A method for preparing a composite material with excellent antibacterial property and super mechanical property

Abstract

The present application relates to a kind of preparation method of composite material with excellent antibacterial property and super mechanical property, the present application adopts specific antibacterial particle and specific preparation water-based polyurethane, successfully adopts electrostatic self-assembly strategy to form a large number of uniform and firm crosslinking points in interface with water-based polyurethane composite antibacterial particle, by the precise electrostatic interaction between components, so that antibacterial particle is anchored as reinforcing phase in matrix.It can not only effectively transfer and disperse stress, significantly improve the mechanical strength and toughness of material, but also can firmly fix high-density antibacterial active group on material surface, avoid its embedding failure or rapid loss, so as to realize efficient, long-lasting contact type antibacterial effect.The method is simple, high in synthesis efficiency, and process controllable, fundamentally solves the problem of mechanical property decline and antibacterial property instability caused by weak interface bonding and stress concentration in traditional physical blending method.

Description

Technical Field

[0001] This invention relates to a method for preparing a composite material with both excellent antibacterial properties and superior mechanical properties, belonging to the field of elastomer material preparation technology. Background Technology

[0002] Bio-based waterborne polyurethane elastomers (WPUs) have become ideal matrices for preparing antibacterial materials such as wound dressings and medical catheters due to their tunable mechanical properties and excellent biocompatibility. Currently, the most convenient strategy for imparting antibacterial function to WPUs is to directly add antibacterial agents to the polymer matrix, thereby constructing antibacterial composite materials.

[0003] However, antibacterial components introduced as exogenous phases (such as nano-silver, titanium dioxide, quaternary ammonium salt modified clay, or natural antibacterial agents) can cause dual damage to the already intricate microstructure of WPU, thereby deteriorating its mechanical properties. Specifically:

[0004] 1) Disruption of the hydrogen bond network. Polar functional groups (such as hydroxyl and carboxyl groups) on the surface of antibacterial fillers compete with polar groups in polyurethane hard segments, such as urethane bonds (NH and C=O), to form filler-hard segment interfacial bonds. This weakens the inherent strong hydrogen bond interactions between hard segments, leading to the dilution or even destruction of the physical cross-linking network, which macroscopically manifests as material softening and a significant reduction in tensile strength and elastic modulus.

[0005] 2) Obstruction of hard segment microregion formation. The filler particles introduce physical steric hindrance in the matrix, interfering with the formation of a regular and dense microregion structure during the self-assembly of hard segments in the microphase separation process. As a result, the size of the hard segment microregions (i.e., physical reinforcement points) decreases and their orderliness declines, thereby significantly weakening their reinforcement efficiency and ultimately destroying the key microphase separation structure of WPU, further aggravating the deterioration of mechanical properties.

[0006] Therefore, how to design materials to enable waterborne polyurethane to possess both excellent mechanical properties and efficient antibacterial functions remains a core challenge that urgently needs to be addressed in this field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a method for preparing a composite material that combines excellent antibacterial properties with superior mechanical properties.

[0008] This invention employs a simple and environmentally friendly electrostatic self-assembly strategy to composite antibacterial particles with waterborne polyurethane, successfully constructing a composite material that combines excellent antibacterial properties with superior mechanical properties. The method of introducing antibacterial particles in this invention does not damage the already precise microstructure of WPU, and while ensuring antibacterial performance, it significantly improves the mechanical properties of waterborne polyurethane elastomers. Its mechanical properties are significantly better than conventional products, and it has excellent prospects for practical applications.

[0009] The technical solution of the present invention is as follows:

[0010] A method for preparing a composite material with both excellent antibacterial properties and superior mechanical properties includes the following steps:

[0011] (1) Mix bio-based diol polycaprolactone (PCL), diisocyanate, hydrophilic chain extender and catalyst evenly, and heat to react to obtain the first prepolymer;

[0012] (2) Add a diol chain extender to an organic solvent and mix well to obtain mixture a;

[0013] (3) Add the first prepolymer to mixture a, mix well, heat to react, and cool to room temperature to obtain the second prepolymer;

[0014] (4) Add triethylamine neutralizing agent to the second prepolymer, stir and react to obtain the third prepolymer;

[0015] (5) Add diamine chain extender to ultrapure water and mix well to obtain mixture b;

[0016] (6) Add the third prepolymer to mixture b and stir to react and obtain an aqueous polyurethane solution;

[0017] (7) After diluting the aqueous polyurethane solution, slowly add the cationic antibacterial aqueous solution, mix and gradually precipitate, collect the precipitate by centrifugation, heat and press to form a film, and obtain a composite material with both excellent antibacterial properties and super strong mechanical properties.

