Bio-based degradable polyurethane film material and preparation method thereof

Abstract

The bio-based degradable polyurethane film material is prepared from the following raw materials in parts by weight: 20.7 to 30.4 parts of bis (2-hydroxyethyl) terephthalate, 34.5 to 51.2 parts of bio-based dimer acid, 10.5 to 33.4 parts of diisocyanate, 2.6 to 8.3 parts of a chain extender, 0.5 to 2.3 parts of p-toluenesulfonic acid, 0.2 to 1.8 parts of dibutyltin dilaurate, 0.6 to 3.5 parts of an internal crosslinking agent, 62.4 to 85 parts of DMF (Dimethyl Formamide), 16.8 to 25.6 parts of butanone and 13.7 to 20.3 parts of a coating raw material, the invention also discloses a preparation method of the membrane material. The raw materials adopt bio-based components, so that the dependence on petrochemical resources is reduced; the preparation process conditions are clear and mild, and industrial production and quality control are facilitated; the product has good performance, degradability, excellent mechanical property, heat resistance and surface performance; the application expansibility is high, the coating raw materials endow antibacterial performance, the antibacterial agent contains a quaternary ammonium salt structure and a complexing functional group, the antibacterial effect is achieved through electrostatic interaction, cell lysis and other mechanisms, and the antibacterial effect is lasting.

Description

Technical Field

[0001] The invention belongs to the technical field of water pipes and relates to a bio-based degradable polyurethane film material and a preparation method thereof. Background Art

[0002] With growing environmental awareness, the environmental pollution caused by traditional plastic products is gaining increasing attention. Traditional plastics are difficult to degrade in the natural environment, and the accumulation of large amounts of discarded plastics creates "white pollution," wreaking havoc on soil, water resources, and ecosystems. Therefore, the development of biodegradable materials to replace traditional plastics has become a research hotspot in materials science. Polyurethane (PU) materials, due to their excellent mechanical properties, wear resistance, and chemical resistance, have been widely used in numerous fields, such as packaging, medical treatment, and construction. However, traditional PU materials are typically derived from non-renewable petroleum resources and are often difficult to degrade, making them unsuitable for sustainable development. Bio-based materials, as a renewable resource, offer advantages such as widespread availability and environmental friendliness. Using bio-based raw materials to produce biodegradable PU materials not only reduces dependence on petroleum resources but also allows them to naturally degrade upon disposal, minimizing environmental pollution. While some research has been conducted on bio-based degradable PU materials, numerous challenges remain in terms of material properties and preparation processes. Furthermore, various pathogenic microorganisms are widely distributed in nature and, under certain conditions, can grow, reproduce, and even mutate, causing corrosion and decomposition of materials and posing a threat to human health. Therefore, antibacterial products that can protect health are becoming more and more popular. Summary of the Invention

[0003] The object of the present invention is to provide a bio-based degradable polyurethane film material and a preparation method thereof, so as to solve the problem of poor antibacterial performance of the polyurethane film material mentioned in the background art.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A bio-based degradable polyurethane film material comprises the following raw materials in parts by weight: 20.7-30.4 parts of bis(2-hydroxyethyl) terephthalate, 34.5-51.2 parts of bio-based dimer acid, 10.5-33.4 parts of diisocyanate, 2.6-8.3 parts of a chain extender, 0.5-2.3 parts of p-toluenesulfonic acid, 0.2-1.8 parts of dibutyltin dilaurate, 0.6-3.5 parts of an internal crosslinking agent, 62.4-85 parts of DMF, 16.8-25.6 parts of butanone, and 13.7-20.3 parts of a coating raw material;

[0006] The bio-based degradable polyurethane film material is prepared by the following steps:

[0007] Step A1, dissolving bis(2-hydroxyethyl) terephthalate in DMF, mixing with bio-based dimer acid, adding p-toluenesulfonic acid, reacting at 160-180° C. for 5-10 hours, dissolving in chloroform after the reaction is complete, and precipitating in methanol to obtain a bio-based polyester polyol;

[0008] Step A2, reacting a bio-based polyester polyol with a diisocyanate and a chain extender at 65-75° C. for 1-3 hours, adding dibutyltin dilaurate, and reacting at 60-80° C. for 1-2 hours to obtain a bio-based polyurethane prepolymer;

