Antioxidant cinnamyl group polymer and preparation method thereof
By preparing antioxidant cinnamaldehyde-based polymers, the problem of low utilization of cinnamaldehyde and tea polyphenols is solved, its wide application in the cosmetics field is achieved, and the antioxidant and antibacterial properties of the polymer are enhanced.
Patent Information
- Application Number
- CN202411886630.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-03-11
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the prior art, cinnamaldehyde and tea polyphenols have low utilization due to their high volatile and poor water solubility, which limits their wide application in cosmetics and other fields.
By preparing antioxidant cinnamaldehyde-based polymers, the cross-linked network structure is generated using chitosan and cinnamaldehyde-based polylactic acid, and the utilization rate of tea polyphenols and cinnamaldehyde is improved, and its antioxidant and antibacterial properties are enhanced through azide and reducing reactions.
The utilization rate of tea polyphenols and cinnamaldehyde is improved, the antioxidant and antibacterial effects of the polymer are enhanced, and because it is a biodegradable material, it has green environmental protection and good biocompatibility.
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Figure CN119591946A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of polymers, in particular to an antioxidant cinnamaldehyde-based polymer and a preparation method thereof. Background Art
[0002] Cinnamaldehyde, also known as cinnamon cinnamaldehyde, has a strong and long-lasting aroma of cinnamon oil and cinnamon oil. It has good antibacterial and antiseptic properties and is widely used in cosmetics, cleaning products and other fields. However, its high volatility and poor water solubility limit the scope of use of cinnamaldehyde. Tea polyphenols are important biologically active substances in tea leaves. They have antioxidant, antibacterial, and anticancer functions and are widely used in cosmetics, food, and chemical industries. However, tea polyphenols are volatile and have low utilization rates, which are not conducive to long-term storage and use. How to improve the utilization rate of cinnamaldehyde and tea polyphenols to expand the scope of application has important application value in the field of cosmetics.
[0003] Polylactic acid is an environmentally friendly polymer material with good biodegradability and biocompatibility. It is widely used in the field of cosmetics. Compared with linear polylactic acid, star-shaped polylactic acid has higher functionality, smaller fluid dynamic volume, better processing performance and other advantages. Gallic acid is a natural weakly acidic polyphenol compound, which is widely found in Chinese medicines such as gallnut, pomegranate, and Polygonum multiflorum. It has antioxidant, antibacterial, and anticancer effects and is widely used in food, cosmetics, and pharmaceuticals. Summary of the invention
[0004] 1. Technical issues to be solved
[0005] In view of the deficiencies of the prior art, the present invention provides an antioxidant cinnamaldehyde-based polymer and a preparation method thereof. The prepared polymer has good antibacterial and antioxidant properties.
[0006] (II) Technical solution
[0007] An antioxidant cinnamaldehyde-based polymer, the antioxidant cinnamaldehyde-based polymer is composed of the following components in parts by weight: 100 parts of chitosan, 10-50 parts of cinnamaldehyde-based polylactic acid, 5-10 parts of gallic acid, 15-25 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 10-20 parts of N-hydroxysuccinimide;
[0008] The preparation method of the antioxidant cinnamaldehyde-based polymer is:
[0009] Chitosan is added into deionized water, stirred and dissolved to obtain liquid A; cinnamaldehyde-based polylactic acid and gallic acid are added into ethanol, stirred and dispersed, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) are added thereto, activated for 30-50 minutes, liquid A is added thereto, stirred and dispersed, dialyzed, and dried to obtain an antioxidant cinnamaldehyde-based polymer.
