Marine resource derived high-strength biomass plastic as well as preparation method and application thereof

Abstract

The invention discloses marine resource derived high-strength biomass plastic as well as a preparation method and application thereof. The high-strength biomass plastic derived from the marine resources is prepared from the chitin nanocrystals, the sodium alginate dendritic colloid, the sodium alginate and the plasticizer as raw materials, a three-dimensional branch network of the sodium alginate dendritic colloid can be uniformly dispersed in a film material and provides stable support, the tensile strength and toughness of the plastic are remarkably improved, and the service life of the plastic is prolonged. The fracture risk caused by excessive brittleness due to addition of the chitin nanocrystals is reduced, and the traditional inherent contradiction between the brittleness and the toughness is balanced. The obtained plastic has an interaction unit similar to a'cement-mortar 'shape, and has extremely high mechanical strength and ideal water resistance. The surface smoothness, the heat stability and the high biodegradability are kept, meanwhile, the strength and the ductility are considered, and the high-strength and high-ductility plastic is superior to traditional petrochemical plastic.

Description

Technical Field

[0001] This invention belongs to the field of green plastics, specifically relating to a biomass plastic composed of chitin nanocrystals prepared by microwave-assisted strong Lewis acid based on sodium alginate dendritic colloid and the preparation method and application thereof. Background Technology

[0002] While traditional petroleum-based plastics exhibit excellent mechanical properties, durability, and processing adaptability, their stable chemical structure often makes them difficult to degrade in the environment, ultimately leading to the long-term accumulation of large amounts of plastic waste and causing white pollution. In recent years, green plastics such as polylactic acid (PLA) and starch-based plastics have emerged, but they generally suffer from insufficient strength, unsatisfactory toughness, and high cost, making it difficult to replace petroleum-based plastics in terms of high strength and functionality.

[0003] Biodegradable polymers such as cellulose, chitin, and silk fibroin, through value-added downstream processing, are gradually becoming nanomaterials that make significant contributions to environmental sustainability. Chitin is the main structural polymer in the exoskeleton of crustaceans and the cell walls of fungi, and is the second most abundant natural polymer on Earth. Therefore, the development and utilization of chitin and its derivatives can not only prevent resource waste caused by landfilling, but also support the growing demand for establishing modern marine ranching systems. Chitin nanocrystals obtained by removing amorphous regions are usually rod-shaped and have excellent dispersibility and engineering properties in water. When incorporated as fillers into hydrophilic polymer films, they interact with the matrix to form strong interfacial bonds, which is beneficial for crack deflection and uniform stress transfer. Similarly, sodium alginate, a naturally derived polysaccharide, is derived from marine organisms such as brown algae. Due to its ability to form dense film structures, suitable gas barrier properties, and good chemical modification potential, it has gradually attracted attention as a packaging material for extending the shelf life of food. However, sodium alginate films have obvious limitations such as moisture sensitivity, significant brittleness, and insufficient mechanical strength, which urgently need to be addressed.

[0004] The preparation and optimization of green biomass plastics involves addressing the inherent trade-off between brittleness and toughness. Traditional inorganic fillers added to natural membranes restrict polymer chain migration, leading to hardening, brittleness, and an increased likelihood of breakage. Natural nanofillers, with their abundant surface polar functional groups, can form strong interfacial interactions with the polymer matrix, improving membrane strength while allowing for high tensile strength. Summary of the Invention

[0005] To address the shortcomings and deficiencies of existing technologies, the primary objective of this invention is to provide a method for preparing high-strength biomass plastics derived from marine resources, a process that is green and simple.

[0006] In this invention, chitin nanocrystals are prepared by using the strong Lewis acid FeCl3•6H2O as a traditional acid substitute, allowing chitin to be rapidly obtained under microwave irradiation. Simultaneously, a sodium alginate dendritic colloid with a synaptic-like morphology is introduced, obtained through calcium ion-induced crosslinking and ultra-high-speed shear homogenization, partially replacing the linear sodium alginate matrix. The chitin nanocrystals, with precisely controlled deacetylation, exhibit lower surface charge density and better dispersibility. When added to sodium alginate as a biomass-based nanofiller, the positive charge (-NH3) carried by the former... + It is expected to have a similar effect to the latter's negative charge (-COO). - The interaction of these elements, along with the presence of strong hydrogen bonds, produces a highly enhanced biomass green plastic.