[0009] Step A3, mixing the bio-based polyurethane prepolymer with an internal crosslinking agent, stirring and reacting at 55-75° C. for 2-4 hours, and adding butanone to dilute the reaction during the reaction to obtain a bio-based polyurethane emulsion;

[0010] Step A4: evenly spread the bio-based polyurethane emulsion on a dry, clean mold to form a liquid layer with uniform thickness and a smooth surface, and dry it at 55-70° C. for 8-10 hours to obtain a preform;

[0011] Step A5: evenly apply the coating material on the preform, and dry it at 60-80° C. for 5-7 hours to obtain a bio-based degradable polyurethane film material.

[0012] Furthermore, the bio-based dimer acid is one of hydrogenated dimer acid (HDA) and dimer acid (DA).

[0013] Furthermore, the diisocyanate is one of hexamethylene diisocyanate, dicyclohexylmethane diisocyanate and toluene diisocyanate.

[0014] Furthermore, the chain extender is one of bis(2-hydroxyethyl) terephthalate, 1,4-butanediol, ethylene glycol, propylene glycol, diethanolamine, and triethanolamine.

[0015] Furthermore, the internal cross-linking agent is one of trimethylolpropane, propylene glycol and glycerol.

[0016] Furthermore, the coating raw material is prepared by the following steps:

[0017] Step S1: polyurethane acrylate, vinyl-terminated polydimethylsiloxane, cellulose acetate propionate, PETA, nano-quartz powder, and silane coupling agent KH550 are shear-mixed to obtain a volatility inhibitor;

[0018] Step S2: Evenly mix the volatile inhibitor, antibacterial agent and DMF to obtain a coating material.

[0019] Furthermore, the weight ratio of the polyurethane acrylate, vinyl-terminated polydimethylsiloxane, cellulose acetate propionate, PETA, nano-quartz powder, and silane coupling agent KH550 in step S1 is 5-6:38-40:13-15:8-9:14-16:5-8.

[0020] Furthermore, in step S2, the weight ratio of the volatile inhibitor, antibacterial agent, and DMF is 1:1:10-20.

[0021] The antibacterial agent is prepared by the following steps:

[0022] Step C1: add a mixed solvent of thiocarbohydrazide, ethanol and water (mixed in a mass ratio of 1:1) to a three-necked flask, heat until thiocarbohydrazide is completely dissolved, cool to 60°C, and then slowly add 2,5-dihydroxybenzaldehyde after diluting it with ethanol. During this period, glacial acetic acid is added dropwise. The reaction is carried out for 4-6 hours, filtered, washed with water, and dried to obtain intermediate 1;

[0023] The reaction process is as follows:

[0024]

[0025] Step C2: Add intermediate 1, methanol and dimethyl sulfoxide mixed solvent (mixed in a mass ratio of 1:1) to a three-necked flask and stir to dissolve. At the same time, weigh anhydrous copper chloride and dissolve it in anhydrous methanol. Add it to the above three-necked flask and react for 10-14 hours to obtain intermediate 2.

[0026] The reaction process is as follows:

[0027]

[0028] Step C3: dissolve succinic anhydride and 3-dimethylamino-1-propanol in THF, reflux at 80°C for 1-2 hours, add 2-chloro-4,6-dimethoxy-1,3,5-triazine and N-methylmorpholine, stir at 0°C for 2-3 hours, add triethylamine to remove by-products, and recrystallize to obtain Intermediate 3;

[0029] The reaction process is as follows:

[0030]

[0031] Step C4, dissolving intermediate 2 and intermediate 3 in dichloromethane, adding palladium acetate and potassium phosphate as catalysts, reflux at 80°C for 2-3 hours, filtering, rotary evaporation, and recrystallization to obtain intermediate 4;

[0032] The reaction process is as follows:

[0033]

[0034] Step C5, dissolve the intermediate 4 in DMF solution, stir for 1-2 hours, remove the solvent by rotary evaporation, dry in vacuum at 60°C for 2-3 days, dissolve in anhydrous ethanol, add 1-chlorohexane, reflux overnight, remove the solvent and dry to obtain the antibacterial agent.

