Degradable bio-based polymer film and preparation process thereof

Abstract

The invention relates to the technical field of degradable films, and discloses a degradable bio-based polymer film and a preparation process thereof, the degradable bio-based polymer film comprises the following raw materials by mass: 70-80 parts of polycaprolactone, 30-40 parts of polyhydroxyalkanoate, 6-10 parts of a reinforcing filler, 3-5 parts of modified nano chitin whisker, and 0.5-1 part of an antibacterial agent. The hydroxyl cucurbit [6] uril is grafted on the surface of the porous carbon-loaded compound as a reinforcing material, so that the water absorption of the polymer film is reduced, and the influence on the service life of the polymer film due to the decay of the polymer film caused by water accumulation is avoided; a three-dimensional network structure combined by hydrogen bonds can be formed among the nano chitin whiskers, the chlorogenic acid modified chitosan and the nano cellulose, namely, the modified nano chitin whiskers can play a role in transferring stress, and the mechanical property of the polymer film is further enhanced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of degradable films, in particular to a degradable bio-based polymeric film and a preparation process thereof. BACKGROUND

[0002] The degradable bio-based polymeric film has the functions and characteristics of traditional plastics and can be disintegrated and degraded in a natural environment through the action of microorganisms in soil and water or the action of ultraviolet rays in sunlight after reaching the service life, and is widely applied to the fields of food and drug packaging, fruit and vegetable preservation and membrane separation, wherein, in the circulation and storage process of fruits and vegetables, bacteria and fungi in the external environment can cause the fruits and vegetables to rot and deteriorate, and many food-borne spoilage bacteria can also multiply in large quantities in the fruits and vegetables and produce toxins, which can enter the human body along with food, cause food-borne diseases and affect human health, the degradable bio-based polymeric film is used to wrap the surface of food and mainly serves to isolate the entry of microorganisms and external pollutants and prolong the quality of food, and can effectively protect food from bacterial infection.

[0003] The poly (caprolactone) and the poly (hydroxyalkanoate) are blended as the base material of the polymeric film, the poly (caprolactone) and the poly (hydroxyalkanoate) are non-toxic and harmless, can reduce the pollution to food, and can gradually decompose in a natural environment as biodegradable materials, thereby reducing the pollution to the environment, but the poly (caprolactone) and the poly (hydroxyalkanoate) contain a large number of hydroxyl groups and ester groups, the formed polymeric film has hydrophilicity, water molecules are easy to be adsorbed to the surface of the polymeric film, the structure of the polymeric film is damaged, the service life of the polymeric film is reduced, and the polymeric film formed by the blending of the poly (caprolactone) and the poly (hydroxyalkanoate) has poor mechanical properties, the polymeric film is easy to be damaged or deformed in the process of transportation, storage and use, and the packaging effect and the food protection performance are affected. SUMMARY

[0004] The application provides a degradable bio-based polymeric film and a preparation process thereof, and solves the problems that the polymeric film is easy to absorb moisture and cause structure damage and has poor mechanical properties.

[0005] The technical scheme of the application is as follows: A degradable bio-based polymeric film, which comprises the following raw materials in parts by mass: 70-80 parts of poly (caprolactone), 30-40 parts of poly (hydroxyalkanoate), 6-10 parts of reinforcing filler, 3-5 parts of modified nanochitin whisker and 0.5-1 part of antibacterial agent. The reinforcing filler is obtained by mixing and reacting a coupling agent, succinic acid and a porous carbon-loaded compound, and then reacting with hydroxyl cucurbit[6]uril. The porous carbon-loaded compound is obtained by mixing and calcining wollastonite and hydrotalcite, and then mixing and reacting with rice husk powder. The modified nanochitin whisker is obtained by mixing the green acid modified chitosan, the dopamine surface modified nanochitin whisker and the nanocellulose.

[0006] A preparation process of a degradable bio-based polymeric film, comprising the following preparation steps: S1. mixing polycaprolactone, polyhydroxyalkanoate, reinforcing filler, modified nanochitin whisker and antibacterial agent, stirring at 1000-1500 r / min for 1-2 h, and then drying to obtain a mixture; S2. The mixture is granulated by extrusion, and then hot-pressed into a film to obtain a degradable bio-based polymeric film.

[0007] Further, the extrusion granulation is performed by a double screw extruder, and the process of the double screw extruder is set as: the temperature of the feeding port is 55-65 DEG C, the screw temperature is 95-105 DEG C, the temperature of the discharging port is 100-110 DEG C, the rotation speed is 25-30 r / min, and the time is 3-6 min.

[0008] Further, the hot-pressing film is performed by a hot press, and the hot-pressing temperature of the hot press is 100-110 DEG C, and the hot-pressing pressure is 30-40 MPa.

[0009] Further, the molecular weight of the polycaprolactone is 2-2.2 million.

[0010] Further, the antibacterial agent is nano silver particles with a particle size of 50-100 nm.

[0011] Further, the reinforcing filler is prepared by the following steps: A1. Mixing wollastonite and hydrotalcite, calcining at 500-600 DEG C for 0.5-1 h, cooling to room temperature, and crushing to 10-15 mu m to obtain a composite; A2. The composite is added to ethanol, rice husk powder is added, stirred uniformly, 36% hydrochloric acid is added, stirred at 65-75 DEG C for 20-30 min, filtered, washed, dried, potassium hydroxide is added, nitrogen is introduced, carbonized at 750-850 DEG C for 3-5 h, cooled to room temperature, taken out, washed, dried to obtain a composite loaded with porous carbon; A3. The composite loaded with porous carbon is added to ethanol and deionized water, stirred uniformly, a coupling agent is added, stirred at 65-75 DEG C for 1-2 h, succinic acid is added, and the stirring is continued for 20-30 min, cooled to room temperature, filtered, washed, dried to obtain a modified composite loaded with porous carbon; A4. Hydroxycucurbit[6]uril is added to anhydrous dimethyl sulfoxide, stirred until completely dissolved, modified porous carbon loaded composite, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride, 4-(dimethylamino) pyridine are added, stirred uniformly, nitrogen is introduced, after reaction at 20-30℃ for 1-2h, filtration, washing, drying, to obtain the enhanced filler.

[0012] Further, in the above-mentioned A1 reaction process, wollastonite and hydrotalcite are mixed, calcined at 500-600℃, so that the organic matter and adsorbed water that partially block the micropores on the surface of wollastonite and hydrotalcite are decomposed by heat, exposing the porous structure, to obtain the composite.