[0010] Preferably, the preparation method of the cinnamaldehyde-based polylactic acid is:
[0011] (1) adding 2,2-dihydroxymethyl propionic acid to thionyl chloride, stirring and dispersing, heating to 70-80° C., stirring and reacting for 30-60 min, distilling under reduced pressure, adding ethyl acetate thereto, stirring and dispersing, then adding tea polyphenols and a catalyst thereto, heating to 35-50° C., reacting for 5-10 h, filtering after the reaction, washing with deionized water, drying, rotary evaporation, and drying to obtain polyhydroxy tea polyphenols;
[0012] (2) under nitrogen atmosphere, polyhydroxy tea polyphenols and stannous octoate are added to tetrahydrofuran solvent, stirred and dispersed, and then L-lactide is added thereto, stirred and reacted at 60-70° C. for 24-36 hours. After the reaction is completed, methanol precipitation is performed and dried to obtain terminal hydroxyl polylactic acid;
[0013] (3) adding hydroxy-terminated polylactic acid and sodium azide to tetrahydrofuran solvent, heating to 90-100° C., stirring and reacting for 30-48 hours, cooling to room temperature after the reaction, adding deionized water, stirring and dispersing, extracting with dichloromethane, drying, and rotary evaporation to obtain azido-terminated polylactic acid;
[0014] (4) Under a nitrogen atmosphere, adding azide-terminated polylactic acid, triphenylphosphine, and deionized water to tetrahydrofuran solvent, stirring the reaction at room temperature for 40-60 hours, and after the reaction is completed, rotary evaporation, adding 5% hydrochloric acid aqueous solution by mass, stirring for 40-80 minutes, filtering, washing the filtrate with ether, adjusting the pH to 9-10 with 10% sodium hydroxide aqueous solution, filtering, and rotary evaporation to obtain amino-terminated polylactic acid;
[0015] (5) Adding amino-terminated polylactic acid and cinnamaldehyde into an ethanol solvent, stirring and dispersing, reacting at 70-80° C. for 5-8 hours, and after the reaction is completed, filtering, washing with deionized water, and drying to obtain cinnamaldehyde-based polylactic acid.
[0016] Preferably, in (1), the molar ratio of 2,2-dihydroxymethylpropionic acid, thionyl chloride and tea polyphenols is 3.5-4:8-10:1.
[0017] Preferably, in (2), the molar ratio of polyhydroxy tea polyphenols, stannous octoate and L-lactide is 1:0.05-0.1:60-100.
[0018] Preferably, in (3), the molar ratio of the hydroxy-terminated polylactic acid to sodium azide is 1:5-8.
[0019] Preferably, in (4), the molar ratio of the azide-terminated polylactic acid, triphenylphosphine and deionized water is 1:4-7.5:6-10.
[0020] Preferably, in (5), the molar ratio of amino-terminated polylactic acid to cinnamaldehyde is 1:5-8.
[0021] (III) Beneficial technical effects
[0022] The invention uses 2,2-dihydroxymethylpropionic acid to undergo chlorination, and then undergoes an esterification reaction with tea polyphenols under the catalysis of p-toluenesulfonic acid to obtain polyhydroxy tea polyphenols, and then uses polyhydroxy tea polyphenols and L-lactide to undergo ring-opening polymerization to prepare terminal hydroxyl polylactic acid, which is used as a raw material to undergo azidation and reduction to obtain amino-terminated polylactic acid, and then uses amino-terminated polylactic acid and cinnamaldehyde to undergo Schiff base reaction to obtain cinnamaldehyde-based polylactic acid, and then chitosan and cinnamaldehyde-based polylactic acid are cross-linked under the catalysis of EDC and NHS, and gallic acid is loaded to finally obtain an antioxidant cinnamaldehyde-based polymer.
[0023] The tea polyphenols and cinnamaldehyde used in the present invention are easy to volatilize, and the utilization rate is low. The present invention prepares cinnamaldehyde-based polylactic acid with tea polyphenol as the core, polylactic acid as the internal block, and cinnamaldehyde as the external block, which reduces the volatilization effect and improves the utilization rate of tea polyphenols and cinnamaldehyde. Gallic acid is also easy to volatilize, but the present invention utilizes the huge cross-linked network structure produced by chitosan and cinnamaldehyde-based polylactic acid to achieve the sustained release transmission of gallic acid, reduce its volatilization effect, and increase its utilization rate. The present invention utilizes the antibacterial and antioxidant effects of tea polyphenols, cinnamaldehyde, and gallic acid to increase the antioxidant and antibacterial effects of the polymer, and the prepared polymer is a biodegradable material, which is green and environmentally friendly, has good biocompatibility, and will not cause secondary pollution to the environment after use. The cinnamaldehyde-based polymer prepared by the present invention has been confirmed to have good antibacterial and antioxidant properties through experiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 is an optical image of Escherichia coli in Comparative Example 1;
[0025] Figure 2 This is an optical image of Escherichia coli in Example 5. DETAILED DESCRIPTION
[0026] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.