[0035] The reaction process is as follows:

[0036]

[0037] Furthermore, the usage ratio of thiocarbohydrazide, the mixed solvent of ethanol and water, 2,5-dihydroxybenzaldehyde, ethanol, and glacial acetic acid in step C1 is 4.2-5.1 g: 90-120 mL: 2.6-3.1 g: 40-50 mL: 0.2-0.5 g.

[0038] Furthermore, the usage ratio of the intermediate 1 in step C2, the mixed solvent of methanol and dimethyl sulfoxide, anhydrous copper chloride, and anhydrous methanol is 2.4-3.6 g:40-50 mL:0.3-0.5 g:50-60 mL.

[0039] Furthermore, the usage ratio of succinic anhydride, 3-dimethylamino-1-propanol, THF, 2-chloro-4,6-dimethoxy-1,3,5-triazine, and N-methylmorpholine in step C3 is 2.5-3.2 g: 3.3-3.5 g: 120-150 mL: 1.4-1.6 g: 1.7-1.8 g.

[0040] Furthermore, the usage ratio of intermediate 2, intermediate 3, dichloromethane, palladium acetate, and potassium phosphate in step C4 is 3.6-4.1 g: 4.2-4.6 g: 50-60 mL: 0.01-0.015 g: 0.02-0.025 g.

[0041] Furthermore, in step C5, the usage ratio of the intermediate 4 and 1-chlorohexane is 1.8-2.2 g: 0.5-0.8 g.

[0042] A method for preparing a biodegradable polyurethane film material comprises the following steps:

[0043] Step A1, dissolving bis(2-hydroxyethyl) terephthalate in DMF, mixing with bio-based dimer acid, adding p-toluenesulfonic acid, reacting at 160-180° C. for 5-10 hours, dissolving in chloroform after the reaction is complete, and precipitating in methanol to obtain a bio-based polyester polyol;

[0044] Step A2, reacting a bio-based polyester polyol with a diisocyanate and a chain extender at 65-75° C. for 1-3 hours, adding dibutyltin dilaurate, and reacting at 60-80° C. for 1-2 hours to obtain a bio-based polyurethane prepolymer;

[0045] Step A3, mixing the bio-based polyurethane prepolymer with an internal crosslinking agent, stirring and reacting at 55-75° C. for 2-4 hours, and adding butanone to dilute the reaction during the reaction to obtain a bio-based polyurethane emulsion;

[0046] Step A4: evenly spread the bio-based polyurethane emulsion on a dry, clean mold to form a liquid layer with uniform thickness and a smooth surface, and dry it at 55-70° C. for 8-10 hours to obtain a preform;

[0047] Step A5: evenly apply the coating material on the preform, and dry it at 60-80° C. for 5-7 hours to obtain a bio-based degradable polyurethane film material.

[0048] Beneficial effects of the present invention: The present invention provides a bio-based degradable polyurethane film material and a preparation method thereof, which include the following beneficial effects: (1) Bio-based raw materials: The use of bio-based raw materials such as bio-based dimer acid helps to reduce dependence on traditional petrochemical resources and conforms to the concept of sustainable development and environmental protection. (2) Controllable preparation process: The reaction conditions (such as temperature, time, etc.) of each step are clear and relatively mild, which is convenient for operation and control in the industrial production process and can ensure the stability of product quality. (3) Product performance optimization: Through a series of reactions and process treatments, including polyol synthesis, polyurethane prepolymer preparation, internal cross-linking reaction, etc., the final bio-based degradable polyurethane film material has degradable characteristics and may have good mechanical properties. Biopolyester polyol has a rigid benzene ring structure and a flexible long chain structure, which gives the bio-based polyurethane material excellent mechanical properties, heat resistance and biodegradability, and can be used to produce high-performance bio-based polyurethane products. Secondly, the surface performance is good, the liquid layer thickness is uniform, and the surface is smooth and flat. (4) Application expansion: By coating the preform with coating materials, the product functions are further enriched, and the bio-based degradable polyurethane film material has antibacterial properties. The combination of volatile inhibitors and antibacterial agents allows the antibacterial agent to be slowly released within the film material, greatly prolonging the antibacterial effect. The antibacterial agent contains a quaternary ammonium salt structure, which is caused by the initial electrostatic interaction between the cationic group of QACs and the negatively charged cell membrane; then the alkyl chain penetrates the cell membrane to cause cell lysis, and the quaternary ammonium salt does not lose its activity after sterilization; secondly, thiocarbazide reacts with 2,5-dihydroxybenzaldehyde to generate an intermediate, and the intermediate is complexed with copper ions to synthesize another functional group in the antibacterial agent, which has the effects of inhibiting cell growth and antibacterial and antifungal effects. DETAILED DESCRIPTION

