Environment-friendly plant-based degradable high molecular material and preparation method thereof
By cross-linking modified chitosan and functionalized hesperidin with modified polyamide, the problem of declining mechanical properties of plant-based polymer materials was solved, and their mechanical properties and anti-aging properties were improved, thus realizing the efficient preparation of environmentally friendly plant-based biodegradable polymer materials.
Patent Information
- Application Number
- CN202510582184.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-07
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2045-05-07
AI Technical Summary
Existing plant-based polymer materials suffer from decreased mechanical properties and poor durability during synthesis, which limits their further development and application.
Modified chitosan was prepared by reacting chitosan with 1-bromo-1,2,2-triphenylethylene, and functionalized hesperidin was prepared by reacting hesperidin with 4-(chloromethyl)-1,3-dioxolane-2-one. The functionalized hesperidin was then mixed with modified polyamide, modified chitosan, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene and injection molded to form a cross-linked network, thereby improving the mechanical properties and flame retardant properties of the material.
It improves the mechanical and anti-aging properties of plant-based biodegradable polymer materials while maintaining their environmental friendliness, thus broadening their application areas.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer materials technology, specifically to an environmentally friendly plant-based biodegradable polymer material and its preparation method. Background Technology
[0002] The development of materials science has greatly promoted the progress of human society, and polymer materials are an important component of this. While polymer materials, characterized by their light weight, convenience, and low cost, have brought great convenience to our production and daily lives, many synthetic polymer materials suffer from defects such as easy aging and difficulty in degradation, leading to environmental pollution that has become a significant global issue. Adding plant-based raw materials such as cellulose and starch to synthetic polymer materials is an effective method to improve their degradability, saving non-renewable resources while being environmentally friendly. Plant-based polymer materials have been extensively studied and widely applied. However, the addition of plant-based raw materials to synthetic polymer materials generally results in a decrease in the mechanical properties and reduced durability, limiting the further development and application of plant-based polymer materials. Therefore, it is necessary to improve existing technologies to enhance the mechanical properties of plant-based polymer materials while retaining the plant-based raw materials, thereby broadening their application areas. This is of great significance for resource conservation and environmental protection. Summary of the Invention
[0003] The purpose of this invention is to provide an environmentally friendly plant-based biodegradable polymer material and its preparation method, so as to solve the problems existing in the prior art.
[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:
[0005] An environmentally friendly plant-based biodegradable polymer material is prepared by reacting pre-modified chitosan and 1-bromo-1,2,2-triphenylethylene to obtain modified chitosan; reacting polyamide and formaldehyde to obtain modified polyamide; and mixing the modified polyamide, modified chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene and then injection molding the mixture.
[0006] The pre-modified chitosan is prepared by reacting chitosan with pinacol 5-aldehyde furan-3-boronic acid ester;
[0007] The polyamide is prepared by polycondensation of dimethyl adipate, a phosphate-containing diacid ester monomer and 1,6-hexanediamine.
[0008] The phosphorus-containing diacid ester monomer is prepared by reacting trans-3-hexenedioic acid dimethyl ester and methylphenyl-phosphorus oxide;
[0009] The functionalized hesperidin is prepared by reacting hesperidin with 4-(chloromethyl)-1,3-dioxolane-2-one.
[0010] A method for preparing an environmentally friendly plant-based biodegradable polymer material, comprising the following preparation steps:
[0011] (1) Premodified chitosan, 1-bromo-1,2,2-triphenylethylene, potassium carbonate, tetra(triphenylphosphine)palladium, and mixed solvent are mixed evenly in a mass ratio of 1:(2~3):(0.6~0.8):(0.1~0.2):(100~110). Under nitrogen protection, the mixture is stirred and refluxed at 70~80℃ and 200~300r / min for 20~24h. Under vacuum conditions, the mixture is dried at 50~60℃ for 2~3h. The mixture is washed 3~5 times each with anhydrous ethanol and deionized water. Under vacuum conditions, the mixture is dried at 50~60℃ for 7~8h to obtain modified chitosan.
[0012] (2) Add hesperidin and 4-(chloromethyl)-1,3-dioxolane-2-one to N,N-dimethylformamide at a molar ratio of 1:3, which is 18 to 22 times the mass of hesperidin. Add benzyltriethylammonium chloride at a mass of 0.04 to 0.06 times the mass of hesperidin. Under nitrogen protection, stir the reaction at 70 to 80°C and 200 to 300 r / min for 2 to 3 hours. Add sodium hydroxide aqueous solution at a uniform rate of 1 to 2 times the mass of hesperidin dropwise over 20 minutes. After the addition is complete, continue stirring the reaction for 50 to 60 minutes. Dry the product under vacuum at 60 to 70°C for 8 to 10 hours to obtain functionalized hesperidin.
[0013] (3) Polyamide, formaldehyde aqueous solution and N,N-dimethylformamide are mixed evenly in a mass ratio of 1:(3~4):(6~8), and stirred at 90~100℃ and 200~300r / min for 55~65min under nitrogen protection. The mixture is then filtered, washed 3~5 times with deionized water, and dried at 50~60℃ for 9~11h under vacuum to obtain modified polyamide.
[0014] (4) Weigh 98-102 parts of modified polyamide, 7-8 parts of modified chitosan, 6-7 parts of functionalized hesperidin, and 1.3-1.5 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene by mass; mix the modified polyamide, modified chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene evenly, place them in an injection molding machine for injection molding, and after injection molding, keep them at 160-170℃ for 80-90 minutes, and let them cool naturally to room temperature to obtain an environmentally friendly plant-based biodegradable polymer material.
