Traditional Chinese medicinal plant fiber degradable plastic and preparation method thereof

Abstract

The invention relates to a traditional Chinese medicine plant fiber degradable plastic and a preparation method thereof, and belongs to the technical field of degradable plastics, the traditional Chinese medicine plant fiber degradable plastic comprises the following preparation raw materials by weight: 20-40 parts of a fiber mixture, 60-90 parts of polylactic acid, and 5-8 parts of a silane coupling agent; wherein the fiber mixture is prepared from the following raw materials in parts by weight: 4-6 parts of bamboo fibers, 3-7 parts of wormwood fibers and 1-3 parts of turmeric fibers. The traditional Chinese medicine plant fiber degradable plastic prepared from a fiber mixture prepared from bamboo fibers, wormwood fibers and turmeric fibers according to a proper proportion, degradable polylactic acid and a silane coupling agent is excellent in antibacterial property and oxidation resistance, and meanwhile, the plastic has the advantages that the antibacterial property and the oxidation resistance are good; according to the present invention, the qualified biodegradation rate of the traditional Chinese medicinal material plant fiber degradable plastic is ensured, the elongation at break of the traditional Chinese medicinal material plant fiber degradable plastic is ensured, in addition, the reproducibility of the preparation ratio and the preparation method is achieved, and the low-cost and high-efficiency industrial production can be conveniently achieved.

Description

Technical Field

[0001] This invention belongs to the field of biodegradable plastics technology, specifically relating to a biodegradable plastic made from Chinese medicinal plant fibers and its preparation method. Background Technology

[0002] Biodegradable plastics are a class of plastic materials that can be decomposed by microorganisms into small molecules such as carbon dioxide, water, and methane under specific environmental conditions, and eventually return to the natural ecological cycle. Their core advantage is to alleviate the white pollution caused by traditional plastics, and they have important application value in disposable and difficult-to-recycle fields such as packaging, agriculture, and medicine.

[0003] Currently, various technological solutions have emerged in the market that integrate plant fibers with plastics, aiming to improve the sustainability, biodegradability, and mechanical properties of materials. These technologies typically involve pretreating conventional plant fibers such as rice husk fiber, wood fiber, and bamboo fiber, then mixing them with plastic matrices such as polyethylene and polypropylene, and finally producing composite materials through processes such as injection molding and extrusion. This approach improves the environmental friendliness of traditional plastics to some extent.

[0004] However, existing technical solutions have significant shortcomings: the conventional plant fibers such as rice husk fiber and wood fiber currently used can only optimize the mechanical properties and degradation characteristics of materials at the structural level, and do not have antibacterial, antioxidant and other bioactive functions, making it difficult to meet the special needs of food preservation, medical protection and daily necessities packaging for additional functions of materials. Summary of the Invention

[0005] The purpose of this invention is to provide a biodegradable plastic made from Chinese medicinal plant fibers and its preparation method in order to solve the above-mentioned problems.

[0006] The present invention achieves the above objectives through the following technical solutions: This invention provides a biodegradable plastic made from Chinese medicinal plant fibers and its preparation method. By weight, the raw materials for preparing the biodegradable plastic made from Chinese medicinal plant fibers include: 20-40 parts of fiber mixture, 60-90 parts of polylactic acid, and 5-8 parts of silane coupling agent. The raw materials for preparing the fiber mixture include: 4-6 parts bamboo fiber, 3-7 parts mugwort fiber, and 1-3 parts turmeric fiber.

[0007] As a further optimization of the present invention, the preparation process of the bamboo fiber is as follows: (i) Select fresh moso bamboo, remove the bamboo nodes and bark, and cut it into bamboo sections 5-10cm long; (ii) After rinsing clean, place it in a 60-70℃ oven to dry for 4-6 hours to obtain dried bamboo with a moisture content of 5-9%; (iii) Crush it into 20-40 mesh particles using a pulverizer, and collect the uniform powder after sieving; (iv) Soak the powder in a 5-8% NaOH solution for 20-40 minutes, and then take out the powder to obtain pretreated bamboo powder; (v) Place the pretreated bamboo powder into a high-pressure reactor. The temperature inside the reactor is controlled at 80-90℃ and kept at that temperature for 2-3 hours. During this period, the reactor is stirred once every 30 minutes at a speed of 50 r / min. After the reaction is completed, the reactor is filtered using a vacuum filter and the filter residue is collected. (vi) The filter residue is repeatedly rinsed with deionized water until the pH of the rinsing solution is 6.5-7.0. Then, it is placed in a 0.5-1% hydrogen peroxide solution and soaked at room temperature for 30 minutes. The filter residue is then rinsed again with deionized water to obtain pretreated filter residue. (vii) The pretreated filter residue is placed in a vacuum drying oven at 50-60℃ and dried for 8-10 hours. After crushing, it is passed through a 60-mesh sieve to obtain bamboo fiber.

[0008] As a further optimization of the present invention, the raw materials for preparing the bamboo fiber include: 10-12 parts of moso bamboo, 30-40 parts of 5-8% sodium hydroxide solution, 180-220 parts of deionized water, and 30-40 parts of 0.5-1% hydrogen peroxide solution.