[0049] With reference to the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0050] Embodiment 1

[0051] The antibacterial agent is prepared by the following steps:

[0052] Step C1, 4.2 g of thiocarbazide, 90 mL of a mixed solvent of ethanol and water (mixed at a mass ratio of 1:1) are added into a three-necked flask, heated to completely dissolve the thiocarbazide, and then cooled to 60°C. 2.6 g of 2,5-dihydroxybenzaldehyde is diluted with 40 mL of ethanol, and then slowly added dropwise. 0.2 g of glacial acetic acid is added dropwise during the process, and the reaction is carried out for 4 h. After filtration, water washing and drying, an intermediate 1 is obtained.

[0053] Step C2, 2.4 g of the intermediate 1 and 40 mL of a mixed solvent of methanol and dimethyl sulfoxide (mixed at a mass ratio of 1:1) are added into a three-necked flask, and stirred and dissolved. 0.3 g of anhydrous copper chloride is dissolved in 50 mL of anhydrous methanol, and then added into the three-necked flask. The reaction is carried out for 10 h to obtain an intermediate 2.

[0054] Step C3, 2.5 g of succinic anhydride and 3.3 g of 3-dimethylamino-1-propanol are dissolved in 120 mL of THF, and then refluxed at 80°C for 1 h. 1.4 g of 2-chloro-4,6-dimethoxy-1,3,5-triazine and 1.7 g of N-methylmorpholine are added, and then stirred at 0°C for 2 h. Triethylamine is added to remove the by-product, and then recrystallized to obtain an intermediate 3.

[0055] Step C4, 3.6 g of the intermediate 2 and 4.2 g of the intermediate 3 are dissolved in 50 mL of dichloromethane, and then 0.01 g of palladium acetate and 0.02 g of potassium phosphate are added as catalysts. The mixture is refluxed at 80°C for 2 h, and then subjected to filtration, rotary evaporation and recrystallization to obtain an intermediate 4.

[0056] Step C5, 1.8 g of the intermediate 4 is dissolved in a DMF solution, and then stirred for 1 h. After removing the solvent by rotary evaporation, the mixture is vacuum dried at 60°C for 2 days, and then dissolved in anhydrous ethanol. 0.5 g of 1-chlorohexane is added, and then refluxed overnight. After removing the solvent and drying, an antibacterial agent is obtained.

[0057] Embodiment 2

[0058] The antibacterial agent is prepared by the following steps:

[0059] Step C1, 4.6 g of thiocarbohydrazide, 100 mL of a mixed solvent of ethanol and water (mixed in a mass ratio of 1:1) were added to a three-necked flask, heated until thiocarbohydrazide was completely dissolved, cooled to 60 ° C, and then 2.8 g of 2,5-dihydroxybenzaldehyde was diluted with 45 mL of ethanol and slowly added dropwise, during which 0.4 g of glacial acetic acid was added dropwise. The reaction was carried out for 5 h, filtered, washed with water, and dried to obtain intermediate 1;

[0060] Step C2: add 3 g of intermediate 1 and 45 mL of a mixed solvent of methanol and dimethyl sulfoxide (mixed in a mass ratio of 1:1) to a three-necked flask and stir to dissolve. At the same time, weigh 0.4 g of anhydrous copper chloride and dissolve it in 55 mL of anhydrous methanol. Add it to the above three-necked flask and react for 12 h to obtain intermediate 2;

[0061] Step C3: 3 g of succinic anhydride and 3.4 g of 3-dimethylamino-1-propanol were dissolved in 130 mL of THF. The mixture was refluxed at 80°C for 2 h, and then 1.5 g of 2-chloro-4,6-dimethoxy-1,3,5-triazine and 1.7 g of N-methylmorpholine were added. The mixture was stirred at 0°C for 2 h. Triethylamine was added to remove by-products, and the mixture was recrystallized to obtain Intermediate 3.