[0027] Example 1
[0028] (1) Add 87.5 mmol of 2,2-dihydroxymethylpropionic acid to 250 mmol of thionyl chloride, stir and disperse, heat to 75°C, stir and react for 40 min, distill under reduced pressure, add ethyl acetate, stir and disperse, then add 25 mmol of tea polyphenols and 6 mmol of p-toluenesulfonic acid catalyst, heat to 35°C, react for 10 h, filter after the reaction, wash with deionized water, dry, rotary evaporate, and dry to obtain polyhydroxy tea polyphenols.
[0029] (2) Under a nitrogen atmosphere, 10 mmol of polyhydroxy tea polyphenols and 0.5 mmol of stannous octoate were added to tetrahydrofuran solvent and dispersed with stirring. Then, 0.8 mol of L-lactide was added thereto and stirred at 70°C for 24 h. After the reaction was completed, methanol was precipitated and dried to obtain terminal hydroxyl polylactic acid.
[0030] (3) 10 mmol of terminal hydroxyl polylactic acid and 60 mmol of sodium azide were added to tetrahydrofuran solvent, the temperature was raised to 95°C, and the reaction was stirred for 48 hours. After the reaction was completed, the mixture was cooled to room temperature, deionized water was added, stirred and dispersed, extracted with dichloromethane, dried, and rotary evaporated to obtain terminal azido polylactic acid.
[0031] (4) Under a nitrogen atmosphere, 12 mmol of azide-terminated polylactic acid, 48 mmol of triphenylphosphine, and 72 mmol of deionized water were added to tetrahydrofuran solvent, and the reaction was stirred for 50 h at room temperature. After the reaction was completed, the mixture was rotary evaporated, and a 5% by weight aqueous solution of hydrochloric acid was added and stirred for 40 min. The mixture was filtered, and the filtrate was washed with ether. The pH was adjusted to 9 with a 10% aqueous solution of sodium hydroxide, and the mixture was filtered and rotary evaporated to obtain amino-terminated polylactic acid.
[0032] (5) 4 mmol of amino-terminated polylactic acid and 32 mmol of cinnamaldehyde were added to an ethanol solvent, stirred and dispersed, and reacted at 75° C. for 8 h. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried to obtain cinnamaldehyde-based polylactic acid.
[0033] (6) Add 10 g of chitosan to deionized water, stir and dissolve to obtain liquid A; add 1 g of cinnamaldehyde-based polylactic acid and 0.5 g of gallic acid to ethanol, stir and disperse, then add 1.5 g of EDC and 2 g of NHS, activate for 50 minutes, add liquid A, stir and disperse, dialyze, and dry to obtain an antioxidant cinnamaldehyde-based polymer.
[0034] Example 2
[0035] (1) Add 100 mmol of 2,2-dihydroxymethylpropionic acid to 220 mmol of thionyl chloride, stir and disperse, heat to 80°C, stir and react for 60 min, distill under reduced pressure, add ethyl acetate, stir and disperse, then add 25 mmol of tea polyphenols and 5 mmol of p-toluenesulfonic acid catalyst, heat to 40°C, react for 6 h, filter after the reaction, wash with deionized water, dry, rotary evaporate, and dry to obtain polyhydroxy tea polyphenols.
[0036] (2) Under a nitrogen atmosphere, 10 mmol of polyhydroxy tea polyphenols and 0.8 mmol of stannous octoate were added to a tetrahydrofuran solvent and dispersed with stirring. Then, 1 mol of L-lactide was added thereto and stirred for reaction at 60° C. for 36 h. After the reaction was completed, methanol was precipitated and dried to obtain terminal hydroxyl polylactic acid.
