Bio-based chain extender and use thereof

Abstract

This application provides a bio-based chain extender and its application. The bio-based chain extender includes the bio-based compounds 2,5-furandicarboxaldehyde dioxime and / or 5-hydroxymethyl-2-furancarboxaldehyde dioxime. Using these as bio-based chain extenders, modified polyurethanes with antibacterial and antifungal properties can be synthesized. This imparts long-lasting, stable, and broad-spectrum antibacterial and antifungal properties to polyurethane materials, eliminating the need for additional antibacterial agents. This avoids problems such as environmental pollution, short antibacterial time, and unstable antibacterial performance caused by antibacterial agent migration during the use of polyurethane materials. In particular, this bio-based chain extender is bio-based, safe, and environmentally friendly, and has a significant effect on the antibacterial and antifungal modification of polyurethane materials, showing broad application prospects in medical materials, public facilities, and health protection.

Description

Technical Field

[0001] This application belongs to the field of polymer materials; it relates to a bio-based chain extender and its application, specifically, to the application of the bio-based chain extender in the synthesis of modified polyurethane with antibacterial and antifungal properties. Background Technology

[0002] Polyurethane (PU) is short for polyurethane, a polymer containing many repeating urethane groups (-NHCOO-) on its main molecular chain. It is typically obtained by stepwise polymerization of polyisocyanates or polyisocyanates with polyols. Polyurethane possesses excellent overall properties, such as superior wear resistance, oil resistance, and water resistance; good radiation resistance and breathability; and excellent mechanical properties and ease of molding and processing, thus finding wide application in many fields. In particular, its presence of amide and ester groups similar to human proteins gives it good biocompatibility, leading to its widespread use in medical materials such as medical catheters, adhesives, and cardiovascular stents. However, ordinary polyurethane products lack antibacterial properties; therefore, developing polyurethane materials with excellent antibacterial properties will greatly benefit its applications in medical materials, personal protective equipment, and aseptic packaging.

[0003] Currently, commonly used antibacterial modification methods include the addition of antibacterial agents, such as mixing small-molecule antibacterial agents into the PU substrate through physical blending or surface coating, and then achieving antibacterial function through the release of bactericides or direct contact with bacteria. This type of antibacterial PU is easy to prepare, but the added antibacterial agents may migrate or lose their antibacterial properties due to physical wear, so the antibacterial performance will decrease over time, and the antibacterial agents that migrate into the environment may also pollute the environment. For example, Hong Fenghong (Preparation and Structure and Performance Study of Polyurethane / Nano Silver Composite Film, 2007, Beijing University of Chemical Technology, Master's Thesis) dissolved polyurethane monomer particles in DMAC, added silver nitrate or silver acetate solution, and then synthesized PU with antibacterial properties through heat treatment. Its main antibacterial mechanism is to use released silver particles for sterilization.

[0004] Alternatively, chemical modification methods can be used to obtain polyurethane (PU) with relatively stable antibacterial properties by graft copolymerization or block copolymerization of antibacterial groups with antibacterial properties. The antibacterial groups are mainly quaternary ammonium salts, guanidine salts, and imidazole heterocyclic quaternary ammonium salts, while the antifungal agents include 8-hydroxyquinolineone, tetrachloro-4-(methanesulfonyl)pyridine, salicylaniline, or bis(tri-n-butyltin)oxide, which can achieve antibacterial and antifungal modification of polyurethane. Among these, quaternary ammonium salt antibacterial agents are currently the most researched and applied antibacterial agents, exhibiting rapid bactericidal action and good bactericidal effect. However, traditional quaternary ammonium salt small molecule antibacterial agents also have drawbacks such as high toxicity, short duration of action, easy volatility, and poor chemical stability. While linking quaternary ammonium salt-containing organic molecules to the polyurethane backbone can prolong its antibacterial effect, the introduction of ionic organic molecules can also change the hydrophilicity and other properties of polyurethane, and there are still risks of environmental hazards. Even with group modification, the preparation process becomes more complicated. Therefore, there is a need to find healthier and greener methods to modify polyurethane for antibacterial purposes. In particular, there are few reports on polyurethanes with both antibacterial and antifungal effects and modification methods, indicating a large market demand.

[0005] Based on this, this application uses bio-based compounds 2,5-furandicarboxaldehyde dioxime and / or 5-hydroxymethyl-2-furancarboxaldehyde oxime as chain extenders. These compounds have dual functions of chain extension, antibacterial and antifungal properties, and also have the characteristics of small molecular size, few branches, and minimal impact on the mechanical properties of polyurethane. The resulting modified polyurethane contains furan oxime urethane bonds and has a stable structure. Furan oxime-based chain extenders are themselves bio-based compounds, safe and environmentally friendly, and are ideal chain extenders for polyurethane modification. Summary of the Invention

[0006] The purpose of this invention is to provide a bio-based chain extender and its application, which is used to synthesize modified polyurethane to solve the problem of poor antibacterial and antifungal effects of polyurethane materials in the prior art. In particular, it avoids the problems of unstable antibacterial effect, short antibacterial time, and environmental pollution caused by antibacterial agent migration caused by the addition of external antibacterial agents to improve the antibacterial performance of polyurethane in the prior art, as well as the problems of high toxicity, short duration, easy volatility, and poor chemical stability of traditional quaternary ammonium salt small molecule antibacterial agents.

[0007] To achieve the above objectives, this application adopts the following technical solution:

[0008] A bio-based chain extender comprising 2,5-furandicarboxaldehyde dioxime and / or 5-hydroxymethyl-2-furancarboxaldehyde dioxime, having the structures shown in formula (I) and / or formula (II):

[0009]

[0010] In equations (I) and (II), -C=NOH is an oxime group.

[0011] The above-mentioned bio-based chain extender can be used to synthesize modified polyurethane with antibacterial and antifungal properties. Using diisocyanate and polypolyol as reaction raw materials, the chain extender is added to react the isocyanate group with the oxime group to generate polyoxime urethane bond (-NH-COO-N=C-), which links the prepolymer molecular chain formed by diisocyanate and polypolyol to form a large molecular polyoxime urethane, which is the modified polyurethane.