[0007] Compared to traditional biomass plastics, the three-dimensional branched network of sodium alginate dendritic colloids provides uniform dispersion and stable support in membrane materials, significantly improving the tensile strength and toughness of the membrane. This reduces the risk of fracture due to excessive brittleness caused by the addition of chitin nanocrystals, balancing the inherent contradiction between brittleness and toughness. The network also restricts the permeation and migration of water molecules, enhancing the dimensional stability and mechanical retention of the membrane in humid environments. Furthermore, the dendritic colloids provide interfacial conditions for multi-point hydrogen bonding and electrostatic interactions with chitin nanocrystals, effectively inhibiting nanocrystal aggregation and forming a highly stable and uniformly distributed composite structure. This results in a dual improvement in both mechanical properties and environmental adaptability for ultra-strong green plastics.

[0008] Another object of the present invention is to provide a high-strength biomass plastic derived from marine resources obtained by the above-described preparation method. The resulting material possesses "cement-mortar"-like interactive units, exhibiting extremely high mechanical strength and ideal water resistance. While maintaining a smooth surface, thermal stability, and high biodegradability, it also achieves superior strength and ductility compared to traditional petrochemical plastics.

[0009] Another object of the present invention is to provide the application of the above-mentioned high-strength biomass plastic derived from marine resources.

[0010] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing high-strength biomass plastics derived from marine resources, comprising the following steps: (1) FeCl3•6H2O was mixed with water to prepare FeCl3•6H2O solution, α-chitosan was added, and microwave hydrolysis was performed. After hydrolysis was completed, the precipitate was washed to obtain initial chitosan nanocrystals. The initial chitosan nanocrystals were dispersed in a strong alkaline solution and heated to obtain deacetylated chitosan nanocrystals. (2) Sodium alginate solution and calcium chloride solution are mixed to obtain sodium alginate dendritic colloid; (3) Sodium alginate dendritic colloid, deacetylated chitin nanocrystals, sodium alginate, plasticizer and water are mixed to obtain a membrane solution, defoamed and dried to obtain a membrane material.

[0011] Preferably, in step (1), FeCl3•6H2O is mixed with water at 60-100°C for 3-8 minutes to obtain a FeCl3•6H2O solution.

[0012] Preferably, the concentration of the FeCl3•6H2O solution in step (1) is 0.5 to 1.5 g / mL, more preferably 0.9 to 1.2 g / mL.

[0013] Preferably, the ratio of α-chitosan to water in step (1) is 1g:10mL to 1g:8mL.

[0014] Preferably, the power of microwave hydrolysis in step (1) is 240-320W, more preferably 280-320W; the temperature is 80-110℃, more preferably 80-90℃; and the time is 0.5-1 hour.

[0015] Preferably, the heating rate of microwave hydrolysis in step (1) is 5 to 15 °C / min; more preferably, it is 10 °C / min.

[0016] Preferably, the end of hydrolysis in step (1) refers to adding water to the hydrolysis system to end the reaction, and the volume ratio of the added water to the hydrolysis system is (150-250):(18-20).

[0017] Preferably, the centrifugal separation speed in step (1) is 8000-10000 rpm; more preferably, it is 9000-10000 rpm.

[0018] Preferably, the washing step (1) refers to washing the precipitate with hydrochloric acid solution followed by ultrasonic treatment.

[0019] More preferably, the concentration of the hydrochloric acid solution is 0.5 to 1.5 mol / L; more preferably, it is 1 mol / L.

[0020] More preferably, the ultrasonic treatment process parameters are 400-500W, 20-30 kHz, 1-3 second on / 1-3 second off pulse mode, ultrasonic temperature of 20-30℃, and ultrasonic time of 6-12 minutes.

[0021] Preferably, the strong base in the strong base solution in step (1) includes at least one of sodium hydroxide and potassium hydroxide.

[0022] Preferably, the concentration of the strong alkali solution in step (1) is 30-50 wt%.

[0023] Preferably, the ratio of the mass of the initial chitin nanocrystals to the volume of the strong alkaline solution in step (1) is 1g:10mL to 1g:20mL.

[0024] Preferably, the temperature of the heating treatment in step (1) is 75 to 90°C and the time is 0 to 4 hours, excluding 0 hours.