[0013] Further, in the above-mentioned A2 reaction process, the silicon hydroxyl groups in the composite can be chemically combined with the oxygen-containing functional groups in the rice husk powder, so that the rice husk powder is coated on the surface of the composite, and after high-temperature carbonization, the rice husk powder is decomposed by heat to form a dense carbon layer, and the potassium hydroxide molecules are decomposed to form pores on the surface of the dense carbon layer, so that porous carbon is synthesized on the surface of the composite, and the porous carbon loaded composite is obtained.

[0014] Further, in the above-mentioned A3 reaction process, the silicon hydroxyl groups generated by the hydrolysis of the coupling agent can be chemically combined with the hydroxyl groups on the surface of the porous carbon loaded composite, and the amine groups in the coupling agent can also be chemically combined with the carboxyl groups in the succinic acid, so that the succinic acid is grafted on the surface of the porous carbon loaded composite through the coupling agent, and the modified porous carbon loaded composite is obtained.

[0015] Further, in the above-mentioned A4 reaction process, in the solvent anhydrous dimethyl sulfoxide, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 4-(dimethylamino) pyridine act as catalysts, so that the carboxyl groups in the modified porous carbon loaded composite can undergo esterification with the hydroxyl groups in hydroxycucurbit[6]uril, so that hydroxycucurbit[6]uril is grafted on the surface of the porous carbon loaded composite, and the enhanced filler is obtained.

[0016] Further, in step A1, the mass ratio of wollastonite to hydrotalcite is (2-3):(1-2).

[0017] Further, in step A2, the ratio of the composite, ethanol, rice husk powder, hydrochloric acid and potassium hydroxide is (4-6)g:(45-55)mL:(4-6)g:(0.4-0.6)mL:(4-6)mL.

[0018] Further, in step A3, the ratio of the porous carbon loaded composite, ethanol, deionized water, coupling agent and succinic acid is (4-6)g:(25-35)mL:(8-12)mL:(1-2)g:(1-2)g.

[0019] Further, in step A4, the amount ratio of the hydroxyl cucurbit[6]uril, anhydrous dimethyl sulfoxide, modified porous carbon loaded complex, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 4-(dimethylamino) pyridine is (2.2-2.4) g:(80-120) mL:(5-5.4) g:(0.22-0.24) g:(0.1-0.3) g.

[0020] Further, the coupling agent is γ-aminopropyl triethoxysilane.

[0021] Further, the modified nanochitin whisker is prepared by the following steps: B1. The chitosan is added to the acetic acid solution and stirred uniformly to obtain a chitosan solution. The chlorogenic acid, N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride are added to ethanol, stirred uniformly, and then added to the chitosan solution. The mixture is stirred and reacted for 35-45 min. The supernatant is collected by centrifugation and freeze-dried to obtain the chlorogenic acid modified chitosan. B2. The nanochitin whisker is added to the Tris-HCl buffer solution and stirred uniformly. Dopamine is added and stirred and reacted for 3-4 h. The product is filtered, washed and dried to obtain the polydopamine modified nanochitin whisker. B3. The nanocellulose and the chlorogenic acid modified chitosan are added to deionized water and stirred uniformly. Sodium hydroxide is added and stirred at 50-60 °C for 10-15 min. The polydopamine modified nanochitin whisker is added and the mixture is continuously stirred and reacted for 10-20 min. The product is freeze-dried to obtain the modified nanochitin whisker.

[0022] Further, in the above B1 reaction process, under the action of N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride, the hydroxyl group in the chlorogenic acid can react with the oxygen-containing functional group in the chitosan to graft the chlorogenic acid on the chitosan through lipid-based combination to obtain the chlorogenic acid modified chitosan.

[0023] Further, in the above B2 reaction process, in the Tris-HCl buffer solution, dopamine can self-polymerize on the surface of the nanochitin whisker to form polydopamine to form the polydopamine modified nanochitin whisker.

[0024] Further, in the above B3 reaction process, the chlorogenic acid modified chitosan and the nanocellulose are combined through hydrogen bonds to form a cross-linked network structure. The phenolic hydroxyl group in the polydopamine modified nanochitin whisker can also be combined with the oxygen-containing functional group in the chlorogenic acid modified chitosan and the nanocellulose through chemical bonds, so that the polydopamine modified nanochitin whisker is embedded in the cross-linked network structure to form a cross-linked network structure aerogel to obtain the modified nanochitin whisker.

[0025] Further, in step B1, the amount ratio of chitosan, acetic acid solution, chlorogenic acid, N-hydroxysuccinimide, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and ethanol is (1-3) g:(45-55) mL:(0.4-0.6) g:(0.1-0.3) g:(0.2-0.24) g:(18-22) mL.

[0026] Further, in step B2, the amount ratio of nano-chitin whisker, Tris-HCl buffer solution and dopamine is (4-6) g:(40-50) mL:(0.2-0.4) g.

[0027] Further, in step B3, the amount ratio of nano-cellulose, chlorogenic acid modified chitosan, deionized water, sodium hydroxide and polydopamine modified nano-chitin whisker is (5-7) g:(2-4) g:(80-120) mL:(6-8) g:(1-3) g.

[0028] Further, the nano-cellulose has a diameter of 20-50 nm and a length of 2-5 um.

[0029] Further, the nano-chitin whisker has a diameter of 15-20 nm and a length of 300-400 nm.

[0030] The present application has the following beneficial effects: (1) In the technical scheme of the present application, after calcination of wollastonite and hydrotalcite, the porous structure is exposed, which can adsorb dirt and moisture, reduce food spoilage, thereby prolonging the preservation period of food and improving the protection of the polymeric film on food; porous carbon is synthesized on the surface of the composite, on the one hand, the synthesized porous carbon has high adsorption performance, which can adsorb and fix impurities in the composite, avoiding the influence of the falling of impurities in the composite on the quality of food and the mechanical properties of the polymeric film, on the other hand, the high porosity of the porous carbon shows good barrier properties, which can effectively prevent the penetration of moisture, oxygen and other harmful substances, avoiding the influence of damp and oxidation factors on the stored goods, thereby prolonging the shelf life of the goods, and avoiding the accumulation of carbon dioxide and moisture, leading to the corruption of the polymeric film and reducing the service life of the polymeric film.

[0031] (2) In the technical scheme of the present application, the carboxyl groups on the surface of the complex of hydroxyl calabash [6] urea and modified supported porous carbon are combined by chemical bonds, and the hydroxyl calabash [6] urea is grafted on the surface of the supported porous carbon complex as a reinforcing material. On the one hand, as a cyclodextrin derivative, the cavity structure of calabash [6] urea has excellent hydrophobic properties. The introduction of hydrophobic groups into the polymer film reduces the water absorption of the polymer film, avoids water accumulation, and prevents the deterioration of the polymer film, thereby affecting the service life of the polymer film. On the other hand, the large ring rigid structure of calabash [6] urea has good stability and mechanical strength, thereby improving the mechanical strength of the polymer film.