[0009] As a further optimization of the present invention, the preparation process of the mugwort fiber is as follows: (i) Select fresh mugwort stems and leaves without mold, wash them clean, cut them into 2-3cm mugwort segments and drain the surface water; (ii) Dry the mugwort segments to obtain dried mugwort with a moisture content of 7-9%; (iii) Put the dried mugwort into a pulverizer and grind it into 30-50 mesh mugwort powder; (iv) Soak the mugwort powder in a 5% sodium bicarbonate solution for 1 hour, take it out, filter it, and obtain mugwort residue; (v) Wash the mugwort residue until neutral, drain the water, and obtain mugwort fiber.

[0010] As a further optimization of the present invention, the raw materials for preparing the mugwort fiber include: 10-12 parts of mugwort fiber and 30-40 parts of 5% sodium bicarbonate solution.

[0011] As a further optimization of the present invention, the preparation process of the turmeric fiber is as follows: (i) Select fresh turmeric rhizomes without mold, clean the surface of the turmeric rhizomes, and cut them into 0.5cm thick slices; (ii) Spread the turmeric slices flat in a ventilated and cool place to air dry naturally to obtain dry slices with a moisture content of 7-9%; (iii) Crush the dry slices to obtain coarse powder of 40-60 mesh; (iv) Immerse the coarse powder in a solution containing 5% sodium bicarbonate, control the immersion time to 180-190 min, control the temperature to 40℃, and then filter to obtain coarse residue; (v) Rinse the coarse residue with clean water until neutral, and dry it in a drying oven for 6-8 hours until the turmeric fiber has a moisture content of 5-8%.

[0012] As a further optimization of the present invention, the raw materials for preparing the turmeric fiber include: 3-8 parts of turmeric rhizome and 30-40 parts of 5% sodium bicarbonate solution.

[0013] This invention also provides a method for preparing biodegradable plastics from Chinese medicinal plant fibers, comprising the following steps: S1. Mix bamboo fiber, mugwort fiber and turmeric fiber, and stir at 300-500 r / min for 10-15 min to obtain a uniform fiber mixture. S2, add silane coupling agent to fiber mixture, stir at 50-70℃ and 400-600r / min for 20-30min to make the coupling agent uniformly coat the fiber surface and obtain the fiber raw material to be processed. S3, add the fiber raw material to be processed into molten polylactic acid at 160-180℃, stir at 600-800r / min for 30-40min to form a homogeneous system and obtain the plastic raw material to be processed; S4. Add the plastic raw material to be processed into the injection molding machine, control the barrel temperature to 170-190℃, the mold temperature to 40-60℃, and the injection pressure to 50-80MPa, and process it into the desired shape. Then, place the product in an environment of 60-80℃ for annealing for 1-2 hours, cool it to room temperature, and finally obtain a biodegradable plastic made from Chinese medicinal plant fiber.

[0014] The beneficial effects of this invention are as follows: A biodegradable plastic made from Chinese medicinal plant fibers, prepared by combining bamboo fiber, mugwort fiber, and turmeric fiber in appropriate proportions, and formulated with biodegradable polylactic acid and silane coupling agent, exhibits excellent antibacterial and antioxidant properties. Simultaneously, it ensures a qualified biodegradability rate and guarantees the elongation at break of the biodegradable plastic. Furthermore, it achieves reproducibility of the preparation ratio and method, facilitating low-cost and high-efficiency industrial production. Detailed Implementation

[0015] The present application will now be described in further detail. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0016] I. Materials Unless otherwise specified, all methods used in this invention are conventional methods known to those skilled in the art, and all reagents and materials used are commercially available products.

[0017] II. Implementation Examples Example 1 A biodegradable plastic made from plant fibers of traditional Chinese medicine, wherein the raw materials for preparing the biodegradable plastic made from plant fibers of traditional Chinese medicine include: 20 parts fiber mixture, 60 parts polylactic acid, and 5 parts silane coupling agent; The raw materials for preparing the fiber blend include: 4 parts bamboo fiber, 3 parts mugwort fiber, and 1 part turmeric fiber; The raw materials for preparing bamboo fiber include: 10 parts of moso bamboo, 30 parts of 5-8% sodium hydroxide solution, 180 parts of deionized water, and 30 parts of 0.5-1% hydrogen peroxide solution. The raw materials for preparing Artemisia argyi fiber include: 10 parts Artemisia argyi fiber and 30 parts 5% sodium bicarbonate solution. The raw materials for preparing turmeric fiber include: 3 parts turmeric rhizomes and 30 parts 5% sodium bicarbonate solution.