[0015] As an optimization, the preparation method of the pre-modified chitosan in step (1) is as follows: chitosan, acetic acid, and methanol are mixed evenly at a mass ratio of 1:(2.5~2.7):(26~28), stirred and swollen at 200~300r / min for 100~120min at 20~30℃, and 5-aldehyde furan-3-boronic acid pinacol ester (2~2.2 times the mass of chitosan) is added. The temperature is raised to 58~62℃, and the reaction is continued to be stirred for 10~12h. Under vacuum conditions, the mixture is dried at 50~60℃ for 3~4h, washed 3~5 times with anhydrous ethanol, and dried under vacuum conditions at 50~60℃ for 7~8h to obtain the pre-modified chitosan. The reaction process is as follows:
[0016]
[0017] As an optimization, the degree of deacetylation of the chitosan is 92%, and the weight-average molecular weight is 200 kDa.
[0018] As an optimization, the preparation method of the mixed solvent in step (1) is as follows: deionized water, tetrahydrofuran and toluene are mixed evenly in a volume ratio of 1:(5~7):(7~9) to prepare a mixed solvent.
[0019] As an optimization, the reaction process of the modified chitosan in step (1) is as follows:
[0020]
[0021] As an optimization, the mass fraction of the sodium hydroxide aqueous solution in step (2) is 16% to 18%.
[0022] As an optimization, the reaction process of the functionalized hesperidin in step (2) is as follows:
[0023]
[0024] As an optimization, the CAS number of the 4-(chloromethyl)-1,3-dioxolane-2-one described in step (2) is 2463-45-8; the structural formula is:
[0025] As an optimization, the preparation method of the polyamide in step (3) is as follows: dimethyl adipate and phosphorus-containing diacid ester monomers are added to N,N-dimethylformamide at a molar ratio of 1:(0.6-0.8) to 6-8 times the mass of dimethyl adipate, and mixed evenly to prepare a diester reaction solution; 1,6-hexanediamine and N,N-dimethylformamide at a molar ratio of 2-2.2 times the molar amount of dimethyl adipate are mixed evenly at a mass ratio of 1:(4-5) to prepare a diester reaction solution. Amine reaction solution: The diester reaction solution was placed in a high-pressure reactor. Under a nitrogen atmosphere, at 40–50 °C and stirring at 200–300 r / min, the diamine reaction solution was added dropwise to the diester reaction solution at a uniform rate over 25 min. After the addition was complete, the temperature was raised to 155–165 °C, and the reaction was continued with stirring for 60–70 min. The mixture was then filtered, washed 3–5 times with diethyl ether, and dried under vacuum at 70–80 °C for 8–10 h to obtain polyamide.
[0026] As an optimization, the preparation method of the phosphorus-containing diacid ester monomer is as follows: dimethyl trans-3-hexenedioic acid and methylphenyl-oxyphosphine are added to toluene at a molar ratio of 1:1 (16-18 times the mass of dimethyl trans-3-hexenedioic acid), and azobisisobutyronitrile (0.03-0.05 times the mass of dimethyl trans-3-hexenedioic acid) is added. The mixture is stirred at 60-70°C and 300-500 r / min for 3-4 h, and then dried under vacuum at 50-60°C for 8-10 h to obtain the phosphorus-containing diacid ester monomer. The reaction process is as follows:
[0027]
[0028] As an optimization, the CAS number of the methylphenyl-phosphine oxide is 19315-13-0; the structural formula is:
[0029]
[0030] As an optimization, the mass fraction of the formaldehyde aqueous solution in step (3) is 35% to 37%.
[0031] As an optimization, the process parameters for injection molding in step (4) are as follows: the melt temperature for injection molding is set to 270-280℃, the injection pressure is set to 80-90MPa, the holding pressure is set to 40-50MPa, the holding time is set to 20-30s, and the mold temperature is set to 60-70℃.
[0032] Compared with the prior art, the beneficial effects achieved by the present invention are:
[0033] In preparing environmentally friendly plant-based biodegradable polymer materials, this invention involves reacting chitosan and pinacol 5-aldehyde furan-3-boronic acid to obtain pre-modified chitosan; reacting the pre-modified chitosan and 1-bromo-1,2,2-triphenylethylene to obtain modified chitosan; reacting hesperidin and 4-(chloromethyl)-1,3-dioxolane-2-one to obtain functionalized hesperidin; reacting dimethyl trans-3-hexenedioic acid and methylphenyl-oxyphosphorus to obtain a phosphorus-containing ester monomer; condensing dimethyl adipate, the phosphorus-containing ester monomer, and 1,6-hexanediamine to obtain polyamide; reacting polyamide and formaldehyde to obtain modified polyamide; and mixing the modified polyamide, modified chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene and then injection molding to obtain environmentally friendly plant-based biodegradable polymer materials.