[0037] (3) 10 mmol of terminal hydroxyl polylactic acid and 70 mmol of sodium azide were added to tetrahydrofuran solvent, the temperature was raised to 95°C, and the reaction was stirred for 36 hours. After the reaction was completed, the mixture was cooled to room temperature, deionized water was added, stirred and dispersed, extracted with dichloromethane, dried, and rotary evaporated to obtain terminal azido polylactic acid.
[0038] (4) Under a nitrogen atmosphere, 12 mmol of azide-terminated polylactic acid, 60 mmol of triphenylphosphine, and 120 mmol of deionized water were added to tetrahydrofuran solvent, and the reaction was stirred for 60 h at room temperature. After the reaction was completed, the mixture was rotary evaporated, and a 5% by weight aqueous solution of hydrochloric acid was added and stirred for 60 min. The mixture was filtered, and the filtrate was washed with ether. The pH was adjusted to 9 with a 10% aqueous solution of sodium hydroxide, and the mixture was filtered and rotary evaporated to obtain amino-terminated polylactic acid.
[0039] (5) 4 mmol of amino-terminated polylactic acid and 20 mmol of cinnamaldehyde were added to an ethanol solvent, stirred and dispersed, and reacted at 80° C. for 5 h. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried to obtain cinnamaldehyde-based polylactic acid.
[0040] (6) 10 g of chitosan was added to deionized water, stirred and dissolved to obtain liquid A; 2 g of cinnamaldehyde-based polylactic acid and 0.6 g of gallic acid were added to ethanol, stirred and dispersed, and then 2.5 g of EDC and 1 g of NHS were added thereto, activated for 40 minutes, and liquid A was added thereto, stirred and dispersed, dialyzed, and dried to obtain an antioxidant cinnamaldehyde-based polymer.
[0041] Example 3
[0042] (1) Add 90 mmol of 2,2-dihydroxymethylpropionic acid to 200 mmol of thionyl chloride, stir and disperse, heat to 70°C, stir and react for 30 minutes, distill under reduced pressure, add ethyl acetate, stir and disperse, then add 25 mmol of tea polyphenols and 3 mmol of p-toluenesulfonic acid catalyst, heat to 50°C, react for 5 hours, filter after the reaction, wash with deionized water, dry, rotary evaporate, and dry to obtain polyhydroxy tea polyphenols.
[0043] (2) Under a nitrogen atmosphere, 10 mmol of polyhydroxy tea polyphenols and 1 mmol of stannous octoate were added to tetrahydrofuran solvent and dispersed with stirring. Then, 0.6 mol of L-lactide was added thereto and stirred at 65° C. for 28 h. After the reaction was completed, methanol was precipitated and dried to obtain terminal hydroxyl polylactic acid.
[0044] (3) 10 mmol of terminal hydroxyl polylactic acid and 50 mmol of sodium azide are added to tetrahydrofuran solvent, the temperature is raised to 100° C., and the reaction is stirred for 30 hours. After the reaction is completed, the mixture is cooled to room temperature, deionized water is added, the mixture is stirred and dispersed, extracted with dichloromethane, dried, and rotary evaporated to obtain terminal azido polylactic acid.
[0045] (4) Under a nitrogen atmosphere, 12 mmol of azide-terminated polylactic acid, 90 mmol of triphenylphosphine, and 100 mmol of deionized water were added to tetrahydrofuran solvent, and the reaction was stirred for 40 h at room temperature. After the reaction was completed, the mixture was rotary evaporated, and a 5% by mass aqueous solution of hydrochloric acid was added and stirred for 80 min. The mixture was filtered, and the filtrate was washed with ether. The pH was adjusted to 10 with a 10% aqueous solution of sodium hydroxide, and the mixture was filtered and rotary evaporated to obtain amino-terminated polylactic acid.
[0046] (5) 4 mmol of amino-terminated polylactic acid and 30 mmol of cinnamaldehyde were added to an ethanol solvent, stirred and dispersed, and reacted at 70° C. for 6 h. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried to obtain cinnamaldehyde-based polylactic acid.