[0032] (3) In the technical scheme of the present application, chitosan is safe, non-toxic, antibacterial, and biodegradable, which can improve the preservation effect of the polymer film. The grafting of chlorogenic acid on chitosan consumes the hydroxyl groups of chitosan, reduces the adsorption of water molecules, and enhances the water vapor barrier property of chitosan. The cross-linked network structure of the aerogel formed by the chlorogenic acid modified chitosan, nanocellulose and polydopamine modified nanochitin whiskers. On the one hand, the hydroxyl groups contained in the chlorogenic acid modified chitosan and nanocellulose can be combined with the polymer film matrix material through chemical bonds, so that the polydopamine modified nanochitin whiskers are fully dispersed in the polymer film matrix, and the formed aerogel has good mechanical strength, which enhances the mechanical properties of the polymer film. On the other hand, the nanochitin whisker, chlorogenic acid modified chitosan and nanocellulose can form a three-dimensional network structure combined by hydrogen bonds, which can transfer stress and further enhance the mechanical properties of the polymer film. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0034] The raw materials used in the embodiments of the present application are as follows, and the reagents used are all analytical grade.

[0035] Among them, the molecular weight of polycaprolactone is 21,000, and Shanghai Yuan Ye Biological Technology Co., Ltd.

[0036] Polyhydroxyalkanoate, industrial grade, model number EM5400F, Shenzhen Yikeman Biological Technology Co., Ltd.

[0037] The antibacterial agent is nano silver particles with a particle size of 80 nm, Beijing Zhongke Keyou Nanometer Technology Co., Ltd.

[0038] The coupling agent is gamma-aminopropyl triethoxysilane.

[0039] Wollastonite, particle size 7.5 μm, Xuefeng Powder Co., Ltd. of Shanggao County, Jiangxi Province.

[0040] Hydrotalcite is magnesium aluminum carbonate hydrotalcite, Kanggao FM308, Jingjiang Kanggao New Material Technology Co., Ltd.

[0041] The hydroxycucurbit[6]uril is specifically prepared by the following steps: Mix 0.25 g of ferrous chloride and 16 mL of hydrogen peroxide to obtain an oxidizing agent, add 2.5 g of cucurbit[6]uril to 30 mL of 36% hydrochloric acid, stir until uniform, add 0.5 g of the oxidizing agent, stir for 1 h, centrifuge, and dry in a 70°C oven for 10 min to obtain hydroxycucurbit[6]uril.

[0042] The nanochitin whisker is specifically prepared by the following steps: Add 2 g of chitin to 3 mol / L hydrochloric acid, stir at 93°C for 3 h, then discard the supernatant after standing, centrifuge the remaining suspension several times at 5000 r / min to remove excess acid, dialyze with deionized water until the pH approaches neutrality, and freeze-dry the obtained product at -20°C to obtain nanochitin whiskers.

[0043] The nanochitin whisker has a diameter of 18 nm and a length of 350 nm.

[0044] Example 1 A degradable bio-based polymeric film includes the following raw materials by mass: 70 parts of polycaprolactone, 30 parts of polyhydroxyalkanoate, 6 parts of reinforcing filler, 3 parts of modified nanochitin whisker, and 0.5 parts of nanosilver particles. A preparation process of a degradable bio-based polymeric film includes the following preparation steps: S1, mix polycaprolactone, polyhydroxyalkanoate, reinforcing filler, modified nanochitin whisker, and nanosilver particles, stir at 1000 r / min for 1 h, and then dry to obtain a mixture; S2, the mixture is extruded and granulated, and then hot-pressed into a film to obtain a degradable bio-based polymeric film.

[0045] The extrusion granulation is performed using a double-screw extruder, and the process settings of the double-screw extruder are as follows: the temperature of the feeding port is 55°C, the screw temperature is 95°C, the temperature of the discharging port is 100°C, the rotation speed is 25 r / min, and the time is 3 min.

[0046] The hot-pressing into a film is performed using a hot press, and the hot-pressing temperature of the hot press is 100°C, and the hot-pressing pressure is 30 MPa.

[0047] The reinforcing filler is specifically prepared by the following steps: A1. Mix 2 g of wollastonite and 1 g of hydrotalcite, calcine at 500°C for 0.5 h, cool to room temperature, and crush to 10 μm to obtain a composite; A2. Add 4 g of the composite to 45 mL of ethanol, add 4 g of rice husk powder, stir until uniform, add 0.6 mL of 36% hydrochloric acid, stir at 65°C for 20 min, filter, wash with deionized water 3 times, dry in an oven at 70°C for 10 min, place in a tube furnace, add 4 mL of potassium hydroxide, introduce nitrogen, carbonize at 750°C for 3 h, cool to room temperature, remove, wash with deionized water 3 times, dry in an oven at 70°C for 10 min to obtain a composite loaded with porous carbon; A3. Add 4 g of the composite loaded with porous carbon to 25 mL of ethanol and 8 mL of deionized water, stir until uniform, add 1 g of γ-aminopropyltriethoxysilane, stir at 65°C for 1 h, add 1 g of succinic acid, continue to stir for 20 min, cool to room temperature, filter, wash with deionized water 3 times, dry in an oven at 70°C for 10 min to obtain a modified composite loaded with porous carbon; A4. Add 2.2 g of hydroxyl cucurbit[6]uril to 80 mL of anhydrous dimethyl sulfoxide, stir until completely dissolved, add 5 g of the modified composite loaded with porous carbon, 0.22 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride, 0.1 g of 4-(dimethylamino) pyridine, stir until uniform, introduce nitrogen, react at 20°C for 1 h, filter, wash with deionized water 3 times, dry in an oven at 70°C for 10 min to obtain a reinforcing filler.