[0034] First, pre-modified chitosan was prepared by reacting chitosan with 5-aldehyde furan-3-boronic acid pinacol ester. Modified chitosan was then prepared by reacting the pre-modified chitosan with 1-bromo-1,2,2-triphenylethylene. A triphenylvinylfuran structure was generated on the modified chitosan via a classic palladium-catalyzed cross-coupling reaction. This triphenylvinylfuran structure can undergo ring-closing under ultraviolet light and ring-opening under visible light. This reversible ring-closing reaction can absorb ultraviolet light and release it in a harmless form, thereby enhancing the anti-aging properties of environmentally friendly plant-based biodegradable polymer materials. The mechanism of action is as follows:
[0035]
[0036] Secondly, functionalized hesperidin was prepared by reacting hesperidin with 4-(chloromethyl)-1,3-dioxolane-2-one. Cyclic carbonate groups were introduced onto the functionalized hesperidin. Hesperidin is a flavonoid natural compound with a rigid structure and a benzopyran ring structure in its molecular structure, which can effectively improve the carbonization rate of polymer materials, reduce heat release, and reduce the release of volatile combustibles, thereby improving the flame retardant performance of environmentally friendly plant-based biodegradable polymer materials. The cyclic carbonate groups introduced onto the functionalized hesperidin can undergo ring-opening etherification with the hydroxyl groups on the modified chitosan and the hydroxyl groups introduced on the side chains of the modified polyamide molecule under the action of the catalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene to form a cross-linked network, inhibit the relative slippage between molecular chains, and improve the mechanical properties of environmentally friendly plant-based biodegradable polymer materials.
[0037] Finally, a phosphorus-containing diacid ester monomer was prepared by reacting trans-3-hexenedioic acid dimethyl ester and methylphenyl-phosphorus oxide; a polyamide was prepared by condensing dimethyl adipate, the phosphorus-containing diacid ester monomer, and 1,6-hexanediamine, and phosphorus was introduced into the side chain of the polyamide molecule. The introduction of phosphorus can further improve the flame retardant properties of the environmentally friendly plant-based biodegradable polymer material; a modified polyamide was prepared by reacting polyamide and formaldehyde, and hydroxymethyl groups were introduced into the side chain of the modified polyamide molecule. The hydroxymethyl groups introduced into the side chain of the modified polyamide molecule can undergo a ring-opening etherification reaction with the cyclic carbonate groups introduced into the functionalized hesperidin under the action of the catalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene to form a cross-linked network, inhibit the relative slippage between molecular chains, and improve the mechanical properties of the environmentally friendly plant-based biodegradable polymer material. Detailed Implementation
[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0039] Example 1:
[0040] A method for preparing an environmentally friendly plant-based biodegradable polymer material, comprising the following preparation steps:
[0041] (1) Chitosan, acetic acid, and methanol were mixed evenly at a mass ratio of 1:2.5:26. The mixture was stirred and swollen at 200 r / min for 120 min at 20℃. Two times the mass of chitosan (5-aldehyde furan-3-boronic acid pinacol ester) were added, and the mixture was heated to 58℃ and stirred for 12 h. The mixture was then dried at 50℃ under vacuum for 4 h, washed three times with anhydrous ethanol, and dried at 50℃ under vacuum for 8 h to obtain pre-modified chitosan. Deionized water, tetrahydrofuran, and toluene were mixed at a volume ratio of... Mix the pre-modified chitosan, 1-bromo-1,2,2-triphenylethylene, potassium carbonate, tetra(triphenylphosphine)palladium, and the mixed solvent in a mass ratio of 1:2:0.6:0.1:100. Under nitrogen protection, stir and reflux at 70°C and 200 r / min for 24 h. Dry at 50°C under vacuum for 3 h. Wash three times each with anhydrous ethanol and deionized water. Dry at 50°C under vacuum for 8 h to obtain the modified chitosan.
[0042] (2) Hesperidin and 4-(chloromethyl)-1,3-dioxolane-2-one were added to N,N-dimethylformamide at a molar ratio of 1:3, which was 18 times the mass of hesperidin. Benzyltriethylammonium chloride was added at a mass of 0.04 times the mass of hesperidin. The mixture was stirred at 70°C and 200 r / min for 3 h under nitrogen protection. A sodium hydroxide aqueous solution with a mass fraction of 18% was added dropwise at a uniform rate over 20 min. After the addition was complete, the mixture was stirred for another 60 min. The mixture was then dried at 60°C under vacuum for 10 h to obtain functionalized hesperidin.
[0043] (3) Dimethyl trans-3-hexenedioic acid and methylphenyl-oxyphosphine were added to toluene at a molar ratio of 1:1, which was 16 times the mass of dimethyl trans-3-hexenedioic acid. Azobisisobutyronitrile (ANOVA) was added at a molar ratio of 0.03 times the mass of dimethyl trans-3-hexenedioic acid. The mixture was stirred at 60°C and 300 r / min for 4 h, and then dried at 50°C under vacuum for 10 h to obtain a phosphorus-containing ester monomer. Dimethyl adipate and the phosphorus-containing ester monomer were added to N,N-dimethylformamide at a molar ratio of 1:0.6, which was 6 times the mass of dimethyl adipate, and mixed thoroughly to prepare a diester reaction solution. 1,6-hexanediamine and N,N-dimethylformamide, which were 2 times the molar amount of dimethyl adipate, were mixed thoroughly at a mass ratio of 1:4 to prepare a solution. Diamine reaction solution; The diester reaction solution was placed in a high-pressure reactor. Under a nitrogen atmosphere, at 40°C and 200 r / min stirring, the diamine reaction solution was added dropwise to the diester reaction solution at a uniform rate over 25 min. After the addition was complete, the temperature was raised to 155°C, and the reaction was stirred for another 70 min. The mixture was then filtered, washed three times with diethyl ether, and dried at 70°C for 10 h under vacuum to obtain polyamide. Polyamide, a 37% formaldehyde aqueous solution, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:3:6. Under nitrogen protection, the mixture was stirred at 90°C and 300 r / min for 65 min. The mixture was then filtered, washed three times with deionized water, and dried at 50°C for 11 h under vacuum to obtain modified polyamide.
