Environment-friendly plant-based degradable high polymer material and preparation method thereof
Through the cross-linking network of modified chitosan, functionalized hesperidin and modified polyamide, the problem of decreased mechanical properties of plant-based polymer materials was solved, the mechanical properties and anti-aging properties of the materials were improved, and their application range was broadened.
Patent Information
- Application Number
- CN202510582184.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-07
- Publication Date
- 2025-09-05
- Estimated Expiration
- 2045-05-07
AI Technical Summary
After adding plant-based raw materials, the mechanical properties and durability of existing plant-based polymer materials decrease, which limits their further development and application.
Modified chitosan was prepared by reacting chitosan with 1-bromo-1,2,2-triphenylethylene, functionalized hesperetin was prepared by reacting hesperetin with 4-(chloromethyl)-1,3-dioxolane-2-one, modified polyamide was prepared by reacting polyamide with formaldehyde, and a cross-linked network was formed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene to improve the mechanical properties and anti-aging properties of the material.
It improves the mechanical properties and anti-aging properties of plant-based biodegradable polymer materials, broadens their application areas, and realizes the sustainable development of environmentally friendly materials.
Smart Images
Figure BDA0005390677860000031 
Figure BDA0005390677860000041 
Figure BDA0005390677860000051
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of polymer materials, in particular to an environmentally friendly plant-based degradable polymer material and a preparation method thereof. Background Art
[0002] The development of materials science has greatly promoted the progress of human society, and polymers are a key component of this advancement. While polymers, with their lightweight, convenient, and affordable properties, have brought significant convenience to our daily lives, many synthetic polymers suffer from defects such as aging and poor degradation, leading to environmental pollution that has become a major concern worldwide. Adding plant-based raw materials, such as cellulose and starch, to synthetic polymers is an effective method for enhancing the biodegradability of these materials. This approach is environmentally friendly and conserves non-renewable resources, leading to the extensive research and application of plant-based polymers. However, the addition of plant-based raw materials to synthetic polymers is often associated with decreased mechanical properties and durability, limiting their further development and application. Therefore, it is necessary to improve existing technologies to enhance the mechanical properties of plant-based polymers while retaining the plant-based raw materials and improving their degradation performance. This approach, along with broadening the application areas of plant-based polymers, is crucial for conserving resources and protecting the environment. Summary of the Invention
[0003] The purpose of the present invention is to provide an environmentally friendly plant-based degradable polymer material and a preparation method thereof, so as to solve the problems existing in the prior art.
[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:
[0005] An environmentally friendly plant-based degradable 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 hesperetin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene and then performing injection molding.
[0006] The pre-modified chitosan is prepared by reacting chitosan and 5-formylfuran-3-boronic acid pinacol ester;
[0007] The polyamide is prepared by polycondensing dimethyl adipate, a phosphorus 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-phosphine oxide;
[0009] The functionalized hesperetin is prepared by reacting hesperetin and 4-(chloromethyl)-1,3-dioxolane-2-one.
[0010] A method for preparing an environmentally friendly plant-based degradable polymer material, comprising the following steps:
[0011] (1) Pre-modified chitosan, 1-bromo-1,2,2-triphenylethylene, potassium carbonate, tetrakis(triphenylphosphine)palladium, and a mixed solvent were mixed uniformly in a mass ratio of 1:(2-3):(0.6-0.8):(0.1-0.2):(100-110), stirred and refluxed at 70-80°C and 200-300 r / min for 20-24 h under nitrogen protection, dried at 50-60°C for 2-3 h under vacuum conditions, washed with anhydrous ethanol and deionized water 3-5 times each, and dried at 50-60°C for 7-8 h under vacuum conditions to obtain modified chitosan;
[0012] (2) Hesperetin and 4-(chloromethyl)-1,3-dioxolane-2-one were added to N,N-dimethylformamide (18 to 22 times the mass of hesperetin) in a molar ratio of 1:3, and benzyltriethylammonium chloride (0.04 to 0.06 times the mass of hesperetin) was added. Under nitrogen protection, the mixture was stirred at 70 to 80°C and 200 to 300 r / min for 2 to 3 hours. A sodium hydroxide aqueous solution (1 to 2 times the mass of hesperetin) was added dropwise at a uniform speed within 20 minutes. After the addition was completed, the mixture was stirred and reacted for 50 to 60 minutes. The mixture was dried at 60 to 70°C under vacuum conditions for 8 to 10 hours to obtain functionalized hesperetin.