[0048] The modified nanochitin whisker is prepared by the following steps: B1. Add 1 g of chitosan to 45 mL of 2% acetic acid solution, stir until uniform to obtain a chitosan solution, add 0.4 g of chlorogenic acid, 0.1 g of N-hydroxysuccinimide, and 0.2 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride to 18 mL of ethanol, stir and mix for 2 h, add to the chitosan solution, stir in an ice water bath for 35 min, centrifuge at 10,000 r / min for 20 min, collect the supernatant, freeze-dry the supernatant at -20°C for 20 min to obtain chlorogenic acid modified chitosan; B2. Add 4 g of nanochitin whisker to 40 mL of Tris-HCl buffer solution with pH 8.5, stir until uniform, add 0.2 g of dopamine, stir for 3 h, filter, wash with deionized water 3 times, dry in an oven at 70°C for 10 min to obtain polydopamine modified nanochitin whisker; B3. 5 g nanocellulose and 2 g chlorogenic acid modified chitosan were added to 80 mL deionized water, stirred uniformly, 6 g sodium hydroxide was added, stirred at 50°C for 10 min, 1 g polydopamine modified nanochitin whisker was added, and the stirring reaction was continued for 10 min., placed in a freeze dryer, freeze dried at -50°C for 2h, to obtain modified nanochitin whisker.

[0049] Example 2 A degradable bio-based polymeric film, comprising the following mass parts of raw materials: 75 parts of polycaprolactone, 35 parts of polyhydroxyalkanoate, 8 parts of reinforcing filler, 4 parts of modified nanochitin whisker, 0.5 parts of nano silver particles; A preparation process of a degradable bio-based polymeric film, comprising the following preparation steps: S1, polycaprolactone, polyhydroxyalkanoate, reinforcing filler, modified nanochitin whisker, and nano silver particles were mixed, stirred at 1300 r / min for 1.5 h, and then dried to obtain a mixture; S2, the mixture was extruded and granulated, and then hot pressed into a film to obtain a degradable bio-based polymeric film.

[0050] The extrusion granulation is carried out by using a double screw extruder, and the process settings of the double screw extruder are as follows: the temperature of the feeding port is 60°C, the screw temperature is 100°C, the temperature of the discharging port is 105°C, the rotation speed is 28 r / min, and the time is 5 min.

[0051] The hot pressing into a film is carried out by using a hot press, and the hot pressing temperature of the hot press is 105°C, and the hot pressing pressure is 35 MPa.

[0052] The reinforcing filler is prepared by the following steps: A1. 2.5 g of wollastonite and 1.5 g of hydrotalcite were mixed, calcined at 550°C for 0.8 h, cooled to room temperature, and ground to 13 μm to obtain a composite; A2. 5 g of the composite was added to 50 mL of ethanol, 5 g of rice husk powder was added, stirred uniformly, 0.5 mL of 36% hydrochloric acid was added, stirred at 70°C for 25 min, filtered, washed with deionized water for 3 times, dried in a 70°C oven for 10 min, placed in a tube furnace, 5 mL of potassium hydroxide was added, nitrogen was introduced, carbonized at 800°C for 4 h, cooled to room temperature, taken out, washed with deionized water for 3 times, dried in a 70°C oven for 10 min, to obtain a composite loaded with porous carbon; A3. 5 g of the modified porous carbon composite was added to 30 mL of ethanol and 10 mL of deionized water, stirred until uniform, 1.5 g of γ-aminopropyl triethoxysilane was added, stirred and reacted at 70°C for 1.5 h, 1.5 g of succinic acid was added, and the stirring reaction was continued for 25 min, cooled to room temperature, filtered, washed with deionized water for 3 times, and dried in an oven at 70°C for 10 min to obtain the modified porous carbon composite; A4. 2.3 g of hydroxyl cucurbit[6]uril was added to 100 mL of anhydrous dimethyl sulfoxide, stirred until completely dissolved, 5.2 g of the modified porous carbon composite, 0.23 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride, and 0.2 g of 4-(dimethylamino) pyridine were added, stirred until uniform, nitrogen was introduced, and reacted at 25°C for 1.5 h, then filtered, washed with deionized water for 3 times, and dried in an oven at 70°C for 10 min to obtain the reinforcing filler.

[0053] The modified nanochitin whisker was prepared by the following steps: B1. 2 g of chitosan was added to 50 mL of 2% acetic acid solution, stirred until uniform to obtain a chitosan solution, 0.5 g of chlorogenic acid, 0.2 g of N-hydroxysuccinimide, and 0.22 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride were added to 20 mL of ethanol, stirred and mixed for 2 h, then added to the chitosan solution, stirred and reacted in an ice water bath for 40 min, centrifuged at 10,000 r / min for 20 min, collected the supernatant, and freeze-dried the supernatant at -20°C for 20 min to obtain chlorogenic acid modified chitosan; B2. 5 g of nanochitin whisker was added to 45 mL of Tris-HCl buffer solution with pH of 8.5, stirred until uniform, 0.3 g of dopamine was added, stirred and reacted for 3.5 h, filtered, washed with deionized water for 3 times, and dried in an oven at 70°C for 10 min to obtain polydopamine modified nanochitin whisker; B3. 6 g of nanocellulose and 3 g of chlorogenic acid modified chitosan were added to 100 mL of deionized water, stirred until uniform, 7 g of sodium hydroxide was added, stirred and reacted at 55°C for 13 min, 2 g of polydopamine modified nanochitin whisker was added, and the stirring reaction was continued for 15 min, then placed in a freeze dryer and freeze-dried at -50°C for 2 h to obtain the modified nanochitin whisker.

[0054] Example 3 A degradable bio-based polymeric film, comprising the following raw materials in mass parts: 80 parts of polycaprolactone, 40 parts of polyhydroxyalkanoate, 10 parts of reinforcing filler, 5 parts of modified nanochitin whisker, and 1 part of nanosilver particle. A preparation process of a degradable bio-based polymeric film, comprising the following preparation steps: S1, mixing polycaprolactone, polyhydroxyalkanoate, reinforcing filler, modified nanochitin whisker, nanosilver particles, stirring at 1500 r / min for 2 h, drying to obtain a mixture; S2, the mixture is granulated by extrusion, and then hot-pressed into a film to obtain a degradable bio-based polymeric film.

[0055] The extrusion granulation is performed by using a double screw extruder, and the process setting of the double screw extruder is as follows: the temperature of the feeding port is 65 DEG C, the screw temperature is 105 DEG C, the temperature of the discharging port is 110 DEG C, the rotating speed is 30 r / min, and the time is 6 min.

[0056] The hot-pressing film is performed by using a hot press, and the hot-pressing temperature of the hot press is 110 DEG C, and the hot-pressing pressure is 40 MPa.