[0012] Preferably, the chain extender includes a bio-based chain extender E.

[0013] More preferably, the bio-chain extender E is 2,5-furandicarboxaldehyde dioxime and / or 5-hydroxymethyl-2-furandicarboxaldehyde dioxime.

[0014] Specifically, the method for preparing the modified polyurethane includes:

[0015] The modified polyurethane is synthesized from diisocyanate A, polyol B and the chain extender; the modified polyurethane is a polyoxime urethane containing furanoxime urethane bonds.

[0016] Preferably, the preparation of the modified polyurethane includes two steps: prepolymerization and polymerization.

[0017] The prepolymer comprises prepolymer C obtained by first performing a prepolymerization reaction between diisocyanate A and polypolyol B;

[0018] The polymerization process involves adding a chain extender to the prepolymer C and then performing a polymerization reaction to prepare a modified polyurethane with antibacterial and antifungal properties.

[0019] The prepolymer C has one or both end groups of -N=C=O and contains structural units of formula (III):

[0020]

[0021] In this context, R1 and the two adjacent amide bonds originate from dicyanate A, R2 and the two adjacent -O- bonds originate from polyol B, n is a positive integer depending on the average molecular weight of the polyol, and x is a positive integer from 1 to 20.

[0022] Optionally, x in the prepolymer C is a positive integer from 1 to 20; preferably, x in the prepolymer C is a positive integer from 1 to 16; more preferably, the lower limit of x in the prepolymer C is 1, 2, 3, 4, 5, 6 or 7; and the upper limit of x in the prepolymer C is 14, 15, 16, 17, 18, 19 or 20.

[0023] After the bio-based chain extender E participates in the formation of modified polyurethane, furanoxime urethane bonds are formed on the molecular backbone. Furanoxime amino esters have antibacterial and antifungal properties, and the chain extender E forms a stable covalent bond with the polyurethane backbone, resulting in a stable structure and good antibacterial durability. There is no problem of antibacterial agent migration, which is fundamentally different from the method of physically adding antibacterial agents such as nano silver to polyurethane.

[0024] As one of the preferred embodiments of the present invention, when the bio-based chain extender E is 2,5-furandicarboxaldehyde dioxime, the modified polyurethane contains the structural unit shown in formula (IV):

[0025]

[0026] As one of the preferred embodiments of the present invention, when the bio-based chain extender E is 5-hydroxymethyl-2-furancarboxaldehyde oxime, the modified polyurethane, i.e., polyoxime urethane, contains the structural unit shown in formula (V):

[0027]

[0028] In this context, R1 and the two adjacent amide bonds originate from diisocyanate A, R2 and the two adjacent -O- bonds originate from polyol B, n is a positive integer depending on the average molecular weight of the polyol, x is a positive integer from 1 to 20, and m is a positive integer from 3 to 10.

[0029] Preferably, x is a positive integer from 1 to 16, the lower limit of x in the modified polyurethane is 1, 2, 3, 4, 5, 6 or 7, and the upper limit of x in the modified polyurethane is 14, 15, 16, 17, 18, 19 or 20.

[0030] Optionally, m is a positive integer from 3 to 10. Preferably, m is a positive integer from 5 to 8 in the modified polyurethane. The lower limit of m in the modified polyurethane is 3, 4, 5 or 6, and the upper limit of m in the modified polyurethane is 7, 8, 9 or 10.

[0031] In one preferred embodiment of the present invention, the chain extender further includes chain extender D.

[0032] The added chain extender D not only plays a chain-extending role, but also allows for better control of the amount of bio-based chain extender E while ensuring the molecular weight of the modified polyurethane, leaving more room for control in terms of antibacterial properties, mechanical properties, permeability, and color.

[0033] Preferably, the chain extender D is C2 to C3. 12 saturated polyols.

[0034] More preferably, the chain extender is a combination of one or more of the following: ethylene glycol, butanediol, pentanediol, hexanediol, octanediol, decanediol, and dodecanediol.

[0035] Preferably, when the chain extender D is present, the synthesized modified polyurethane contains structural units represented by formula (VI) and / or formula (VII):

[0036]

[0037] Wherein, R1 and the two adjacent amide bonds are derived from diisocyanate A, R2 and the two adjacent -O- bonds are derived from polyol B, R3 and the adjacent -O- bonds are derived from the chain extender D, n is a positive integer depending on the average molecular weight of the polyol, x is a positive integer from 1 to 20, y is a positive integer from 1 to 20, m is a positive integer from 3 to 10, and z is a positive integer from 0 to 10.

[0038] Preferably, x is a positive integer from 1 to 16, the lower limit of x in the modified polyurethane is 1, 2, 3, 4, 5, 6 or 7, and the upper limit of x in the modified polyurethane is 14, 15, 16, 17, 18, 19 or 20.

[0039] Preferably, y is a positive integer from 1 to 16, the lower limit of y in the modified polyurethane is 1, 2, 3, 4, 5, 6 or 7, and the upper limit of x in the modified polyurethane is 14, 15, 16, 17, 18, 19 or 20.

[0040] Preferably, m is a positive integer from 3 to 10; more preferably, m is a positive integer from 5 to 8 in the modified polyurethane; the lower limit of m in the modified polyurethane is 3, 4, 5 or 6, and the upper limit of m in the modified polyurethane is 7, 8, 9 or 10.

[0041] Preferably, z is a positive integer from 0 to 10. More preferably, z in the modified polyurethane is a positive integer from 0 to 8. The lower limit of z in the modified polyurethane is 0, 1, 2, 3, 4, 5 or 6, and the upper limit of z in the modified polyurethane is 7, 8, 9 or 10.

[0042] Furthermore, the diisocyanate A is selected from one or a combination of several of hexamethylene diisocyanate, L-lysine diisocyanate, trimethylhexane diisocyanate, isophorone diisocyanate (IPDI), trans-1,4-cyclohexane diisocyanate, and dicyclohexamethane 4,4′-diisocyanate (HMDI).

[0043] Preferably, the structures of the above diisocyanates do not contain benzene rings.