[0013] (3) polyamide, formaldehyde aqueous solution, and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:(3-4):(6-8), stirred at 90-100°C and 200-300 r / min for 55-65 min under nitrogen protection, filtered, washed with deionized water 3-5 times, and dried at 50-60°C under vacuum conditions for 9-11 h to obtain modified polyamide;
[0014] (4) Weigh 98-102 parts of modified polyamide, 7-8 parts of modified chitosan, 6-7 parts of functionalized hesperetin, 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 hesperetin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene evenly, place them in an injection molding machine for injection molding, keep them warm at 160-170°C for 80-90 minutes after injection molding, and naturally cool them 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 uniformly mixed in a mass ratio of 1: (2.5-2.7): (26-28), stirred and swelled at 20-30° C. and 200-300 r / min for 100-120 min, 5-formaldehyde furan-3-boronic acid pinacol ester 2-2.2 times the mass of chitosan is added, the temperature is raised to 58-62° C., the stirring reaction is continued for 10-12 h, dried at 50-60° C. for 3-4 h under vacuum conditions, washed with anhydrous ethanol 3-5 times, and dried at 50-60° C. for 7-8 h under vacuum conditions to obtain pre-modified chitosan; the reaction process is as follows:
[0016]
[0017] As an optimization, the chitosan has a deacetylation degree of 92% and a weight average molecular weight of 200 kDa.
[0018] As an optimization, the preparation method of the mixed solvent in step (1) is: deionized water, tetrahydrofuran, and toluene are uniformly mixed 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 functionalized hesperetin in step (2) is as follows:
[0023]
[0024] As an optimization, the CAS number of 4-(chloromethyl)-1,3-dioxolane-2-one 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 monomer are added to N, N-dimethylformamide with a molar ratio of 1: (0.6-0.8) at a mass ratio of 1: (0.6-0.8) at a mass ratio of 6-8 times the mass of dimethyl adipate, and the mixture is uniformly mixed to prepare a diester reaction liquid; 1,6-hexanediamine with a molar ratio of 2-2.2 times the mass of dimethyl adipate and N, N-dimethylformamide are uniformly mixed at a mass ratio of 1: (4-5) at a mass ratio to prepare a diester reaction liquid. The amine reaction liquid; the diester reaction liquid is placed in a high-pressure reactor, and under a nitrogen atmosphere, at 40-50° C. and 200-300 r / min stirring conditions, the diamine reaction liquid is uniformly added dropwise to the diester reaction liquid within 25 minutes, after the dropwise addition is completed, the temperature is raised to 155-165° C., and the stirring reaction is continued for 60-70 minutes, filtered, washed with ether 3-5 times, and dried at 70-80° C. under vacuum conditions for 8-10 hours to obtain polyamide.
[0026] As an optimization, the preparation method of the phosphorus-containing diacid ester monomer is as follows: trans-3-hexenedioic acid dimethyl ester and methylphenyl-phosphine oxide are added in a molar ratio of 1:1 to toluene with a mass of 16 to 18 times that of trans-3-hexenedioic acid dimethyl ester, and azobisisobutyronitrile with a mass of 0.03 to 0.05 times that of trans-3-hexenedioic acid dimethyl ester is added, and the mixture is stirred at 60 to 70° C. and 300 to 500 r / min for 3 to 4 hours, and dried at 50 to 60° C. under vacuum conditions for 8 to 10 hours 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 of the injection molding in step (4) are as follows: the melt temperature of the injection molding is set to 270-280°C, the injection pressure is set to 80-90 MPa, the holding pressure is set to 40-50 MPa, the holding time is set to 20-30s, and the mold temperature is set to 60-70°C.
[0032] Compared with the prior art, the beneficial effects achieved by the present invention are:
[0033] The present invention prepares an environmentally friendly plant-based degradable polymer material by reacting chitosan and 5-formylfuran-3-boronic acid pinacol ester to obtain pre-modified chitosan; reacting the pre-modified chitosan and 1-bromo-1,2,2-triphenylethylene to obtain modified chitosan; reacting hesperetin and 4-(chloromethyl)-1,3-dioxolane-2-one to obtain functionalized hesperetin; reacting trans-3-hexenedioic acid dimethyl ester and methylphenyl-phosphine to obtain a phosphorus-containing diacid ester monomer; polycondensing the dimethyl adipate and the phosphorus-containing diacid ester monomer with 1,6-hexanediamine to obtain polyamide; reacting the polyamide and formaldehyde to obtain a modified polyamide; and mixing the modified polyamide, modified chitosan, functionalized hesperetin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene, followed by injection molding to obtain the environmentally friendly plant-based degradable polymer material.
