CN114230485A - Polyfunctional azine derivative and polyurethane elastomer prepared from same - Google Patents
Polyfunctional azine derivative and polyurethane elastomer prepared from same Download PDFInfo
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- CN114230485A CN114230485A CN202111586281.XA CN202111586281A CN114230485A CN 114230485 A CN114230485 A CN 114230485A CN 202111586281 A CN202111586281 A CN 202111586281A CN 114230485 A CN114230485 A CN 114230485A
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- C07C251/72—Hydrazones
- C07C251/88—Hydrazones having also the other nitrogen atom doubly-bound to a carbon atom, e.g. azines
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- C07C323/00—Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups
- C07C323/10—Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups containing thio groups and singly-bound oxygen atoms bound to the same carbon skeleton
- C07C323/11—Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups containing thio groups and singly-bound oxygen atoms bound to the same carbon skeleton having the sulfur atoms of the thio groups bound to acyclic carbon atoms of the carbon skeleton
- C07C323/12—Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups containing thio groups and singly-bound oxygen atoms bound to the same carbon skeleton having the sulfur atoms of the thio groups bound to acyclic carbon atoms of the carbon skeleton the carbon skeleton being acyclic and saturated
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- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/30—Low-molecular-weight compounds
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- C08G18/3203—Polyhydroxy compounds
- C08G18/3206—Polyhydroxy compounds aliphatic
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- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/30—Low-molecular-weight compounds
- C08G18/38—Low-molecular-weight compounds having heteroatoms other than oxygen
- C08G18/3819—Low-molecular-weight compounds having heteroatoms other than oxygen having nitrogen
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- C08G18/30—Low-molecular-weight compounds
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- C08G18/3855—Low-molecular-weight compounds having heteroatoms other than oxygen having sulfur
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- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
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- C08G18/40—High-molecular-weight compounds
- C08G18/48—Polyethers
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- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
- C08G18/66—Compounds of groups C08G18/42, C08G18/48, or C08G18/52
- C08G18/6666—Compounds of group C08G18/48 or C08G18/52
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- C08G18/6666—Compounds of group C08G18/48 or C08G18/52
- C08G18/667—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38
- C08G18/6674—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/3203
- C08G18/6677—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/3203 having at least three hydroxy groups
Abstract
The invention discloses a polyfunctional azine derivative and a polyurethane elastomer prepared from the polyfunctional azine derivative, and belongs to the technical field of polymer material synthesis. The structure of the azine derivative is shown as a general formula (1):
polyurethane elastomers prepared using azine derivatives of the invention as chain extenders or crosslinkers, both thermoplastic and thermoset polymersThe polyurethane has the advantages of high-temperature creep resistance, excellent mechanical properties, recyclability and excellent inherent antibacterial property.
Description
Technical Field
The invention relates to the technical field of polymer material synthesis, in particular to a polyfunctional azine derivative and a polyurethane elastomer prepared from the polyfunctional azine derivative.
Background
The polyurethane elastomer has excellent mechanical property, self-repairing property, resilience property and biocompatibility, and is widely applied to the fields of buffering and damping, adhesives, self-repairing coatings, flexible electronics, 3D printing and the like. Polyurethane elastomers fall into two categories: thermoplastic polyurethane elastomers (thermoplastic PU) and thermoset polyurethane elastomers (thermoset PU). Thermoplastic polyurethane elastomers are polymers with linear structures synthesized from diisocyanates, polyols and small molecule chain extenders. The polyurethane is solid at low temperature, and the intermolecular hydrogen bond of the linear polyurethane is destroyed after heating, so that the polyurethane has fluidity; when the temperature is reduced, intermolecular hydrogen bonding interactions form physical crosslinks and the elastomer resolidifies. Therefore, the thermoplastic polyurethane elastomer has the characteristics of easy processing and recycling, and the hydrogen bonds between molecular chains have excellent self-repairing property at room temperature. But the linear structure results in poor mechanical, chemical and heat resistance properties. While thermoset polyurethanes have a crosslinked network, exhibiting higher strength, creep resistance, chemical resistance, and heat resistance. However, due to the permanent cross-linked structure, the thermosetting polyurethane has the problems of non-recyclability, non-reworkability and the like, thereby exerting adverse effects on the environment, increasing the material cost and being not beneficial to sustainable development.