[0018] A method for preparing biodegradable plastics from plant fibers of traditional Chinese medicinal materials includes the following steps: The preparation process of bamboo fiber is as follows: (I) Select fresh moso bamboo, remove the bamboo nodes and bark, and cut it into 5cm long bamboo sections; (II) After rinsing clean, put it into a 60℃ oven to dry for 4 hours to obtain dried bamboo with a moisture content of 5%; (III) Crush it into 20 mesh particles with a pulverizer, and collect the uniform powder after sieving; (IV) Soak the powder in a 5% NaOH solution for 20 minutes, and then take out the powder to obtain pretreated bamboo powder; (V) Put the pretreated bamboo powder into a high-pressure reactor and control the temperature inside the reactor to 8℃. 0℃, keep warm for 2 hours, stirring once every 30 minutes during the period, at a speed of 50 r / min. After the reaction is completed, filter with a vacuum filter and collect the filter residue; (vi) repeatedly rinse the filter residue with deionized water until the pH value of the rinsing solution is 6.5. Then, place it in 0.5% hydrogen peroxide solution and soak at room temperature for 30 minutes. Filter and rinse again with deionized water to obtain pretreated filter residue; (vii) put the pretreated filter residue into a vacuum drying oven at 50℃ and dry for 8 hours. After crushing, pass through a 60-mesh sieve to obtain bamboo fiber; The preparation process of mugwort fiber is as follows: (i) Select fresh mugwort stems and leaves without mold, wash them clean, cut them into 2cm sections and drain the surface water; (ii) Dry the mugwort sections to obtain dried mugwort with a moisture content of 7%; (iii) Put the dried mugwort into a pulverizer and grind it into 30-mesh mugwort powder; (iv) Soak the mugwort powder in a 5% sodium bicarbonate solution for 1 hour, take it out, filter it, and obtain mugwort residue; (v) Wash the mugwort residue until it is neutral, drain the water, and obtain mugwort fiber. The preparation process of turmeric fiber is as follows: (i) Select fresh turmeric rhizomes without mold, clean the surface of the turmeric rhizomes, and cut them into 0.5cm thick slices; (ii) Spread the turmeric slices flat in a ventilated and cool place to air dry naturally to obtain dry slices with a moisture content of 7%; (iii) Crush the dry slices to obtain 40-mesh coarse powder; (iv) Immerse the coarse powder in a 5% sodium bicarbonate solution, control the immersion time for 180 minutes, control the temperature at 40℃, and then filter to obtain coarse residue; (v) Rinse the coarse residue with clean water until neutral, and dry it in a drying oven for 6 hours until the turmeric fiber has a moisture content of 5%. Bamboo fiber, mugwort fiber, and turmeric fiber were mixed and stirred at 300 r / min for 10 min to obtain a uniform fiber mixture. Add silane coupling agent to fiber mixture and stir for 20 minutes at 50°C and 400 r / min to make the coupling agent uniformly coat the fiber surface and obtain the fiber raw material to be processed. The fiber raw material to be processed is added to polylactic acid molten at 160℃ and stirred at 600 r / min for 30 min to form a homogeneous system and obtain the plastic raw material to be processed. The plastic raw material to be processed is added to the injection molding machine, and the barrel temperature is controlled at 170℃, the mold temperature at 40℃, and the injection pressure at 50MPa to process it into the desired shape. Then the product is placed in an environment of 60℃ for annealing for 1 hour and cooled to room temperature to finally obtain a biodegradable plastic made from Chinese medicinal plant fiber.

[0019] Example 2 A biodegradable plastic made from plant fibers of traditional Chinese medicine, wherein the raw materials for preparing the biodegradable plastic made from plant fibers of traditional Chinese medicine include: 30 parts fiber mixture, 75 parts polylactic acid, and 6.5 parts silane coupling agent; The raw materials for preparing the fiber blend include: 5 parts bamboo fiber, 4.5 parts mugwort fiber, and 2 parts turmeric fiber; The raw materials for preparing bamboo fiber include: 11 parts of moso bamboo, 35 parts of 5-8% sodium hydroxide solution, 200 parts of deionized water, and 35 parts of 0.75% hydrogen peroxide solution. The raw materials for preparing Artemisia argyi fiber include: 11 parts Artemisia argyi fiber and 35 parts 5% sodium bicarbonate solution. The raw materials for preparing turmeric fiber include: 5 parts turmeric rhizomes and 35 parts 5% sodium bicarbonate solution.

