A multifunctional starch-based composite film material and preparation method thereof

Abstract

The present application relates to the technical field of food packaging materials, and specifically discloses a multifunctional starch-based composite film material and a preparation method thereof. The multifunctional starch-based composite film material comprises the following materials in parts by weight: 600-1000 parts of starch; 10 parts of tea processing residues; 0.1-1 parts of antibacterial agent; 0.01-0.1 parts of cross-linking agent; 30-72 parts of water. Its preparation method is: S1, pretreatment; S2, slurry preparation; S3, film material preparation. The starch-based composite film material of the present application can be used in many fields such as food, textiles, daily chemicals, and medicine. It has the advantages of excellent mechanical properties, hydrophobicity, oil resistance, antibacterial and gas barrier.

Description

Technical Field

[0001] The present application relates to the technical field of food packaging materials, and more specifically, to a multifunctional starch-based composite film material and a preparation method thereof. Background Art

[0002] With the development of society, plastic products are widely used in all aspects of life. More and more petroleum-based plastic wastes are causing serious environmental problems due to their non-degradability. Alternative materials based on biodegradable ingredients such as starch, cellulose, and protein have received continuous attention from society. Starch is a rich, economical, and environmentally friendly renewable resource. It is widely used in the preparation of bio-based materials and has excellent mechanical and barrier properties. It shows great application prospects in the packaging industry.

[0003] Although starch is considered to be an excellent substitute for petroleum-based plastics, the strong hydrophilicity of thermoplastic starch makes starch film easily eroded by water, which may lead to poor dimensional stability; the mechanical properties and physical and chemical properties of pure starch film are still far from those of traditional plastics. Therefore, starch-based materials have the problems of brittleness, poor mechanical properties, easy water absorption, and poor antibacterial properties, which limit their practical application. Summary of the invention

[0004] In order to improve the problems of starch being brittle, having poor mechanical properties, being easy to absorb water, and having poor antibacterial properties, the present application provides a multifunctional starch-based composite film material and a preparation method thereof.

[0005] The present application provides a multifunctional starch-based composite film material, which adopts the following technical solution:

[0006] In a first aspect, the present application provides a multifunctional starch-based composite film material, comprising the following materials in parts by weight:

[0007] 600-1000 parts of starch;

[0008] 10 parts of tea processing residues;

[0009] Antibacterial agent 0.1-1 part;

[0010] Cross-linking agent 0.01-0.1 part;

[0011] 30-102 parts of water.

[0012] By adopting the above technical scheme, the main raw materials of the present invention are starch from plant sources and tea processing residues, which are rich in raw materials, widely available, and not limited by origin and season. Only a small amount of antibacterial agent is added to prepare a composite film material with good mechanical properties and antibacterial properties. The composite film material can be applied to many fields such as food, textiles, daily chemicals, and medicine, and has broad market prospects. Utilizing abundant agricultural biomass resources to develop environmentally friendly bio-based antibacterial materials is of great significance for solving the oil crisis and plastic pollution and building a resource-saving and environmentally friendly society.

[0013] Optionally, the antibacterial agent includes one or more of chitosan, tea tree essential oil, lysozyme, ε-polylysine, nano zinc, nano silver, vanillin, quaternary ammonium salt, and quaternized biochar.

[0014] Optionally, the antibacterial agent is wrapped with a shell, and the shell includes gelatin or sodium alginate.

[0015] By adopting the above technical scheme, gelatin or sodium alginate is wrapped around the antibacterial agent, so that the antibacterial agent can form a slow-release core-shell structure, so that the antibacterial agent can be slowly released, and the antibacterial time of the composite film can be extended. Secondly, gelatin can cross-link with starch base to form an interlaced three-dimensional network in the composite film, strengthen the interaction between the components in the composite film, and improve the strength of the composite film. Sodium alginate is composed of D-mannuronic acid segment and L-guluronic acid segment structure, and has excellent viscosity and gel properties. Sodium alginate can strongly hydrogen bond with starch molecules to form a network interpenetrating structure, which improves the density of the composite film, thereby improving the air barrier, oil barrier, and water repellent effect of the composite film, that is, the composite film is used to isolate the wrapped object from the environment; at the same time, the skeleton strength of the composite film is also enhanced, thereby improving the strength of the composite film.