[0044] (4) Weigh 98 parts of modified polyamide, 7 parts of modified chitosan, 6 parts of functionalized hesperidin, and 1.3 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene by mass. Mix the modified polyamide, modified chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene evenly, place them in an injection molding machine for injection molding, set the melt temperature of injection molding to 270℃, the injection pressure to 80MPa, the holding pressure to 40MPa, the holding time to 30s, the mold temperature to 60℃, and after injection molding, keep at 160℃ for 90min, and cool naturally to room temperature to obtain an environmentally friendly plant-based biodegradable polymer material.
[0045] Example 2:
[0046] A method for preparing an environmentally friendly plant-based biodegradable polymer material, comprising the following preparation steps:
[0047] (1) Chitosan, acetic acid, and methanol were mixed evenly at a mass ratio of 1:2.6:27. The mixture was stirred and swollen at 25°C and 250 r / min for 110 min. 2.1 times the mass of chitosan (5-aldehyde furan-3-boronic acid pinacol ester) was added. The mixture was heated to 60°C and stirred for 11 h. The mixture was then dried at 55°C under vacuum for 3.5 h, washed four times with anhydrous ethanol, and dried at 55°C under vacuum for 7.5 h to obtain pre-modified chitosan. Deionized water, tetrahydrofuran, and toluene were mixed at a volume ratio of 1:2.6:27. The mixtures were prepared by mixing the pre-modified chitosan, 1-bromo-1,2,2-triphenylethylene, potassium carbonate, tetra(triphenylphosphine)palladium, and the mixed solvent in a mass ratio of 1:2.5:0.7:0.15:105. The mixture was stirred and refluxed at 75°C and 250 r / min for 22 h under nitrogen protection. It was then dried at 55°C for 2.5 h under vacuum. The mixture was washed four times each with anhydrous ethanol and deionized water. Finally, it was dried at 55°C for 7.5 h under vacuum to obtain the modified chitosan.
[0048] (2) Hesperidin and 4-(chloromethyl)-1,3-dioxolane-2-one were added to N,N-dimethylformamide at a molar ratio of 1:3, which was 20 times the mass of hesperidin. Benzyltriethylammonium chloride was added at a mass of 0.05 times the mass of hesperidin. The mixture was stirred at 75°C and 250 r / min for 2.5 h under nitrogen protection. A 17% sodium hydroxide aqueous solution, which was 1.5 times the mass of hesperidin, was added dropwise over 20 min. After the addition was complete, the mixture was stirred for another 55 min. The mixture was then dried at 65°C under vacuum for 9 h to obtain functionalized hesperidin.
[0049] (3) Dimethyl trans-3-hexenedioic acid and methylphenyl-oxyphosphine were added to toluene at a molar ratio of 1:1, which was 17 times the mass of dimethyl trans-3-hexenedioic acid. Azobisisobutyronitrile (ANOVA) was added at a molar ratio of 0.04 times the mass of dimethyl trans-3-hexenedioic acid. The mixture was stirred at 65°C and 400 r / min for 3.5 h, and then dried at 55°C under vacuum for 9 h to obtain a phosphorus-containing ester monomer. Dimethyl adipate and the phosphorus-containing ester monomer were added to N,N-dimethylformamide at a molar ratio of 1:0.7, which was 7 times the mass of dimethyl adipate, and mixed thoroughly to prepare a diester reaction solution. 1,6-hexanediamine and N,N-dimethylformamide, which were 2.1 times the molar mass of dimethyl adipate, were mixed thoroughly at a mass ratio of 1:4.5 to prepare a solution. A diamine reaction solution was prepared. The diester reaction solution was placed in a high-pressure reactor. Under a nitrogen atmosphere, the diamine reaction solution was added dropwise to the diester reaction solution at a uniform rate over 25 minutes at 45°C and 250 r / min stirring. After the addition was complete, the temperature was raised to 160°C, and the reaction was continued with stirring for 65 minutes. The mixture was then filtered, washed four times with diethyl ether, and dried at 75°C for 9 hours under vacuum to obtain polyamide. Polyamide, a 36% formaldehyde aqueous solution, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:3.5:7. Under nitrogen protection, the mixture was stirred at 95°C and 250 r / min for 60 minutes. The mixture was then filtered, washed four times with deionized water, and dried at 55°C for 10 hours under vacuum to obtain modified polyamide.
[0050] (4) Weigh 100 parts of modified polyamide, 7.5 parts of modified chitosan, 6.5 parts of functionalized hesperidin, and 1.4 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene by mass. Mix the modified polyamide, modified chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene evenly, place them in an injection molding machine for injection molding, set the melt temperature for injection molding to 275℃, the injection pressure to 85MPa, the holding pressure to 45MPa, the holding time to 25s, the mold temperature to 65℃, and after injection molding, keep at 165℃ for 85min, and let it cool naturally to room temperature to obtain an environmentally friendly plant-based biodegradable polymer material.