[0034] First, chitosan and 5-formylfuran-3-boronic acid pinacol ester are reacted to produce pre-modified chitosan. The pre-modified chitosan and 1-bromo-1,2,2-triphenylethylene are then reacted to produce modified chitosan. A triphenylvinylfuran structure is generated on the modified chitosan through a classic palladium-catalyzed cross-coupling reaction. The triphenylvinylfuran structure can undergo a ring-closing reaction under the action of ultraviolet light and a ring-opening reaction under the action of visible light. This reversible ring-opening reaction can absorb ultraviolet light and release it in a harmless form, thereby improving the anti-aging properties of the environmentally friendly plant-based biodegradable polymer material. The mechanism of action is as follows:
[0035]
[0036] Secondly, hesperetin and 4-(chloromethyl)-1,3-dioxolane-2-one are reacted to obtain functionalized hesperetin; a cyclic carbonate group is introduced into the functionalized hesperetin; hesperetin is a natural flavonoid compound whose molecular structure contains a rigid structure and a benzopyran ring structure, which can effectively increase the carbonization rate of polymer materials, reduce heat release, and reduce the release of volatile combustibles, thereby improving the flame retardant properties of environmentally friendly plant-based degradable polymer materials; the cyclic carbonate group introduced into the functionalized hesperetin can undergo a ring-opening etherification reaction 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 the catalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene to form a cross-linked network, inhibit the relative slip between molecular chains, and improve the mechanical properties of the environmentally friendly plant-based degradable polymer materials.
[0037] Finally, trans-3-hexenedioic acid dimethyl ester and methylphenylphosphine oxide are reacted to prepare a phosphorus-containing diacid ester monomer; dimethyl adipate and the phosphorus-containing diacid ester monomer are condensed with 1,6-hexanediamine to prepare polyamide, and phosphorus elements are introduced into the side chains of the polyamide molecular chains. The introduction of phosphorus elements can further improve the flame retardant properties of the environmentally friendly plant-based degradable polymer material; polyamide and formaldehyde are reacted to prepare modified polyamide, 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 a ring-opening etherification reaction with the cyclic carbonate groups introduced on the functionalized hesperetin under the action of the catalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene, forming a cross-linked network, inhibiting the relative slip between molecular chains, and improving the mechanical properties of the environmentally friendly plant-based degradable polymer material. DETAILED DESCRIPTION
[0038] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0039] Example 1:
[0040] A method for preparing an environmentally friendly plant-based degradable polymer material, comprising the following steps:
[0041] (1) Chitosan, acetic acid, and methanol were mixed uniformly in a mass ratio of 1:2.5:26, stirred and swollen at 20°C and 200 r / min for 120 min, 5-formyl furan-3-boronic acid pinacol ester (2 times the mass of chitosan) was added, the temperature was raised to 58°C, and the stirring reaction was continued for 12 h. The mixture was dried at 50°C for 4 h under vacuum conditions, washed with anhydrous ethanol 3 times, and dried at 50°C for 8 h under vacuum conditions to obtain pre-modified chitosan. Deionized water, tetrahydrofuran, and toluene were mixed in a volume ratio of 1:2.5:26. 1:5:7 were mixed to prepare a mixed solvent; pre-modified chitosan, 1-bromo-1,2,2-triphenylethylene, potassium carbonate, tetrakis(triphenylphosphine)palladium and the mixed solvent were mixed in a mass ratio of 1:2:0.6:0.1:100, under nitrogen protection, stirred and refluxed at 70 ° C and 200 r / min for 24 h, dried at 50 ° C for 3 h under vacuum conditions, washed with anhydrous ethanol and deionized water 3 times each, and dried at 50 ° C for 8 h under vacuum conditions to obtain modified chitosan;
[0042] (2) Hesperetin and 4-(chloromethyl)-1,3-dioxolane-2-one were added to N,N-dimethylformamide (18 times the mass of hesperetin) in a molar ratio of 1:3, and benzyltriethylammonium chloride (0.04 times the mass of hesperetin) was added. Under nitrogen protection, the mixture was stirred at 70°C and 200 r / min for 3 hours. An 18% sodium hydroxide aqueous solution (1 times the mass of hesperetin) was added dropwise at a constant speed within 20 minutes. After the addition was completed, the mixture was stirred and reacted for 60 minutes. The mixture was dried at 60°C for 10 hours under vacuum conditions to obtain functionalized hesperetin.