[0016] Optionally, the shell is a shell modified by a modifier, and the modifier includes a silane coupling agent or a plant polysaccharide.

[0017] By adopting the above technical solution, the shell is modified by using a silane coupling agent, and a long-chain alkyl group can be grafted on the shell, further improving the dispersion effect of the shell in the composite film material, so that the composite film material obtains a uniform network structure and uniform reinforcement. The shell is modified by using plant polysaccharides, which can be evenly dispersed in the composite film material through hydrogen bonds and hydrophobic effects, improving the stability of the gel network formed by sodium alginate and starch, and further improving the density of the composite film material, thereby improving the strength, air barrier, oil barrier and water repellent effects of the composite film material, that is, improving the isolation effect of the composite film material.

[0018] Optionally, the composite membrane material further includes fillers, and the fillers include Ulva perforata and vermiculite.

[0019] By adopting the above technical scheme, Ulva porifera and vermiculite are added to the composite film material. Ulva porifera is a seaweed plant with a lamellar structure, a fiber structure and a plant protein. It can introduce a fiber network structure and a lamellar shielding layer into the composite film material, and form a micron-nano structure on the surface of the composite film material, which can stably improve the strength and barrier effect of the composite film material. At the same time, under heat treatment, the plant protein in Ulva porifera can cross-link with starch to form a water vapor twisted channel in the composite film material, further improving the barrier effect of the composite film material. Vermiculite is a layered structure material. When vermiculite is added to the composite film material, it can not only further improve the strength of the composite film material, but also further introduce a gas channel into the composite film material, making the path of the gas through the composite film material more tortuous. Through the cooperation of vermiculite and Ulva porifera, a micron-nano and a maze structure are formed in the composite film material, which improves the hydrophobicity of the composite film material and improves the barrier effect of the composite film material.

[0020] Optionally, the filler is loaded with magnetic particles.

[0021] By adopting the above technical solution, by loading magnetic particles on the filler, the addition of magnetic particles can increase the interlayer spacing of the layered structure in the filler, which is conducive to the penetration of starch molecular chains, forming a tighter intermolecular force, and improving the density of the composite film material. At the same time, after the filler is loaded with magnetic particles, the filler is induced by the magnetic field, and the filler can be oriented in the composite film material in the direction perpendicular to the molecular penetration, forming a longer maze-like gas diffusion path, further improving the barrier effect of the composite film material.

[0022] Optionally, the tea processing residues include one or more of green tea, white tea, yellow tea, oolong tea, black tea and dark tea processing residues.

[0023] Optionally, the cross-linking agent includes one or more of epichlorohydrin, sodium trimetaphosphate, phosphorus oxychloride, epihydrogen alcohol, acetic acid, and the like.

[0024] Optionally, the raw materials of the starch include one or more of corn, wheat, potato, cassava, rice, sweet potato, and sago, and the content of amylose in the starch is greater than 50%.

[0025] In a second aspect, the present application provides a method for preparing a multifunctional starch-based composite film material, using the following technical solution:

[0026] A method for preparing a multifunctional starch-based composite film material comprises the following steps:

[0027] S1. Pretreatment: grind the tea processing residue into 80-200 mesh, add the antibacterial agent and the cross-linking agent, mix well, place at 50-90°C for reaction for 0.2-1 h, and obtain a modified material;

[0028] S2. Slurry preparation: adding the modified material to starch, adding water, and mixing to obtain slurry;

[0029] S3. Film material preparation: A twin-screw extruder is used as a reactor, and the barrel temperature, screw speed, and screw length-diameter ratio are set to 100-130°C, 120-200 r / min, and 1:5-10, respectively. The extrusion process is cycled 2-6 times to finally obtain a multifunctional starch-based composite film material.

[0030] By adopting the above technical solution, the processing steps are simple, easy to operate, low cost, and the conditions are controllable. It uses bio-based raw materials and green and clean processes and is basically pollution-free to the environment.

[0031] In summary, this application has the following beneficial effects:

[0032] 1. Since the main raw materials of this application are starch and tea processing residues from plants, the raw materials are abundant and widely available, and are not restricted by origin and season. By adding only a small amount of antibacterial agent, a composite film with good mechanical properties and antibacterial properties can be prepared, which can be applied to many fields such as food, textiles, daily chemicals, and medicine, and has broad market prospects. Utilizing abundant agricultural biomass resources to develop environmentally friendly bio-based antibacterial materials is of great significance for solving the oil crisis and plastic pollution and building a resource-saving and environmentally friendly society.