[0057] The reinforcing filler is prepared by the following steps: A1. Mixing 3 g of wollastonite and 2 g of hydrotalcite, calcining at 600 DEG C for 1 h, cooling to room temperature, and crushing to 15 mu m to obtain a composite; A2. 6 g of the composite is added to 55 mL of ethanol, 6 g of rice husk powder is added, stirred uniformly, 0.6 mL of 36% hydrochloric acid is added, stirred at 75 DEG C for 30 min, filtered, washed with deionized water for 3 times, dried in a 70 DEG C oven for 10 min, placed in a tube furnace, added with potassium hydroxide, nitrogen was introduced, carbonized at 850 DEG C for 5 h, cooled to room temperature, taken out, washed with deionized water for 3 times, dried in a 70 DEG C oven for 10 min to obtain a composite loaded with porous carbon; A3. 6 g of the composite loaded with porous carbon is added to 35 mL of ethanol and 12 mL of deionized water, stirred uniformly, 2 g of gamma-aminopropyl triethoxysilane is added, stirred at 75 DEG C for 2 h, 2 g of succinic acid is added, and the stirring is continued for 30 min, cooled to room temperature, filtered, washed with deionized water for 3 times, dried in a 70 DEG C oven for 10 min to obtain a composite loaded with modified porous carbon; A4. 2.4 g of hydroxyl cucurbit[6]urea is added to 120 mL of anhydrous dimethyl sulfoxide, stirred until completely dissolved, 5.4 g of the composite loaded with modified porous carbon, 0.24 g of 1-ethyl-(3-dimethylaminopropyl) carbonyl diimide hydrochloride, and 0.3 g of 4-(dimethylamino) pyridine are added, stirred uniformly, nitrogen is introduced, reacted at 30 DEG C for 2 h, filtered, washed with deionized water for 3 times, dried in a 70 DEG C oven for 10 min to obtain a reinforcing filler.

[0058] The modified nanochitin whisker is prepared by the following steps: B1. 3 g of chitosan was added into 55 mL of 2% acetic acid solution, stirred uniformly to obtain a chitosan solution, 0.6 g of chlorogenic acid, 0.3 g of N-hydroxysuccinimide and 0.24 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride were added into 22 mL of ethanol, stirred and mixed for 2 h, then added into the chitosan solution, stirred in an ice water bath for 45 min, centrifuged at 10,000 r / min for 20 min, the supernatant was collected, and the supernatant was freeze-dried at -20℃ for 20 min to obtain chlorogenic acid modified chitosan; B2. 6 g of nano-chitin whiskers were added into 50 mL of Tris-HCl buffer solution with pH of 8.5, stirred uniformly, 0.4 g of dopamine was added, stirred and reacted for 4 h, filtered, washed with deionized water for 3 times, and dried in an oven at 70℃ for 10 min to obtain polydopamine modified nano-chitin whiskers; B3. 7 g of nano-cellulose and 4 g of chlorogenic acid modified chitosan were added into 120 mL of deionized water, stirred uniformly, 8 g of sodium hydroxide was added, stirred at 60℃ for 15 min, 3 g of polydopamine modified nano-chitin whiskers was added, and the stirring was continued for 20 min, and then placed in a freeze dryer and freeze-dried at -50℃ for 2 h to obtain modified nano-chitin whiskers.

[0059] Comparative Example 1 A degradable bio-based polymeric film, comprising the following raw materials by mass fraction: 80 parts of polycaprolactone, 40 parts of polyhydroxyalkanoate, 10 parts of reinforcing filler, 5 parts of modified nano-chitin whiskers, and 1 part of nano-silver particles. A preparation process of a degradable bio-based polymeric film, comprising the following preparation steps: S1. The polycaprolactone, polyhydroxyalkanoate, reinforcing filler, modified nano-chitin whiskers and nano-silver particles were mixed, stirred at 1500 r / min for 2 h, and then dried to obtain a mixture; S2. The mixture was extruded and granulated, and then hot-pressed into a film to obtain the degradable bio-based polymeric film.

[0060] The extrusion granulation was performed by a double screw extruder, and the process of the double screw extruder was set as follows: the temperature of the feeding port was 65℃, the screw temperature was 105℃, the temperature of the discharging port was 110℃, the rotation speed was 30 r / min, and the time was 6 min.

[0061] The hot-pressing into a film was performed by a hot press, and the hot-pressing temperature of the hot press was 110℃, and the hot-pressing pressure was 40 MPa.

[0062] The reinforcing filler was prepared by the following steps: A1. 3 g wollastonite and 2 g hydrotalcite were mixed, calcined at 600℃ for 1 h, cooled to room temperature, and ground to 15 μm to obtain a composite; A2. 6 g of the composite was added to 35 mL of ethanol and 12 mL of deionized water, stirred until uniform, 2 g of γ-aminopropyl triethoxysilane was added, stirred and reacted at 75℃ for 2 h, 2 g of succinic acid was added, and stirred and reacted for 30 min, cooled to room temperature, filtered, washed with deionized water 3 times, and dried in an oven at 70℃ for 10 min to obtain a modified porous carbon-loaded composite; A3. 2.4 g of hydroxyl cucurbit[6]urea was added to 120 mL of anhydrous dimethyl sulfoxide, stirred until completely dissolved, 5.4 g of the modified porous carbon-loaded composite, 0.24 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride, and 0.3 g of 4-(dimethylamino) pyridine were added, stirred until uniform, nitrogen was introduced, reacted at 30℃ for 2 h, filtered, washed with deionized water 3 times, and dried in an oven at 70℃ for 10 min to obtain a reinforcing filler.

[0063] The modified nanochitin whisker was prepared by the following steps: B1. 3 g of chitosan was added to 55 mL of a 2% by mass acetic acid solution, stirred until uniform to obtain a chitosan solution, 0.6 g of chlorogenic acid, 0.3 g of N-hydroxysuccinimide, and 0.24 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride were added to 22 mL of ethanol, stirred and mixed for 2 h, added to the chitosan solution, stirred and reacted in an ice water bath for 45 min, centrifuged at 10,000 r / min for 20 min, the supernatant was collected, and the supernatant was freeze-dried at -20℃ for 20 min to obtain chlorogenic acid-modified chitosan; B2. 6 g of nanochitin whisker was added to 50 mL of Tris-HCl buffer solution with a pH of 8.5, stirred until uniform, 0.4 g of dopamine was added, stirred and reacted for 4 h, filtered, washed with deionized water 3 times, and dried in an oven at 70℃ for 10 min to obtain polydopamine-modified nanochitin whisker; B3. 7 g of nanocellulose and 4 g of chlorogenic acid-modified chitosan were added to 120 mL of deionized water, stirred until uniform, 8 g of sodium hydroxide was added, stirred and reacted at 60℃ for 15 min, 3 g of polydopamine-modified nanochitin whisker was added, stirred and reacted for 20 min, and placed in a freeze dryer and freeze-dried at -50℃ for 2 h to obtain a modified nanochitin whisker.