[0043] (3) Add trans-3-hexenedioic acid dimethyl ester and methylphenyl-phosphine in a molar ratio of 1:1 to toluene with a mass of 16 times that of trans-3-hexenedioic acid dimethyl ester, add azobisisobutyronitrile with a mass of 0.03 times that of trans-3-hexenedioic acid dimethyl ester, stir and react at 60°C, 300r / min for 4h, and dry at 50°C for 10h under vacuum conditions to obtain a phosphorus-containing diacid ester monomer; add dimethyl adipate and phosphorus-containing diacid ester monomer in a molar ratio of 1:0.6 to N,N-dimethylformamide with a mass of 6 times that of dimethyl adipate, mix them evenly to prepare a diester reaction liquid; mix 1,6-hexanediamine with a mass of 2 times that of dimethyl adipate and N,N-dimethylformamide at a mass ratio of 1:4 to prepare a diamine reaction liquid; placing the diester reaction liquid in a high-pressure reactor, under a nitrogen atmosphere, at 40°C, 200r / min stirring conditions, the diamine reaction liquid is uniformly added dropwise to the diester reaction liquid within 25 minutes, after the dropwise addition is completed, the temperature is raised to 155°C, stirring and reacting for 70 minutes, filtering, washing with ether three times, and drying at 70°C under vacuum conditions for 10 hours to obtain polyamide; polyamide, a 37% formaldehyde aqueous solution, and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:3:6, under nitrogen protection, at 90°C, 300r / min stirring and reacting for 65 minutes, filtering, washing with deionized water three times, and drying at 50°C under vacuum conditions for 11 hours to obtain modified polyamide;
[0044] (4) According to the mass ratio, 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 were weighed; the modified polyamide, modified chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene were mixed evenly, placed in an injection molding machine for injection molding, and the melt temperature of the injection molding was set to 270°C, the injection pressure was 80MPa, the holding pressure was 40MPa, the holding time was 30s, and the mold temperature was 60°C. After injection molding, the mixture was kept at 160°C for 90min and naturally cooled 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 degradable polymer material, comprising the following steps:
[0047] (1) Chitosan, acetic acid and methanol were mixed uniformly in a mass ratio of 1:2.6:27, stirred and swollen at 25°C and 250 r / min for 110 min, 5-formyl furan-3-boronic acid pinacol ester (2.1 times the mass of chitosan) was added, the temperature was raised to 60°C, and the stirring reaction was continued for 11 h. The mixture was dried at 55°C for 3.5 h under vacuum conditions, washed with anhydrous ethanol 4 times, and dried at 55°C for 7.5 h under vacuum conditions to obtain pre-modified chitosan. Deionized water, tetrahydrofuran and toluene were mixed in a volume ratio of 1:2.6:27. :6:8 are mixed evenly to prepare a mixed solvent; pre-modified chitosan, 1-bromo-1,2,2-triphenylethylene, potassium carbonate, tetrakis(triphenylphosphine)palladium, and the mixed solvent are mixed evenly in a mass ratio of 1:2.5:0.7:0.15:105, under nitrogen protection, stirred and refluxed at 75°C and 250r / min for 22h, dried at 55°C for 2.5h under vacuum conditions, washed with anhydrous ethanol and deionized water 4 times each, and dried at 55°C for 7.5h under vacuum conditions to obtain modified chitosan;
[0048] (2) Hesperetin and 4-(chloromethyl)-1,3-dioxolane-2-one were added to N,N-dimethylformamide (20 times the mass of hesperetin) in a molar ratio of 1:3, and benzyltriethylammonium chloride (0.05 times the mass of hesperetin) was added. Under nitrogen protection, the mixture was stirred at 75°C and 250 r / min for 2.5 hours. A 17% sodium hydroxide aqueous solution (1.5 times the mass of hesperetin) was added dropwise at a constant speed within 20 minutes. After the addition was completed, the mixture was stirred and reacted for 55 minutes. The mixture was dried at 65°C under vacuum for 9 hours to obtain functionalized hesperetin.
[0049] (3) Add trans-3-hexenedioic acid dimethyl ester and methylphenyl-phosphine in a molar ratio of 1:1 to toluene with a mass of 17 times that of trans-3-hexenedioic acid dimethyl ester, add azobisisobutyronitrile with a mass of 0.04 times that of trans-3-hexenedioic acid dimethyl ester, stir and react at 65°C, 400r / min for 3.5h, and dry at 55°C under vacuum for 9h to obtain phosphorus-containing diacid ester monomer; add dimethyl adipate and phosphorus-containing diacid ester monomer in a molar ratio of 1:0.7 to N,N-dimethylformamide with a mass of 7 times that of dimethyl adipate, mix well to prepare diester reaction liquid; mix 1,6-hexanediamine with a mass of 2.1 times that of dimethyl adipate and N,N-dimethylformamide in a mass ratio of 1:4.5 to prepare preparing a diamine reaction liquid; placing the diester reaction liquid in a high-pressure reactor, under a nitrogen atmosphere, at 45° C., 250 r / min stirring conditions, uniformly adding the diamine reaction liquid dropwise to the diester reaction liquid within 25 minutes, raising the temperature to 160° C. after the addition is complete, continuing to stir and react for 65 minutes, filtering with suction, washing with ether four times, and drying at 75° C. under vacuum conditions for 9 hours to obtain a polyamide; uniformly mixing the polyamide, a 36% formaldehyde aqueous solution, and N,N-dimethylformamide in a mass ratio of 1:3.5:7, stirring and reacting at 95° C., 250 r / min under nitrogen protection for 60 minutes, filtering with suction, washing with deionized water four times, and drying at 55° C. under vacuum conditions for 10 hours to obtain a modified polyamide;
[0050] (4) According to the mass ratio, 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 were weighed; the modified polyamide, modified chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene were mixed evenly, placed in an injection molding machine for injection molding, and the melt temperature of the injection molding was set to 275°C, the injection pressure was 85MPa, the holding pressure was 45MPa, the holding time was 25s, and the mold temperature was 65°C. After injection molding, the temperature was kept at 165°C for 85min and naturally cooled to room temperature to obtain an environmentally friendly plant-based degradable polymer material.