[0018] According to a preferred embodiment of the present invention, in step (1), the selected diisocyanate is selected from one or a mixture of two or more of 4,4'-dicyclohexylmethane diisocyanate (HMDI), diphenylmethane-4,4'-diisocyanate (MDI), isophorone diisocyanate (IPDI), toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI).

[0019] According to a preferred embodiment of the present invention, in step (1), the hydrophilic chain extender is one or a mixture of two or more of dimethylolpropionic acid (DMPA), dimethylolbutyric acid (DMBA), sodium ethylenediamine ethanesulfonate and sodium 1,4-butanediol-2-sulfonate.

[0020] According to a preferred embodiment of the present invention, in step (1), the selected catalyst is selected from one or more of dibutyltin dilaurate (DBTDL), bismuth laurate, stannous octoate or bismuth isooctanoate.

[0021] According to a preferred embodiment of the present invention, in step (1), the molar ratio of the hydrophilic chain extender to the diisocyanate is (0.20-2):1.

[0022] According to a preferred embodiment of the present invention, in step (1), the molar ratio of catalyst to diisocyanate is (0.002-0.05):1.

[0023] According to a preferred embodiment of the present invention, in step (1), the mass ratio of bio-based diol polycaprolactone (PCL) to diisocyanate is (4-10):(1-5).

[0024] According to a preferred embodiment of the present invention, in step (1), the temperature of the heating reaction is 60-80°C and the reaction time is 2-6 hours.

[0025] According to a preferred embodiment of the present invention, in step (2), the diol chain extender is one or a mixture of two or more of 1,3-propanediol (PDO), 1,4-butanediol (BDO), 1,6-hexanediol (HDO), or N,N-bis(2-hydroxyethyl)oxalamide (BHO).

[0026] According to a preferred embodiment of the present invention, in step (2), the molar ratio of the amount of the diol chain extender to the diisocyanate is (0.05-1):1.

[0027] According to a preferred embodiment of the present invention, in step (2), the organic solvent is acetone.

[0028] According to a preferred embodiment of the present invention, in step (2), the mass-volume ratio of the diol chain extender to the organic solvent is (0.05-0.5):(10-50), unit, g / mL.

[0029] According to a preferred embodiment of the present invention, in step (3), the temperature of the heating reaction is 45-60°C and the reaction time is 2-6 hours.

[0030] According to a preferred embodiment of the present invention, in step (4), the molar ratio of the triethylamine neutralizing agent to the hydrophilic chain extender in step (1) is (0.9-1):1.

[0031] According to a preferred embodiment of the present invention, in step (4), the stirring reaction is carried out at a stirring speed of 200-400 r / min for 0.1-1 h.

[0032] According to a preferred embodiment of the present invention, in step (5), the diamine chain extender is 1,5-diaminopentane (PDA), 1,6-diaminohexane (HMDA), 1,3-diaminopropane (DAP), p-phenylenediamine (PPD), or triethylenetetramine (TETA).

[0033] According to a preferred embodiment of the present invention, in step (5), the molar ratio of the diamine chain extender to the diisocyanate in step (1) is (0.1-2):1.

[0034] According to a preferred embodiment of the present invention, in step (5), the mass ratio of the diamine chain extender to ultrapure water is (0.1-0.8):(30-50).

[0035] According to a preferred embodiment of the present invention, in step (6), the stirring reaction is carried out at 1000-2000 r / min for 10-20 h.

[0036] According to a preferred embodiment of the present invention, in step (7), the aqueous polyurethane solution is diluted by a factor of 2-4.

[0037] According to a preferred embodiment of the present invention, in step (7), the cationic antibacterial agent is polyhexamethylene guanidine (PHMG), polyhexamethylene biguanide (PHMB), chitosan, or ε-polylysine.

