts of gum arabic, and 0.5 parts of PLA.

[0081] The preparation method comprises the following steps: firstly preparing a PLA solution with a solvent (dichloromethane) for later use, preparing a solution of gum arabic with deionized water, and uniformly mixing Aspergillus niger and Bacillus cereus for later use; then spraying the gum arabic solution into the mixture of Aspergillus niger and Bacillus cereus, stirring while spraying, and adding a coptis root extract to mix uniformly; finally, spraying the mixture with a PLA solution, stirring while spraying, and drying at 65°C for 6 hours after spraying, and then removing the solvent and water.

[0082] Comparative Example 1

[0083] The method is basically the same as Example 1, except that: no silane coupling agent and maleic anhydride are added, and PBAT is used instead. A degradable bamboo fiber-based polymer material, in parts by weight, includes 35 parts of bamboo fiber raw material, 27 parts of PBAT, 38 parts of PE, 1 part of polyethylene wax, 1 part of calcium stearate, 5 parts of talc and 1 part of ECO organic degradation agent.

[0084] Comparative Example 2

[0085] It is basically the same as Example 2, except that: no silane coupling agent and maleic anhydride are added, and PBAT is used instead. A degradable bamboo fiber-based polymer material, calculated by weight, includes 45 parts of bamboo fiber raw material, 28 parts of PBAT, 38 parts of PE, 1 part of polyethylene wax, 1 part of calcium stearate, 5 parts of talc and 1 part of ECO organic degradation agent.

[0086] Comparative Example 3

[0087] The invention is basically the same as Example 1, except that: no maleic anhydride is added, a degradable bamboo fiber-based polymer material, in parts by weight, including 35 parts of bamboo fiber raw material, 27 parts of PBAT, 38 parts of PE, 1 part of silane coupling agent, 1 part of polyethylene wax, 1 part of calcium stearate, 5 parts of talc and 1 part of ECO organic degradation agent.

[0088] Comparative Example 4

[0089] The invention is basically the same as Example 2, except that: no maleic anhydride is added, a degradable bamboo fiber-based polymer material, in parts by weight, including 45 parts of bamboo fiber raw material, 27 parts of PBAT, 38 parts of PE, 1 part of silane coupling agent, 1 part of polyethylene wax, 1 part of calcium stearate, 5 parts of talc and 1 part of ECO organic degradation agent.

[0090] Comparative Examples 5-10

[0091] The method is basically the same as Example 1, except that no silane coupling agent is added. The specific ingredient ratio is shown in Table 1.

[0092] The preparation method comprises the following steps: (1) baking the bamboo fiber raw material at 100° C. in a hot mixer for 30 minutes and setting aside.

[0093] Comparative Example 11

[0094] The invention is basically the same as Example 1, except that: no ECO organic degradation agent is added, a degradable bamboo fiber-based polymer material, in parts by weight, includes 35 parts of bamboo fiber raw material, 27 parts of PBAT, 38 parts of PE, 1 part of silane coupling agent, 1 part of polyethylene wax, 3 parts of maleic anhydride, 1 part of calcium stearate and 5 parts of talc.

[0095] Table 1 Specific raw material ratios of different embodiments and comparative examples

[0096] Performance Testing

[0097] The degradable bamboo fiber-based polymer materials prepared in Examples 1, 2, 6, 7 and Comparative Examples 1-11 were blown into 0.1 mm films using a film blowing machine for performance testing.

[0098] The tensile strength is measured according to GB / T1040.3-2006 standard;

[0099] The breaking strength is measured according to GB / T1040.3-2006 standard;

[0100] Young's modulus of elasticity is tested according to GB / T1040.3-2006 standard;

[0101] The elongation at break is measured according to GB / T1040.3-2006;

[0102] It is stipulated that the non-proportional elongation strength Rp0.2 shall be measured in accordance with GB / T1040.3-2006 standard;

[0103] The tear strength is measured according to GB / T1040.3-2006 standard.

[0104] The specific measurement data are shown in Table 2.

[0105] Table 2 Performance measurement results of different embodiments

[0106] As shown in Table 2, silane coupling agents have a unique chemical structure, forming a very thin organic silicone film with silicon-oxygen bonds on the surface of bamboo fiber. This enhances the adhesion and compatibility between the bamboo fiber and polyethylene, improving the mechanical properties and heat resistance of the material. LLDPE has a low thermal conductivity and high thermal stability, effectively reducing heat conduction and enhancing the thermal insulation properties of biodegradable bamboo fiber-based polymers, making it suitable for applications requiring thermal insulation. LLDPE also possesses excellent tensile strength and impact resistance, enhancing the mechanical properties of biodegradable bamboo fiber-based polymers, improving their durability and service life. Silane coupling agents and linear low-density polyethylene both play a vital role in the development of bamboo fiber-based polymers, improving their adhesion, compatibility, thermal insulation, and mechanical properties, enhancing their overall performance and expanding their application range. Bamboo fiber and talc surface-treated with γ-aminopropyltriethoxysilane exhibit significant improvements in various physical properties, making them indispensable in formulations high in bamboo fiber content.

[0107] The addition of trace amounts of degradants has almost no effect on the performance of the product.

[0108] Biodegradation testing

[0109] The polymer materials prepared in Examples 1, 6, 7, and Comparative Example 11 were subjected to biodegradation tests using the ASTM D5511-18 method. The specific results are shown in Table 3. The formulation of Example 1 was submitted to Intertek for testing and obtained a Green Leaf Certification (certificate number: GLF-08-APAC-22-1515). This certificate proves that the biodegradation rate of this formulation in the 45-day ASTM D5511-18 test was 8.88%.