[0062] Step C4, 3.9 g of intermediate 2 and 4.4 g of intermediate 3 were dissolved in 55 mL of dichloromethane, 0.013 g of palladium acetate and 0.022 g of potassium phosphate were added as catalysts, refluxed at 80° C. for 2 h, filtered, rotary evaporated, and recrystallized to obtain intermediate 4;

[0063] In step C5, 2 g of intermediate 4 was dissolved in DMF solution, stirred for 1 h, and the solvent was removed by rotary evaporation. The mixture was dried in vacuo at 60°C for 2 days and then dissolved in anhydrous ethanol. 0.6 g of 1-chlorohexane was added and refluxed overnight. The solvent was removed and dried to obtain the antibacterial agent.

[0064] Example 3

[0065] The antibacterial agent is prepared by the following steps:

[0066] Step C1, 5.1 g of thiocarbohydrazide, 120 mL of a mixed solvent of ethanol and water (mixed in a mass ratio of 1:1) were added to a three-necked flask, heated until thiocarbohydrazide was completely dissolved, cooled to 60 ° C, and then 3.1 g of 2,5-dihydroxybenzaldehyde was diluted with 50 mL of ethanol and slowly added dropwise, during which 0.5 g of glacial acetic acid was added dropwise. The reaction was carried out for 6 hours, filtered, washed with water, and dried to obtain intermediate 1;

[0067] Step C2: add 3.6 g of intermediate 1 and 50 mL of a mixed solvent of methanol and dimethyl sulfoxide (mixed in a mass ratio of 1:1) to a three-necked flask and stir to dissolve. At the same time, weigh 0.5 g of anhydrous copper chloride and dissolve it in 60 mL of anhydrous methanol. Add it to the above three-necked flask and react for 14 h to obtain intermediate 2;

[0068] Step C3: 3.2 g of succinic anhydride and 3.5 g of 3-dimethylamino-1-propanol were dissolved in 150 mL of THF. The mixture was refluxed at 80°C for 2 h, and then 1.6 g of 2-chloro-4,6-dimethoxy-1,3,5-triazine and 1.8 g of N-methylmorpholine were added. The mixture was stirred at 0°C for 3 h. Triethylamine was added to remove by-products, and the mixture was recrystallized to obtain Intermediate 3.

[0069] Step C4, 4.1 g of intermediate 2 and 4.6 g of intermediate 3 were dissolved in 60 mL of dichloromethane, 0.015 g of palladium acetate and 0.025 g of potassium phosphate were added as catalysts, refluxed at 80° C. for 3 h, filtered, rotary evaporated, and recrystallized to obtain intermediate 4;

[0070] In step C5, 2.2 g of intermediate 4 was dissolved in DMF solution, stirred for 2 h, and the solvent was removed by rotary evaporation. The mixture was dried in vacuo at 60° C. for 3 days and then dissolved in anhydrous ethanol. 0.8 g of 1-chlorohexane was added and refluxed overnight. The solvent was removed and dried to obtain the antibacterial agent.

[0071] Example 4

[0072] The coating material is prepared by the following steps:

[0073] Step S1: polyurethane acrylate, vinyl-terminated polydimethylsiloxane, cellulose acetate propionate, PETA, nano-quartz powder, and silane coupling agent KH550 are shear-mixed and uniformly prepared to obtain a volatility inhibitor, wherein the weight ratio of polyurethane acrylate, vinyl-terminated polydimethylsiloxane, cellulose acetate propionate, PETA, nano-quartz powder, and silane coupling agent KH550 is 5:38:13:8:14:5;

[0074] Step S2: Evenly mix the volatile inhibitor, the antibacterial agent, and DMF to obtain a coating material, wherein the weight ratio of the volatile inhibitor, the antibacterial agent, and DMF is 1:1:10.