[0051] Example 3:
[0052] A method for preparing an environmentally friendly plant-based biodegradable polymer material, comprising the following preparation steps:
[0053] (1) Chitosan, acetic acid, and methanol were mixed evenly in a mass ratio of 1:2.7:28. The mixture was stirred and swollen at 300 r / min for 100 min at 30℃. Then, 2.2 times the mass of chitosan (5-aldehyde furan-3-boronic acid pinacol ester) was added. The mixture was heated to 62℃ and stirred for 10 h. The mixture was dried at 60℃ under vacuum for 3 h. The mixture was washed 5 times with anhydrous ethanol and dried at 60℃ under vacuum for 7 h to obtain pre-modified chitosan. Deionized water, tetrahydrofuran, and toluene were mixed in a volume ratio of... The mixture was prepared by mixing the pre-modified chitosan, 1-bromo-1,2,2-triphenylethylene, potassium carbonate, tetra(triphenylphosphine)palladium, and the mixed solvent in a mass ratio of 1:3:0.8:0.2:110. The mixture was stirred and refluxed at 80°C and 300 r / min for 20 h under nitrogen protection. It was then dried at 60°C for 2 h under vacuum. The mixture was washed 5 times each with anhydrous ethanol and deionized water. Finally, it was dried at 60°C for 7 h under vacuum to obtain the modified chitosan.
[0054] (2) Hesperidin and 4-(chloromethyl)-1,3-dioxolane-2-one were added to N,N-dimethylformamide at a molar ratio of 1:3, which was 22 times the mass of hesperidin. Benzyltriethylammonium chloride was added at a mass of 0.06 times the mass of hesperidin. The mixture was stirred at 80°C and 300 r / min for 2 h under nitrogen protection. A 16% sodium hydroxide aqueous solution with a mass fraction of 2 times the mass of hesperidin was added dropwise over 20 min. After the addition was complete, the mixture was stirred for another 60 min. The mixture was then dried at 60°C under vacuum for 10 h to obtain functionalized hesperidin.
[0055] (3) Dimethyl trans-3-hexenedioic acid and methylphenyl-oxyphosphine were added to toluene at a molar ratio of 1:1, which was 18 times the mass of dimethyl trans-3-hexenedioic acid. Azobisisobutyronitrile (ANOVA) was added at a molar ratio of 0.05 times the mass of dimethyl trans-3-hexenedioic acid. The mixture was stirred at 70°C and 500 r / min for 3 h, and then dried at 60°C under vacuum for 8 h to obtain a phosphorus-containing ester monomer. Dimethyl adipate and the phosphorus-containing ester monomer were added to N,N-dimethylformamide at a molar ratio of 1:0.8, which was 8 times the mass of dimethyl adipate, and mixed thoroughly to prepare a diester reaction solution. 1,6-hexanediamine and N,N-dimethylformamide, which were 2.2 times the molar mass of dimethyl adipate, were mixed thoroughly at a mass ratio of 1:5 to prepare a... A diamine reaction solution was prepared. The diester reaction solution was placed in a high-pressure reactor. Under a nitrogen atmosphere, the diamine reaction solution was added dropwise to the diester reaction solution at 50°C and 300 r / min stirring over 25 min. After the addition was complete, the temperature was raised to 165°C, and the reaction was stirred for another 60 min. The mixture was then filtered, washed five times with diethyl ether, and dried at 80°C for 8 h under vacuum to obtain polyamide. Polyamide, a 35% formaldehyde aqueous solution, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:4:8. Under nitrogen protection, the mixture was stirred at 100°C and 300 r / min for 55 min. The mixture was then filtered, washed five times with deionized water, and dried at 60°C for 9 h under vacuum to obtain modified polyamide.
[0056] (4) Weigh 102 parts of modified polyamide, 8 parts of modified chitosan, 7 parts of functionalized hesperidin, and 1.5 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene by mass. Mix the modified polyamide, modified chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene evenly, place them in an injection molding machine for injection molding, set the melt temperature of injection molding to 280℃, the injection pressure to 90MPa, the holding pressure to 50MPa, the holding time to 20s, the mold temperature to 70℃, and after injection molding, keep at 170℃ for 80min, and cool naturally to room temperature to obtain an environmentally friendly plant-based biodegradable polymer material.
[0057] Comparative Example 1:
[0058] The preparation method of the environmentally friendly plant-based biodegradable polymer material in Comparative Example 1 differs from that in Example 2 in that step (1) is omitted, and step (4) is modified as follows: 100 parts of modified polyamide, 7.5 parts of chitosan, 6.5 parts of functionalized hesperidin, and 1.4 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene are weighed by mass. The modified polyamide, chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene are mixed evenly and placed in an injection molding machine for injection molding. The melt temperature for injection molding is set to 275°C, the injection pressure to 85 MPa, the holding pressure to 45 MPa, the holding time to 25 s, and the mold temperature to 65°C. After injection molding, the material is held at 165°C for 85 min and then naturally cooled to room temperature to obtain the environmentally friendly plant-based biodegradable polymer material. The remaining steps are the same as in Example 2.
[0059] Comparative Example 2:
[0060] The preparation method of the environmentally friendly plant-based biodegradable polymer material in Comparative Example 2 differs from that in Example 2 in that step (2) is omitted, and step (4) is modified as follows: 100 parts of modified polyamide, 7.5 parts of modified chitosan, 6.5 parts of hesperidin, and 1.4 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene are weighed by mass. The modified polyamide, modified chitosan, hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene are mixed evenly and placed in an injection molding machine for injection molding. The melt temperature for injection molding is set to 275°C, the injection pressure to 85 MPa, the holding pressure to 45 MPa, the holding time to 25 s, and the mold temperature to 65°C. After injection molding, the material is held at 165°C for 85 min and then naturally cooled to room temperature to obtain the environmentally friendly plant-based biodegradable polymer material. The remaining steps are the same as in Example 2.