[0047] (6) 10 g of chitosan was added to deionized water, stirred and dissolved to obtain liquid A; 3 g of cinnamaldehyde-based polylactic acid and 0.8 g of gallic acid were added to ethanol, stirred and dispersed, and then 1.5 g of EDC and 1.5 g of NHS were added thereto, activated for 40 minutes, and liquid A was added thereto, stirred and dispersed, dialyzed, and dried to obtain an antioxidant cinnamaldehyde-based polymer.
[0048] Example 4
[0049] (1) Add 95 mmol of 2,2-dihydroxymethylpropionic acid to 250 mmol of thionyl chloride, stir and disperse, heat to 75°C, stir and react for 40 minutes, distill under reduced pressure, add ethyl acetate, stir and disperse, then add 25 mmol of tea polyphenols and 5 mmol of p-toluenesulfonic acid catalyst, heat to 40°C, react for 6 hours, filter after the reaction, wash with deionized water, dry, rotary evaporate, and dry to obtain polyhydroxy tea polyphenols.
[0050] (2) Under a nitrogen atmosphere, 10 mmol of polyhydroxy tea polyphenols and 0.8 mmol of stannous octoate were added to tetrahydrofuran solvent and dispersed with stirring. Then, 0.7 mol of L-lactide was added thereto and stirred for reaction at 65° C. for 36 h. After the reaction was completed, methanol was precipitated and dried to obtain terminal hydroxyl polylactic acid.
[0051] (3) 10 mmol of terminal hydroxyl polylactic acid and 60 mmol of sodium azide were added to tetrahydrofuran solvent, the temperature was raised to 95°C, and the reaction was stirred for 36 hours. After the reaction was completed, the mixture was cooled to room temperature, deionized water was added, stirred and dispersed, extracted with dichloromethane, dried, and rotary evaporated to obtain terminal azido polylactic acid.
[0052] (4) Under a nitrogen atmosphere, 12 mmol of azide-terminated polylactic acid, 90 mmol of triphenylphosphine, and 90 mmol of deionized water were added to tetrahydrofuran solvent, and the reaction was stirred for 50 h at room temperature. After the reaction was completed, the mixture was rotary evaporated, and a 5% by weight aqueous solution of hydrochloric acid was added thereto, and stirred for 60 min. The mixture was filtered, and the filtrate was washed with ether. The pH was adjusted to 10 with a 10% aqueous solution of sodium hydroxide, and the mixture was filtered and rotary evaporated to obtain amino-terminated polylactic acid.
[0053] (5) 4 mmol of amino-terminated polylactic acid and 25 mmol of cinnamaldehyde were added to an ethanol solvent, stirred and dispersed, and reacted at 80° C. for 5 h. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried to obtain cinnamaldehyde-based polylactic acid.
[0054] (6) 10 g of chitosan was added to deionized water, stirred and dissolved to obtain liquid A; 4 g of cinnamaldehyde-based polylactic acid and 0.9 g of gallic acid were added to ethanol, stirred and dispersed, and then 2 g of EDC and 2 g of NHS were added thereto, activated for 30 minutes, and liquid A was added thereto, stirred and dispersed, dialyzed, and dried to obtain an antioxidant cinnamaldehyde-based polymer.
[0055] Example 5
[0056] (1) Add 95 mmol of 2,2-dihydroxymethylpropionic acid to 250 mmol of thionyl chloride, stir and disperse, heat to 70°C, stir and react for 50 min, distill under reduced pressure, add ethyl acetate, stir and disperse, then add 25 mmol of tea polyphenols and 5 mmol of p-toluenesulfonic acid catalyst, heat to 40°C, react for 6 h, filter after the reaction, wash with deionized water, dry, rotary evaporate, and dry to obtain polyhydroxy tea polyphenols.
[0057] (2) Under a nitrogen atmosphere, 10 mmol of polyhydroxy tea polyphenols and 1 mmol of stannous octoate were added to a tetrahydrofuran solvent and dispersed with stirring. Then, 1 mol of L-lactide was added thereto and stirred for reaction at 60°C for 36 hours. After the reaction was completed, methanol was precipitated and dried to obtain terminal hydroxyl polylactic acid.