[0033] 2. The present application adopts gelatin or sodium alginate wrapped around the antibacterial agent, which can make the antibacterial agent form a slow-release core-shell structure, so that the antibacterial agent can be slowly released, and the antibacterial time of the composite film material can be extended. Secondly, gelatin can cross-link with starch base to form an interlaced three-dimensional network in the composite film material, strengthen the interaction between the components in the composite film, and improve the strength of the composite film material. Sodium alginate is composed of D-mannuronic acid segment and L-guluronic acid segment structure, and has excellent viscosity and gel properties. Sodium alginate can strongly hydrogen bond with starch molecules to form a network interpenetrating structure, which improves the density of the composite film material, thereby improving the air barrier, oil barrier, and water repellent effect of the composite film material, that is, the composite film material is used to isolate the wrapped object from the environment; at the same time, the skeleton strength of the composite film material is also enhanced, thereby improving the strength of the composite film material.

[0034] 3. The method of the present application has simple steps, is easy to operate, has low cost, and has controllable conditions. It uses bio-based raw materials and green and clean processes and has basically no pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a scanning electron microscope morphology image of the composite film of Example 1 of the present invention. DETAILED DESCRIPTION

[0036] The present application is further described in detail below with reference to the embodiments.

[0037] In the examples of the present application, the selected drugs are as follows, but not limited thereto:

[0038] Medicines: Tea processing residues include broken tea powder, low-quality tea and tea stems left over from the tea processing process; black tea processing residues include black tea powder from Fu'an Xinrui Tea Shop; green tea processing residues include green tea stems from Wuyi Fuyuan Tea Co., Ltd.; dark tea processing residues include Pu'er broken tea powder from Yunnan Caimao Xingjie Trading Co., Ltd.; porous starch is the porous starch from Liaoning Lida Biotechnology Co., Ltd.; nanosilver is Dr. Mold K-009 nanosilver powder from Guangdong Zanyu Anti-Mold Technology Co., Ltd.

[0039] Preparation Example: Preparation Example of Antibacterial Agent Microcapsules

[0040] Preparation Example 1

[0041] Tea tree essential oil and porous starch were mixed in a mass ratio of 1:1, stirred at high speed for 30 minutes, ultrasonicated for 30 minutes, centrifuged, the solids were retained, washed with anhydrous ethanol three times, and dried to obtain powder microspheres. 20g of powder microspheres were mixed with 10mL of sodium dodecyl sulfate (mass fraction 5%), 20mL of sodium alginate solution (mass fraction 3%) was added and stirred, and then 40mL of chitosan solution (mass fraction 3%) was added and stirred to obtain a mixed solution, 20mL of glutaraldehyde solution (mass fraction 2%) was added to the mixed solution, and the mixture was allowed to stand, centrifuged, the solids were retained, and dried to obtain antibacterial agent microcapsules.

[0042] Preparation Example 2

[0043] Tea tree essential oil and porous starch were mixed in a mass ratio of 1:1, stirred at high speed for 30 minutes, ultrasonicated for 30 minutes, centrifuged, the solids were retained, washed with anhydrous ethanol three times, and dried to obtain powder microspheres. 20g of powder microspheres were mixed with 10mL of sodium dodecyl sulfate (mass fraction 5%), 20mL of gelatin solution (mass fraction 3%) was added and stirred, and then 40mL of chitosan solution (mass fraction 3%) was added and stirred to obtain a mixed solution, 20mL of glutaraldehyde solution (mass fraction 2%) was added to the mixed solution, and the mixture was allowed to stand, centrifuged, the solids were retained, and dried to obtain antibacterial agent microcapsules.

[0044] Preparation Example 3

[0045] The antibacterial agent microcapsules prepared in Preparation Example 1 were immersed in the silane coupling agent KH-550, stirred and mixed, filtered, and dried to obtain modified microcapsules.

[0046] Preparation Example 4

[0047] The antibacterial agent microcapsules prepared in Preparation Example 1 and tea polysaccharides were stirred and mixed to obtain a modified microcapsule emulsion.