[0061] Comparative Example 3:
[0062] The preparation method of the environmentally friendly plant-based biodegradable polymer material in Comparative Example 3 differs from that in Example 2 in that step (2) is omitted, and step (4) is modified as follows: 100 parts of modified polyamide, 7.5 parts of modified chitosan, and 1.4 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene are weighed by mass. The modified polyamide, modified chitosan, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene are mixed evenly and placed in an injection molding machine for injection molding. The melt temperature for injection molding is set to 275°C, the injection pressure to 85 MPa, the holding pressure to 45 MPa, the holding time to 25 s, and the mold temperature to 65°C. After injection molding, the material is held at 165°C for 85 min and then naturally cooled to room temperature to obtain the environmentally friendly plant-based biodegradable polymer material. The remaining steps are the same as in Example 2.
[0063] Comparative Example 4:
[0064] The preparation method of the environmentally friendly plant-based biodegradable polymer material in Comparative Example 4 differs from that in Example 2 only in step (3). Step (3) is modified as follows: dimethyl adipate and trans-3-hexenedioic acid dimethyl ester are added to N,N-dimethylformamide at a molar ratio of 1:0.7, and mixed evenly to prepare a diester reaction solution; 1,6-hexanediamine and N,N-dimethylformamide at a molar ratio of 2.1 times that of dimethyl adipate are mixed evenly at a mass ratio of 1:4.5 to prepare a diamine reaction solution; the diester reaction solution is placed in a high-pressure reactor and, under a nitrogen atmosphere, at 45°C, 2 Under stirring at 50 rpm, the diamine reaction solution was added dropwise to the diester reaction solution at a uniform rate over 25 min. After the addition was complete, the temperature was raised to 160°C, and the reaction was continued with stirring for 65 min. The mixture was then filtered, washed four times with diethyl ether, and dried at 75°C for 9 h under vacuum to obtain polyamide. Polyamide, a 36% (w / w) formaldehyde aqueous solution, and N,N-dimethylformamide were mixed uniformly at a mass ratio of 1:3.5:7. Under nitrogen protection, the mixture was stirred at 95°C and 250 rpm for 60 min. The mixture was then filtered, washed four times with deionized water, and dried at 55°C for 10 h under vacuum to obtain modified polyamide. The remaining steps were the same as in Example 2.
[0065] Comparative Example 5:
[0066] The preparation method of the environmentally friendly plant-based biodegradable polymer material in Comparative Example 5 differs from that in Example 2 only in step (3). Step (3) is modified as follows: dimethyl trans-3-hexenedioic acid and methylphenyl-oxyphosphine are added to toluene at a molar ratio of 1:1, which is 17 times the mass of dimethyl trans-3-hexenedioic acid. Azobisisobutyronitrile is added at a molar ratio of 0.04 times the mass of dimethyl trans-3-hexenedioic acid. The mixture is stirred at 65°C and 400 r / min for 3.5 h, and then dried at 55°C under vacuum for 9 h to obtain a phosphorus-containing diacid ester monomer. Dimethyl adipate and the phosphorus-containing diacid ester monomer are added to dimethyl adipate at a molar ratio of 1:0.7, which is 1:0.7, to dimethyl adipate. A diester reaction solution was prepared by uniformly mixing N,N-dimethylformamide in 7 times the molar amount of dimethyl adipic acid. A diamine reaction solution was prepared by uniformly mixing 1,6-hexanediamine and N,N-dimethylformamide in a mass ratio of 1:4.5 in 2.1 times the molar amount of dimethyl adipic acid. The diester reaction solution was placed in a high-pressure reactor, and under a nitrogen atmosphere, at 45°C and 250 rpm stirring, the diamine reaction solution was uniformly added dropwise to the diester reaction solution over 25 minutes. After the addition was complete, the temperature was raised to 160°C, and the reaction was continued with stirring for 65 minutes. The mixture was then filtered, washed four times with diethyl ether, and dried at 75°C for 9 hours under vacuum to obtain the modified polyamide. The remaining steps were the same as in Example 2.
[0067] Test Example 1
[0068] Testing of mechanical properties and anti-aging properties
[0069] Test method: Standard specimens were prepared according to GB / T1040 for the examples and comparative examples. The tensile strength F of the standard specimens was tested. The standard specimens were irradiated with a xenon arc lamp for 15 days, and their tensile strength M was tested. The change rate of tensile strength of the examples and comparative examples before and after ultraviolet aging treatment was calculated as follows: tensile strength change rate = (FM) / F × 100%. The results are shown in Table 1.
[0070] Table 1
[0071]
[0072] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-5 in Table 1 reveals that the environmentally friendly plant-based biodegradable polymer material prepared by this invention has good mechanical properties and anti-aging properties.
[0073] By comparison, the tensile strength of Examples 1-3 is greater than that of Comparative Examples 2-3, indicating that functionalized hesperidin is prepared by reacting hesperidin with 4-(chloromethyl)-1,3-dioxolane-2-one; cyclic carbonate groups are introduced onto the functionalized hesperidin; the cyclic carbonate groups introduced onto the functionalized hesperidin can undergo ring-opening etherification reactions with the hydroxyl groups on the modified chitosan and the hydroxyl groups introduced on the side chains of the modified polyamide molecules under the action of a catalyst, forming a cross-linked network, inhibiting the relative slippage between molecular chains, and improving the mechanical properties of environmentally friendly plant-based biodegradable polymer materials.