[0038] According to a preferred embodiment of the present invention, in step (7), the mass ratio of the aqueous polyurethane solution to the cationic antibacterial agent in the aqueous antibacterial agent solution is 1:(0.1 to 0.3).

[0039] According to a preferred embodiment of the present invention, in step (7), the concentration of the cationic antibacterial agent aqueous solution is 0.01-0.05 g / mL.

[0040] According to a preferred embodiment of the present invention, in step (7), the hot pressing temperature is 100-120°C, the reaction time is 1-2 hours, and the pressure is 1 MPa-5 MPa.

[0041] A composite material with both excellent antibacterial properties and superior mechanical properties was prepared using the method described above.

[0042] The aforementioned composite materials, which combine excellent antibacterial properties and superior mechanical strength, are applied in high-end wound dressings, medical catheters, wearable monitoring patches, antibacterial surgical gowns / gloves, or tissue engineering scaffolds.

[0043] The beneficial effects of this invention are as follows:

[0044] 1. Compared with traditional physical doping composites, this invention combines positively charged antibacterial particles and negatively charged waterborne polyurethane through an electrostatic self-assembly strategy, significantly enhancing the composite ability of the two materials and thus greatly improving the mechanical properties of the antibacterial composite material. This method is simple to operate, has high synthesis efficiency, and is controllable, effectively solving the problem that the introduction of exogenous antibacterial components in traditional antibacterial composite materials causes severe damage to the precise microstructure of WPU, thereby deteriorating its mechanical properties.

[0045] 2. This invention uses specific antibacterial particles and specially prepared waterborne polyurethane, and successfully employs an electrostatic self-assembly strategy to composite the antibacterial particles with waterborne polyurethane, constructing a composite material that combines excellent antibacterial properties and superior mechanical properties. The method of this invention does not damage the already precise microstructure of WPU, and while ensuring antibacterial performance, it significantly improves the mechanical properties of waterborne polyurethane elastomers. Its mechanical properties are significantly better than conventional products, and it has excellent prospects for practical applications.

[0046] 3. The composite material prepared by this invention has both good toughness and antibacterial effect. Attached Figure Description

[0047] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0048] Figure 1 Fourier transform infrared (FTIR) spectrum of the composite material prepared in Example 1 of this invention.

[0049] Figure 2 This is a comparison diagram of the toughness of the composite materials prepared in Example 1 and Comparative Example 1.

[0050] Figure 3 Comparison of stress-strain tests on the composite materials prepared in Example 2 and Comparative Example 2;

[0051] Figure 4 A comparison diagram of the tensile strength of the composite materials prepared in Example 3 and Comparative Example 3;

[0052] Figure 5 This is a comparison diagram of the antibacterial effects of the composite materials prepared in Example 4 and Comparative Example 4 on Escherichia coli.

[0053] Figure 6 This is a comparison diagram of the antibacterial effects of the composite materials prepared in Example 5 and Comparative Example 5 against Staphylococcus aureus. Detailed Implementation

[0054] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0055] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0056] Example 1:

[0057] The preparation method of a composite material with both excellent antibacterial properties and superior mechanical strength includes the following steps:

[0058] (1) Add 9g of bio-based diol polycaprolactone (PCL) and 4g of isophorone diisocyanate (IPDI) to a 250mL three-necked flask, along with 50μL of dibutyltin dilaurate (DBTDL) catalyst and 0.9g of dimethylolbutyrate (DMBA). Heat to 75℃ and stir for 3 hours to obtain the first prepolymer. Cool to 50℃ for later use.

[0059] (2) Add 0.18 g of 1,4-butanediol BDO to 20 mL of acetone, mix well, and obtain mixture a;

[0060] (3) Add mixture a to the first prepolymer, mix evenly, and react at 50°C for 3 hours to obtain the second prepolymer;

[0061] (4) After the reaction temperature drops to 25°C, 0.6 g of triethylamine neutralizing agent is added to the second prepolymer, and the reaction is stirred at 300 r / min for 0.5 h to obtain the third prepolymer;

[0062] (5) Add 0.27g of p-phenylenediamine (PPD) to 38g of ultrapure water and mix well to obtain mixture b;

[0063] (6) Add the third prepolymer to mixture b and stir at 1500 r / min for 12 h to obtain an aqueous polyurethane solution.