[0075] Example 5

[0076] The coating material is prepared by the following steps:

[0077] Step S1: polyurethane acrylate, vinyl-terminated polydimethylsiloxane, cellulose acetate propionate, PETA, nano-quartz powder, and silane coupling agent KH550 are shear-mixed and uniformly prepared to obtain a volatility inhibitor, wherein the weight ratio of polyurethane acrylate, vinyl-terminated polydimethylsiloxane, cellulose acetate propionate, PETA, nano-quartz powder, and silane coupling agent KH550 is 5:39:14:8:15:6;

[0078] Step S2: mix the volatile inhibitor and the antibacterial agent, DMF, uniformly to obtain a coating raw material, wherein the weight ratio of the volatile inhibitor, the antibacterial agent and DMF is 1:1:15.

[0079] Example 6

[0080] The coating raw material is prepared by the following steps:

[0081] Step S1: uniformly mix polyurethane acrylate, end-vinyl polydimethylsiloxane, cellulose acetate propionate, PETA, nano-quartz powder and silane coupling agent KH550 to obtain a volatile inhibitor, wherein the weight ratio of polyurethane acrylate, end-vinyl polydimethylsiloxane, cellulose acetate propionate, PETA, nano-quartz powder and silane coupling agent KH550 is 6:40:15:9:16:8;

[0082] Step S2: mix the volatile inhibitor and the antibacterial agent, DMF, uniformly to obtain a coating raw material, wherein the weight ratio of the volatile inhibitor, the antibacterial agent and DMF is 1:1:15.

[0083] Example 7

[0084] A bio-based degradable polyurethane film material, comprising the following raw materials in parts by weight: bis(2-hydroxyethyl) terephthalate 20.7 parts, hydrogenated dimer acid (HDA) 34.5 parts, hexamethylene diisocyanate 10.5 parts, bis(2-hydroxyethyl) terephthalate 2.6 parts, p-toluenesulfonic acid 0.5 parts, dibutyltin dilaurate 0.2 parts, trimethylolpropane 0.6 parts, DMF 62.4 parts, butanone 16.8 parts, and coating raw material 13.7 parts;

[0085] The bio-based degradable polyurethane film material is prepared by the following steps:

[0086] Step A1: dissolve bis(2-hydroxyethyl) terephthalate in DMF, mix with hydrogenated dimer acid (HDA), add p-toluenesulfonic acid, react at 160°C for 5h, dissolve in chloroform after the reaction is completed, and precipitate in methanol to obtain a bio-based polyester polyol;

[0087] Step A2: mix the bio-based polyester polyol with hexamethylene diisocyanate and bis(2-hydroxyethyl) terephthalate at 65°C for 1h, add dibutyltin dilaurate, and react at 60°C for 1h to obtain a bio-based polyurethane prepolymer;

[0088] Step A3: mix the bio-based polyurethane prepolymer with trimethylolpropane, stir and react at 555°C for 2h, and add butanone for dilution during the reaction to obtain a bio-based polyurethane emulsion;

[0089] Step A4: evenly spread the bio-based polyurethane emulsion on a dry, clean mold to form a liquid layer with uniform thickness and a smooth surface, and dry it at 55° C. for 8 hours to obtain a preform;

[0090] Step A5: evenly apply the coating material on the preform, and dry it at 600° C. for 5 hours to obtain a bio-based degradable polyurethane film material.

[0091] Example 8

[0092] A biodegradable polyurethane film material comprises the following raw materials in parts by weight: 25.6 parts of bis(2-hydroxyethyl) terephthalate, 43.2 parts of hydrogenated dimer acid (HDA), 22.8 parts of dicyclohexylmethane diisocyanate, 5.7 parts of 1,4-butanediol, 1.6 parts of p-toluenesulfonic acid, 1.2 parts of dibutyltin dilaurate, 2.6 parts of an internal crosslinking agent, 74.5 parts of DMF, 18.9 parts of butanone, and 15.7 parts of a coating raw material;

[0093] The bio-based degradable polyurethane film material is prepared by the following steps:

[0094] Step A1, dissolving bis(2-hydroxyethyl) terephthalate in DMF, mixing with hydrogenated dimer acid (HDA), adding p-toluenesulfonic acid, reacting at 170° C. for 7 h, dissolving in chloroform after the reaction is complete, and precipitating in methanol to obtain a bio-based polyester polyol;