[0064] Comparative Example 2 A degradable bio-based polymeric film, comprising the following raw materials by mass fraction: 80 parts of polycaprolactone, 40 parts of polyhydroxyalkanoate, 10 parts of reinforcing filler, 5 parts of modified nanochitin whisker, and 1 part of nanosilver particles. A preparation process of a degradable bio-based polymeric film, comprising the following preparation steps: S1, mixing polycaprolactone, polyhydroxyalkanoate, reinforcing filler, modified nanochitin whisker, and nano-silver particles, stirring at 1500 r / min for 2h, and then drying to obtain a mixture; S2, after the mixture is extruded and granulated, hot pressing is performed to form a film to obtain the degradable bio-based polymeric film.

[0065] The extrusion granulation is performed by a double-screw extruder, and the process of the double-screw extruder is set as: the temperature of the feeding port is 65℃, the screw temperature is 105℃, the temperature of the discharging port is 110℃, the rotation speed is 30r / min, and the time is 6min.

[0066] The hot pressing is performed by a hot press, and the hot pressing temperature of the hot press is 110℃, and the hot pressing pressure is 40MPa.

[0067] The reinforcing filler is prepared by the following steps: A1. Mixing 3g of wollastonite and 2g of hydrotalcite, calcining at 600℃ for 1h, cooling to room temperature, and crushing to 15μm to obtain a composite; A2. Adding 6g of the composite to 55mL of ethanol, adding 6g of rice husk powder, stirring uniformly, adding 0.6mL of hydrochloric acid with a mass fraction of 36%, stirring and reacting at 75℃ for 30min, filtering, washing with deionized water for 3 times, drying in a 70℃ oven for 10min, placing in a tube furnace, adding potassium hydroxide, introducing nitrogen, carbonizing at 850℃ for 5h, cooling to room temperature, taking out, washing with deionized water for 3 times, drying in a 70℃ oven for 10min to obtain a composite loaded with porous carbon; A3. Adding 2.4g of hydroxycucurbit[6]urea to 120mL of anhydrous dimethyl sulfoxide, stirring until completely dissolved, adding 5.4g of the composite loaded with porous carbon, 0.24g of 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride, and 0.3g of 4-(dimethylamino) pyridine, stirring uniformly, introducing nitrogen, reacting at 30℃ for 2h, filtering, washing with deionized water for 3 times, drying in a 70℃ oven for 10min to obtain the reinforcing filler.

[0068] The modified nanochitin whisker is prepared by the following steps: B1. 3 g of chitosan was added into 55 mL of 2% acetic acid solution, stirred uniformly to obtain a chitosan solution, 0.6 g of chlorogenic acid, 0.3 g of N-hydroxysuccinimide and 0.24 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride were added into 22 mL of ethanol, stirred and mixed for 2 h, then added into the chitosan solution, stirred in an ice water bath for 45 min, centrifuged at 10,000 r / min for 20 min, the supernatant was collected, and the supernatant was freeze-dried at -20℃ for 20 min to obtain chlorogenic acid modified chitosan; B2. 6 g of nano-chitin whiskers were added into 50 mL of Tris-HCl buffer solution with pH of 8.5, stirred uniformly, 0.4 g of dopamine was added, stirred and reacted for 4 h, filtered, washed with deionized water for 3 times, and dried in an oven at 70℃ for 10 min to obtain polydopamine modified nano-chitin whiskers; B3. 7 g of nano-cellulose and 4 g of chlorogenic acid modified chitosan were added into 120 mL of deionized water, stirred uniformly, 8 g of sodium hydroxide was added, stirred at 60℃ for 15 min, 3 g of polydopamine modified nano-chitin whiskers was added, and the stirring was continued for 20 min, and then placed in a freeze dryer and freeze-dried at -50℃ for 2 h to obtain modified nano-chitin whiskers.

[0069] Comparative Example 3 A degradable bio-based polymeric film, comprising the following raw materials in parts by mass: 80 parts of polycaprolactone, 40 parts of polyhydroxyalkanoate, 10 parts of reinforcing filler, 5 parts of modified nano-chitin whisker, and 1 part of nano-silver particle; A preparation process of a degradable bio-based polymeric film, comprising the following preparation steps: S1. The polycaprolactone, polyhydroxyalkanoate, reinforcing filler, modified nano-chitin whisker and nano-silver particle were mixed, stirred at 1500 r / min for 2 h, and then dried to obtain a mixture; S2. The mixture was extruded and granulated, and then hot-pressed into a film to obtain the degradable bio-based polymeric film.

[0070] The extrusion granulation was performed by a double screw extruder, and the process of the double screw extruder was set as follows: the temperature of the feeding port was 65℃, the screw temperature was 105℃, the temperature of the discharging port was 110℃, the rotation speed was 30 r / min, and the time was 6 min.

[0071] The hot-pressing into a film was performed by a hot press, and the hot-pressing temperature of the hot press was 110℃, and the hot-pressing pressure was 40 MPa.

[0072] The reinforcing filler was prepared by the following steps: A1. Mix 3g of wollastonite and 2g of hydrotalcite, calcine at 600℃ for 1h, cool to room temperature, and pulverize to 15μm to obtain the composite. A2. Add 6g of the composite to 55mL of ethanol, add 6g of rice husk powder, stir well, add 0.6mL of 36% hydrochloric acid, stir and react at 75℃ for 30min, filter, wash 3 times with deionized water, dry in an oven at 70℃ for 10min, place in a tube furnace, add potassium hydroxide, purge with nitrogen, carbonize at 850℃ for 5h, cool to room temperature, take out, wash 3 times with deionized water, dry in an oven at 70℃ for 10min to obtain the composite loaded with porous carbon; A3. Add 6g of the composite loaded with porous carbon to 35mL of ethanol and 12mL of deionized water, stir well, add 2g of γ-aminopropyltriethoxysilane, stir at 75℃ for 2h, add 2g of succinic acid, continue stirring for 30min, cool to room temperature, filter, wash 3 times with deionized water, dry in an oven at 70℃ for 10min to obtain the composite loaded with modified porous carbon. A4. Add 2.4g of hydroxycucurbita[6]urea to 120mL of anhydrous dimethyl sulfoxide and stir until completely dissolved. Add 5.4g of modified supported porous carbon composite, 0.24g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 0.3g of 4-(dimethylamino)pyridine. Stir until uniform, introduce nitrogen gas, and react at 30℃ for 2h. After filtration and washing with deionized water 3 times, dry in an oven at 70℃ for 10min to obtain the reinforcing filler.