To address the above problems, dynamic covalent bonds have been introduced into networks to form "covalently adaptable networks" (CANS), which combine the advantages of thermoplastic and thermoset resins. Report to date, a number of dynamic covalent bonds were designed and introduced to make excellent performing, recyclable polyurethane elastomers, such as disulfide bonds, ditellurium bonds, boroxine rings, boronate exchange, DA reactions, oxime-formate bonds, schiff bases, and the like. Despite rapid development, the creep resistance of the dynamic covalent polyurethane elastomers reported to date is still generally poor, resulting in their inability to perform high-strength work, such as high-strength cushioning and high-temperature conditions. For example, disulfide bonds and ditelluril bonds can be exchanged reversibly at room temperature, which can result in poor heat resistance and low working temperature of the elastomer; the oxime dynamic covalent polyurethane elastomer prepared by Zhao Ning subject group has good creep resistance below 100 ℃, and has high residual strain with high deformation rate at 110 ℃. Furthermore, the double bonds in the DA system are at risk of self-polymerization and oxidation at high temperatures; the isocyanate groups formed after dissociation of the oxy-carbonate bonds may react with water vapor in the air. It is therefore a challenge to develop a polyurethane elastomer that has high working temperature, high temperature creep resistance, good mechanical properties, and is recyclable.
Disclosure of Invention
In view of the above problems in the prior art, the present inventors have provided a polyfunctional azine derivative and a polyurethane elastomer prepared therefrom. The polyurethane elastomer prepared by the multifunctional azine derivative has the advantages of thermoplastic polyurethane and thermosetting polyurethane, and has high-temperature creep resistance, excellent mechanical property, recyclability and excellent inherent antibacterial property.
The technical scheme of the invention is as follows:
a polyfunctional azine derivative having a structure represented by general formula (1):
in the general formula (1), R represents hydrogen or C1-6One of alkyl and phenyl of (1);
R1、R2each independently represents hydrogen, hydroxy, -O- (CH)2)2-OH、-O-CH2CHOHCH2S(CH2)2-OH、-O-CH2CHOHCH2SCH2CHOHCH2One of OH.
Further, the structure of the azine derivative is represented by any one of general formula (1-1) to general formula (1-5):
the meaning of R is as defined above.
Preferably, the azine derivative has a structure of any one of the following structures:
the use of said polyfunctional azine derivative as a chain extender or crosslinker for the preparation of polyurethane elastomers.
A polyurethane elastomer prepared from the multifunctional azine derivative, wherein the polyurethane elastomer is prepared by taking the azine derivative shown in the general formula (1-1) as a chain extender, carrying out a blocking reaction on polyol and isocyanate at 40-100 ℃, and then continuing to react with a cross-linking agent; the cross-linking agent is one or more of trimethylolpropane, triethanolamine and glycerol.
The polyurethane elastomer is prepared from an azine derivative shown as a general formula (1-1) as a chain extender, a polyol and isocyanate, wherein the polyurethane elastomer is subjected to a blocking reaction at 40-100 ℃, and then is subjected to a crosslinking reaction with a structure shown as any one of general formulas (1-2) - (1-5) as a crosslinking agent.
Preferably, the isocyanate is one or more of isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), Hexamethylene Diisocyanate (HDI); the polyol is one of polyether polyol, polyester polyol and polycarbonate polyol.
Further, the solvent for reaction is one of N, N-dimethylformamide, N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, acetone and toluene; the catalyst for the reaction is one of an organic tin catalyst, an organic bismuth catalyst, an organic zinc catalyst and a tertiary amine catalyst.
Further, the molar ratio of the azine derivative represented by the general formula (1-1) to the isocyanate is 0.1 to 0.9: 1;
further, the molar ratio of the polyol to the isocyanate is 0.1-0.9: 1;
furthermore, the dosage of the catalyst is 0.1-1% of the total mass of the isocyanate, the polyol, the chain extender and the cross-linking agent.