[0025] Preferably, the deacetylated chitin nanocrystals obtained in step (1) need to be purified before use in step (3). The specific method is to disperse the deacetylated chitin nanocrystals in water and dialyze them to obtain a chitin nanocrystal suspension.

[0026] More preferably, the dialysis membrane used for dialysis has a capacity of 3500–5000 Da, and the dialysis duration is 48–72 hours.

[0027] More preferably, the deacetylated chitosan nanocrystal suspension is freeze-dried at -80°C and then stored in a desiccator for later use.

[0028] Preferably, in the sodium alginate solution in step (2), the solid-liquid ratio of sodium alginate to water is 1g:30mL to 1g:35mL.

[0029] Preferably, the concentration of the calcium chloride solution in step (2) is 0.01 to 0.015 mol / L.

[0030] Preferably, in step (2), the ratio of the mass of sodium alginate to the molar mass of calcium chloride is 1.8g:0.01mol to 1.8g:0.015mol.

[0031] Preferably, the mixing method in step (2) is as follows: sodium alginate solution is injected into calcium chloride solution, and then sodium alginate dendritic colloid is obtained by homogenization.

[0032] More preferably, the homogenization mixing speed is 18,000 to 22,000 rpm, and the time is 3 to 6 minutes.

[0033] Preferably, the sodium alginate dendritic colloid described in step (2) is freeze-dried at -80°C and then stored in a desiccator at room temperature.

[0034] Preferably, in the membrane solution described in step (3), the mass ratio of sodium alginate dendritic colloid, deacetylated chitin nanocrystals, sodium alginate, and plasticizer is (0.3-0.36):(0.075-0.09):(1.5-1.8):(0.1-0.3).

[0035] Preferably, the total mass concentration of the membrane solution in step (3) is 3 to 3.5 wt%.

[0036] Preferably, step (3) specifically involves: first adding sodium alginate dendritic colloid and deacetylated chitin nanocrystals to water and dispersing them evenly using ultrasonication in a water bath, then adding sodium alginate and plasticizer to mix and obtain a membrane solution.

[0037] More preferably, the power of the water bath ultrasound is 150-300W, and the duration is 8-10 minutes.

[0038] Preferably, the plasticizer in step (3) is a commonly used plasticizer, including at least one of glycerol, polyethylene glycol and sorbitol.

[0039] Preferably, the defoaming method in step (3) is to let the membrane solution stand at room temperature for 2 to 4 hours.

[0040] Preferably, the drying temperature in step (3) is 30-50°C and the time is 12-24 hours.

[0041] Secondly, the present invention provides a high-strength biomass plastic derived from marine resources obtained by the above preparation method.

[0042] Thirdly, the present invention provides the application of the above-mentioned high-strength biomass plastic derived from marine resources.

[0043] Preferably, the applications include food packaging, medical consumables, and the replacement of some engineering plastics.

[0044] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) Among the raw materials selected in this invention, chitin nanocrystals have high crystallinity and high strength, which can provide effective reinforcement; the dendritic colloid made from sodium alginate disperses stress and improves toughness through its three-dimensional branched structure. The two interact in the composite system, which enhances the tensile strength of the film while improving its ductility, effectively solving the contradiction between strength and stretchability in existing bio-based plastics.

[0045] (2) The preparation process of this invention introduces physical methods such as stirring, ultrasound, microwave digestion, high-speed shear homogenization, and freeze drying, without involving complex chemical modification or high-energy-consuming processes, and does not require the use of organic solvents or toxic additives. The entire preparation process is mild and has a high raw material utilization rate. Compared with existing bioplastic preparation methods that require the use of crosslinking agents, plasticizers, or chemical modifiers, the preparation process of this invention is greener and safer, and has the advantages of clean production and sustainable development.

[0046] (3) This invention uses chitin nanocrystals and sodium alginate dendritic colloids as the main raw materials, both of which are derived from marine renewable resources, thus avoiding dependence on petroleum-based raw materials. Compared with traditional plastics, this super-strong biomass plastic can degrade in the natural environment and will not produce long-term residual microplastic pollution.

[0047] (4) Compared with common bio-based plastics, the dendritic colloidal network in the material of this invention can restrict the migration and permeation of water molecules, so that the composite membrane can still maintain good dimensional stability and mechanical properties in a humid environment. This feature effectively overcomes the defect of traditional green plastics that are easily affected by humidity and thus suffer performance degradation.