[0020] A method for preparing biodegradable plastics from plant fibers of traditional Chinese medicinal materials includes the following steps: The preparation process of bamboo fiber is as follows: (I) Select fresh moso bamboo, remove the bamboo nodes and bark, and cut it into 7cm long bamboo sections; (II) After rinsing clean, dry it in a 65℃ oven for 5 hours to obtain dried bamboo with a moisture content of 7%; (III) Crush it into 30-mesh particles using a pulverizer, and collect the uniform powder after sieving; (IV) Soak the powder in a 6.5% NaOH solution for 30 minutes, and then take out the powder to obtain pretreated bamboo powder; (V) Put the pretreated bamboo powder into a high-pressure reactor and control the temperature inside the reactor to 85℃. ℃, keep warm for 2.5h, stir once every 30 minutes during the period, speed 50r / min, after the reaction is completed, filter with vacuum filter and collect the filter residue; (vi) rinse the filter residue repeatedly with deionized water until the pH value of the rinsing solution is 6.55, then place it in 0.75% hydrogen peroxide solution, soak at room temperature for 30 minutes, and filter and rinse again with deionized water to obtain pretreated filter residue; (vii) put the pretreated filter residue into a vacuum drying oven at 55℃ and dry for 9 hours, crush it and pass it through a 60 mesh sieve to obtain bamboo fiber; The preparation process of mugwort fiber is as follows: (i) Select fresh mugwort stems and leaves without mold, wash them clean, cut them into 2.5cm mugwort segments and drain the surface water; (ii) Dry the mugwort segments to obtain dried mugwort with a moisture content of 8%; (iii) Put the dried mugwort into a pulverizer and grind it into 40-mesh mugwort powder; (iv) Soak the mugwort powder in a 5% sodium bicarbonate solution for 1 hour, take it out, filter it, and obtain mugwort residue; (v) Wash the mugwort residue until it is neutral, drain the water, and obtain mugwort fiber. The preparation process of turmeric fiber is as follows: (i) Select fresh turmeric rhizomes without mold, clean the surface of the turmeric rhizomes, and cut them into 0.5cm thick slices; (ii) Spread the turmeric slices flat in a ventilated and cool place to air dry naturally to obtain dry slices with a moisture content of 8%; (iii) Crush the dry slices to obtain 50-mesh coarse powder; (iv) Immerse the coarse powder in a 5% sodium bicarbonate solution, control the immersion time to 185min, control the temperature to 40℃, and then filter to obtain coarse residue; (v) Rinse the coarse residue with clean water until neutral, and dry it in a drying oven for 7h until the turmeric fiber has a moisture content of 6.5%; Bamboo fiber, mugwort fiber, and turmeric fiber were mixed and stirred at 400 r / min for 12.5 min to obtain a uniform fiber mixture. Add silane coupling agent to fiber mixture and stir at 60℃ and 500r / min for 25min to make the coupling agent uniformly coat the fiber surface and obtain the fiber raw material to be processed. The fiber raw material to be processed is added to polylactic acid molten at 170℃ and stirred at 700 r / min for 35 min to form a homogeneous system and obtain the plastic raw material to be processed. The plastic raw material to be processed is added to the injection molding machine, and the barrel temperature is controlled at 180℃, the mold temperature at 50℃, and the injection pressure at 65MPa to process it into the desired shape. Then the product is placed in an environment of 70℃ for annealing for 1.5 hours and cooled to room temperature to finally obtain a biodegradable plastic made from Chinese medicinal plant fiber.

[0021] Example 3 A biodegradable plastic made from plant fibers of traditional Chinese medicine, wherein the raw materials for preparing the biodegradable plastic made from plant fibers of traditional Chinese medicine include: 40 parts fiber mixture, 90 parts polylactic acid, and 8 parts silane coupling agent; The raw materials for preparing the fiber blend include: 6 parts bamboo fiber, 7 parts mugwort fiber, and 3 parts turmeric fiber; The raw materials for preparing bamboo fiber include: 12 parts of moso bamboo, 40 parts of 8% sodium hydroxide solution, 220 parts of deionized water, and 40 parts of 1% hydrogen peroxide solution. The raw materials for preparing Artemisia argyi fiber include: 12 parts Artemisia argyi fiber and 40 parts 5% sodium bicarbonate solution. The raw materials for preparing turmeric fiber include: 8 parts turmeric rhizomes and 40 parts 5% sodium bicarbonate solution.