The beneficial technical effects of the invention are as follows:
the azine groups in the azine derivative of the invention are capable of exchange reaction at high temperature, and by utilizing the characteristic of the azine groups, the polyurethane elastomer containing the azine groups can be recycled at high temperature.
The azine derivative has conjugated benzene rings, provides a hard chain segment for a polyurethane elastomer, and improves the mechanical property and the high-temperature creep resistance of the polyurethane elastomer.
The Schiff base has an inhibiting effect on various harmful bacteria and fungi, and the azine groups are special Schiff bases, so that the polyurethane elastomer containing the azine groups also has excellent inherent antibacterial property.
Drawings
FIG. 1 is a test curve of creep resistance of the product of example 1 of the present invention.
FIG. 2 shows the results of the creep resistance test of example 2 of the present invention.
FIG. 3 shows the results of the recovery experiment of the product of example 2 of the present invention.
FIG. 4 is an IR spectrum of a sample of example 2 of the present invention after three recoveries.
FIG. 5 is a graph showing the tensile properties of the sample of example 2 after three recoveries.
FIG. 6 shows the results of the antibacterial performance of the sample of example 2 according to the present invention.
FIG. 7 is an IR spectrum of Compound 1 obtained in example 1 of the present invention.
FIG. 8 is an IR spectrum of a polyurethane elastomer obtained in example 1 of the present invention.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings and examples.
Example 1
A process for preparing polyfunctional azine derivatives (4-hydroxyethoxybenzaldehyde azines) comprising the steps of:
(1) 4-hydroxybenzaldehyde (122.12g, 1mol) was added to a 500mL four-necked flask equipped with a stirrer, reflux condenser, thermometer, and poured into 300mL of ethanol to dissolve, warmed to 40 ℃, and slowly added dropwise (30.9g, 0.525mol) hydrazine hydrate solution (85%), the reaction was exothermic, the temperature was controlled at 50 ℃ to continue the reaction for 1h, after the reaction was completed, the ethanol was filtered and distilled to obtain yellow powder (4-hydroxybenzaldehyde azine, 115g) with a yield of 95.7%.
(2) Adding 4-hydroxybenzaldehyde azine (48g, 0.2mol), ethylene carbonate (38.75g, 0.44mol), potassium carbonate (0.868g, 1%) and N, N-dimethylacetamide (130g) into a 250mL four-neck flask provided with a stirring, reflux condenser and thermometer, reacting at 130 ℃ for 5 hours under the protection of nitrogen, precipitating the solution in 1M sodium hydroxide solution after the reaction is finished, and washing off unreacted phenol; suction filtration, water washing of the filter cake to neutrality, suction filtration again, vacuum drying of the product at 80 ℃ for 24h to remove water, and light yellow powder, namely compound 1 (4-hydroxyethoxybenzaldehyde azine, 62g), with a yield of 94.4%, was obtained. The infrared spectrum of compound 1 is shown in figure 7. Compound 1 nuclear magnetic data is:1H NMR(400MHz,DMSO)δ8.63(s,1H),7.81(d,J＝8.3Hz,2H),7.06(d,J＝8.4Hz,2H),4.94(s,1H),4.07(t,J＝4.9Hz,2H),3.75(t,J＝4.8Hz,2H).
a100 mL four-neck flask is charged with the compound 1 (4-hydroxyethoxybenzaldehyde azine) (1.97g, 6mmol) prepared in the example, polytetrahydrofuran 1000(6g, 6mmol), isophorone diisocyanate (4.67g, 21mmol), DBTDL (0.067g, 0.5%), N-dimethylformamide (20.2g) is added to adjust the total solid content to 40%, the reaction is carried out at 60 ℃ for 2h under the protection of nitrogen, trimethylolpropane (0.805g, 6mmol) is added, the reaction is continued for 1h, vacuum deaeration is carried out, the solution is poured into a tetrafluoro mold and is put into an oven, the temperature is gradually increased from 50 ℃ to 100 ℃ in 24h, then the solution is put into the vacuum oven, and the solution is placed at 80 ℃ for 24h to remove the residual solvent, so that a dynamic covalent polyurethane yellow transparent film, namely the polyurethane elastomer, is obtained. The infrared spectrum is shown in figure 8.