[0051] Example 3:
[0052] A method for preparing an environmentally friendly plant-based degradable polymer material, comprising the following steps:
[0053] (1) Chitosan, acetic acid, and methanol were mixed uniformly in a mass ratio of 1:2.7:28, stirred and swollen at 30°C and 300 r / min for 100 min, 5-formyl furan-3-boronic acid pinacol ester (2.2 times the mass of chitosan) was added, the temperature was raised to 62°C, and the stirring reaction was continued for 10 h. The mixture was dried at 60°C for 3 h under vacuum conditions, washed with anhydrous ethanol 5 times, and dried at 60°C for 7 h under vacuum conditions to obtain pre-modified chitosan. Deionized water, tetrahydrofuran, and toluene were mixed in a volume ratio of 1:2.7:28. The pre-modified chitosan, 1-bromo-1,2,2-triphenylethylene, potassium carbonate, tetrakis(triphenylphosphine)palladium and the mixed solvent were mixed in a mass ratio of 1:3:0.8:0.2:110, stirred and refluxed at 80°C and 300 r / min for 20 h under nitrogen protection, dried at 60°C for 2 h under vacuum conditions, washed with anhydrous ethanol and deionized water 5 times each, and dried at 60°C for 7 h under vacuum conditions to obtain modified chitosan;
[0054] (2) Hesperetin and 4-(chloromethyl)-1,3-dioxolane-2-one were added to N,N-dimethylformamide (22 times the mass of hesperetin) in a molar ratio of 1:3, and benzyltriethylammonium chloride (0.06 times the mass of hesperetin) was added. Under nitrogen protection, the mixture was stirred at 80°C and 300 r / min for 2 hours. A 16% sodium hydroxide aqueous solution (2 times the mass of hesperetin) was added dropwise at a constant speed within 20 minutes. After the addition was completed, the mixture was stirred and reacted for 60 minutes. The mixture was dried at 60°C for 10 hours under vacuum conditions to obtain functionalized hesperetin.
[0055] (3) Add trans-3-hexenedioic acid dimethyl ester and methylphenyl-phosphine in a molar ratio of 1:1 to toluene with a mass of 18 times that of trans-3-hexenedioic acid dimethyl ester, add azobisisobutyronitrile with a mass of 0.05 times that of trans-3-hexenedioic acid dimethyl ester, stir and react at 70°C, 500r / min for 3h, and dry at 60°C under vacuum for 8h to obtain phosphorus-containing diacid ester monomer; add dimethyl adipate and phosphorus-containing diacid ester monomer in a molar ratio of 1:0.8 to N,N-dimethylformamide with a mass of 8 times that of dimethyl adipate, mix them evenly to prepare diester reaction liquid; mix 1,6-hexanediamine with a mass of 2.2 times that of dimethyl adipate and N,N-dimethylformamide at a mass ratio of 1:5 to prepare The diester reaction liquid was placed in a high-pressure reactor, and under a nitrogen atmosphere, at 50°C and 300 r / min stirring conditions, the diamine reaction liquid was uniformly added dropwise to the diester reaction liquid within 25 minutes. After the dropwise addition was completed, the temperature was raised to 165°C, and the stirring reaction was continued for 60 minutes. The mixture was filtered, washed with ether 5 times, and dried at 80°C under vacuum conditions for 8 hours to obtain polyamide; polyamide, a 35% formaldehyde aqueous solution, and N,N-dimethylformamide were uniformly mixed in a mass ratio of 1:4:8, and under nitrogen protection, the mixture was stirred at 100°C and 300 r / min for 55 minutes. The mixture was filtered, washed with deionized water 5 times, and dried at 60°C under vacuum conditions for 9 hours to obtain modified polyamide;
[0056] (4) According to the mass ratio, 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 were weighed; the modified polyamide, modified chitosan, functionalized hesperidin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene were mixed evenly, placed in an injection molding machine for injection molding, and the melt temperature of the injection molding was set to 280°C, the injection pressure was 90 MPa, the holding pressure was 50 MPa, the holding time was 20 s, and the mold temperature was 70°C. After injection molding, the mixture was kept at 170°C for 80 minutes and naturally cooled to room temperature to obtain an environmentally friendly plant-based biodegradable polymer material.