[0022] A method for preparing biodegradable plastics from plant fibers of traditional Chinese medicinal materials includes the following steps: The preparation process of bamboo fiber is as follows: (I) Select fresh moso bamboo, remove the nodes and bark, and cut it into 10cm long bamboo sections; (II) After rinsing clean, dry it in a 70℃ oven for 6 hours to obtain dried bamboo with a moisture content of 9%; (III) Crush it into 40-mesh particles using a pulverizer, sieve it, and collect the uniform powder; (IV) Soak the powder in an 8% NaOH solution for 40 minutes, then remove the powder to obtain pretreated bamboo powder; (V) Place the pretreated bamboo powder into a high-pressure reactor and control the temperature inside the reactor to be... 90℃, keep warm for 3 hours, stir once every 30 minutes during the period, speed 50r / min. After the reaction is completed, filter with a vacuum filter and collect the filter residue; (vi) rinse the filter residue repeatedly with deionized water until the pH value of the rinsing solution is 7.0. Then, place it in 1% hydrogen peroxide solution and soak at room temperature for 30 minutes. Then filter and rinse again with deionized water to obtain pretreated filter residue; (vii) put the pretreated filter residue into a vacuum drying oven at 60℃ and dry for 10 hours. After crushing, pass through a 60-mesh sieve to obtain bamboo fiber; The preparation process of mugwort fiber is as follows: (i) Select fresh mugwort stems and leaves without mold, wash them clean, cut them into 3cm mugwort sections and drain the surface water; (ii) Dry the mugwort sections to obtain dried mugwort with a moisture content of 9%; (iii) Put the dried mugwort into a pulverizer and grind it into 50-mesh mugwort powder; (iv) Soak the mugwort powder in a 5% sodium bicarbonate solution for 1 hour, take it out, filter it, and obtain mugwort residue; (v) Wash the mugwort residue until it is neutral, drain the water, and obtain mugwort fiber. The preparation process of turmeric fiber is as follows: (i) Select fresh turmeric rhizomes without mold, clean the surface of the turmeric rhizomes, and cut them into 0.5cm thick slices; (ii) Spread the turmeric slices flat in a ventilated and cool place to air dry naturally to obtain dry slices with a moisture content of 9%; (iii) Crush the dry slices to obtain 60-mesh coarse powder; (iv) Immerse the coarse powder in a 5% sodium bicarbonate solution, control the immersion time to 190min, control the temperature to 40℃, and then filter to obtain coarse residue; (v) Rinse the coarse residue with clean water until neutral, and dry it in a drying oven for 8h until the turmeric fiber has a moisture content of 8%. Bamboo fiber, mugwort fiber, and turmeric fiber were mixed and stirred at 500 r / min for 15 min to obtain a uniform fiber mixture. Add silane coupling agent to fiber mixture and stir at 70℃ and 600r / min for 30min to make the coupling agent uniformly coat the fiber surface and obtain the fiber raw material to be processed. The fiber raw material to be processed is added to polylactic acid molten at 180℃ and stirred at 800 r / min for 40 min to form a homogeneous system and obtain the plastic raw material to be processed. The plastic raw material to be processed is added to the injection molding machine, and the barrel temperature is controlled at 190℃, the mold temperature at 60℃, and the injection pressure at 80MPa to process it into the desired shape. Then the product is placed in an annealing environment at 80℃ for 2 hours and cooled to room temperature to finally obtain a biodegradable plastic made from Chinese medicinal plant fiber.

[0023] Comparative Example 1 A biodegradable plastic made from plant fibers of traditional Chinese medicine, wherein the raw materials for preparing the biodegradable plastic made from plant fibers of traditional Chinese medicine include: 30 parts fiber mixture, 75 parts polylactic acid, and 6.5 parts silane coupling agent; The raw materials for preparing the fiber blend include: 8.5 parts Artemisia argyi fiber and 3 parts Curcuma zedoaria fiber; The raw materials for preparing Artemisia argyi fiber include: 11 parts Artemisia argyi fiber and 35 parts 5% sodium bicarbonate solution. The raw materials for preparing turmeric fiber include: 5 parts turmeric rhizomes and 35 parts 5% sodium bicarbonate solution.

[0024] A method for preparing biodegradable plastics from plant fibers of traditional Chinese medicinal materials includes the following steps: The preparation process of mugwort fiber is as follows: (i) Select fresh mugwort stems and leaves without mold, wash them clean, cut them into 2.5cm mugwort segments and drain the surface water; (ii) Dry the mugwort segments to obtain dried mugwort with a moisture content of 8%; (iii) Put the dried mugwort into a pulverizer and grind it into 40-mesh mugwort powder; (iv) Soak the mugwort powder in a 5% sodium bicarbonate solution for 1 hour, take it out, filter it, and obtain mugwort residue; (v) Wash the mugwort residue until it is neutral, drain the water, and obtain mugwort fiber. The preparation process of turmeric fiber is as follows: (i) Select fresh turmeric rhizomes without mold, clean the surface of the turmeric rhizomes, and cut them into 0.5cm thick slices; (ii) Spread the turmeric slices flat in a ventilated and cool place to air dry naturally to obtain dry slices with a moisture content of 8%; (iii) Crush the dry slices to obtain 50-mesh coarse powder; (iv) Immerse the coarse powder in a 5% sodium bicarbonate solution, control the immersion time to 185min, control the temperature to 40℃, and then filter to obtain coarse residue; (v) Rinse the coarse residue with clean water until neutral, and dry it in a drying oven for 7h until the turmeric fiber has a moisture content of 6.5%; Artemisia fiber and turmeric fiber were mixed and stirred at 400 r / min for 12.5 min to obtain a uniform fiber mixture. Add silane coupling agent to fiber mixture and stir at 60℃ and 500r / min for 25min to make the coupling agent uniformly coat the fiber surface and obtain the fiber raw material to be processed. The fiber raw material to be processed is added to polylactic acid molten at 170℃ and stirred at 700 r / min for 35 min to form a homogeneous system and obtain the plastic raw material to be processed. The plastic raw material to be processed is added to the injection molding machine, and the barrel temperature is controlled at 180℃, the mold temperature at 50℃, and the injection pressure at 65MPa to process it into the desired shape. Then the product is placed in an environment of 70℃ for annealing for 1.5 hours and cooled to room temperature to finally obtain a biodegradable plastic made from Chinese medicinal plant fiber.