[0044] Optionally, the above-mentioned diisocyanate is any one or a combination of the following structures:

[0045]

[0046] The polyol B is selected from one or more of polyethylene glycol, polypropylene glycol, polytetrahydrofuran glycol, polycaprolactone glycol, and polybutadiene glycol. The molecular weight range of the polyol is 400–10000 g / mol. Optionally, the lower limit of the molecular weight of the polyol is 400 g / mol, 500 g / mol, 600 g / mol, 700 g / mol, or 800 g / mol, and the upper limit of the molecular weight of the polyol is 4000 g / mol, 5000 g / mol, 6000 g / mol, 7000 g / mol, 8000 g / mol, 9000 g / mol, or 10000 g / mol.

[0047] When diisocyanate A and polypolyol B are prepolymerized, the molar ratio is 1 to 3:1, the amount of catalyst is 0.005 to 0.3% of the total mass of diisocyanate A and polypolyol B, the reaction temperature is 50 to 80°C, the reaction time is 1 to 8 hours, preferably 2 to 5 hours, and the reaction gas atmosphere is an inert gas, such as nitrogen or argon.

[0048] Optionally, when the molar ratio of diisocyanate A to polyol B is 1:1 during prepolymerization, prepolymers with end groups of -OH and -C=N=O are easily formed; when the molar ratio of diisocyanate A to polyol B is 2:1 during prepolymerization, prepolymers with most molecular chains having end groups of -C=N=O are easily formed; when the molar ratio of diisocyanate A to polyol B is greater than 2:1 during prepolymerization, prepolymer molecular chains with end groups of -C=N=O are easily formed.

[0049] Preferably, when the diisocyanate A and the polyol B are prepolymerized, the molar ratio is 1.025 to 2.5:1. Optionally, when the diisocyanate A and the polyol B are prepolymerized, the molar ratio is 1 to 1.025:1, 1.025 to 1.5:1, 1.5 to 2:1, 2 to 2.5:1, or 2.5 to 3:1.

[0050] Preferably, the amount of catalyst used is 0.01 to 0.1% of the total mass of AB. Optionally, the amount of catalyst used is 0.005 to 0.01%, 0.01 to 0.02%, 0.02 to 0.05%, 0.05 to 0.1%, 0.1 to 0.2%, or 0.2% to 0.3% of the total mass of AB.

[0051] In a preferred embodiment, the catalyst in the prepolymerization step is a tin-containing catalyst, including stannous octoate, octyltin maleate, dibutyltin diacetate, and tin monobutyltriisooctanoate.

[0052] In a preferred embodiment, the catalyst in the prepolymerization step includes a titanate catalyst, including tetrabutyl titanate.

[0053] In a preferred embodiment, the catalyst in the prepolymerization step includes an antimony-containing catalyst, including antimony glycolate and antimony acetate.

[0054] Furthermore, the molar ratio of the bio-based chain extender E to the diisocyanate is 0.1–3:1, and the chain extender D is C2–C4. 12 Saturated polyols, such as ethylene glycol, butanediol, pentanediol, hexanediol, octanediol, decanediol, and dodecanediol, or combinations of the latter two.

[0055] The molar ratio of chain extender D to diisocyanate A is 0 to 2:1. Preferably, the molar ratio of chain extender D to diisocyanate A is 0 to 1.5:1. Optionally, the molar ratio of chain extender D to diisocyanate A is 0 to 0.01:1, 0.01 to 0.03:1, 0.03 to 0.05:1, 0.05 to 0.07:1, 0.07 to 0.4:1, 0.4 to 0.5:1, 0.5 to 1:1, 1 to 1.5:1, or 1.5 to 2:1.

[0056] After adding chain extender D and bio-based chain extender E, the reaction temperature is 50-100℃, the reaction time is 2-10 hours, the reaction gas atmosphere is inert gas, and a polyurethane oxime solution is obtained after the reaction is completed.

[0057] Optionally, the reaction temperature after adding chain extender D and bio-based chain extender E is 50–100°C. Preferably, the reaction temperature after adding chain extender D and bio-based chain extender E is 70–95°C. The lower limit of the reaction temperature after adding chain extender D and bio-based chain extender E is 50°C, 55°C, 60°C, 65°C, or 70°C, and the upper limit of the reaction temperature after adding chain extender D and bio-based chain extender E is 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, or 100°C.

[0058] Optionally, the reaction time after adding chain extender D and bio-based chain extender E is 2 to 10 hours. Preferably, the reaction time after adding chain extender D and bio-based chain extender E is 2 to 3 hours, 3 to 4 hours, 4 to 5 hours, 5 to 6 hours, 7 to 8 hours, or 9 to 10 hours.

[0059] In a preferred embodiment, a dispersant F may also be added to the polymerization process; the dispersant F includes any one or a combination of several of methanol, ethanol, toluene, tetrahydrofuran, dichloromethane, and trichloromethane.

[0060] Preferably, the amount of the dispersant is 5% to 50% of the total mass of the reactants in the polymerization reaction system.

[0061] More preferably, the amount of dispersant F is 5-10%, 10-20%, 20-30%, 30-40%, or 40-50% of the total mass of the reactants.

[0062] After the modified polyurethane solution is desolventized, the modified polyurethane, which is one of the objectives of this invention, is obtained. The obtained modified polyurethane contains furanoxime urethane bonds, that is, it is a polyoxime urethane.

[0063] Preferably, the solvent removal method includes any one of rotary evaporation, vacuum drying, plate heating, water bath or oil bath nitrogen blowing, with a temperature of 60-120°C.

[0064] More preferably, the solvent removal temperature is 70-100°C; the lower limit of the solvent removal temperature is 60°C, 65°C, 70°C, 75°C or 80°C, and the upper limit of the solvent removal temperature is 85°C, 90°C, 95°C, 100°C, 110°C or 120°C.

[0065] The modified polyurethane prepared based on the above technical solution has inhibitory and / or bactericidal effects on bacteria and fungi.

[0066] Specifically, the bacteria include Escherichia coli and Staphylococcus aureus; and / or, the fungi include Aspergillus niger, Chaetomium globosum, Penicillium cordiformis, Penicillium wansii, and Trichoderma longifolium.