[0057] Comparative Example 1:
[0058] The difference between the preparation method of the environmentally friendly plant-based degradable polymer material of Comparative Example 1 and Example 2 is that step (1) is not performed, and step (4) is modified as follows: 100 parts of modified polyamide, 7.5 parts of chitosan, 6.5 parts of functionalized hesperetin, and 1.4 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene are weighed by mass; the modified polyamide, chitosan, functionalized hesperetin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene are mixed uniformly, placed in an injection molding machine for injection molding, and the melt temperature of the injection molding is set to 275°C, the injection pressure is 85MPa, the holding pressure is 45MPa, the holding time is 25s, and the mold temperature is 65°C. After injection molding, the temperature is kept at 165°C for 85min and naturally cooled to room temperature to obtain an environmentally friendly plant-based degradable 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 degradable polymer material of Comparative Example 2 differs from that of Example 2 in that step (2) is not performed, and step (4) is modified as follows: 100 parts of modified polyamide, 7.5 parts of modified chitosan, 6.5 parts of hesperetin, and 1.4 parts of 1,5,7-triazabicyclo[4.4.0]dec-5-ene are weighed by mass; the modified polyamide, modified chitosan, hesperetin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene are mixed uniformly, placed in an injection molding machine for injection molding, and the melt temperature for injection molding is set to 275°C, the injection pressure is 85MPa, the holding pressure is 45MPa, the holding time is 25s, and the mold temperature is 65°C. After injection molding, the temperature is kept at 165°C for 85min and naturally cooled to room temperature to obtain an environmentally friendly plant-based degradable 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 degradable polymer material of Comparative Example 3 differs from that of Example 2 in that step (2) is not performed, 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 uniformly, placed in an injection molding machine for injection molding, and the melt temperature for injection molding is set to 275°C, the injection pressure is 85MPa, the holding pressure is 45MPa, the holding time is 25s, and the mold temperature is 65°C. After injection molding, the temperature is kept at 165°C for 85min and naturally cooled to room temperature to obtain an environmentally friendly plant-based degradable polymer material. The remaining steps are the same as those in Example 2.
[0063] Comparative Example 4:
[0064] The preparation method of the environmentally friendly plant-based degradable polymer material of Comparative Example 4 is different from that of Example 2 only in step (3). Step (3) is modified as follows: dimethyl adipate and trans-3-hexenedioate are added to N, N-dimethylformamide with a molar ratio of 1:0.7, and mixed evenly to prepare a diester reaction liquid; 1,6-hexanediamine with a molar amount of 2.1 times that of dimethyl adipate and N, N-dimethylformamide are mixed evenly in a mass ratio of 1:4.5 to prepare a diamine reaction liquid; the diester reaction liquid is placed in a high-pressure reactor and heated under a nitrogen atmosphere at 45°C, 2 The diamine reaction solution was added dropwise to the diester reaction solution at a constant rate over 25 minutes under stirring at 50 rpm. After the addition was complete, the temperature was raised to 160°C and the mixture was stirred for 65 minutes. The mixture was filtered, washed four times with ether, and dried at 75°C under vacuum for 9 hours to produce polyamide. The polyamide, a 36% formaldehyde aqueous solution, and N,N-dimethylformamide were mixed in a mass ratio of 1:3.5:7, stirred at 95°C and 250 rpm under nitrogen for 60 minutes, filtered, washed four times with deionized water, and dried at 55°C under vacuum for 10 hours to produce 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 degradable polymer material of Comparative Example 5 is different from that of Example 2 only in step (3). Step (3) is modified as follows: trans-3-hexenedioic acid dimethyl ester and methylphenyl-phosphine are added in a molar ratio of 1:1 to toluene 17 times the mass of trans-3-hexenedioic acid dimethyl ester, and azobisisobutyronitrile is added in a molar ratio of 0.04 times the mass of trans-3-hexenedioic acid dimethyl ester. The mixture is stirred at 65°C and 400r / min for 3.5h, and dried at 55°C for 9h under vacuum conditions to obtain a phosphorus-containing diacid ester monomer; dimethyl adipate and phosphorus-containing diacid ester monomer are added in a molar ratio of 1:0.7 to dimethyl adipate. A diester reaction solution was prepared by uniformly mixing 7 times the molar amount of dimethyl adipate with N,N-dimethylformamide to form a diester reaction solution. 1,6-hexanediamine (2.1 times the molar amount of dimethyl adipate) and N,N-dimethylformamide were uniformly mixed in a mass ratio of 1:4.5 to form a diamine reaction solution. The diester reaction solution was placed in an autoclave and, under a nitrogen atmosphere, stirred at 45°C and 250 rpm, 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 product was filtered, washed four times with ether, and dried under vacuum at 75°C for 9 hours to produce a 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: Example and comparative examples were prepared into standard bars according to GB / T 1040. The tensile strength F of the standard bars was measured. The standard bars were irradiated with a xenon arc lamp for 15 days, and their tensile strength M was measured. The change in tensile strength of the example and comparative example before and after UV aging was calculated: tensile strength change = (F / F) / F × 100%. The results are shown in Table 1.
[0070] Table 1
[0071]
[0072] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 1, it can be found that the environmentally friendly plant-based degradable polymer material prepared by the present invention has good mechanical properties and anti-aging properties.