[0048] (5) The super-strong green plastic prepared by the present invention has high strength, good ductility and environmental stability, and has good potential for substitution in food packaging, disposable products, medical consumables, functional films and some engineering plastics. Attached Figure Description

[0049] Figure 1 This is a front view of the ultra-strong green plastic prepared based on sodium alginate dendritic colloid and chitin nanocrystals in Example 1 of the present invention, obtained by scanning electron microscopy (SEM).

[0050] Figure 2 This is a scanning electron microscope (SEM) cross-sectional image of the ultra-strong green plastic prepared based on sodium alginate dendritic colloid and chitin nanocrystals in Example 1 of the present invention.

[0051] Figure 3 This is a SEM image of the sodium alginate dendritic colloid prepared in Example 1 of the present invention.

[0052] Figure 4 This is an optical image of the ultra-strong green plastic prepared based on sodium alginate dendritic colloid and chitin nanocrystals in Example 1 of the present invention.

[0053] Figure 5 The bar charts show the Young's modulus of the ultra-strong green plastics prepared based on sodium alginate dendritic colloid and chitin nanocrystals in Examples 1 and 2 of this invention, and the comparative examples 1 and 2.

[0054] Figure 6 Examples 1 and 2 of this invention show the ultra-strong green plastics prepared based on sodium alginate dendritic colloids and chitin nanocrystals, and the water contact angles of comparative examples 1 and 2. Detailed Implementation

[0055] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0056] Unless otherwise specified in the embodiments of this invention, the conditions shall be performed according to conventional conditions or conditions recommended by the manufacturer. All raw materials and reagents used, unless otherwise specified, are commercially available conventional products.

[0057] Example 1 A high-strength biomass plastic derived from marine resources and its preparation method, comprising the following steps: Dissolve 20 g of FeCl3•6H2O in 20 mL of deionized water and stir in a water bath at 80 °C for 5 minutes. Add 2 g of α-chitin, and under microwave digestion at 280 W for 0.75 h at 80 °C with a heating rate of 10 °C / min. Dilute with 150 mL of deionized water to terminate the reaction. After centrifuging at 9000 rpm, wash with 1 mol / L hydrochloric acid until the iron ion content is negligible. Ultrasonically treat for 10 minutes in a 450 W, 25 kHz, 2 s on / 2 s off pulse mode, and the resulting precipitate is the initial chitin nanocrystals. Subsequently, disperse 2.5 g of the initial chitin nanocrystals in 25 mL of a 50 wt% sodium hydroxide solution for deacetylation. After heating and stirring in a water bath at 80 °C for 1.5 hours, add deionized water to end the reaction and centrifuge at 9000 rpm. The washed precipitate is dispersed in water and the suspension is dialyzed through a 5000 Da membrane for 72 hours to obtain a chitin nanocrystal Ch3 suspension. Lyophilize at -80 °C and store in a desiccator for subsequent use.

[0058] Dissolve 1.8 g of sodium alginate in 58.2 mL of deionized water, and quickly inject it into 1 L of a 0.0136 mol / L CaCl2•2H2O solution using a syringe. Homogenize at high speed with a high-speed shear homogenizer at a speed of 20000 rpm for 5 minutes. Centrifuge and wash three times with deionized water to obtain a sodium alginate dendritic colloid.

[0059] Mix 0.3 g of the sodium alginate dendritic colloid, 1.5 g of sodium alginate, 0.09 g of chitin nanocrystal Ch3, 0.1 g of glycerol, and 58.1 g of deionized water to obtain a membrane solution. The specific operation is to first add the Ch3 powder and the sodium alginate dendritic colloid to deionized water and ultrasonically treat in a water bath at 200 W for 10 minutes for uniform dispersion, then add sodium alginate and glycerol and mix evenly. Let the resulting solution stand at room temperature for 3 hours to remove bubbles, and then pour it into a polystyrene petri dish and dry at 40 °C for 12 hours to obtain a green plastic.

[0060] According to Example 1, the deacetylation degree of Ch3 is 36.15%, and the ζ potential reaches +42 mV at pH = 6. The turbidity of the membrane solution is 74.99%, the water contact angle of the prepared green plastic is 85.1°, and the solubility after soaking in water for 20 minutes is 54.71%. The strain is 20.29%, the stress is 308.46 MPa, and the Young's modulus is 8845.21 MPa, proving that the green plastic achieves high strain maintenance while maintaining high strength.