[0058] (3) 10 mmol of terminal hydroxyl polylactic acid and 80 mmol of sodium azide were added to tetrahydrofuran solvent, the temperature was raised to 90°C, and the reaction was stirred for 48 hours. After the reaction was completed, the mixture was cooled to room temperature, deionized water was added, stirred and dispersed, extracted with dichloromethane, dried, and rotary evaporated to obtain terminal azido polylactic acid.
[0059] (4) Under a nitrogen atmosphere, 12 mmol of azide-terminated polylactic acid, 50 mmol of triphenylphosphine, and 120 mmol of deionized water were added to tetrahydrofuran solvent, and the reaction was stirred for 50 h at room temperature. After the reaction was completed, the mixture was rotary evaporated, and a 5% by weight aqueous solution of hydrochloric acid was added and stirred for 80 min. The mixture was filtered, and the filtrate was washed with ether. The pH was adjusted to 10 with a 10% aqueous solution of sodium hydroxide, and the mixture was filtered and rotary evaporated to obtain amino-terminated polylactic acid.
[0060] (5) 4 mmol of amino-terminated polylactic acid and 32 mmol of cinnamaldehyde were added to an ethanol solvent, stirred and dispersed, and reacted at 75° C. for 6 h. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried to obtain cinnamaldehyde-based polylactic acid.
[0061] (6) Add 10 g of chitosan to deionized water, stir and dissolve to obtain liquid A; add 5 g of cinnamaldehyde-based polylactic acid and 1 g of gallic acid to ethanol, stir and disperse, then add 1.5 g of EDC and 1.5 g of NHS, activate for 35 minutes, add liquid A, stir and disperse, dialyze, and dry to obtain an antioxidant cinnamaldehyde-based polymer.
[0062] Comparative Example 1
[0063] The difference between this comparative example and Example 1 is that polylactic acid is used in step (6) instead of cinnamaldehyde-based polylactic acid.
[0064] Antioxidant activity test:
[0065] Weigh 0.2 g of the polymer in methanol solvent, protect from light at room temperature for 24 h, then add 10 mL, 0.1 mmol of 2,2-diphenyl-1-picrylhydrazyl (DPPH) methanol solution, mix well, place in the dark to react for 30 min, use methanol as a blank solvent to adjust to 0, use a UV-visible spectrophotometer to measure the solution absorbance A1 at 517 nm, use an equal volume of deionized water instead of the sample solution as a reference, measure the solution absorbance A0, and calculate the sample DPPH scavenging activity, DPPH scavenging rate (%) = [(A0-A1) / A0] × 100%.
[0066] Free radical scavenging activity test:
[0067] 7.4 mM ABTS and 2.4 mM potassium persulfate solution were mixed in a ratio of 1:1, and 0.2 g of polymer was added thereto. The mixture was reacted at 37° C. in the dark for 30 min. The absorbance A1 of the solution was measured at 730 nm using a UV-visible spectrophotometer. An equal volume of potassium persulfate solution was used as a reference to replace the sample solution, and the absorbance A0 of the solution was measured. The ABTS scavenging activity of the sample was calculated. ABTS scavenging rate (%) = [(A0-A1) / A0]×100%.
[0068] Table 1:
[0069]
[0070]
[0071] It can be seen from the table that the polymer prepared by the present invention has good antioxidant properties.
[0072] Antibacterial activity test: The polymer was placed in a circular mold and a disc with a diameter of 0.8 cm was cut. Escherichia coli bacterial suspension was dropped into LB agar medium. After plating, the disc was placed in the center of the plate. The plate was cultured at 37°C under visible light for 12 hours, and the diameter of the inhibition zone was measured.
[0073] Table 2:
[0074] Diameter of inhibition zone (cm) Example 1 1.6 Example 2 1.9 Example 3 2.3 Example 4 2.5 Example 5 2.6 Comparative Example 1 1.4
[0075] By table and Figure 1 , Figure 2 It can be seen that the polymer prepared by the present invention has good antibacterial properties.