[0073] By comparison, the tensile strength of Examples 1 to 3 is greater than that of Comparative Examples 2 to 3, indicating that functionalized hesperetin is prepared by reacting hesperetin and 4-(chloromethyl)-1,3-dioxolane-2-one; a cyclic carbonate group is introduced into the functionalized hesperetin; the cyclic carbonate group introduced into the functionalized hesperetin can undergo a ring-opening etherification reaction 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 to form a cross-linked network, thereby inhibiting the relative slip between the molecular chains and improving the mechanical properties of the environmentally friendly plant-based degradable polymer material.
[0074] By comparison, the tensile strength of Examples 1 to 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 a ring-opening etherification reaction with the cyclic carbonate groups introduced into the functionalized hesperetin to form a cross-linked network, thereby inhibiting the relative slip between the molecular chains and improving the mechanical properties of the environmentally friendly plant-based degradable polymer material.
[0075] By comparison, the rate of change of tensile strength of Examples 1 to 3 is less than the rate of change of tensile strength of Comparative Example 1, indicating that pre-modified chitosan is prepared by reacting chitosan and 5-formylfuran-3-boronic acid pinacol ester; modified chitosan is prepared by reacting pre-modified chitosan and 1-bromo-1,2,2-triphenylethylene; and a triphenylvinylfuran structure is generated on the modified chitosan through a classic palladium-catalyzed cross-coupling reaction. The triphenylvinylfuran structure can undergo a ring-closing reaction under the action of ultraviolet light and a ring-opening reaction under the action of visible light. This reversible ring-opening reaction can absorb ultraviolet light and release the ultraviolet light in a harmless form, thereby improving the anti-aging properties of the environmentally friendly plant-based degradable polymer material.
[0076] Test Example 2
[0077] Flame retardant performance test
[0078] Test method: The examples and comparative examples were prepared into standard specimens according to GB / T 2406, and the limiting oxygen index of the standard specimens 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] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 2, it can be found that the environmentally friendly plant-based degradable polymer material prepared by the present invention has good flame retardant properties.
[0082] By comparison, the limiting oxygen index of Examples 1 to 3 is greater than that of Comparative Example 3, indicating that hesperetin is a natural flavonoid compound whose molecular structure contains a rigid structure and a benzopyran ring structure. Adding hesperetin to a polymer material can effectively increase the carbonization rate of the polymer material, reduce heat release, and reduce the release of volatile combustibles, thereby improving the flame retardant properties of the environmentally friendly plant-based degradable polymer material.
[0083] By comparison, the limiting oxygen index of Examples 1 to 3 is greater than that of Comparative Example 4, indicating that a phosphorus-containing diacid ester monomer is prepared by reacting trans-3-hexenedioic acid dimethyl ester and methylphenyl-phosphine; and a polyamide is prepared by condensing dimethyl adipate, the phosphorus-containing diacid ester monomer and 1,6-hexanediamine, and introducing phosphorus elements into the side chains of the polyamide molecular chains. The introduction of phosphorus elements can further enhance the flame retardant properties of the environmentally friendly plant-based degradable polymer material.
[0084] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method 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 in the scope of protection of the present invention.
Claims
1. An environmentally friendly plant-based degradable 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 to obtain modified chitosan; reacting polyamide and formaldehyde to obtain modified polyamide; and mixing the modified polyamide, modified chitosan, functionalized hesperetin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene and then performing injection molding. The pre-modified chitosan is prepared by reacting chitosan and 5-formylfuran-3-boronic acid pinacol ester; The polyamide is prepared by polycondensing dimethyl adipate, a phosphorus diacid ester monomer and 1,6-hexanediamine; The phosphorus-containing diacid ester monomer is prepared by reacting trans-3-hexenedioic acid dimethyl ester and methylphenyl-phosphine oxide; The functionalized hesperetin is prepared by reacting hesperetin and 4-(chloromethyl)-1,3-dioxolane-2-one.