[0067] The modified polyurethane prepared using the technical solution of this invention, which has inhibitory and / or bactericidal effects on bacteria and fungi, can be applied in the fields of medical materials, personal protective equipment, and aseptic packaging.

[0068] The beneficial effects that this application can produce include:

[0069] 1) The bio-based chain extender provided in this application has a good chain extension effect and a significant increase in molecular weight when used to synthesize polyurethane materials.

[0070] 2) This application uses bio-based compounds 2,5-furandicarboxaldehyde dioxime and / or 5-hydroxymethyl-2-furancarboxaldehyde dioxime as chain extenders to synthesize modified polyurethanes with dual antibacterial and antifungal effects. The modified polyurethanes formed contain furan oxime urethane bonds, have stable structures, low migration rates, and also have the characteristics of small introduced molecules, no more branches, and minimal impact on the mechanical properties of polyurethanes.

[0071] 3) The polyurethane synthesized using the technical solution of this application, based on furanoxime group chain extenders, can significantly improve the antibacterial and antifungal effects of polyurethane, achieving the intrinsic antibacterial effect without the need for additional antibacterial agents. This avoids problems such as environmental pollution, short antibacterial time, and unstable antibacterial performance caused by antibacterial agent migration during the use of polyurethane materials. In particular, it eliminates the need for additional additions of small molecule antibacterial agents such as quaternary ammonium salts, which can lead to problems such as high toxicity, short antibacterial time, easy volatility, and poor chemical stability in polyurethane materials.

[0072] 4) The bio-based chain extender provided in this application is a bio-based chemical with a wide range of raw material sources, low ecotoxicity, and is safe and environmentally friendly.

[0073] 5) The polyurethane (polyoxime urethane) based on furanoxime urethane bonds synthesized using the chain extender provided in this application not only has amide bonds similar to human proteins, but also has antibacterial and antifungal functions, and has great application prospects in the fields of medical and health care.

[0074] 6) In the technical solution provided in this application, two chain extenders are selected for synergistic use in the synthesis and modification of polyurethane. The amount of bio-based chain extender can be designed and effectively adjusted as needed to improve the antibacterial and antifungal properties of polyurethane more economically and efficiently. Attached Figure Description

[0075] Figure 1 This is the Fourier infrared spectrum of the modified polyurethane obtained after polymerization in Example 1 of this application. Detailed Implementation

[0076] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0077] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values, but should be understood to include those approximations of such ranges or values. For numerical ranges, the endpoint values ​​of the various ranges and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0078] Unless otherwise specified, all reaction reagents or raw materials used in this application were purchased commercially and are of AR grade or >98%.

[0079] In the bio-based chain extender E, 5-hydroxymethyl-2-furanaldehyde oxime is a commercially available product (purchased from Jinjinle Chemicals in the examples below).

[0080] The preparation method of 2,5-furandicarboxaldehyde dioxime in bio-based chain extender E includes using 2,5-furandicarboxaldehyde from biomass as raw material, hydroxylamine aqueous solution as oximating agent, adding acid to adjust the pH of the reaction system, and the generated 2,5-furandicarboxaldehyde dioxime acting as a catalyst to autocatalyze the reaction process. In this application, it is used as a chain extender, which is a bio-based chain extender E. Specifically, the preparation method of 2,5-furandicarboxaldehyde dioxime (DFFD) is described in CN112830911B.

[0081] In this application, the concentration of isocyanate is determined by hydrochloric acid-di-n-butylamine titration, specifically referring to "GB / T12009.4-2016 Aromatic Isocyanates for Polyurethane Production - Part 4: Determination of Isocyanate Content" to determine the reaction progress.

[0082] The molecular weight of prepolymers and polymers was determined using the Ubbelohde viscometer method.

[0083] The technical solution of this application will be described in detail below through specific embodiments.

[0084] Example 1

[0085] This embodiment provides a method for preparing a modified polyurethane based on furan rings and oxime groups, specifically including the following steps:

[0086] 1. Prepolymerization: 15 g (15 mmol) of anhydrous polytetrahydrofuran diol (PTMG, average molecular weight 1000 g / mol) was placed in a flask. Two stoichiometric amounts (30 mmol) of isophorone diisocyanate (IPDI) were added to the flask. Stannous isooctanoate was added at 0.02% of the sum of the mass of PTMG and IPDI. The mixture was stirred at 65 °C for 3.5 hours with nitrogen continuously purging to obtain the prepolymer. The average molecular weight of the prepolymer was approximately 2300 g / mol, and x was approximately 2.

[0087] 2. Polymerization: 15 mmol of 2,5-furandicarboxaldehyde dioxime (DFFD) and 20% of anhydrous tetrahydrofuran (by mass of the total polymerization system) were added to a flask. The mixture was heated to 75°C and stirred continuously under a nitrogen atmosphere for 5 hours. The polymerization reaction was completed, and a modified polyurethane solution was obtained. This solution was a homogeneous viscous solution.

[0088] 3. Solvent removal: The modified polyurethane solution obtained from the polymerization reaction in step 2 was placed on a heating platform at 80°C and heated for 48 hours to remove the solvent, resulting in modified polyurethane with an average molecular weight of 22000 g / mol and m of approximately 9.

[0089] See Figure 1 The image shows the infrared spectrum of the modified polyurethane obtained after polymerization, with 3324 cm⁻¹ as the focal length. -1The characteristic peak of NH on the amide bond, combined with 1708 cm⁻¹ -1 C=O and 1101cm -1 The presence of CO indicates the formation of urethane bonds, 2850–2940 cm⁻¹ -1 -CH2 on polyols, 770~960cm -1 And 1536cm -1 The bending vibrations and C=O stretching vibrations on the furan ring indicate that the furan ring chain extender is attached to the polyurethane. 3170cm -1 The OH group on the DFFD oxime. Figure 1 The absence of this characteristic peak indicates the absence of free oxime groups, 1435–1465 cm⁻¹ -1 The result of NO indicates that the oxime group on chain extender E is connected to the isocyanate group.