[0025] Comparative Example 2 A biodegradable plastic made from plant fibers of traditional Chinese medicine, wherein the raw materials for preparing the biodegradable plastic made from plant fibers of traditional Chinese medicine include: 30 parts fiber mixture, 75 parts polylactic acid, and 6.5 parts silane coupling agent; The raw materials for preparing the fiber blend include: 9 parts bamboo fiber and 2.5 parts turmeric fiber; The raw materials for preparing bamboo fiber include: 11 parts of moso bamboo, 35 parts of 5-8% sodium hydroxide solution, 200 parts of deionized water, and 35 parts of 0.75% hydrogen peroxide solution. The raw materials for preparing turmeric fiber include: 5 parts turmeric rhizomes and 35 parts 5% sodium bicarbonate solution.

[0026] A method for preparing biodegradable plastics from plant fibers of traditional Chinese medicinal materials includes the following steps: The preparation process of bamboo fiber is as follows: (I) Select fresh moso bamboo, remove the bamboo nodes and bark, and cut it into 7cm long bamboo sections; (II) After rinsing clean, dry it in a 65℃ oven for 5 hours to obtain dried bamboo with a moisture content of 7%; (III) Crush it into 30-mesh particles using a pulverizer, and collect the uniform powder after sieving; (IV) Soak the powder in a 6.5% NaOH solution for 30 minutes, and then take out the powder to obtain pretreated bamboo powder; (V) Put the pretreated bamboo powder into a high-pressure reactor and control the temperature inside the reactor to 85℃. ℃, keep warm for 2.5h, stir once every 30 minutes during the period, speed 50r / min, after the reaction is completed, filter with vacuum filter and collect the filter residue; (vi) rinse the filter residue repeatedly with deionized water until the pH value of the rinsing solution is 6.55, then place it in 0.75% hydrogen peroxide solution, soak at room temperature for 30 minutes, and filter and rinse again with deionized water to obtain pretreated filter residue; (vii) put the pretreated filter residue into a vacuum drying oven at 55℃ and dry for 9 hours, crush it and pass it through a 60 mesh sieve to obtain bamboo fiber; The preparation process of turmeric fiber is as follows: (i) Select fresh turmeric rhizomes without mold, clean the surface of the turmeric rhizomes, and cut them into 0.5cm thick slices; (ii) Spread the turmeric slices flat in a ventilated and cool place to air dry naturally to obtain dry slices with a moisture content of 8%; (iii) Crush the dry slices to obtain 50-mesh coarse powder; (iv) Immerse the coarse powder in a 5% sodium bicarbonate solution, control the immersion time to 185min, control the temperature to 40℃, and then filter to obtain coarse residue; (v) Rinse the coarse residue with clean water until neutral, and dry it in a drying oven for 7h until the turmeric fiber has a moisture content of 6.5%; Bamboo fiber and turmeric fiber were mixed and stirred at 400 r / min for 12.5 min to obtain a uniform fiber mixture. Add silane coupling agent to fiber mixture and stir at 60℃ and 500r / min for 25min to make the coupling agent uniformly coat the fiber surface and obtain the fiber raw material to be processed. The fiber raw material to be processed is added to polylactic acid molten at 170℃ and stirred at 700 r / min for 35 min to form a homogeneous system and obtain the plastic raw material to be processed. The plastic raw material to be processed is added to the injection molding machine, and the barrel temperature is controlled at 180℃, the mold temperature at 50℃, and the injection pressure at 65MPa to process it into the desired shape. Then the product is placed in an environment of 70℃ for annealing for 1.5 hours and cooled to room temperature to finally obtain a biodegradable plastic made from Chinese medicinal plant fiber.