[0061] Figure 1 and Figure 2 are the front and sectional views of the SEM of the super-strong green plastic prepared based on the sodium alginate dendritic colloid and Ch3 nanocrystals; by Figure 1 and Figure 2It can be seen that the surface of the material is relatively flat and dense, without obvious agglomeration or pores, and occasionally the branches of sodium alginate dendritic colloid are visible.

[0062] Figure 3 The image shows a SEM image of the prepared sodium alginate dendritic colloid, which clearly shows the presence of a synaptic network. The diameter of the cross-linked region in the center of the colloid is approximately 10 μm.

[0063] Figure 4 This is an optical image of the ultra-strong green plastic prepared based on sodium alginate dendritic colloid and Ch3 nanocrystals in Example 1. The material is relatively smooth and transparent, can be folded and bent, and can support a weight of 1400g without breaking.

[0064] Example 2 A high-strength biomass plastic derived from marine resources and its preparation method, comprising the following steps: 20g of FeCl3•6H2O was dissolved in 20mL of deionized water and stirred in an 80℃ water bath for 5 minutes. 2g of α-chitosan was added, and the mixture was microwave-digested at 80℃ for 0.75h at 280W with a heating rate of 10℃ / min. The reaction was terminated by dilution with 150mL of deionized water. After centrifugation at 9000rpm, the mixture was washed with 1mol / L hydrochloric acid until the iron ion content was negligible. The mixture was then sonicated for 10 minutes at 450W, 25kHz, 2-second on / 2-second off pulse mode, yielding the initial chitosan nanocrystals as the precipitate. Subsequently, 2.5g of the initial chitosan nanocrystals were dispersed in 25mL of 50wt% sodium hydroxide solution, heated and stirred in an 80℃ water bath for 4 hours, and then deionized water was added to terminate the reaction. The mixture was centrifuged at 9000rpm, and the washed precipitate was dissolved in water and then dialyzed through a 3500Da membrane for 72 hours to obtain a chitosan nanocrystal Ch5 suspension. This suspension was then lyophilized at -80℃ and stored in a desiccator for later use.

[0065] Dissolve 1.8 g of sodium alginate in 58.2 mL of deionized water, and quickly inject the solution into 1 L of 0.0136 mol / L CaCl2•2H2O solution using a syringe. Homogenize the solution using a high-speed shear homogenizer at 20,000 rpm for 5 minutes. Wash the homogenate three times with deionized water to obtain sodium alginate dendritic colloid.

[0066] A membrane solution was prepared by mixing 0.3g sodium alginate dendritic colloid, 1.5g sodium alginate, 0.09g chitosan nanocrystals Ch5, 0.1g glycerol, and 58.1g deionized water. Specifically, Ch5 powder and sodium alginate dendritic colloid were first added to deionized water and sonicated in a 200W water bath for 10 minutes to ensure uniform dispersion. Then, sodium alginate and glycerol were added and mixed thoroughly. The resulting solution was left at room temperature for 3 hours to remove air bubbles, then poured into a polystyrene petri dish and dried at 40℃ for 12 hours.

[0067] According to Example 3, the degree of deacetylation of Ch5 was 49.35%, and the zeta potential reached +60mV at Ph=6. The turbidity of the membrane solution was 59.56%, the water contact angle of the prepared green plastic was 63.3°, and the solubility in water after immersion for 20 minutes was 66.08%. The strain was 19.05%, the stress was 181.08 MPa, and the Young's modulus was 7204.26 MPa.

[0068] Comparative Example 1 A method for preparing a marine resource-derived sodium alginate dendritic colloidal biomass plastic includes the following steps: Dissolve 1.8 g of sodium alginate in 58.2 mL of deionized water, and quickly inject the solution into 1 L of 0.0136 mol / L CaCl2•2H2O solution using a syringe. Homogenize using a high-speed shear homogenizer at 20,000 rpm for 5 minutes. Centrifuge and wash three times with deionized water to obtain sodium alginate dendritic colloid.