[0076] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.
Claims
1. An antioxidant cinnamaldehyde-based polymer, characterized in that The antioxidant cinnamaldehyde-based polymer is composed of the following components in parts by weight: 100 parts of chitosan, 10-50 parts of cinnamaldehyde-based polylactic acid, 5-10 parts of gallic acid, 15-25 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 10-20 parts of N-hydroxysuccinimide; The preparation method of the antioxidant cinnamaldehyde-based polymer is: Chitosan is added into deionized water, stirred and dissolved to obtain liquid A; cinnamaldehyde-based polylactic acid and gallic acid are added into ethanol, stirred and dispersed, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) are added thereto, activated for 30-50 minutes, liquid A is added thereto, stirred and dispersed, dialyzed, and dried to obtain an antioxidant cinnamaldehyde-based polymer.
2. The antioxidant cinnamaldehyde-based polymer according to claim 1, characterized in that The preparation method of the cinnamaldehyde-based polylactic acid is: (1) adding 2,2-dihydroxymethyl propionic acid to thionyl chloride, stirring and dispersing, heating to 70-80° C., stirring and reacting for 30-60 min, distilling under reduced pressure, adding ethyl acetate thereto, stirring and dispersing, then adding tea polyphenols and a catalyst thereto, heating to 35-50° C., reacting for 5-10 h, filtering after the reaction, washing with deionized water, drying, rotary evaporation, and drying to obtain polyhydroxy tea polyphenols; (2) under nitrogen atmosphere, polyhydroxy tea polyphenols and stannous octoate are added to tetrahydrofuran solvent, stirred and dispersed, and then L-lactide is added thereto, stirred and reacted at 60-70° C. for 24-36 hours. After the reaction is completed, methanol precipitation is performed and dried to obtain terminal hydroxyl polylactic acid; (3) adding hydroxy-terminated polylactic acid and sodium azide to tetrahydrofuran solvent, heating to 90-100° C., stirring and reacting for 30-48 hours, cooling to room temperature after the reaction, adding deionized water, stirring and dispersing, extracting with dichloromethane, drying, and rotary evaporation to obtain azido-terminated polylactic acid; (4) Under a nitrogen atmosphere, adding azide-terminated polylactic acid, triphenylphosphine, and deionized water to tetrahydrofuran solvent, stirring the reaction at room temperature for 40-60 hours, and after the reaction is completed, rotary evaporation, adding 5% hydrochloric acid aqueous solution by mass, stirring for 40-80 minutes, filtering, washing the filtrate with ether, adjusting the pH to 9-10 with 10% sodium hydroxide aqueous solution, filtering, and rotary evaporation to obtain amino-terminated polylactic acid; (5) Adding amino-terminated polylactic acid and cinnamaldehyde into an ethanol solvent, stirring and dispersing, reacting at 70-80° C. for 5-8 hours, and after the reaction is completed, filtering, washing with deionized water, and drying to obtain cinnamaldehyde-based polylactic acid.
3. The antioxidant cinnamaldehyde-based polymer according to claim 2, characterized in that In the above (1), the molar ratio of 2,2-dihydroxymethylpropionic acid, thionyl chloride and tea polyphenols is 3.5-4:8-10:
1.
4. The antioxidant cinnamaldehyde-based polymer according to claim 2, characterized in that In the above (2), the molar ratio of polyhydroxy tea polyphenols, stannous octoate and L-lactide is 1:0.05-0.1:60-100.
5. The antioxidant cinnamaldehyde-based polymer according to claim 2, characterized in that In the above (3), the molar ratio of terminal hydroxyl polylactic acid to sodium azide is 1:5-8.
6. The antioxidant cinnamaldehyde-based polymer according to claim 2, characterized in that In the above (4), the molar ratio of the azide-terminated polylactic acid, triphenylphosphine and deionized water is 1:4-7.5:6-10.
7. The antioxidant cinnamaldehyde-based polymer according to claim 2, characterized in that In the above (5), the molar ratio of amino-terminated polylactic acid to cinnamaldehyde is 1:5-8.