[0095] Step A2, reacting bio-based polyester polyol with dicyclohexylmethane diisopropyl and 1,4-butanediol at 69° C. for 2 h, adding dibutyltin dilaurate, and reacting at 70° C. for 1 h to obtain a bio-based polyurethane prepolymer;

[0096] Step A3, mixing the bio-based polyurethane prepolymer with propylene glycol, stirring and reacting at 60° C. for 3 hours, and adding butanone to dilute the mixture during the reaction to obtain a bio-based polyurethane emulsion;

[0097] Step A4: evenly spread the bio-based polyurethane emulsion on a dry, clean mold to form a liquid layer with uniform thickness and a smooth surface, and dry it at 60° C. for 9 hours to obtain a preform;

[0098] Step A5: evenly apply the coating material on the preform, and dry it at 70° C. for 6 hours to obtain a biodegradable polyurethane film material.

[0099] Example 9

[0100] A kind of bio-based degradable polyurethane film material, including the following raw materials by weight ratio: bis (2-hydroxyethyl) terephthalate 30.4 parts, dimer acid (DA) 51.2 parts, toluene diisocyanate 33.4 parts, propylene glycol 8.3 parts, p-toluene sulfonic acid 2.3 parts, dibutyltin dilaurate 1.8 parts, glycerol 3.5 parts, DMF 85 parts, butanone 25.6 parts, coating raw material 20.3 parts;

[0101] The bio-based degradable polyurethane film material is made by the following steps:

[0102] Step A1, bis (2-hydroxyethyl) terephthalate is dissolved in DMF, mixed with dimer acid (DA), p-toluene sulfonic acid is added, reacted at 180 DEG C for 10 h, after the reaction is completed, it is dissolved in chloroform, and precipitated in methanol, to obtain a bio-based polyester polyol;

[0103] Step A2, the bio-based polyester polyol is reacted with toluene diisocyanate, propylene glycol at 75 DEG C for 3 h, dibutyltin dilaurate is added, and reacted at 80 DEG C for 2 h to obtain a bio-based polyurethane prepolymer;

[0104] Step A3, the bio-based polyurethane prepolymer is mixed with glycerol, and stirred at 75 DEG C for 4 h, and butanone is added during the reaction to dilute, to obtain a bio-based polyurethane emulsion;

[0105] Step A4, the bio-based polyurethane emulsion is evenly laid on a dry and clean mold to form a liquid layer with uniform thickness and smooth surface, and dried at 70 DEG C for 10 h to obtain a preform;

[0106] Step A5, the coating raw material is uniformly coated on the preform, and dried at 80 DEG C for 7 h to obtain a bio-based degradable polyurethane film material.

[0107] Comparative Example 1

[0108] Bio-based polyurethane film produced by Hu Zhou Heda Tu Hong New Material Technology Co., Ltd.

[0109] Comparative Example 2

[0110] The preparation method of the bio-based degradable polyurethane film material of Comparative Example 2 refers to Example 7, except that the coating raw material coating operation is not performed.

[0111] The following performance tests were conducted on the polyurethane film materials obtained in Examples 7-9 and Comparative Examples 1-2: (1) The mechanical properties of the biodegradable polyurethane film materials were measured using a tensile strength testing machine; (2) The above examples and comparative examples were placed in a culture medium inoculated with Staphylococcus aureus and Escherichia coli at 37°C and sealed for 3 days, and the growth of microorganisms in each culture medium was tested. The examples were first placed at 37°C for 100 days and then subjected to the above tests; +++: The culture medium was fully grown with bacteria and had no antibacterial ability; ++: Half of the culture medium was grown with bacteria and had essentially no antibacterial ability; +: The culture medium had less than 5 colonies and had partial antibacterial ability; -: The culture medium was essentially sterile. The antibacterial test results are shown in Table 1:

[0112] Table 1

[0113]

[0114] As shown in Table 1, compared with Comparative Examples 1-2, Examples 7-9 have excellent antibacterial ability and the antibacterial ability lasts longer.