[0064] (7) Take an aqueous polyurethane solution (solid content of 2g), dilute it twice, and slowly add 10mL of 0.02g / mL polyhexamethylene guanidine (PHMG) aqueous solution (0.2g of polyhexamethylene guanidine). Mix and allow it to precipitate gradually. Collect the precipitate by centrifugation. Hot press the precipitate at 100℃ and 2MPa pressure to form a film to obtain an antibacterial composite material.

[0065] Example 2:

[0066] The preparation method of a composite material with both excellent antibacterial properties and superior mechanical strength includes the following steps:

[0067] (1) Add 9g of polycaprolactone (PCL) and 4.7g of 4,4'-dicyclohexylmethane diisocyanate (HMDI), 50μL of dibutyltin dilaurate (DBTDL) catalyst, and 0.8g of dimethylolpropionic acid (DMPA) hydrophilic chain extender to a 250mL three-necked flask. Heat to 75℃ and stir for 3h to obtain the first prepolymer. Cool to 50℃ for later use.

[0068] (2) Add 0.18 g of 1,4-butanediol BDO to 20 mL of acetone, mix well, and obtain mixture a;

[0069] (3) Add mixture a to the first prepolymer, mix evenly, and react at 50°C for 3 hours to obtain the second prepolymer;

[0070] (4) After the reaction temperature drops to 25°C, 0.6 g of triethylamine neutralizing agent is added to the second prepolymer, and the reaction is stirred at 300 r / min for 0.5 h to obtain the third prepolymer;

[0071] (5) Add 0.26g of 1,5-diaminopentane (PDA) to 38g of ultrapure water and mix well to obtain mixture b;

[0072] (6) Add the third prepolymer to mixture b and stir at 1500 r / min for 12 h to obtain an aqueous polyurethane solution.

[0073] (7) Take an aqueous polyurethane solution (solid content of 2g), dilute it twice, and slowly add 10mL of 0.02g / mL polyhexamethylene biguanide (PHMB) aqueous solution (0.2g of polyhexamethylene biguanide). Mix and allow it to precipitate gradually. Collect the precipitate by centrifugation. Hot press the precipitate at 100℃ and 1MPa pressure to form a film to obtain an antibacterial composite material.

[0074] Example 3:

[0075] The preparation method of a composite material with both excellent antibacterial properties and superior mechanical strength includes the following steps:

[0076] (1) Add 9g of polycaprolactone (PCL) and 4.5g of diphenylmethane-4,4'-diisocyanate (MDI), 50μL of dibutyltin dilaurate (DBTDL) catalyst, and 0.8g of dimethylolpropionic acid (DMPA) hydrophilic chain extender to a 250mL three-necked flask. Heat to 75℃ and stir for 3h to obtain the first prepolymer. Cool to 50℃ for later use.

[0077] (2) Add 0.15 g of 1,3-propanediol (PDO) to 20 mL of acetone and mix well to obtain mixture a;

[0078] (3) Add mixture a to the first prepolymer, mix evenly, and react at 50°C for 3 hours to obtain the second prepolymer;

[0079] (4) After the reaction temperature drops to 25°C, 0.6 g of triethylamine neutralizing agent is added to the second prepolymer, and the reaction is stirred at 300 r / min for 0.5 h to obtain the third prepolymer;

[0080] (5) Add 0.185 g of 1,3-diaminopropane (DAP) to 38 g of ultrapure water and mix well to obtain mixture b;

[0081] (6) Add the third prepolymer to mixture b and stir at 1500 r / min for 12 h to obtain an aqueous polyurethane solution.

[0082] (7) Take an aqueous polyurethane solution (solid content of 2g), dilute it twice, and slowly add 10mL of 0.02g / mL polyhexamethylene biguanide (PHMB) aqueous solution (0.2g of polyhexamethylene biguanide). Mix and allow it to precipitate gradually. Collect the precipitate by centrifugation. Hot press the precipitate at 100℃ and 1MPa pressure to form a film to obtain an antibacterial composite material.