[0090] Example 2

[0091] In this embodiment, the modified polyurethane was prepared using the method of Example 1, except that the amount of 2,5-furandicarboxaldehyde dioxime (DFFD) was changed to 13.5 mmol and 1.5 mmol of butanediol was added. The prepolymer had an average molecular weight of about 2200 g / mol and x was about 2. The modified polyurethane had an average molecular weight of 23000 g / mol and m was about 10.

[0092] Example 3

[0093] This embodiment uses the method of Example 2 to prepare modified polyurethane, except that the average molecular weight of polytetrahydrofuran diol is changed to 400 g / mol, the molar amounts of DFFD and butanediol are changed to 3 mmol and 12 mmol respectively, the prepolymerization temperature is changed to 80℃, the prepolymerization time is changed to 2 hours, the polymerization temperature is changed to 75℃, and the polymerization time is changed to 5 hours. The resulting prepolymer has an average molecular weight of approximately 3300 g / mol and x is approximately 5. The resulting modified polyurethane has an average molecular weight of 24000 g / mol and m is approximately 7.

[0094] Example 4

[0095] 1. Prepolymerization: 15 g (15 mmol) of anhydrous polycaprolactone diol (average molecular weight 1000 g / mol) was placed in a flask. Twice the stoichiometric amount (30 mmol) of polycaprolactone diol hexamethylene diisocyanate was added to the flask. The above two reagents and 0.02% octyltin maleate were added. The mixture was stirred at 70 °C for 3.5 hours with nitrogen continuously purging to obtain the prepolymer. The average molecular weight of the prepolymer was approximately 3600 g / mol, and x was approximately 3.

[0096] 2. Polymerization: 18 mmol of DFFD and 20% of anhydrous tetrahydrofuran were added to a flask, heated to 75°C, and stirred continuously for 5 hours under a nitrogen atmosphere. The polymerization reaction was completed, and a modified polyurethane solution was obtained. This solution was a homogeneous viscous solution.

[0097] 3. Desolventization: The modified polyurethane solution obtained from the reaction is placed in a vacuum drying oven at 50°C for desolventization until it is completely dried, to obtain modified polyurethane with an average molecular weight of approximately 29,000 g / mol and m of approximately 8.

[0098] Example 5

[0099] 1. Prepolymerization: 15 g (15 mmol) of anhydrous polypropylene glycol (average molecular weight 2000 g / mol) was placed in a flask. 1.5 times the stoichiometric amount of polypropylene glycol (22.5 mmol) of L-lysine diisocyanate was added to the flask. The above two reagents and 0.005% octyltin maleate were added. The mixture was stirred and reacted at 70 °C for 5 hours with nitrogen continuously purging to obtain the prepolymer. The average molecular weight of the prepolymer was approximately 9000 g / mol, and x was approximately 4.

[0100] 2. Polymerization: 9 mmol of DFFD, 1.5 mmol of ethylene glycol, and 5% of anhydrous tetrahydrofuran were added to a flask. The mixture was heated to 75°C and stirred continuously for 4 hours under a nitrogen atmosphere. The polymerization reaction was completed, and a modified polyurethane solution was obtained. This solution was a homogeneous viscous solution.

[0101] 3. Solvent removal: The modified polyurethane solution obtained from the reaction is placed in a vacuum drying oven at 50°C to remove the reaction solvent until it is completely dried, resulting in modified polyurethane with an average molecular weight of approximately 27,000 g / mol and m of approximately 3.

[0102] Example 6

[0103] 1. Prepolymerization: 15 g (15 mmol) of anhydrous polyethylene glycol (average molecular weight 10000 g / mol) was placed in a flask. 1.5 times the stoichiometric amount of polyethylene glycol (15.375 mmol) of trimethylhexamethylene diisocyanate was added to the flask. The above two reagents and 0.005% octyltin maleate were added. The mixture was stirred and reacted at 80 °C for 1 hour while nitrogen was continuously introduced to obtain the prepolymer.

[0104] 2. Polymerization: 46.125 mmol of DFFD, 30.75 mmol of ethylene glycol, and 5% of anhydrous tetrahydrofuran were added to a flask. The mixture was heated to 50°C and stirred continuously under a nitrogen atmosphere for 10 hours. The polymerization reaction was completed, and a modified polyurethane solution was obtained. This solution was a homogeneous viscous solution.

[0105] 3. Solvent removal: The modified polyurethane solution obtained from the reaction is placed in a vacuum drying oven at 80°C to remove the reaction solvent until it is completely dried, resulting in modified polyurethane with an average molecular weight of approximately 31200 g / mol and m of approximately 3.

[0106] Example 7

[0107] 1. Prepolymerization: 15 g (15 mmol) of anhydrous polytetrahydrofuran diol (average molecular weight 1000 g / mol) was placed in a flask. Twice the stoichiometric amount (30 mmol) of polytetrahydrofuran diol trans-1,4-cyclohexane diisocyanate was added to the flask. The above two reagents and 0.3% tetrabutyl titanate were added. The mixture was stirred and reacted at 70 °C for 1 hour, with nitrogen gas continuously introduced to obtain the prepolymer.

[0108] 2. Polymerization: 7.5 mmol of DFFD, 7.5 mmol of pentanediol, and 50% of anhydrous toluene by total mass were added to a flask. The mixture was heated to 100°C and stirred continuously for 2 hours under a nitrogen atmosphere. The polymerization reaction was completed, and a modified polyurethane solution was obtained. This solution was a homogeneous viscous solution.

[0109] 3. Solvent removal: The modified polyurethane solution obtained from the reaction is placed in a vacuum drying oven at 90°C to remove the reaction solvent until it is completely dry, thus obtaining modified polyurethane with an average molecular weight of approximately 11000 g / mol and m of approximately 7.