[0048] Preparation Example 5

[0049] Take Ulva perforata, wash, dry, crush, and pass through a 30-mesh sieve to obtain Ulva perforata powder. Take 5 kg of Ulva perforata powder and 5 kg of vermiculite powder, stir and mix, and obtain a filler.

[0050] Preparation Example 6

[0051] Preparation of modified vermiculite: First, 2.0 g of vermiculite powder was added to 200 mL of deionized water, and the vermiculite suspension was ultrasonically treated at 200 W for 20 min to fully disperse it. 3 6H 2 O and 0.858 g of FeCl 2 ·4H 2 O was dissolved in 100 mL of deionized water, and then 4 drops of APTES were added under magnetic stirring at 60 ° C and 400 r / min, followed by the addition of 200 mL of the prepared vermiculite suspension, and then the pH was adjusted to 10.0 using aqueous ammonia. The mixture was magnetically stirred at 60 ° C and 200 r / min for 1 h. After naturally cooling to room temperature, the static mixture was separated with a magnet and washed with ethanol. The modified vermiculite powder was dried in air.

[0052] 5 kg of Ulva porphyra powder and 5 kg of modified vermiculite powder were taken, stirred and mixed to obtain a filler.

[0053] Embodiments: Embodiment 1: On the one hand, the present application provides a multifunctional starch-based composite film material, including starch, tea processing residues, an antibacterial agent, a cross-linking agent and water, and the specific mass is shown in the table below.

[0054] Among them, the starch in this embodiment is corn starch with an amylose content of 55%; the tea processing residue is black tea processing residue, the antibacterial agent is ε-polylysine with a mass fraction of 2.5%, and the cross-linking agent is epichlorohydrin with a mass fraction of 0.2%.

[0055] On the other hand, the present application provides a method for preparing a multifunctional starch-based composite film material, comprising the following steps:

[0056] (1) The leftover black tea processing material was finely ground into 100 mesh, 2.5% ε-polylysine and 0.2% epichlorohydrin were added and mixed, and the mixture was reacted at 50°C for 0.2 h to obtain a modified material;

[0057] (2) adding the modified material to the corn starch, mixing well and adjusting the water content to 5% to obtain a slurry;

[0058] (3) A twin-screw extruder was used as the reactor. The barrel temperature was set to 105 °C, the screw speed was set to 120 r / min, and the screw length-to-diameter ratio was set to 1:6. The extrusion process was cycled twice to finally obtain a multifunctional starch-based composite film material.

[0059] Table 1 Composition of composite membrane materials in Examples 1-3

[0060]

[0061] Example 2: On the one hand, the present application provides a multifunctional starch-based composite film material, including starch, tea processing residues, antibacterial agent, cross-linking agent and water, and the specific quality is shown in the table above.

[0062] Among them, the starch in this embodiment is potato starch with an amylose content of 80%; the tea processing residue is green tea processing residue, the antibacterial agent is nanosilver, and the cross-linking agent is sodium trimetaphosphate.

[0063] On the other hand, the present application provides a method for preparing a multifunctional starch-based composite film material, comprising the following steps:

[0064] (1) The green leaf processing residue was finely ground into 200 mesh, 10% nanosilver and 0.4% sodium trimetaphosphate were added and mixed, and the mixture was reacted at 90°C for 0.2h to obtain a modified material;

[0065] (2) adding the modified material to potato starch, mixing and adjusting the moisture content to 10% to obtain a slurry;

[0066] (3) A twin-screw extruder was used as the reactor. The barrel temperature was set to 130 °C, the screw speed was set to 120 r / min, and the screw length-to-diameter ratio was set to 1:8. The extrusion process was cycled three times to finally obtain a multifunctional starch-based composite film material.

[0067] Example 3: On the one hand, the present application provides a multifunctional starch-based composite film material, including starch, tea processing residues, antibacterial agent, cross-linking agent and water, and the specific quality is shown in the table above.

[0068] Among them, the starch in this embodiment is cassava starch with an amylose content of 63%; the tea processing residue is black tea processing residue, the antibacterial agent is chitosan, and the cross-linking agent is phosphorus oxychloride.