[0074] By comparison, the tensile strength of Examples 1-3 is greater than that of Comparative Example 5, indicating that the modified polyamide is prepared by reacting polyamide and formaldehyde, and hydroxymethyl groups are introduced into the side chains of the modified polyamide molecules. The hydroxymethyl groups introduced into the side chains of the modified polyamide molecules can undergo ring-opening etherification reactions with the cyclic carbonate groups introduced into the functionalized hesperidin to form a cross-linked network, which inhibits the relative slippage between molecular chains and improves the mechanical properties of environmentally friendly plant-based biodegradable polymer materials.
[0075] By comparison, the tensile strength change rate of Examples 1-3 was less than that of Comparative Example 1, indicating that pre-modified chitosan was prepared by reacting chitosan with 5-aldehyde furan-3-boronic acid pinacol ester; modified chitosan was prepared by reacting pre-modified chitosan with 1-bromo-1,2,2-triphenylethylene; and a triphenylvinylfuran structure was generated on the modified chitosan through a classic palladium-catalyzed cross-coupling reaction. The triphenylvinylfuran structure can undergo a ring-closing reaction under ultraviolet light and a ring-opening reaction under visible light. This reversible ring-opening and closing reaction can absorb ultraviolet light and release it in a harmless form, thereby improving the anti-aging performance of environmentally friendly plant-based biodegradable polymer materials.
[0076] Test Example 2
[0077] Flame retardant performance testing
[0078] Test method: Standard samples were prepared according to GB / T2406 for the examples and comparative examples, and the limiting oxygen index of the standard samples was tested. The results are shown in Table 2.
[0079] Table 2
[0080] Limiting oxygen index (%) Limiting oxygen index (%) Example 1 34.78 Comparative Example 1 34.65 Example 2 35.21 Comparative Example 2 34.39 Example 3 35.14 Comparative Example 3 29.46 Comparative Example 4 28.18 Comparative Example 5 34.71
[0081] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-5 in Table 2 reveals that the environmentally friendly plant-based biodegradable polymer material prepared by this invention has good flame retardant properties.
[0082] By comparison, the limiting oxygen index of Examples 1-3 is greater than that of Comparative Example 3, indicating that hesperidin is a flavonoid natural compound with a rigid structure and a benzopyran ring structure in its molecular structure. Adding hesperidin to polymer materials can effectively increase the carbonization rate of the polymer materials, reduce heat release, and reduce the release of volatile combustibles, thereby improving the flame retardant performance of environmentally friendly plant-based biodegradable polymer materials.
[0083] By comparison, the limiting oxygen index of Examples 1-3 is greater than that of Comparative Example 4, indicating that the phosphorus-containing diacid ester monomer is prepared by reacting dimethyl trans-3-hexenedioic acid and methylphenyl-phosphorus oxide; and the polyamide is prepared by polycondensation of dimethyl adipate, the phosphorus-containing diacid ester monomer and 1,6-hexanediamine, and the introduction of phosphorus element into the side chain of the polyamide molecular chain can further improve the flame retardant performance of environmentally friendly plant-based biodegradable polymer materials.
[0084] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. An environmentally friendly plant-based biodegradable polymer material, characterized in that, The environmentally friendly plant-based biodegradable polymer material is prepared by reacting pre-modified chitosan and 1-bromo-1,2,2-triphenylethylene at a mass ratio of 1:(2-3) to obtain modified chitosan; reacting polyamide and formaldehyde to obtain modified polyamide; and mixing 98-102 parts of modified polyamide, 7-8 parts of modified chitosan, 6-7 parts of functionalized hesperidin, and 1.3-1.5 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene and then injection molding the mixture. The reaction of polyamide and formaldehyde is prepared by reacting an aqueous solution of polyamide and formaldehyde at a mass ratio of 1:(3-4); the mass fraction of the aqueous formaldehyde solution is 35%-37%. The pre-modified chitosan is prepared by reacting chitosan and 5-aldehyde furan-3-boronic acid pinacol ester in a mass ratio of 1:(2-2.2); The polyamide is prepared by polycondensation of dimethyl adipate, a phosphate-containing diacid ester monomer, and 1,6-hexanediamine in a molar ratio of 1:(0.6-0.8):(2-2.2). The phosphorus-containing diacid ester monomer is prepared by reacting trans-3-hexenedioic acid dimethyl ester and methylphenyl-oxyphosphorus in a molar ratio of 1:
1. The functionalized hesperidin is prepared by reacting hesperidin and 4-(chloromethyl)-1,3-dioxolane-2-one in a molar ratio of 1:
3.