[0110] Example 8

[0111] 1. Prepolymerization: 15 g (15 mmol) of anhydrous polybutadiene glycol (average molecular weight 5000 g / mol) was placed in a flask. Three times the stoichiometric amount (45 mmol) of polybutadiene glycol dicyclohexane 4,4′-diisocyanate was added to the flask. The above two reagents and 0.1% antimony acetate were added. The mixture was stirred and reacted at 50 °C for 8 hours with nitrogen gas continuously introduced to obtain the prepolymer. The average molecular weight of the prepolymer was 10700 g / mol, and x was approximately 2.

[0112] 2. Polymerization: 30 mmol of DFFD, 3 mmol of dodecanediol, and 20% of dichloromethane by total mass were added to a flask. The mixture was heated to 80°C and stirred continuously for 6 hours under a nitrogen atmosphere. The polymerization reaction was completed, and a modified polyurethane solution was obtained. This solution was a homogeneous viscous solution.

[0113] 3. Solvent removal: The modified polyurethane solution obtained from the reaction is placed in a vacuum drying oven at 120℃ to remove the reaction solvent until it is completely dry, thus obtaining modified polyurethane with an average molecular weight of approximately 31600 g / mol and m of approximately 3.

[0114] Example 9

[0115] 1. Prepolymerization: 15 g (15 mmol) of anhydrous polypropylene glycol (average molecular weight 400 g / mol) was placed in a flask. 2.2 times the stoichiometric amount (33 mmol) of dicyclohexamethylene 4,4′-diisocyanate was added to the flask. The above two reagents and 0.02% monobutyltriisooctanoate were added. The mixture was stirred and reacted at 50 °C for 5 hours with nitrogen continuously purging to obtain the prepolymer. The prepolymer had an average molecular weight of 3800 g / mol and x was approximately 6.

[0116] 2. Polymerization: 15 mmol of 5-hydroxymethyl-2-furanaldehyde oxime (HMFO) and 3 mmol of ethylene glycol, along with 20% of the total mass of triazine, were added to a flask. The mixture was heated to 75°C and stirred continuously under a nitrogen atmosphere for 6 hours. The polymerization reaction was completed, and a modified polyurethane solution was obtained. This solution was a homogeneous viscous solution.

[0117] 3. Solvent removal: The modified polyurethane solution obtained from the reaction is placed in a vacuum drying oven at 80°C to remove the reaction solvent until it is completely dry, thus obtaining modified polyurethane with an average molecular weight of approximately 31000 g / mol and m of approximately 8.

[0118] Example 10

[0119] This embodiment uses a similar method to Example 9 to prepare modified polyurethane, except that the isocyanate is replaced with 1.05 times the chemical equivalent of polypropylene glycol (15.75 mmol) of L-lysine diisocyanate, the chain extender is replaced with 47.25 mmol of HMFO and 31.5 mmol of ethylene glycol, the prepolymerization temperature is changed to 60°C, the gas is changed to argon, and the dispersant is changed to tetrahydrofuran, resulting in modified polyurethane with an average molecular weight of approximately 24000 g / mol.

[0120] Example 11

[0121] This embodiment uses a method similar to Example 9 to prepare modified polyurethane, except that the average molecular weight of the polypropylene glycol reagent is increased to 3000 g / mol, the isocyanate is replaced with twice the stoichiometric amount of polypropylene glycol (30 mmol) of trimethylhexamethylene diisocyanate, the chain extender is replaced with 13.5 mmol of HMFO and 1.5 mmol of hexanediol, the dispersant is replaced with tetrahydrofuran at 50% of the total mass, the prepolymerization temperature is changed to 70°C, the prepolymerization time is changed to 4 hours, the polymerization temperature is changed to 50°C, and the polymerization time is changed to 10 hours. The prepolymer has an average molecular weight of approximately 8000 g / mol and x is approximately 3, resulting in a modified polyurethane with an average molecular weight of approximately 58000 g / mol and m approximately 6.

[0122] Example 12

[0123] This embodiment uses a method similar to Example 9 to prepare modified polyurethane, except that polypropylene glycol is replaced with polytetrahydrofuran glycol with an average molecular weight of 1000 g / mol, isocyanate is replaced with isophorone diisocyanate at 1.5 times the stoichiometric weight of polytetrahydrofuran glycol (22.5 mmol), the catalyst is replaced with stannous isooctanoate at 0.005% of the total mass of polytetrahydrofuran glycol and isophorone diisocyanate, the chain extender is replaced with 2.25 mmol of HMFO and 5.25 mmol of decanediol, the dispersant is replaced with methanol, the prepolymerization temperature is changed to 60°C, and the prepolymerization time is changed to 4 hours. The resulting modified polyurethane has an average molecular weight of approximately 27000 g / mol.

[0124] Example 13

[0125] This embodiment uses a method similar to that in Example 12 to prepare modified polyurethane, except that the amount of catalyst added is 0.02% of the total mass of polytetrahydrofuran diol and isophorone diisocyanate, and the chain extender is changed to 3 mmol of HMFO and 4.5 mmol of DFFD to obtain modified polyurethane with an average molecular weight of about 24000 g / mol and m of about 5.

[0126] Example 14

[0127] 1. Prepolymerization: 15g (15mmol) of anhydrous polyethylene glycol (average molecular weight 10000g / mol) was placed in a flask. Three times the stoichiometric amount (45mmol) of polyethylene glycol trans-1,4-cyclohexane diisocyanate was added to the flask. The above two reagents and 0.02% antimony glycol were added. The mixture was stirred and reacted at 80°C for 2 hours with nitrogen gas continuously introduced to obtain the prepolymer.

[0128] 2. Polymerization: 28.5 mmol of HMFO, 1.5 mmol of octanediol, and 5% of toluene by total mass were added to a flask. The mixture was heated to 90°C and stirred for 4 hours under a nitrogen atmosphere. The polymerization reaction was completed, and a modified polyurethane solution was obtained. This solution was a homogeneous viscous solution.

[0129] 3. Desolventization: The modified polyurethane solution obtained from the reaction is heated on a hot plate at 120°C until it is dry to obtain modified polyurethane with an average molecular weight of about 61000 g / mol and m of about 6.