[0069] On the other hand, the present application provides a method for preparing a multifunctional starch-based composite film material, comprising the following steps:

[0070] (1) The leftover dark tea was finely ground into 140 mesh, 1% chitosan and 0.6% phosphorus oxychloride were added and mixed, and the mixture was reacted at 55°C for 1 h to obtain a modified material;

[0071] (2) adding the modified material to the cassava starch, mixing and adjusting the moisture content to 7% to obtain a slurry;

[0072] (3) A twin-screw extruder was used as the reactor. The barrel temperature was set to 120 °C, the screw speed was set to 170 r / min, and the screw length-to-diameter ratio was set to 1:10. The extrusion process was cycled 4 times to finally obtain a multifunctional starch-based composite film material.

[0073] Example 4: The difference from Example 3 is that the antibacterial agent includes 0.1g chitosan and 0.1g antibacterial agent microcapsules in Preparation Example 1.

[0074] Example 5: The difference from Example 3 is that the antibacterial agent includes 0.1g chitosan and 0.1g antibacterial agent microcapsules in Preparation Example 2.

[0075] Example 6: The difference from Example 3 is that the antibacterial agent includes 0.1g chitosan and 0.1g modified microcapsules in Preparation Example 3.

[0076] Example 7: The difference from Example 3 is that the antibacterial agent includes 0.1g chitosan and 0.1g modified microcapsule emulsion in Preparation Example 4.

[0077] Example 8: The difference from Example 3 is that the composite film material further includes 30 g of the filler in Preparation Example 5.

[0078] Example 9: The difference from Example 3 is that the composite film material further includes 30 g of the filler in Preparation Example 6;

[0079] (1) The leftover dark tea was finely ground into 140 mesh, 1% chitosan and 0.6% phosphorus oxychloride were added, mixed, and reacted at 55°C for 1 h;

[0080] (2) adding the modified material and filler to the cassava starch, mixing and adjusting the moisture content to 7%, and gelatinizing at 90°C for 1 hour to obtain a slurry;

[0081] (3) The slurry is cast in a polyethylene container, oriented using an external magnetic field parallel to the container floor, and is isothermally dried at 35°C to obtain a composite film material.

[0082] Comparative Example: Comparative Example 1

[0083] The difference between this comparative example and Example 1 is that no antibacterial agent is added in this comparative example.

[0084] Performance test: 1. Surface morphology analysis: The sample is cut into small pieces, attached to the sample table, gold-plated, and observed using a scanning electron microscope at a magnification of 1000 times.

[0085] 2. Mechanical properties determination: TA-XTPlus physical property analyzer, A / TG fixture was used for determination. The film was cut into 1×5 cm rectangular blocks. The initial distance between the fixtures was 25 mm. The stretching speed was 1 mm / s, the return speed was 10 mm / s, and each group of samples was paralleled 5 times. The elongation at break and tensile strength were calculated according to the following formula: Elongation at break E (%) = (LL 0 ) / L 0 ×100;

[0086] L—length of the film after stretching (mm); 0 —initial length of the membrane (mm);

[0087] Tensile strength TS (MPa) = F / (D×d);

[0088] F—axial tensile force (N); D—membrane width (mm); d—membrane thickness (mm).

[0089] 3. Determination of antibacterial properties: The tested bacteria were Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus). The bacteria were streaked on LB solid medium and cultured at 37℃ for 12 hours. A single colony was picked and then cultured in LB medium at 37℃ for 8 hours for activation. 0.1 mL of the activated bacterial solution was drawn from the activated bacterial solution and added to the surface of the LB solid medium and evenly coated. A 10 mm diameter antibacterial composite film that had been disinfected with ultraviolet light was prepared and attached to the medium. The culture was cultured at 37℃ for 24-36 hours. The living conditions of the bacteria were observed and the diameter of the inhibition zone was measured. Each group of samples was repeated three times.

[0090] Table 2 Performance test

[0091]

[0092] Combining the performance test comparison in Table 2, we can find that:

[0093] 1. By comparing Examples 1-3 with Comparative Example 1, it can be found that the tensile strength, elongation at break and antibacterial zone diameter of the composite film materials prepared in Examples 1-3 are improved, which means that only a small amount of antibacterial agent is added in the present application to prepare a composite film with good mechanical properties and antibacterial properties, which can be applied to many fields such as food, textiles, daily chemicals, and medicine, and has broad market prospects.