[0083] Example 4:

[0084] The preparation method of a composite material with both excellent antibacterial properties and superior mechanical strength includes the following steps:

[0085] (1) Add 9g of polycaprolactone (PCL) and 3g of hexamethylene diisocyanate (HDI) to a 250mL three-necked flask, along with 50μL of dibutyltin dilaurate (DBTDL) catalyst and 0.9g of dimethylolbutyric acid (DMBA). Heat to 75℃ and stir for 3h to obtain the first prepolymer. Cool to 50℃ for later use.

[0086] (2) Add 0.24 g of 1,6-hexanediol (HDO) to 20 mL of acetone, mix well, and obtain mixture a;

[0087] (3) Add mixture a to the first prepolymer, mix evenly, and react at 50°C for 3 hours to obtain the second prepolymer;

[0088] (4) After the reaction temperature drops to 25°C, 0.6 g of triethylamine neutralizing agent is added to the second prepolymer, and the reaction is stirred at 300 r / min for 0.5 h to obtain the third prepolymer;

[0089] (5) Add 0.29 g of 1,6-diaminohexane (HMDA) to 38 g of ultrapure water and mix well to obtain mixture b;

[0090] (6) Add the third prepolymer to mixture b and stir at 1500 r / min for 12 h to obtain an aqueous polyurethane solution.

[0091] (7) Take an aqueous polyurethane solution (solid content of 2g), dilute it twice, and slowly add 10mL of chitosan aqueous solution with a concentration of 0.02g / mL (0.2g chitosan). Mix and gradually precipitate. Collect the precipitate by centrifugation. Hot press the precipitate at 100℃ and 1MPa pressure to form a film to obtain an antibacterial composite material.

[0092] Example 5:

[0093] The preparation method of a composite material with both excellent antibacterial properties and superior mechanical strength includes the following steps:

[0094] (1) Add 9g of polycaprolactone (PCL) and 3.13g of toluene diisocyanate (TDI) to a 250mL three-necked flask, along with 50μL of dibutyltin dilaurate (DBTDL) as catalyst and 0.8g of dimethylolpropionic acid (DMPA). Heat to 75℃ and stir for 3h to obtain the first prepolymer. Cool to 50℃ for later use.

[0095] (2) Add 0.18 g of 1,4-butanediol (BDO) to 20 mL of acetone, mix well, and obtain mixture a;

[0096] (3) Add mixture a to the first prepolymer, mix evenly, and react at 50°C for 3 hours to obtain the second prepolymer;

[0097] (4) After the reaction temperature drops to 25°C, 0.6 g of triethylamine neutralizing agent is added to the second prepolymer, and the reaction is stirred at 300 r / min for 0.5 h to obtain the third prepolymer;

[0098] (5) Add 0.55g of triethylenetetramine (TETA) to 38g of ultrapure water and mix well to obtain mixture b;

[0099] (6) Add the third prepolymer to mixture b and stir at 1500 r / min for 12 h to obtain an aqueous polyurethane solution.

[0100] (7) Take an aqueous polyurethane solution (solid content of 2g) and dilute it twice. Then slowly add 10mL of 0.02g / mL ε-polylysine aqueous solution (0.2g ε-polylysine). Mix and gradually precipitate. Collect the precipitate by centrifugation. Hot press the precipitate at 100℃ and 1MPa pressure to form a film to obtain an antibacterial composite material.

[0101] Comparative Example 1:

[0102] The preparation method is the same as that described in Example 1, except that:

[0103] In step (7), 10 mL of 0.02 g / mL polyhexamethylene guanidine (PHMG) aqueous solution is replaced with 10 mL of 0.02 g / mL Ag aqueous solution, and the rest is carried out as in Example 1.

[0104] Comparative Example 2:

[0105] The preparation method is the same as that described in Example 2, except that:

[0106] In step (7), 10 mL of 0.02 g / mL polyhexamethylene biguanide (PHMB) aqueous solution is replaced with 10 mL of 0.02 g / mL Ag aqueous solution, and the rest is carried out as in Example 1.

[0107] Comparative Example 3:

[0108] The preparation method is the same as that described in Example 3, except that:

[0109] In step (7), 10 mL of 0.02 g / mL polyhexamethylene biguanide (PHMB) aqueous solution is replaced with 10 mL of 0.02 g / mL Ag aqueous solution, and the rest is carried out as in Example 1.