[0073] Modified nano-chitosan whiskers are prepared by the following steps: B1. Add 6g of nano-chitosan whiskers to 50mL of Tris-HCl buffer solution with pH 8.5, stir well, add 0.4g of dopamine, stir and react for 4h, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain polydopamine-modified nano-chitosan whiskers. B3. Add 7g of nanocellulose and 4g of chitosan to 120mL of deionized water, stir well, add 8g of sodium hydroxide, stir at 60℃ for 15min, add 3g of polydopamine-modified nanochitosan whiskers, continue stirring and reacting for 20min, place in a freeze dryer, freeze dry at -50℃ for 2h to obtain modified nanochitosan whiskers.

[0074] Comparative Example 4 A biodegradable bio-based polymeric membrane comprises the following raw materials in parts by weight: 80 parts polycaprolactone, 40 parts polyhydroxyalkanoate, 10 parts reinforcing filler, 5 parts modified nano-chitosan whiskers, and 1 part nano-silver particles. A preparation process of a degradable bio-based polymeric film, comprising the following preparation steps: S1, polycaprolactone, polyhydroxyalkanoate, reinforcing filler, modified nanochitin whisker, nanosilver particle are mixed, stirred at 1500 r / min for 2h, dried to obtain a mixture; S2, the mixture is granulated by extrusion, and then hot-pressed into a film to obtain the degradable bio-based polymeric film.

[0075] Among them, the extrusion granulation is carried out by a double screw extruder, and the process of the double screw extruder is set as: the temperature of the feeding port is 65℃, the screw temperature is 105℃, the temperature of the discharging port is 110℃, the rotating speed is 30r / min, and the time is 6min.

[0076] The hot-pressing film is carried out by a hot press, and the hot-pressing temperature of the hot press is 110℃, and the hot-pressing pressure is 40MPa.

[0077] The reinforcing filler is prepared by the following steps: A1. 3g of wollastonite and 2g of hydrotalcite are mixed, calcined at 600℃ for 1h, cooled to room temperature, crushed to 15μm, and a composite is obtained; A2. 6g of the composite is added to 55mL of ethanol, 6g of rice husk powder is added, stirred uniformly, 0.6mL of 36% hydrochloric acid is added, stirred at 75℃ for 30min, filtered, washed with deionized water for 3 times, dried in a 70℃ oven for 10min, placed in a tube furnace, added with potassium hydroxide, nitrogen is introduced, carbonized at 850℃ for 5h, cooled to room temperature, taken out, washed with deionized water for 3 times, dried in a 70℃ oven for 10min, and a composite loaded with porous carbon is obtained; A3. 6g of the composite loaded with porous carbon is added to 35mL of ethanol and 12mL of deionized water, stirred uniformly, 2g of γ-aminopropyl triethoxysilane is added, stirred at 75℃ for 2h, 2g of succinic acid is added, and stirred for 30min, cooled to room temperature, filtered, washed with deionized water for 3 times, dried in a 70℃ oven for 10min, and a modified composite loaded with porous carbon is obtained; A4. 2.4g of hydroxyl cucurbit[6]urea is added to 120mL of anhydrous dimethyl sulfoxide, stirred until completely dissolved, 5.4g of the modified composite loaded with porous carbon, 0.24g of 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride, and 0.3g of 4-(dimethylamino) pyridine are added, stirred uniformly, nitrogen is introduced, reacted at 30℃ for 2h, filtered, washed with deionized water for 3 times, dried in a 70℃ oven for 10min, and the reinforcing filler is obtained.

[0078] The modified nanochitin whisker is prepared by the following steps: B1. 3 g of chitosan was added into 55 mL of 2% acetic acid solution, stirred uniformly to obtain a chitosan solution, 0.6 g of chlorogenic acid, 0.3 g of N-hydroxysuccinimide and 0.24 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride were added into 22 mL of ethanol, stirred and mixed for 2 h, then added into the chitosan solution, stirred in an ice water bath for 45 min, centrifuged at 10,000 r / min for 20 min, the supernatant was collected, and the supernatant was freeze-dried at -20℃ for 20 min to obtain chlorogenic acid modified chitosan; B2. 7 g of nanocellulose and 4 g of chlorogenic acid modified chitosan were added into 120 mL of deionized water, stirred uniformly, 8 g of sodium hydroxide was added, stirred at 60℃ for 15 min, 3 g of nanochitin whiskers was added, and the stirring reaction was continued for 20 min, and then placed in a freeze dryer and freeze-dried at -50℃ for 2 h to obtain modified nanochitin whiskers.

[0079] The degradable bio-based polymeric films prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to performance testing.

[0080] Mechanical testing: The degradable bio-based polymeric films prepared above were subjected to performance testing according to the tensile property test method of GB13022-91.

[0081] Biodegradability testing: The degradable bio-based polymeric films prepared above were subjected to simulated soil burial degradation experiments according to GB / T19811-2005, and the weight loss rates at 10 d, 20 d and 40 d were detected.

[0082] Fresh-keeping effect testing: 500 g of fresh litchi was sealed and stored using the degradable bio-based polymeric films prepared above, and after storage at 12℃ for 48 h, the number of rotten fruits was counted and the rotten fruit rate was calculated.

[0083] The test results are shown in Table 1 below.

[0084] Table 1 Performance testing of degradable bio-based polymeric films prepared in Examples 1-3 and Comparative Examples 1-4

[0085] As can be seen from the data in Table 1, the degradable bio-based polymeric film prepared in Example 1-3 has high mechanical properties and excellent fresh-keeping effect.

[0086] The mechanical properties and fresh-keeping properties of the degradable bio-based polymeric film prepared by replacing the modified porous carbon-loaded complex with the complex in Comparative Example 1 are decreased, which proves that the synthesis of porous carbon on the surface of the complex can adsorb and fix the impurities in the complex, avoiding the influence of the falling of the impurities in the complex on the quality of the food and the mechanical properties of the polymeric film; the large porosity of the porous carbon shows good barrier properties, which can effectively prevent the penetration of moisture, oxygen and other harmful substances, avoiding the influence of the moisture and oxidation factors on the stored goods, thereby prolonging the shelf life of the goods.

[0087] The mechanical properties and fresh-keeping properties of the degradable bio-based polymeric film prepared by replacing the modified porous carbon-loaded complex with the complex in Comparative Example 2 are decreased, which proves that the hydroxyl cucurbit[6]urea grafted on the surface of the modified porous carbon-loaded complex introduces hydrophobic groups into the polymeric film, avoiding the aggregation of water, which leads to the corruption of the polymeric film, and the rigid structure of the cucurbit[6]urea macrocycle improves the mechanical strength of the polymeric film.