[0069] A membrane solution was prepared by mixing 0.3g of sodium alginate dendritic colloid, 1.5g of sodium alginate, 0.1g of glycerol, and 58.1g of deionized water. Specifically, the sodium alginate dendritic colloid was first added to the deionized water and sonicated in a 200W water bath for 10 minutes to ensure uniform dispersion. Then, sodium alginate and glycerol were added and mixed thoroughly. The resulting solution was left at room temperature for 3 hours to remove air bubbles, then poured into a polystyrene petri dish and dried at 40℃ for 12 hours.

[0070] According to Comparative Example 1, the turbidity of the membrane solution was 83.18%, the water contact angle of the prepared green plastic was 57.7°, and the solubility after soaking in water for 20 minutes was 76.79%. The strain was 10.70%, the stress was 126.03 MPa, and the Young's modulus was 3975.44 MPa.

[0071] Comparative Example 2 A high-strength biomass plastic derived from marine resources and its preparation method, comprising the following steps: 20g of FeCl3•6H2O was dissolved in 20mL of deionized water and stirred in an 80℃ water bath for 5 minutes. 2g of α-chitosan was added, and the mixture was microwave-digested at 80℃ for 0.75h at 280W with a heating rate of 10℃ / min. The reaction was terminated by dilution with 150mL of deionized water. After centrifugation at 9000rpm, the mixture was washed with 1mol / L hydrochloric acid until the iron ion content was negligible. The mixture was sonicated for 10 minutes at 450W, 25kHz, 2-second on / 2-second off pulse mode, yielding the initial chitosan nanocrystals as the precipitate. Without performing sodium hydroxide deacetylation, the suspension of the precipitate dispersed in water was dialyzed against a 5000Da membrane for 72 hours to obtain the chitosan nanocrystal Ch1 suspension. This suspension was then lyophilized at -80℃ and stored in a desiccator for later use.

[0072] Dissolve 1.8 g of sodium alginate in 58.2 mL of deionized water, and quickly inject the solution into 1 L of 0.0136 mol / L CaCl2•2H2O solution using a syringe. Homogenize the solution using a high-speed shear homogenizer at 20,000 rpm for 5 minutes. Wash the homogenate three times with deionized water to obtain sodium alginate dendritic colloid.

[0073] A membrane solution was prepared by mixing 0.3g sodium alginate dendritic colloid, 1.5g sodium alginate, 0.09g chitosan nanocrystals (Ch1), 0.1g glycerol, and 58.1g deionized water. Specifically, the Ch3 powder and sodium alginate dendritic colloid were first added to deionized water and sonicated in a 200W water bath for 10 minutes to ensure uniform dispersion. Then, sodium alginate and glycerol were added and mixed thoroughly. The resulting solution was left at room temperature for 3 hours to remove air bubbles, then poured into a polystyrene petri dish and dried at 40℃ for 12 hours to obtain green plastic.

[0074] According to Example 2, the degree of deacetylation of Ch1 was 22.15%, and the zeta potential reached +25mV at Ph=6. The turbidity of the membrane solution was 80.54%, the water contact angle of the prepared green plastic was 80.3°, and the solubility in water after immersion for 20 minutes was 72.18%. The strain was 16.94%, the stress was 221.06 MPa, and the Young's modulus was 4239.69 MPa.

[0075] Figure 5 The images show Young's modulus histograms of the ultra-strong green plastics prepared based on sodium alginate dendritic colloids and chitin nanocrystals in Examples 1 and 2 of this invention, and Comparative Examples 1 and 2. It is clear that the addition of chitin nanocrystals with appropriate deacetylation degree effectively improves the strength of the sodium alginate dendritic colloid-based green plastics.

[0076] Figure 6 Examples 1 and 2 of this invention show the ultra-strong green plastics prepared based on sodium alginate dendritic colloids and chitin nanocrystals, and the water contact angles of comparative examples 1 and 2.

[0077] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method of preparing a high-strength biomass plastic derived from marine resources, characterized by, The method comprises the following steps: (1) FeCl3•6H2O is mixed with water to prepare a FeCl3•6H2O solution, and α-chitin is added to perform microwave hydrolysis, and after the hydrolysis is completed, the obtained precipitate is washed to obtain initial chitin nanocrystals, and the initial chitin nanocrystals are dispersed in a strong alkali solution and heated to obtain deacetylated chitin nanocrystals; (2) A sodium alginate solution and a calcium chloride solution are mixed to obtain sodium alginate dendritic colloids; (3) The sodium alginate dendritic colloids, the deacetylated chitin nanocrystals, sodium alginate, a plasticizer and water are mixed to obtain a film solution, the film solution is degassed and dried to obtain a film material.