Example 2
A process for preparing polyfunctional azine derivatives (4-hydroxyethoxybenzaldehyde azines) comprising the steps of:
the procedure for the preparation of compound 1 is the same as in example 1.
A100 mL four-neck flask is charged with the compound 1 (4-hydroxyethoxybenzaldehyde azine) (4.92g, 15mmol) prepared in the example, polytetrahydrofuran 1000(10g, 10mmol), isophorone diisocyanate (8.89g, 40mmol), DBTDL (0.125g, 0.5%), N-dimethylformamide (20.2g) is added to adjust the total solid content to 40%, the reaction is carried out at 60 ℃ for 2h under the protection of nitrogen, trimethylolpropane (1.34g, 10mmol) is added, the reaction is continued for 1h, vacuum deaeration is carried out, the solution is poured into a tetrafluoro mold and is put into an oven, the temperature is gradually increased from 50 ℃ to 100 ℃ in 24h, then the solution is put into the vacuum oven, and the solution is placed at 80 ℃ for 24h to remove the residual solvent, so that a dynamic covalent polyurethane yellow transparent film, namely the polyurethane elastomer, is obtained.
Example 3
A process for the preparation of polyfunctional azine derivatives comprising the steps of:
to a 500mL four-necked flask equipped with a stirrer, reflux condenser, thermometer was added 4-hydroxybenzaldehyde (122.12g, 1mol) and poured 300mL of ethanol to dissolve, warmed to 40 deg.C, slowly added dropwise (30.9g, 0.525mol) hydrazine hydrate solution (85%), the reaction was exothermic, the temperature was controlled at 50 deg.C and the reaction was continued for 1h, filtered and the ethanol was distilled to give a yellow powder (4-hydroxybenzaldehyde azine, 115g) with a yield of 95.7%.
To a 250mL four-necked flask equipped with a stirrer, reflux condenser and thermometer was added 4-hydroxybenzaldehyde azine (12.01g, 0.05mol), 1.2g (10%) tetrabutylammonium bromide (TBAB), and 115.6g (1.25mol) of epichlorohydrin was poured, and the mixture was heated to 80 ℃ under nitrogen atmosphere and reacted for 2 hours; cooling to room temperature in a water bath, dropwise adding 15g of 40% sodium hydroxide aqueous solution within 30 minutes, adding 20mL of chloroform after the dropwise adding is completed, continuing to react for 5h, washing the reaction solution with water for three times, dropwise adding petroleum ether for precipitation to obtain a white solid, and drying in a vacuum oven at 80 ℃ for 12h to obtain 4-glycidyl ether benzaldehyde azine, 14.1g, and the yield is 80.1%. To a 250mL four-necked flask equipped with a stirrer, reflux condenser, and thermometer was added 4-glycidyl ether benzaldehyde azine (14.09g, 0.04mol), mercaptoethanol 7.5g (0.096mol), and catalyst N, N, N ', N' -tetramethyl-1, 8-naphthalenediamine 0.291g, and 32.4g N, N-dimethylacetamide (30% solid content) was poured in, and the mixture was heated to 80 ℃ under nitrogen protection, reacted overnight, poured in ether for precipitation, and dried in a vacuum oven at 75 ℃ for 24h to obtain a pale yellow powder, i.e., Compound 2(14.4g, 70.9% yield).
The nuclear magnetic data for compound 2 is:1H NMR(400MHz,DMSO)δ8.63(s,1H),7.86–7.76(m,2H),7.11–7.01(m,2H),5.27(d,J＝5.0Hz,1H),4.78(t,J＝5.5Hz,1H),4.13–3.89(m,3H),3.55(td,J＝6.9,5.5Hz,2H),2.82–2.58(m,4H).
adding compound 1(1.97g, 6mmol), polytetrahydrofuran 1000(6g, 6mmol), isophorone diisocyanate (4.67g, 21mmol) and DBTDL (0.075g, 0.5%), adding N, N-dimethylformamide (20.2g) to adjust the total solid content to 40%, reacting at 60 ℃ for 2h under the protection of nitrogen, adding compound 2(2.29g, 4.5mmol) to perform crosslinking reaction for 0.5h, performing vacuum defoaming, pouring the solution into a tetrafluoro mold, putting the solution into an oven, gradually increasing the temperature from 50 ℃ to 100 ℃ within 24h, then putting the solution into a vacuum oven, standing at 80 ℃ for 24h, and removing residual solvent to obtain a dynamic covalent polyurethane yellow transparent film, namely the polyurethane elastomer.