[0115] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0116] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A biodegradable polyurethane film material, characterized in that: The invention comprises the following raw materials in parts by weight: 20.7-30.4 parts of bis(2-hydroxyethyl) terephthalate, 34.5-51.2 parts of bio-based dimer acid, 10.5-33.4 parts of diisocyanate, 2.6-8.3 parts of chain extender, 0.5-2.3 parts of p-toluenesulfonic acid, 0.2-1.8 parts of dibutyltin dilaurate, 0.6-3.5 parts of internal crosslinking agent, 62.4-85 parts of DMF, 16.8-25.6 parts of butanone, and 13.7-20.3 parts of coating raw materials; The coating raw material is prepared by the following steps: Step S1: polyurethane acrylate, vinyl-terminated polydimethylsiloxane, cellulose acetate propionate, PETA, nano-quartz powder, and silane coupling agent KH550 are shear-mixed to obtain a volatility inhibitor; Step S2: Evenly mix the volatile inhibitor, antibacterial agent and DMF to obtain a coating material.

2. The biodegradable polyurethane film material according to claim 1, characterized in that: The bio-based dimer acid is one of hydrogenated dimer acid (HDA) and dimer acid (DA); the diisocyanate is one of hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, and toluene diisocyanate; the chain extender is one of bis(2-hydroxyethyl) terephthalate, 1,4-butanediol, ethylene glycol, propylene glycol, diethanolamine, and triethanolamine; and the internal cross-linking agent is one of trimethylolpropane, propylene glycol, and glycerol.

3. The biodegradable polyurethane film material according to claim 1, characterized in that: The antibacterial agent is prepared by the following steps: Step C1: add thiocarbohydrazide, a mixed solvent of ethanol and water to a three-necked flask, heat and then cool, then add 2,5-dihydroxybenzaldehyde diluted with ethanol dropwise, and add glacial acetic acid dropwise during the reaction. The mixture is filtered, washed with water, and dried to obtain intermediate 1; Step C2: Add intermediate 1, a mixed solvent of methanol and dimethyl sulfoxide to a three-necked flask and stir to dissolve. At the same time, weigh anhydrous copper chloride and dissolve it in anhydrous methanol. Add it to the three-necked flask and react to obtain intermediate 2. Step C3: dissolve succinic anhydride and 3-dimethylamino-1-propanol in THF, reflux, add 2-chloro-4,6-dimethoxy-1,3,5-triazine and N-methylmorpholine, stir at 0°C, add triethylamine to remove by-products, and recrystallize to obtain Intermediate 3; Step C4, dissolving intermediate 2 and intermediate 3 in dichloromethane, adding palladium acetate and potassium phosphate, reflux reaction, suction filtration, rotary evaporation, and recrystallization to obtain intermediate 4; Step C5, dissolve the intermediate 4 in DMF solution, stir, and remove the solvent by rotary evaporation. After drying, dissolve it in anhydrous ethanol, add 1-chlorohexane, and reflux overnight to obtain an antibacterial agent.

4. The method for preparing a biodegradable polyurethane film material according to claim 1, characterized in that: The method comprises the following preparation steps: Step A1, dissolving bis(2-hydroxyethyl) terephthalate in DMF, mixing with bio-based dimer acid, adding p-toluenesulfonic acid, reacting at 160-180° C. for 5-10 hours, dissolving in chloroform after the reaction is complete, and precipitating in methanol to obtain a bio-based polyester polyol; Step A2, reacting a bio-based polyester polyol with a diisocyanate and a chain extender at 65-75° C. for 1-3 hours, adding dibutyltin dilaurate, and reacting at 60-80° C. for 1-2 hours to obtain a bio-based polyurethane prepolymer; Step A3, mixing the bio-based polyurethane prepolymer with an internal crosslinking agent, stirring and reacting at 55-75° C. for 2-4 hours, and adding butanone to dilute the reaction during the reaction to obtain a bio-based polyurethane emulsion; Step A4: evenly spread the bio-based polyurethane emulsion on a dry, clean mold to form a liquid layer with uniform thickness and a smooth surface, and dry it at 55-70° C. for 8-10 hours to obtain a preform; Step A5: evenly apply the coating material on the preform, and dry it at 60-80° C. for 5-7 hours to obtain a bio-based degradable polyurethane film material.

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