2. The preparation method according to claim 1, characterized in that, In the sodium alginate solution of step (2), the solid-liquid ratio of sodium alginate and water is 1g:30mL-1g:35mL; And / or, the concentration of the calcium chloride solution in step (2) is 0.01-0.015mol / L; And / or, the mass ratio of sodium alginate to the molar amount of calcium chloride in step (2) is 1.8g:0.01mol-1.8g:0.015mol.

3. The method of claim 1 or 2, wherein the method further comprises, In the film solution of step (3), the mass ratio of sodium alginate dendritic colloids, deacetylated chitin nanocrystals, sodium alginate and plasticizer is (0.3-0.36):(0.075-0.09):(1.5-1.8):(0.1-0.3); And / or, the plasticizer in step (3) comprises at least one of glycerol, polyethylene glycol and sorbitol; And / or, the total mass concentration of the film solution in step (3) is 3-3.5wt%.

4. The method of claim 1 or 2, wherein the method is carried out at a temperature of from 20 to 40°C. The concentration of the FeCl3•6H2O solution in step (1) is 0.5-1.5g / mL; And / or, the liquid-solid ratio of α-chitin to water in step (1) is 1g:10mL-1g:8mL.

5. The method of claim 1 or 2, wherein the step of preparing the mixture is performed at a temperature of 20 to 30°C. The power of the microwave hydrolysis in step (1) is 240-320W; the temperature is 80-110℃; and the time is 0.5-1 hour; And / or, the temperature rising speed of the microwave hydrolysis in step (1) is 5-15℃ / min.

6. The method of claim 1 or 2, wherein the step of preparing the mixture is performed at a temperature of 20°C to 30°C. The concentration of the strong alkali solution in step (1) is 30-50wt%; And / or, the strong alkali in the strong alkali solution in step (1) comprises at least one of sodium hydroxide and potassium hydroxide; And / or, the ratio of the mass of the initial chitin nanocrystals to the volume of the strong alkali solution in step (1) is 1g:10mL-1g:20mL; And / or, the heating temperature in step (1) is 75-90℃; and the heating time is 0-4 hours, excluding 0 hour.

7. The preparation method according to claim 1 or 2, characterized in that, The mixing method in step (2) is that the sodium alginate solution is injected into the calcium chloride solution, and then the sodium alginate dendritic colloids are obtained by homogenization mixing; The rotation speed of the homogenization mixing is 18000-22000rpm, and the time is 3-6 minutes; And / or, the degassing method in step (3) is that the film solution is placed at room temperature for 2-4 hours; And / or, the drying temperature in step (3) is 30-50℃, and the time is 12-24 hours.

8. The method of claim 1 or 2, wherein the method is carried out at a temperature of from 20°C to 30°C. The FeCl3•6H2O is mixed with water at 60-100℃ for 3-8 minutes to obtain the FeCl3•6H2O solution in step (1); And / or, the end of hydrolysis in step (1) refers to adding water to the hydrolysis system to end the reaction, at this time the volume ratio of the added water to the hydrolysis system is (150-250):(18-20); And / or, the centrifugal separation speed in step (1) is 8000-10000 rpm; And / or, the washing in step (1) refers to washing the precipitate with a hydrochloric acid solution and then ultrasonic treatment; The concentration of the hydrochloric acid solution is 0.5-1.5 mol / L; the process parameters of the ultrasonic treatment are 400-500 W, 20-30 kHz, 1-3 seconds on / 1-3 seconds off pulse mode, the ultrasonic temperature is 20-30℃, and the ultrasonic time is 6-12 minutes; And / or, the deacetylated chitin nanocrystals obtained in step (1) need to be purified before being used in step (3), and the specific method is: dispersing the deacetylated chitin nanocrystals in water, dialysis, to obtain a chitin nanocrystal suspension; The dialysis membrane used in the dialysis is 3500-5000 Da, and the dialysis time is 48-72 hours.

9. A high-strength biomass plastic derived from marine resources obtained by the preparation method of any one of claims 1-8.

10. The use of the high-strength biomass plastic derived from marine resources of claim 9.

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