[0110] Comparative Example 4:

[0111] The preparation method is the same as that described in Example 4, except that:

[0112] In step (7), 10 mL of 0.02 g / mL chitosan aqueous solution is replaced with 10 mL of 0.02 g / mL Ag aqueous solution, and the rest is carried out as in Example 1.

[0113] Comparative Example 5:

[0114] The preparation method is the same as that described in Example 4, except that:

[0115] In step (7), 10 mL of 0.02 g / mL ε-polylysine aqueous solution is replaced with 10 mL of 0.02 g / mL Ag aqueous solution, and the rest is carried out as in Example 1.

[0116] Test case

[0117] 1. The composite material of Example 1, which exhibits both excellent antibacterial properties and superior mechanical strength, was subjected to infrared testing using a Fourier transform infrared spectrometer. The test results are shown in [Figure 1]. Figure 1 As shown.

[0118] Depend on Figure 1 It can be seen that the composite material prepared in this embodiment has a compressibility of 1701 cm⁻¹. -1 WPU characteristic peaks are present, and at 1601 cm⁻¹ -1 The presence of characteristic peaks of PHMG proves that the composite material with both excellent antibacterial properties and superior mechanical strength has been successfully synthesized.

[0119] 2. The toughness of the composite materials prepared in Example 1 and Comparative Example 1 was tested using a universal tensile testing machine; the stress-strain of the composite materials prepared in Example 2 and Comparative Example 2 was tested; and the tensile strength of the composite materials prepared in Example 3 and Comparative Example 3 was tested. The test results of toughness, stress-strain, and tensile strength are shown in the figures below. Figure 2 , 3 4.

[0120] pass Figure 2 , 3 As shown in Figures 4 and 5, the antibacterial particles Ag that were only physically blended in Comparative Examples 1 to 3 had lower toughness, stress-strain, and tensile strength mechanical properties than the composite material prepared in the embodiments of this invention. This is because the present invention uses specific antibacterial particles and specifically prepared waterborne polyurethane, and successfully uses an electrostatic self-assembly strategy to composite the antibacterial particles with waterborne polyurethane. Compared with the composite material obtained by physical blending only, the electrostatic self-assembly strategy introduces antibacterial particles into the polymer backbone, which has better interaction and compatibility, and does not damage the precise microstructure of WPU, thereby deteriorating its mechanical properties.

[0121] 3. The antibacterial effects of the composite materials prepared in Example 4 and Comparative Example 4 against Escherichia coli are shown in [the table below]. Figure 5 The antibacterial effects of the composite materials prepared in Example 5 and Comparative Example 5 against Staphylococcus aureus are shown in the figure. Figure 6 Compared with Comparative Examples 4 and 5, the composite materials prepared by electrostatic assembly in Examples 4 and 5 have better antibacterial effects than the antibacterial composite materials prepared by simple physical blending. This is because the antibacterial particles introduced by electrostatic self-assembly are all positively charged (cationic) macromolecular polymers, which can kill bacteria by destroying the negatively charged cell membranes of microorganisms, thus having a good bactericidal effect.

[0122] In summary, this invention synthesizes antibacterial composite materials using an electrostatic self-assembly method. This not only forms numerous and uniform electrostatic cross-linking points between different components, firmly "anchoring" the antibacterial particles as reinforcing phases within the material matrix, but also effectively transfers and disperses stress, reducing interface defects and stress concentrations that may result from simple blending. Furthermore, it often forms a biomimetic dense structure similar to "brick-and-mortar," thereby synergistically improving the material's toughness, hardness, or wear resistance. Moreover, this self-assembly mode can precisely and stably fix high-density antibacterial active groups on the material surface, avoiding the failure or rapid loss of antibacterial agents embedded in the bulk phase. When bacteria come into contact with the material, their negatively charged cell membranes interact strongly and continuously with the high concentration of positive charges on the material surface, greatly improving the efficiency and long-lasting effect of physical membrane disruption and sterilization.