2. A method for preparing an environmentally friendly plant-based biodegradable polymer material, characterized in that, The preparation method of the environmentally friendly plant-based biodegradable polymer material includes the following preparation steps: (1) Premodified chitosan, 1-bromo-1,2,2-triphenylethylene, potassium carbonate, tetra(triphenylphosphine)palladium, and mixed solvent are mixed evenly in a mass ratio of 1:(2~3):(0.6~0.8):(0.1~0.2):(100~110). Under nitrogen protection, the mixture is stirred and refluxed at 70~80℃ and 200~300r / min for 20~24h. Under vacuum conditions, the mixture is dried at 50~60℃ for 2~3h. The mixture is washed 3~5 times each with anhydrous ethanol and deionized water. Under vacuum conditions, the mixture is dried at 50~60℃ for 7~8h to obtain modified chitosan. (2) Add hesperidin and 4-(chloromethyl)-1,3-dioxolane-2-one to N,N-dimethylformamide at a molar ratio of 1:3, which is 18 to 22 times the mass of hesperidin. Add benzyltriethylammonium chloride at a mass of 0.04 to 0.06 times the mass of hesperidin. Under nitrogen protection, stir the reaction at 70 to 80°C and 200 to 300 r / min for 2 to 3 hours. Add sodium hydroxide aqueous solution at a uniform rate of 1 to 2 times the mass of hesperidin dropwise over 20 minutes. After the addition is complete, continue stirring the reaction for 50 to 60 minutes. Dry the product under vacuum at 60 to 70°C for 8 to 10 hours to obtain functionalized hesperidin. (3) Polyamide, formaldehyde aqueous solution and N,N-dimethylformamide are mixed evenly in a mass ratio of 1:(3~4):(6~8), and stirred at 90~100℃ and 200~300r / min for 55~65min under nitrogen protection. The mixture is then filtered, washed 3~5 times with deionized water, and dried at 50~60℃ for 9~11h under vacuum to obtain modified polyamide. (4) Weigh 98-102 parts of modified polyamide, 7-8 parts of modified chitosan, 6-7 parts of functionalized hesperidin, and 1.3-1.5 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene by mass; mix the modified polyamide, modified chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene evenly, place them in an injection molding machine for injection molding, and after injection molding, keep them at 160-170℃ for 80-90 minutes, and let them cool naturally to room temperature to obtain an environmentally friendly plant-based biodegradable polymer material.
3. The method for preparing an environmentally friendly plant-based biodegradable polymer material according to claim 2, characterized in that, The preparation method of the pre-modified chitosan in step (1) is as follows: chitosan, acetic acid and methanol are mixed evenly in a mass ratio of 1:(2.5~2.7):(26~28), stirred and swollen at 200~300r / min for 100~120min at 20~30℃, 5-aldehyde furan-3-boronic acid pinacol ester with a mass of 2~2.2 times that of chitosan is added, the temperature is raised to 58~62℃, and the reaction is continued to be stirred for 10~12h. Under vacuum conditions, it is dried at 50~60℃ for 3~4h, washed 3~5 times with anhydrous ethanol, and dried at 50~60℃ for 7~8h under vacuum conditions to obtain pre-modified chitosan.
4. The method for preparing an environmentally friendly plant-based biodegradable polymer material according to claim 3, characterized in that, The degree of deacetylation of the chitosan is 92%, and the weight-average molecular weight is 200 kDa.
5. The method for preparing an environmentally friendly plant-based biodegradable polymer material according to claim 2, characterized in that, The method for preparing the mixed solvent in step (1) is as follows: Deionized water, tetrahydrofuran, and toluene are mixed evenly in a volume ratio of 1:(5~7):(7~9) to prepare a mixed solvent.
6. The method for preparing an environmentally friendly plant-based biodegradable polymer material according to claim 2, characterized in that, The sodium hydroxide aqueous solution in step (2) has a mass fraction of 16% to 18%.
7. The method for preparing an environmentally friendly plant-based biodegradable polymer material according to claim 2, characterized in that, The preparation method of the polyamide in step (3) is as follows: Dimethyl adipate and phosphorus diacid ester monomers are added to N,N-dimethylformamide at a molar ratio of 1:(0.6-0.8) to 6-8 times the mass of dimethyl adipate, and mixed evenly to prepare a diester reaction solution; 1,6-hexanediamine and N,N-dimethylformamide at a molar ratio of 2-2.2 times the molar amount of dimethyl adipate are mixed evenly at a mass ratio of 1:(4-5) to prepare a diamine reaction solution; the diester reaction solution is placed in a high-pressure reactor, and under a nitrogen atmosphere, at 40-50℃ and stirring at 200-300 r / min, the diamine reaction solution is added dropwise to the diester reaction solution at a uniform rate within 25 min. After the addition is completed, the temperature is raised to 155-165℃, and the reaction is continued to be stirred for 60-70 min. The mixture is then filtered, washed 3-5 times with diethyl ether, and dried at 70-80℃ for 8-10 h under vacuum to obtain the polyamide.
8. The method for preparing an environmentally friendly plant-based biodegradable polymer material according to claim 7, characterized in that, The method for preparing the phosphorus-containing diacid ester monomer is as follows: dimethyl trans-3-hexenedioic acid and methylphenyl-oxyphosphine are added to toluene at a molar ratio of 1:1 to 16-18 times the mass of dimethyl trans-3-hexenedioic acid, and azobisisobutyronitrile is added at 0.03-0.05 times the mass of dimethyl trans-3-hexenedioic acid. The mixture is stirred at 300-500 r / min for 3-4 h at 60-70 °C, and then dried at 50-60 °C under vacuum for 8-10 h to obtain the phosphorus-containing diacid ester monomer.
9. The method for preparing an environmentally friendly plant-based biodegradable polymer material according to claim 2, characterized in that, The formaldehyde aqueous solution in step (3) has a mass fraction of 35% to 37%.
10. The method for preparing an environmentally friendly plant-based biodegradable polymer material according to claim 2, characterized in that, The process parameters for injection molding in step (4) are as follows: the melt temperature for injection molding is set to 270-280℃, the injection pressure is set to 80-90MPa, the holding pressure is set to 40-50MPa, the holding time is set to 20-30s, and the mold temperature is set to 60-70℃.