[0110] Table 3 Biodegradation results of different materials

[0111] As shown in Table 3, the addition of an ECO organic degradation agent to the degradable bamboo fiber-based polymer material of the present invention effectively increases the degradation rate. Compared to Comparative Example 11, which did not add an ECO organic degradation agent, Example 1 showed a 45-day biodegradation rate increase of over 158%, and a 90-day biodegradation rate increase of over 172%. This indicates that the addition of an ECO organic degradation agent effectively increases the biodegradation rate. Furthermore, further testing revealed that the biodegradable bamboo fiber-based polymer material prepared in Example 1 achieved a biodegradation rate of 91.3% within 365 days. Examples 6 and 7 demonstrate that the addition of Aspergillus niger powder and Bacillus cereus powder can effectively increase the biodegradation rate. Aspergillus niger is a fungus capable of degrading a variety of organic substances. Its role in biodegradable plastics is to produce enzymes and microbial metabolites, thereby breaking down the polymer structure of the plastic. Aspergillus niger produces enzymes, such as amylase, cellulase, and lipase, that can degrade the main components of plastics, such as polyethylene, polypropylene, and polylactic acid. By breaking down the chain structure of polymers, Aspergillus niger can accelerate the degradation of plastics and convert them into small molecules that can be further used by microorganisms.

[0112] The role of Bacillus cereus in biodegradable plastics is to degrade the lipid components in plastics by producing lipase and other enzymes that have the ability to decompose lipid substances. Bacillus cereus can decompose lipid additives in polyethylene, such as wax oil, thereby destroying the structure of the plastic and accelerating the degradation process. However, Aspergillus niger powder and Bacillus cereus powder are microorganisms, and there is a risk of contamination of polymer materials. Therefore, the addition of Coptis chinensis extract in this embodiment can effectively play an antibacterial role. Since the preparation method of the present invention needs to be carried out at high temperatures, the present invention adopts a method of forming a solid layer (Coptis chinensis extract) and a PLA layer on the outside of the bacterial powder to reduce the impact of high temperature on the activity of the bacterial powder and effectively protect the activity of the bacterial powder. The melting point of PLA is between 155-185°C, which is not affected at the processing temperature of the present invention, thereby protecting the activity of the bacterial powder and improving the biodegradation rate. At the same time, double coating with gum arabic can further protect the microorganisms from damage by high temperature, further improving the biodegradation rate and degradation rate.

[0113] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A degradable bamboo fiber-based polymer material, characterized in that: According to weight parts, it includes 30-45 parts of bamboo fiber raw material, 17-40 parts of PBAT, 30-40 parts of PE, 1-3 parts of silane coupling agent, 1-3 parts of polyethylene wax, 3-5 parts of maleic anhydride, 1-3 parts of calcium stearate, 2-5 parts of talc and 1-5 parts of ECO organic degradation agent; The silane coupling agent is γ-aminopropyltriethoxysilane; The maleic anhydride is polyethylene grafted maleic anhydride; ECO organic degradation agent is ECO-E1000; The PE is linear low-density polyethylene.

2. The degradable bamboo fiber-based polymer material according to claim 1, characterized in that: The bamboo fiber raw material is selected from bamboo fiber of plant origin, and the particle size is 400-1000 meshes.

3. The degradable bamboo fiber-based polymer material according to claim 1, characterized in that: The talcum powder is 1000-3000 mesh talcum powder.

4. The degradable bamboo fiber-based polymer material according to claim 1, characterized in that: The number average molecular weight of the PBAT is >100, and the melt index is 3-10 / 10min.

5. The degradable bamboo fiber-based polymer material according to claim 1, characterized in that: The molecular weight of the polyethylene wax is 1500-5000.

6. The degradable bamboo fiber-based polymer material according to claim 1, characterized in that: It also includes 0.1-0.5 parts of a degradation aid, which includes, by weight, 30 parts of Aspergillus niger, 18 parts of Bacillus cereus, 1 part of Coptis chinensis extract, and 1 part of PLA; The preparation method comprises the following steps: firstly, preparing a PLA solution with a solvent for later use, and evenly mixing Aspergillus niger and Bacillus cereus for later use; then spraying 1 / 3 of the PLA solution into the mixture of Aspergillus niger and Bacillus cereus, stirring while spraying, and adding a coptis chinensis extract to mix evenly after the mixture is finished; finally, spraying the remaining PLA solution onto the mixture, stirring while spraying, and drying at a temperature of 60-70 degrees Celsius after the spraying is finished to remove the solvent.

7. A method for preparing the degradable bamboo fiber polymer material according to any one of claims 1 to 6, characterized in that: The steps include: (1) Bamboo fiber raw materials are baked in a hot mixer at 100° C. for 30 minutes, talcum powder is added, and then atomized silane coupling agent is added to perform surface treatment on the bamboo fiber and talcum powder. The treatment conditions are 50-100 r / min and the temperature is 90-110° C.; (2) adding polyethylene wax, calcium stearate, maleic anhydride and ECO organic degradation agent into a hot mixer, mixing with the surface treated bamboo fiber raw material and talcum powder, and melt processing at 110-120° C. and 50-100 r / min; (3) Add PBAT and PE to the heat mixer, heat to 130°C, and mix at 150-200r / min for 30 minutes. After mixing in a machine, it is then processed into a premix in a cold mixer at 40°C, 50-100r / min; (4) placing the premix in a feeder and adding it quantitatively from the first feed port of a twin-screw extruder, and obtaining degradable bamboo fiber polymer material particles through twin-screw blending, extrusion, cooling, and pelletizing.

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