[0130] Example 15

[0131] 1. Prepolymerization: 15 g (15 mmol) of anhydrous polyethylene glycol (average molecular weight 800 g / mol) was placed in a flask. 12 mmol of hexamethylene diisocyanate and 15 mmol of isophorone diisocyanate were added to the flask. Dibutyltin diacetate was added, which is 0.02% of the total mass of the above reagents. The mixture was stirred and reacted at 80 °C for 2 hours, with nitrogen gas continuously introduced to obtain the prepolymer.

[0132] 2. Polymerization: 15 mmol of HMFO and 20% of toluene by total mass were added to a flask, heated to 100°C, and stirred continuously for 2 hours under a nitrogen atmosphere. The polymerization reaction was completed, and a modified polyurethane solution was obtained. This solution was a homogeneous viscous solution.

[0133] 3. Desolventization: The modified polyurethane solution obtained from the reaction is placed on a heating plate at 120°C and heated until dry to obtain modified polyurethane with an average molecular weight of approximately 23,000 g / mol.

[0134] Comparative Example 1

[0135] This comparative example provides a polyurethane whose preparation method differs from the method for preparing modified polyurethane in Example 2 in that only the content of DFFD is changed to 0 and the amount of butanediol added is changed to 15 mmol. The average molecular weight of the prepolymer is about 2200 mol / g, x is about 2, and the molecular weight of the polyurethane is about 17600 g / mol, m is about 7. The polyurethane structure does not include furan rings and oxime groups.

[0136] Comparative Example 2

[0137] This comparative example uses the method of Example 2 to prepare modified polyurethane, except that DFFD is replaced with 2,4-pentanedione dioxime and the dispersant is replaced with ethanol. The obtained polyoxime urethane was titrated with hydrochloric acid-butanediamine solvent and the isohydrochloric acid content was 0. The molecular weight of the obtained polyurethane was 18800 g / mol and m was approximately 8.

[0138] Antibacterial test

[0139] The antibacterial properties of the prepared polyurethane and modified polyurethane were determined in accordance with GB / T 31402-2015 Test Method for Antibacterial Properties of Plastic Surfaces.

[0140] The bacteria were tested using Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P, respectively. The viable count of Escherichia coli directly obtained after inoculation of the unprocessed sample was 2.4 × 10⁻⁶. 4 (cfu / cm 2 The viable bacterial count obtained after inoculating unprocessed sample pieces and leaving them for 24 hours was 2.1 × 10⁻⁶. 5 (cfu / cm 2For specific test results, please refer to Table 1.

[0141] Table 1. Antibacterial test results

[0142] Sample source Escherichia coli inhibition rate Staphylococcus aureus inhibition rate Comparative Example 1 3％ 0.05％ Comparative Example 2 2％ 1％ Example 1 100％ 100％ Example 2 99％ 98％ Example 3 96％ 95％ Example 5 99％ 97％ Example 6 100％ 100％ Example 9 100％ 100％ Example 13 99％ 99％ Example 15 100％ 99％

[0143] Anti-mildew performance test:

[0144] The anti-mold properties of the prepared polyurethane and modified polyurethane were determined in accordance with GB / T 24128-2018 Evaluation of the anti-mold effect of plastic anti-mold agents. The anti-mold grade is shown in Table 2. The lower the grade, the better the anti-mold effect.

[0145] Table 2 Explanation of Mildew Resistance Levels

[0146] Mold growth Anti-mildew rating No obvious bacterial growth was observed when the concentration was increased to approximately 50 times. Level 0 The bacteria are invisible or barely visible to the naked eye, but are clearly visible under a magnifying glass. Level 1 Bacterial growth was clearly visible to the naked eye, covering 10-30% of the sample surface. Level 2 Bacterial growth was clearly visible to the naked eye, covering 30-60% of the sample surface. Level 3 Bacterial growth is clearly visible to the naked eye, covering more than 60% of the sample surface. Level 4

[0147] The fungal strains used for the anti-mold performance test were: Aspergillus niger CGMCC 3.3928, Chaetomium globulus CGMCC 3.3601, Penicillium cordiformis CGMCC 3.3875, Penicillium wansi CGMCC 3.4253, and Trichoderma longifolia ATCC 13631. The anti-mold test results are shown in Table 3.

[0148] Table 3. Results of mold resistance test

[0149] Sample source Anti-mildew rating Comparative Example 1 Level 4 Comparative Example 2 Level 4 Example 1 Level 0 Example 2 Level 0 Example 3 Level 0 Example 5 Level 0 Example 6 Level 0 Example 9 Level 0 Example 13 Level 0 Example 15 Level 0

[0150] As can be seen from the comparison of the antifungal and antibacterial test results in Tables 1-3, the modified polyurethane containing furanoxime urethane bonds prepared using the technical solution of this invention has significant antibacterial and antifungal effects.

[0151] In particular, DFFD and HMFO, as chain extenders, can effectively modify the antibacterial and antifungal properties of polyurethane. They are structurally stable, have simple preparation methods, are safe and environmentally friendly, and do not require additional antibacterial agents, thus avoiding the problems that may occur during the use of polyurethane materials. They have broad application prospects.

[0152] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. The application of a bio-based chain extender in the synthesis of polyurethane with antibacterial and antifungal properties; The bio-based chain extender comprises 2,5-furandicarboxaldehyde dioxime and / or 5-hydroxymethyl-2-furandicarboxaldehyde dioxime, having the structures shown in formula (I) and / or formula (II): ； In equations (I) and (II), -C=NOH is an oxime group.

2. A modified polyurethane, characterized in that, Using diisocyanate A and polypolyol B as reactants, a chain extender is added to react the isocyanate group with the oxime group to generate an oxime urethane bond -NH-COO-N=C-, which links the prepolymer molecular chains formed by the diisocyanate and the polypolyol, forming a macromolecular polyoxime urethane containing furanoxime urethane bonds on the molecular backbone, which is the modified polyurethane. The chain extender includes bio-based chain extender E; The biological chain extender E is 2,5-furandicarboxaldehyde dioxime and / or 5-hydroxymethyl-2-furandicarboxaldehyde dioxime; The modified polyurethane can inhibit and / or kill bacteria and fungi; the bacteria include Escherichia coli and Staphylococcus aureus; the fungi include Aspergillus niger, Chaetomium globosum, Penicillium cordiformis, Penicillium wansii, and Trichoderma longifolium.