[0027] Comparative Example 3 A biodegradable plastic made from plant fibers of traditional Chinese medicine, wherein the raw materials for preparing the biodegradable plastic made from plant fibers of traditional Chinese medicine include: 30 parts fiber mixture, 75 parts polylactic acid, and 6.5 parts silane coupling agent; The raw materials for preparing the fiber blend include: 6.2 parts bamboo fiber and 5.3 parts mugwort fiber; The raw materials for preparing bamboo fiber include: 11 parts of moso bamboo, 35 parts of 5-8% sodium hydroxide solution, 200 parts of deionized water, and 35 parts of 0.75% hydrogen peroxide solution. The raw materials for preparing Artemisia argyi fiber include: 11 parts Artemisia argyi fiber and 35 parts 5% sodium bicarbonate solution. A method for preparing biodegradable plastics from plant fibers of traditional Chinese medicinal materials includes the following steps: The preparation process of bamboo fiber is as follows: (I) Select fresh moso bamboo, remove the bamboo nodes and bark, and cut it into 7cm long bamboo sections; (II) After rinsing clean, dry it in a 65℃ oven for 5 hours to obtain dried bamboo with a moisture content of 7%; (III) Crush it into 30-mesh particles using a pulverizer, and collect the uniform powder after sieving; (IV) Soak the powder in a 6.5% NaOH solution for 30 minutes, and then take out the powder to obtain pretreated bamboo powder; (V) Put the pretreated bamboo powder into a high-pressure reactor and control the temperature inside the reactor to 85℃. ℃, keep warm for 2.5h, stir once every 30 minutes during the period, speed 50r / min, after the reaction is completed, filter with vacuum filter and collect the filter residue; (vi) rinse the filter residue repeatedly with deionized water until the pH value of the rinsing solution is 6.55, then place it in 0.75% hydrogen peroxide solution, soak at room temperature for 30 minutes, and filter and rinse again with deionized water to obtain pretreated filter residue; (vii) put the pretreated filter residue into a vacuum drying oven at 55℃ and dry for 9 hours, crush it and pass it through a 60 mesh sieve to obtain bamboo fiber; The preparation process of mugwort fiber is as follows: (i) Select fresh mugwort stems and leaves without mold, wash them clean, cut them into 2.5cm mugwort segments and drain the surface water; (ii) Dry the mugwort segments to obtain dried mugwort with a moisture content of 8%; (iii) Put the dried mugwort into a pulverizer and grind it into 40-mesh mugwort powder; (iv) Soak the mugwort powder in a 5% sodium bicarbonate solution for 1 hour, take it out, filter it, and obtain mugwort residue; (v) Wash the mugwort residue until it is neutral, drain the water, and obtain mugwort fiber. Bamboo fiber and mugwort fiber were mixed and stirred at 400 r / min for 12.5 min to obtain a uniform fiber mixture. Add silane coupling agent to fiber mixture and stir at 60℃ and 500r / min for 25min to make the coupling agent uniformly coat the fiber surface and obtain the fiber raw material to be processed. The fiber raw material to be processed is added to polylactic acid molten at 170℃ and stirred at 700 r / min for 35 min to form a homogeneous system and obtain the plastic raw material to be processed. The plastic raw material to be processed is added to the injection molding machine, and the barrel temperature is controlled at 180℃, the mold temperature at 50℃, and the injection pressure at 65MPa to process it into the desired shape. Then the product is placed in an environment of 70℃ for annealing for 1.5 hours and cooled to room temperature to finally obtain a biodegradable plastic made from Chinese medicinal plant fiber.

[0028] III. Detection Methods 3.1 Test on the effect of fiber blends on the properties of biodegradable plastics made from the fibers of a traditional Chinese medicinal herb ①The antibacterial properties of a biodegradable plastic made from plant fiber of a traditional Chinese medicine were tested according to GB / T 31402-2023 "Determination of antibacterial activity of plastics and other non-porous materials". See Table 1. ②Antioxidant testing was performed on a biodegradable plastic made from plant fibers of a traditional Chinese medicine according to GB / T 19466.6-2009 / 2021 "Differential Scanning Calorimetry (DSC) for Plastics - Part 6: Determination of Oxidation Induction Time (OIT)", as shown in Table 1; ③ The biodegradability of a biodegradable plastic made from plant fiber of a traditional Chinese medicine was tested according to GB / T 19277.1-2023 "Determination of final aerobic biodegradability of materials under controlled composting conditions - Part 1: General method", as shown in Table 2; ④ The mechanical properties of a biodegradable plastic made from Chinese medicinal plant fiber were tested according to GB / T 1040.2-2006 "Determination of tensile properties of plastics - Part 2: Test conditions for molded and extruded plastics", as shown in Table 3; As shown in Table 1: Group Staphylococcus aureus (inhibition rate) Escherichia coli (inhibition rate) Oxidation induction time (OIT) Example 1 70% 70% 15min Example 2 75% 71% 26min Example 3 71% 70% 19min Comparative Example 1 68% 70% 15min Comparative Example 2 71% 64% 15min Comparative Example 3 68% 69% 15min Among them, in Table 1, an inhibition rate of ≥70% for Staphylococcus aureus and ≥70% for Escherichia coli are considered excellent; an oxidation induction time of ≥15 min is also considered excellent.

[0029] As shown in Table 2: Group 28-day biodegradation rate Example 1 90% Example 2 95% Example 3 92% Comparative Example 1 90% Comparative Example 2 88% Comparative Example 3 87% Among them, those with a degradation rate of ≥90% after 28 days are considered excellent, as shown in Table 2.

[0030] As shown in Table 3: Group Elongation at break Example 1 3.51% Example 2 3.7% Example 3 3.43% Comparative Example 1 3.1% Comparative Example 2 2.2% Comparative Example 3 3.2% Among them, an elongation at break of ≥3.5% is considered superior.

[0031] As can be seen from Tables 1, 2, and 3, compared with Examples 1, 3, and Comparative Examples 1-3, the biodegradable plastic made from medicinal plant fibers prepared in Example 2 is the best. The biodegradable plastic made from medicinal plant fibers prepared by combining bamboo fiber, artemisia fiber, and turmeric fiber in appropriate proportions, together with biodegradable polylactic acid and silane coupling agent, exhibits excellent antibacterial and antioxidant properties. At the same time, it ensures a qualified biodegradability rate and guarantees the elongation at break of the biodegradable plastic. In addition, it achieves the reproducibility of the preparation ratio and preparation method, which is convenient for low-cost and high-efficiency industrial production.

[0032] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A biodegradable plastic made from plant fibers of traditional Chinese medicinal materials, characterized in that, The raw materials for preparing the biodegradable plastic made from plant fibers of traditional Chinese medicine, by weight, include: 20-40 parts fiber mixture, 60-90 parts polylactic acid, and 5-8 parts silane coupling agent. The raw materials for preparing the fiber mixture include: 4-6 parts bamboo fiber, 3-7 parts mugwort fiber, and 1-3 parts turmeric fiber.