[0094] 2. By comparing Example 4-5 with Example 3, it can be found that the tensile strength, elongation at break and antibacterial zone diameter of the composite film prepared in Example 4-5 are all improved, and the water vapor permeability is reduced. This shows that in the present application, gelatin or sodium alginate is wrapped around the antibacterial agent, which can form a sustained-release core-shell structure of the antibacterial agent, so that the antibacterial agent can be slowly released, and the antibacterial time of the composite film is prolonged. Secondly, gelatin can cross-link with starch base to form an interlaced three-dimensional network in the composite film; sodium alginate can strongly hydrogen bond with starch molecules to form a network interpenetrating structure, which improves the density of the composite film, thereby improving the air barrier, oil barrier and water repellent effects of the composite film, that is, the composite film is used to isolate the wrapped object from the environment; at the same time, the skeleton strength of the composite film is also enhanced, thereby improving the strength of the composite film.

[0095] 3. By comparing Examples 6-7 with Example 3, it can be found that the tensile strength, elongation at break and antibacterial zone diameter of the composite film material prepared in Examples 6-7 are improved, and the water vapor permeability is reduced. This shows that plant polysaccharides are used to modify the shell in the present application. Plant polysaccharides can be evenly dispersed in the composite film material through hydrogen bonds and hydrophobic effects, thereby improving the stability of the gel network formed by sodium alginate and starch, and further improving the density of the composite film material.

[0096] 4. By comparing Examples 8-9 with Example 3, it can be found that the tensile strength, elongation at break and antibacterial zone diameter of the composite film material obtained in Examples 8-9 are all improved, and the water vapor permeability is reduced, which shows that adding vermiculite to the composite film material in this application can not only further improve the strength of the composite film material, but also further introduce gas channels in the composite film material, making the path of gas passing through the composite film material more tortuous. Through the cooperation of vermiculite and Ulva perforata, micron-nano and maze structures are formed in the composite film material, which improves the hydrophobicity of the composite film material and improves the barrier effect of the composite film material. After the filler is loaded with magnetic particles, the filler is induced by a magnetic field, and the filler can be oriented in the composite film material in the direction perpendicular to the molecular penetration, forming a longer maze-type gas diffusion path, further improving the barrier effect of the composite film material.

[0097] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A multifunctional starch-based composite film material, characterized in that: The materials include the following parts by weight: 600-1000 parts of starch; 10 parts of tea processing residues; Antibacterial agent 0.1-1 part; Cross-linking agent 0.01-0.1 part; 30-72 parts of water; The composite membrane material further comprises fillers, wherein the fillers are Ulva perforata and modified vermiculite. The modified vermiculite is prepared as follows: first, 2.0 g of vermiculite powder is added to 200 mL of deionized water, and the vermiculite suspension is ultrasonically treated at 200 W for 20 min to fully disperse it, 2.334 g of FeCl3·6H2O and 0.858 g of FeCl2·4H2O are dissolved in 100 mL of deionized water, and then 4 drops of APTES are dropped under magnetic stirring at 60° C. and 400 r / min, and then 200 mL of the prepared vermiculite suspension is added, and then the pH is adjusted to 10.0 with ammonia water, and the mixture is magnetically stirred at 60° C. and 200 r / min for 1 h. After naturally cooling to room temperature, the static mixture is separated by a magnet, washed with ethanol, and the modified vermiculite powder is dried in air.

2. A multifunctional starch-based composite film material according to claim 1, characterized in that: The antibacterial agent includes one or more of chitosan, lysozyme, tea tree essential oil, ε-polylysine, nano zinc, nano silver, vanillin, quaternary ammonium salt, and quaternized biochar.

3. The multifunctional starch-based composite film material according to claim 1, characterized in that: The tea processing residues include one or more of green tea, white tea, yellow tea, oolong tea, black tea and dark tea processing residues.

4. The multifunctional starch-based composite film material according to claim 1, characterized in that: The cross-linking agent includes one or more of epichlorohydrin, sodium trimetaphosphate, and phosphorus oxychloride.

5. The multifunctional starch-based composite film material according to claim 1, characterized in that: The raw materials of the starch include one or more of corn, wheat, potato, cassava, rice, sweet potato and sago, and the content of amylose in the starch is greater than 50%.

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