Claims

1. A method for preparing a composite material with both excellent antibacterial properties and superior mechanical properties, comprising the following steps: (1) Mix bio-based diol polycaprolactone (PCL), diisocyanate, hydrophilic chain extender and catalyst evenly, and heat to react to obtain the first prepolymer; (2) Add a diol chain extender to an organic solvent and mix well to obtain mixture a; (3) Add the first prepolymer to mixture a, mix well, heat to react, and cool to room temperature to obtain the second prepolymer; (4) Add triethylamine neutralizing agent to the second prepolymer, stir to react, and obtain the third prepolymer; (5) Add diamine chain extender to ultrapure water and mix well to obtain mixture b; (6) Add the third prepolymer to mixture b and stir to react and obtain an aqueous polyurethane solution; (7) After diluting the aqueous polyurethane solution, slowly add the cationic antibacterial aqueous solution, mix and gradually precipitate, collect the precipitate by centrifugation, heat and press to form a film, and obtain a composite material with both excellent antibacterial properties and super strong mechanical properties.

2. The preparation method according to claim 1, characterized in that, In step (1), the selected diisocyanate is selected from one or more of 4,4'-dicyclohexylmethane diisocyanate (HMDI), diphenylmethane-4,4'-diisocyanate (MDI), isophorone diisocyanate (IPDI), toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI), the hydrophilic chain extender is one or more of dimethylolpropionic acid (DMPA), dimethylolbutyric acid (DMBA), sodium ethylenediamine ethanesulfonate and sodium 1,4-butanediol-2-sulfonate, and the selected catalyst is selected from one or more of dibutyltin dilaurate (DBTDL), bismuth laurate, stannous octoate or bismuth isooctanoate.

3. The preparation method according to claim 1, characterized in that, In step (1), the molar ratio of the hydrophilic chain extender to the diisocyanate is (0.20-2):1, the molar ratio of the catalyst to the diisocyanate is (0.002-0.05):1, the mass ratio of the bio-based diol polycaprolactone (PCL) to the diisocyanate is (4-10):(1-5), and the heating reaction temperature is 60-80℃ and the reaction time is 2-6h.

4. The preparation method according to claim 1, characterized in that, In step (2), the diol chain extender is one or more of 1,3-propanediol (PDO), 1,4-butanediol (BDO), 1,6-hexanediol (HDO), or N,N-bis(2-hydroxyethyl)oxalamide (BHO), and the molar ratio of the diol chain extender to the diisocyanate is (0.05-1):

1. The organic solvent is acetone, and the mass-volume ratio of the diol chain extender to the organic solvent is (0.05-0.5):(10-50), in g / mL.

5. The preparation method according to claim 1, characterized in that, In step (3), the heating reaction temperature is 45-60℃ and the reaction time is 2-6h. In step (4), the molar ratio of the triethylamine neutralizer to the hydrophilic chain extender in step (1) is (0.9-1):

1. The stirring reaction is carried out at a stirring speed of 200-400r / min for 0.1-1h.

6. The preparation method according to claim 1, characterized in that, In step (5), the diamine chain extender is 1,5-diaminopentane (PDA), 1,6-diaminohexane (HMDA), 1,3-diaminopropane (DAP), p-phenylenediamine (PPD), or triethylenetetramine (TETA). The molar ratio of the diamine chain extender to the diisocyanate in step (1) is (0.1-2):1, and the mass ratio of the diamine chain extender to ultrapure water is (0.1-0.8):(30-50).

7. The preparation method according to claim 1, characterized in that, In step (6), the stirring reaction is carried out at 1000-2000 r / min for 10-20 h. In step (7), the water-based polyurethane solution is diluted by 2-4 times.

8. The preparation method according to claim 1, characterized in that, In step (7), the cationic antibacterial agent is polyhexamethylene guanidine (PHMG), polyhexamethylene biguanide (PHMB), chitosan, or ε-polylysine. In step (7), the mass ratio of the aqueous polyurethane solution to the cationic antibacterial agent in the aqueous solution is 1:(0.1-0.3). In step (7), the concentration of the cationic antibacterial agent aqueous solution is 0.01-0.05 g / mL. The hot pressing temperature is 100-120℃, the reaction time is 1-2 h, and the pressure is 1 MPa-5 MPa.

9. A composite material with both excellent antibacterial properties and superior mechanical properties, prepared by the method described in any one of claims 1-8.

10. The application of the composite material with excellent antibacterial properties and superior mechanical properties as described in claim 9, in high-end wound dressings, medical catheters, wearable monitoring patches, antibacterial surgical gowns / gloves, or tissue engineering scaffolds.

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