2. The biodegradable plastic made from medicinal plant fibers according to claim 1 and its preparation method, characterized in that, The preparation process of the bamboo fiber is as follows: (i) Select fresh moso bamboo, remove the bamboo nodes and bark, and cut it into bamboo sections 5-10cm long; (ii) After rinsing clean, dry it in an oven at 60-70℃ for 4-6 hours to obtain dried bamboo with a moisture content of 5-9%; (iii) Crush it into 20-40 mesh particles using a pulverizer, and collect the uniform powder after sieving; (iv) Soak the powder in a 5-8% NaOH solution for 20-40 minutes, and then remove the powder to obtain pretreated bamboo powder; (v) Place the pretreated bamboo powder into a high-pressure reactor and control the temperature inside the reactor. The temperature is 80-90℃, and the temperature is kept for 2-3 hours. During this period, the mixture is stirred once every 30 minutes at a speed of 50 r / min. After the reaction is completed, the mixture is filtered using a vacuum filter and the filter residue is collected. (vi) The filter residue is repeatedly rinsed with deionized water until the pH value of the rinsing solution is 6.5-7.

0. Then, it is placed in a 0.5-1% hydrogen peroxide solution and soaked at room temperature for 30 minutes. It is then filtered and rinsed again with deionized water to obtain pretreated filter residue. (vii) The pretreated filter residue is placed in a vacuum drying oven at 50-60℃ and dried for 8-10 hours. After crushing, it is passed through a 60-mesh sieve to obtain bamboo fiber.

3. The biodegradable plastic made from medicinal plant fibers according to claim 2, characterized in that, The raw materials for preparing the bamboo fiber include: 10-12 parts of moso bamboo, 30-40 parts of 5-8% sodium hydroxide solution, 180-220 parts of deionized water, and 30-40 parts of 0.5-1% hydrogen peroxide solution.

4. The biodegradable plastic made from medicinal plant fibers according to claim 1, characterized in that, The preparation process of the mugwort fiber is as follows: (i) Select fresh mugwort stems and leaves without mold, wash them clean, cut them into 2-3cm mugwort segments and drain the surface water; (ii) Dry the mugwort segments to obtain dried mugwort with a moisture content of 7-9%; (iii) Put the dried mugwort into a pulverizer and grind it into 30-50 mesh mugwort powder; (iv) Soak the mugwort powder in a 5% sodium bicarbonate solution for 1 hour, take it out, filter it, and obtain mugwort residue; (v) Wash the mugwort residue until it is neutral, drain the water, and obtain mugwort fiber.

5. The biodegradable plastic made from medicinal plant fibers according to claim 4, characterized in that, The raw materials for preparing the Artemisia argyi fiber include: 10-12 parts Artemisia argyi fiber and 30-40 parts of 5% sodium bicarbonate solution.

6. The biodegradable plastic made from medicinal plant fibers according to claim 1, characterized in that, The preparation process of the turmeric fiber is as follows: (i) Select fresh turmeric rhizomes without mold, clean the surface of the turmeric rhizomes, and cut them into 0.5cm thick slices; (ii) Spread the turmeric slices flat in a ventilated and cool place to air dry naturally to obtain dry slices with a moisture content of 7-9%; (iii) Crush the dry slices to obtain coarse powder of 40-60 mesh; (iv) Immerse the coarse powder in a solution containing 5% sodium bicarbonate, control the immersion time to 180-190 min, control the temperature to 40℃, and then filter to obtain coarse residue; (v) Rinse the coarse residue with clean water until neutral, and dry it in a drying oven for 6-8 hours until the turmeric fiber has a moisture content of 5-8%.

7. The biodegradable plastic made from medicinal plant fibers according to claim 6, characterized in that, The raw materials for preparing the turmeric fiber include: 3-8 parts of turmeric rhizome and 30-40 parts of 5% sodium bicarbonate solution.

8. A method for preparing biodegradable plastics from medicinal plant fibers according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Mix bamboo fiber, mugwort fiber and turmeric fiber, and stir at 300-500 r / min for 10-15 min to obtain a uniform fiber mixture. S2, add silane coupling agent to fiber mixture, stir at 50-70℃ and 400-600r / min for 20-30min to make the coupling agent uniformly coat the fiber surface and obtain the fiber raw material to be processed. S3, add the fiber raw material to be processed into molten polylactic acid at 160-180℃, stir at 600-800r / min for 30-40min to form a homogeneous system and obtain the plastic raw material to be processed; S4. Add the plastic raw material to be processed into the injection molding machine, control the barrel temperature to 170-190℃, the mold temperature to 40-60℃, and the injection pressure to 50-80MPa, and process it into the desired shape. Then, place the product in an environment of 60-80℃ for annealing for 1-2 hours, cool it to room temperature, and finally obtain a biodegradable plastic made from Chinese medicinal plant fiber.