3. The modified polyurethane according to claim 2, characterized in that, It includes two steps: prepolymerization and polymerization; The prepolymer comprises prepolymer C obtained by first performing a prepolymerization reaction between diisocyanate A and polypolyol B; The polymerization process involves adding the chain extender to the prepolymer C and then carrying out a polymerization reaction to prepare a modified polyurethane with antibacterial and antifungal properties. The prepolymer C contains structural units as shown in formula (III), and the end groups at both ends contain -N=C=O; Formula (III); R1 and the two adjacent amide bonds or isocyanate bonds are derived from diisocyanate A; R2 and the two adjacent -O- bonds originate from polyol B; n is a positive integer, which depends on the average molecular weight of polyol B; x is a positive integer from 1 to 20.

4. The modified polyurethane according to claim 2, characterized in that, When the bio-based chain extender E is 2,5-furandicarboxaldehyde dioxime, the synthesized modified polyurethane contains the formula ( The structural unit shown is: ； Mode( ); When the bio-based chain extender E is 5-hydroxymethyl-2-furanaldehyde oxime, the synthesized polyurethane contains the formula ( The structural unit shown is: ； Mode( ); Among them, R1 and the two adjacent amide bonds are derived from diisocyanate A; R2 and the two adjacent -O- bonds originate from polyol B; n is a positive integer, which depends on the average molecular weight of polyol B; x is a positive integer from 1 to 20; m is a positive integer from 3 to 10.

5. The modified polyurethane as described in claim 2, characterized in that, The chain extender also includes chain extender D; The modified polyurethane was synthesized from diisocyanate A, polyol B, chain extender D, and bio-based chain extender E. The chain extender D is C2~C 12 saturated polyols; The synthesized modified polyurethane contains structural units represented by formula (VI) and / or formula (VII): ； Formula (VI); ； Equation (VII); Wherein, R1 and the two adjacent amide bonds are derived from diisocyanate A; R2 and the two adjacent -O- bonds are derived from polyol B; R3 and the adjacent -O- bonds are derived from the chain extender D; n is a positive integer, depending on the average molecular weight of polyol B; m is a positive integer from 3 to 10; x is a positive integer from 1 to 20; y is a positive integer from 1 to 20; z is a positive integer from 0 to 10, and z≠0.

6. The modified polyurethane according to claim 5, characterized in that, The chain extender D includes one or a combination of several of the following: ethylene glycol, butanediol, pentanediol, hexanediol, octanediol, decanediol, and dodecanediol.

7. The modified polyurethane according to claim 5, characterized in that, A catalyst is added to the diisocyanate A and the polypolyol B to carry out a prepolymerization reaction, and the molar ratio of the diisocyanate A and the polypolyol B is 1~3:1; The reaction temperature in the prepolymerization step is 50~80℃, the reaction time is 1~8 hours, and the reaction gas atmosphere is an inert gas. The catalyst in the prepolymerization step is a tin-containing catalyst, including stannous octoate, octyltin maleate, dibutyltin diacetate, and tin monobutyltriisooctoate.

8. The modified polyurethane according to claim 7, characterized in that, The reaction time is 2 to 5 hours.

9. The modified polyurethane according to claim 7, characterized in that, The catalyst includes titanium-containing catalysts, including tetrabutyl titanate.

10. The modified polyurethane according to claim 7, characterized in that, The catalyst includes antimony-containing catalysts, including antimony glycolate and antimony acetate; The amount of catalyst used is 0.005 to 0.3% of the total mass of diisocyanate A and polyol B.

11. The modified polyurethane according to claim 5, characterized in that, The molar ratio of the bio-based chain extender E to diisocyanate A is 0.1~3:

1.

12. The modified polyurethane according to claim 5, characterized in that, The molar ratio of the bio-based chain extender E to diisocyanate A is 0.5~2:

1.

13. The modified polyurethane according to claim 5, characterized in that, The molar ratio of chain extender D to diisocyanate A is 0~2:

1.

14. The modified polyurethane according to claim 5, characterized in that, The molar ratio of chain extender D to diisocyanate A is 0~1.5:

1.

15. The modified polyurethane according to claim 3, characterized in that, After adding the bio-based chain extender E to the polymerization process, the reaction temperature is 50~100℃, the reaction time is 2~10 hours, the reaction gas atmosphere is inert gas, and a modified polyurethane solution is obtained after the reaction is completed.

16. The modified polyurethane according to claim 3, characterized in that, The polymerization also includes the addition of dispersant F, which includes any one or a combination of methanol, ethanol, toluene, tetrahydrofuran, dichloromethane, and trichloromethane; the amount of the dispersant is 5 to 50% of the total mass of the reactants in the polymerization reaction system.

17. The modified polyurethane according to claim 15, characterized in that, The modified polyurethane is obtained by desolventizing the modified polyurethane solution. The solvent removal method includes any one of rotary evaporation, vacuum drying, plate heating, and water bath nitrogen blowing; the solvent removal temperature is 60~120℃.

18. The modified polyurethane according to any one of claims 2-17, characterized in that, The diisocyanate A is selected from one or a combination of several of hexamethylene diisocyanate, L-lysine diisocyanate, trimethylhexane diisocyanate, isophorone diisocyanate, trans-1,4-cyclohexane diisocyanate, and dicyclohexamethane 4,4'-diisocyanate.

19. The modified polyurethane according to claim 18, characterized in that, The polyol B is selected from one or a combination of several of polyethylene glycol, polypropylene glycol, polytetrahydrofuran glycol, polycaprolactone glycol, and polybutadiene glycol.

20. The modified polyurethane according to claim 18, characterized in that, The molecular weight range of the polyol B is 400~10000 g / mol.

21. The modified polyurethane according to claim 18, characterized in that, The molecular weight range of the polyol B is 800~4000 g / mol.

22. The application of the modified polyurethane as described in any one of claims 2-21 as an antibacterial and antifungal material in the fields of medical materials, personal protective equipment, and aseptic packaging.

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