2. A method for preparing an environmentally friendly plant-based degradable polymer material, characterized in that: The preparation method of the environmentally friendly plant-based degradable polymer material comprises the following preparation steps: (1) Pre-modified chitosan, 1-bromo-1,2,2-triphenylethylene, potassium carbonate, tetrakis(triphenylphosphine)palladium, and a mixed solvent were mixed uniformly in a mass ratio of 1:(2-3):(0.6-0.8):(0.1-0.2):(100-110), stirred and refluxed at 70-80°C and 200-300 r / min for 20-24 h under nitrogen protection, dried at 50-60°C for 2-3 h under vacuum conditions, washed with anhydrous ethanol and deionized water 3-5 times each, and dried at 50-60°C for 7-8 h under vacuum conditions to obtain modified chitosan; (2) Hesperetin and 4-(chloromethyl)-1,3-dioxolane-2-one were added to N,N-dimethylformamide (18 to 22 times the mass of hesperetin) in a molar ratio of 1:3, and benzyltriethylammonium chloride (0.04 to 0.06 times the mass of hesperetin) was added. Under nitrogen protection, the mixture was stirred at 70 to 80°C and 200 to 300 r / min for 2 to 3 hours. A sodium hydroxide aqueous solution (1 to 2 times the mass of hesperetin) was added dropwise at a uniform speed within 20 minutes. After the addition was completed, the mixture was stirred and reacted for 50 to 60 minutes. The mixture was dried at 60 to 70°C under vacuum conditions for 8 to 10 hours to obtain functionalized hesperetin. (3) polyamide, formaldehyde aqueous solution, and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:(3-4):(6-8), stirred at 90-100°C and 200-300 r / min for 55-65 min under nitrogen protection, filtered, washed with deionized water 3-5 times, and dried at 50-60°C under vacuum conditions for 9-11 h to obtain modified polyamide; (4) Weigh 98-102 parts of modified polyamide, 7-8 parts of modified chitosan, 6-7 parts of functionalized hesperetin, 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 hesperetin, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene evenly, place them in an injection molding machine for injection molding, keep them warm at 160-170°C for 80-90 minutes after injection molding, and naturally cool them to room temperature to obtain an environmentally friendly plant-based biodegradable polymer material.
3. The method for preparing an environmentally friendly plant-based degradable 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 uniformly mixed in a mass ratio of 1: (2.5-2.7): (26-28), stirred and swelled at 20-30° C. and 200-300 r / min for 100-120 min, 5-formyl furan-3-boronic acid pinacol ester (2-2.2 times the mass of chitosan) is added, the temperature is raised to 58-62° C., the stirring reaction is continued for 10-12 h, the mixture is dried at 50-60° C. for 3-4 h under vacuum conditions, washed with anhydrous ethanol 3-5 times, and dried at 50-60° C. for 7-8 h under vacuum conditions to obtain pre-modified chitosan.
4. The method for preparing an environmentally friendly plant-based degradable polymer material according to claim 3, characterized in that: The chitosan has a deacetylation degree of 92% and a weight-average molecular weight of 200 kDa.
5. The method for preparing an environmentally friendly plant-based degradable polymer material according to claim 2, characterized in that: The preparation method of the mixed solvent in step (1) is as follows: deionized water, tetrahydrofuran and toluene are uniformly mixed 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 degradable polymer material according to claim 2, characterized in that: The mass fraction of the sodium hydroxide aqueous solution in step (2) is 16% to 18%.
7. The method for preparing an environmentally friendly plant-based degradable 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-containing diacid ester monomer are added to N,N-dimethylformamide with a molar ratio of 1:(0.6-0.8) at a mass ratio of 1:(0.6-0.8) at a mass ratio of 6-8 times the mass of dimethyl adipate, and the mixture is evenly mixed to prepare a diester reaction liquid; 1,6-hexanediamine with a molar ratio of 2-2.2 times the mass of dimethyl adipate and N,N-dimethylformamide are evenly mixed at a mass ratio of 1:(4-5) to prepare a diamine reaction liquid; the diester reaction liquid is placed in a high-pressure reactor, and under a nitrogen atmosphere, at 40-50° C. and 200-300 r / min of stirring, the diamine reaction liquid is uniformly added dropwise to the diester reaction liquid within 25 minutes, and after the dropwise addition is completed, the temperature is raised to 155-165° C., the stirring reaction is continued for 60-70 minutes, the mixture is filtered, washed with ether for 3-5 times, and dried at 70-80° C. under vacuum conditions for 8-10 hours to prepare the polyamide.
8. The method for preparing an environmentally friendly plant-based degradable polymer material according to claim 7, characterized in that: The preparation method of the phosphorus-containing diacid ester monomer comprises the following steps: adding trans-3-hexenedioic acid dimethyl ester and methylphenylphosphine oxide in a molar ratio of 1:1 to toluene with a mass 16 to 18 times that of trans-3-hexenedioic acid dimethyl ester, adding azobisisobutyronitrile with a mass 0.03 to 0.05 times that of trans-3-hexenedioic acid dimethyl ester, stirring at 60 to 70° C. and 300 to 500 r / min for reaction for 3 to 4 hours, and drying at 50 to 60° C. under vacuum conditions for 8 to 10 hours to obtain the phosphorus-containing diacid ester monomer.
9. The method for preparing an environmentally friendly plant-based degradable polymer material according to claim 2, characterized in that: The mass fraction of the formaldehyde aqueous solution in step (3) is 35% to 37%.
10. The method for preparing an environmentally friendly plant-based degradable polymer material according to claim 2, characterized in that: The process parameters of the injection molding in step (4) are as follows: setting the melt temperature of the injection molding to 270-280°C, the injection pressure to 80-90 MPa, the holding pressure to 40-50 MPa, the holding time to 20-30 s, and the mold temperature to 60-70°C.