[0088] The fresh-keeping properties of the degradable bio-based polymeric film prepared by replacing the chlorogenic acid-modified chitosan with chitosan in Comparative Example 3 are decreased, which proves that the grafting of chlorogenic acid on chitosan consumes the hydroxyl groups of chitosan, reducing the adsorption of water molecules, and further enhancing the barrier property of chitosan to water vapor.

[0089] The mechanical properties of the degradable bio-based polymeric film prepared by replacing the polydopamine-modified nanochitin whisker with nanochitin whisker in Comparative Example 4 are decreased, which proves that the polydopamine-modified nanochitin whisker can form a three-dimensional network structure combined by hydrogen bonds with the chlorogenic acid-modified chitosan and nanocellulose, playing a role in transmitting stress, and further enhancing the mechanical properties of the polymeric film.

[0090] In the description of the specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0091] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements or use similar ways to replace the described specific embodiments, as long as they do not deviate from the scope of the invention or exceed the scope defined by the present claims, which shall be within the protection scope of the present application.

Claims

1. A degradable bio-based polymeric film, characterized in that, The polymeric material comprises the following raw materials by mass: 70-80 parts of polycaprolactone, 30-40 parts of polyhydroxyalkanoate, 6-10 parts of reinforcing filler, 3-5 parts of modified nanochitin whisker, and 0.5-1 part of antibacterial agent. The reinforcing filler is obtained by mixing and reacting a coupling agent, succinic acid and a porous carbon-loaded composite, and then reacting with hydroxyl calix[6]urea. The porous carbon-loaded composite is obtained by mixing and calcining wollastonite and hydrotalcite, and then mixing and reacting with rice husk powder. The modified nanochitin whisker is obtained by modifying chitosan with chlorogenic acid, and then mixing and reacting with dopamine surface-modified nanochitin whisker and nanocellulose.

2. The degradable bio-based polymeric film according to claim 1, wherein, The reinforcing filler is specifically prepared by the following steps: A1. Mix wollastonite and hydrotalcite, calcine at 500-600 DEG C for 0.5-1 h, cool to room temperature, and crush to 10-15 mu m to obtain a composite; A2. Add the composite to ethanol, add rice husk powder, stir until uniform, add 36% hydrochloric acid by mass, stir at 65-75 DEG C for 20-30 min, filter, wash, dry, add potassium hydroxide, pass nitrogen, carbonize at 750-850 DEG C for 3-5 h, cool to room temperature, remove, wash, and dry to obtain the porous carbon-loaded composite; A3. Add the porous carbon-loaded composite to ethanol and deionized water, stir until uniform, add a coupling agent, stir at 65-75 DEG C for 1-2 h, add succinic acid, continue to stir for 20-30 min, cool to room temperature, filter, wash, and dry to obtain the modified porous carbon-loaded composite; A4. Add hydroxyl calix[6]urea to anhydrous dimethyl sulfoxide, stir until completely dissolved, add the modified porous carbon-loaded composite, 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride, and 4-(dimethylamino) pyridine, stir until uniform, pass nitrogen, react at 20-30 DEG C for 1-2 h, filter, wash, and dry to obtain the reinforcing filler.

3. The degradable bio-based polymeric film according to claim 2, wherein, In step A1, the mass ratio of the wollastonite to the hydrotalcite is (2-3):(1-2).

4. The degradable bio-based polymeric film according to claim 2, wherein, In step A2, the amount ratio of the composite, ethanol, rice husk powder, hydrochloric acid, and potassium hydroxide is (4-6) g:(45-55) mL:(4-6) g:(0.4-0.6) mL:(4-6) mL.

5. The degradable bio-based polymeric film according to claim 2, wherein, In step A3, the amount ratio of the porous carbon-loaded composite, ethanol, deionized water, coupling agent, and succinic acid is (4-6) g:(25-35) mL:(8-12) mL:(1-2) g:(1-2) g.

6. The degradable bio-based polymeric film according to claim 2, wherein, In step A4, the amount ratio of the hydroxyl calix[6]urea, anhydrous dimethyl sulfoxide, modified porous carbon-loaded composite, 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride, and 4-(dimethylamino) pyridine is (2.2-2.4) g:(80-120) mL:(5-5.4) g:(0.22-0.24) g:(0.1-0.3) g.

7. The degradable bio-based polymeric film according to claim 1, wherein, The modified nanochitin whisker is specifically prepared by the following steps: B1. Chitosan is added to acetic acid solution, stirred uniformly to obtain chitosan solution, chlorogenic acid, N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride are added to ethanol, stirred uniformly, added to chitosan solution, stirred and reacted for 35-45 min, the supernatant is collected by centrifugation, and the supernatant is freeze-dried to obtain chlorogenic acid modified chitosan; B2. The nanochitin whisker is added to Tris-HCl buffer solution, stirred uniformly, dopamine is added, stirred and reacted for 3-4 h, filtered, washed, dried to obtain polydopamine modified nanochitin whisker; B3. The nanocellulose and chlorogenic acid modified chitosan are added to deionized water, stirred uniformly, sodium hydroxide is added, stirred at 50-60℃ for 10-15 min, the polydopamine modified nanochitin whisker is added, and the stirring is continued to react for 10-20 min, and freeze-drying is performed to obtain modified nanochitin whisker.

8. The degradable bio-based polymeric film according to claim 7, wherein, In step B1, the amount ratio of chitosan, acetic acid solution, chlorogenic acid, N-hydroxysuccinimide, 1-ethyl-(3-dimethylaminopropyl) carbonyldiimidazole hydrochloride and ethanol is (1-3) g:(45-55) mL:(0.4-0.6) g:(0.1-0.3) g:(0.2-0.24) g:(18-22) mL.

9. The degradable bio-based polymeric film according to claim 7, wherein, In step B2, the amount ratio of nanochitin whisker, Tris-HCl buffer solution and dopamine is (4-6) g:(40-50) mL:(0.2-0.4) g; In step B3, the amount ratio of nanocellulose, chlorogenic acid modified chitosan, deionized water, sodium hydroxide and polydopamine modified nanochitin whisker is (5-7) g:(2-4) g:(80-120) mL:(6-8) g:(1-3) g.

10. A process for the preparation of the degradable bio-based polymeric film according to any one of claims 1 to 9, characterized in that, The preparation steps include the following: S1, poly-caprolactone, poly-hydroxyalkanoate, reinforcing filler, modified nanochitin whisker and antibacterial agent are mixed, stirred at 1000-1500 r / min for 1-2 h, and then dried to obtain a mixture; S2, the mixture is extruded and granulated, and then hot-pressed into a film to obtain a degradable bio-based polymeric film.

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