Example 4
A process for the preparation of polyfunctional azine derivatives comprising the steps of:
to a 500mL four-necked flask equipped with a stirrer, reflux condenser and thermometer was added 3, 5-dihydroxybenzaldehyde (138.1g, 1mol), and 300mL of ethanol was poured to dissolve it, and the mixture was heated to 40 deg.C, and then hydrazine hydrate solution (85%) was slowly added dropwise (30.9g, 0.525mol), the reaction was allowed to proceed at 60 deg.C, with the exotherm and the reaction was controlled for 3 hours. Filtration and distillation of ethanol gave a yellow powder, i.e., 3, 5-dihydroxybenzaldehyde azine, in 93.0% yield.
Adding 3, 5-dihydroxy benzaldehyde azine (54.5g, 0.2mol), ethylene carbonate (38.75g, 0.44mol), potassium carbonate (0.933g, 1%), N, N-dimethylacetamide (140g) into a 250mL four-neck flask provided with a stirring, reflux condenser and thermometer, reacting at 130 ℃ for 5h under the protection of nitrogen, precipitating the solution in 1M sodium hydroxide solution after the reaction is finished, and washing off unreacted phenol; and (3) carrying out suction filtration, washing a filter cake to be neutral, carrying out suction filtration again, and carrying out vacuum drying on a product at the temperature of 80 ℃ for 24 hours to remove water to obtain the compound 3(3, 5-dihydroxyethoxy benzaldehyde azine) with the yield of 95.6%.
Adding compound 1(1.97g, 6mmol), polytetrahydrofuran 1000(6g, 6mmol), isophorone diisocyanate (4.67g, 21mmol) and DBTDL (0.073g, 0.5%), adding N, N-dimethylformamide (20.2g) to adjust the total solid content to 40%, reacting at 60 ℃ for 2h under the protection of nitrogen, adding compound 3(2.02g, 4.5mmol), performing crosslinking reaction for 0.5h, performing vacuum defoaming, pouring the solution into a tetrafluoro mold, putting the solution into an oven, gradually increasing the temperature from 50 ℃ to 100 ℃ within 24h, then putting the solution into a vacuum oven, and standing at 80 ℃ for 24h to remove residual solvent to obtain a dynamic covalent polyurethane film, namely the polyurethane elastomer.
Example 5
A process for the preparation of polyfunctional azine derivatives comprising the steps of:
to a 500mL four-necked flask equipped with a stirrer, reflux condenser and thermometer was added 3, 4-dihydroxybenzaldehyde (138.1g, 1mol), and 300mL of ethanol was poured to dissolve it, and the mixture was heated to 40 deg.C, and then hydrazine hydrate solution (85%) was slowly added dropwise (30.9g, 0.525mol), the reaction was allowed to proceed at 60 deg.C, with the exotherm, for 5 h. Filtration and distillation of ethanol gave a yellow powder, i.e., 3, 4-dihydroxybenzaldehyde azine, in 94.2.0% yield.
A250 mL four-neck flask equipped with a stirring reflux condenser and a thermometer was charged with 3, 4-dihydroxybenzaldehyde azine (54.5g, 0.2mol), ethylene carbonate (38.75g, 0.44mol), potassium carbonate (0.933g, 1%), N, N-dimethylacetamide (145g), and reacted at 130 ℃ for 5 hours under nitrogen protection, after the reaction was completed, the solution was precipitated in 1M sodium hydroxide solution, unreacted phenol was washed off, suction filtration was performed, the filter cake was washed with water to neutrality, suction filtration was performed again, and the product was vacuum-dried at 80 ℃ for 24 hours to remove moisture, yielding compound 4(3, 4-dihydroxybenzoaldehyde azine) in a yield of 91.3%.
Adding compound 1(1.97g, 6mmol), polytetrahydrofuran 1000(6g, 6mmol), isophorone diisocyanate (4.67g, 21mmol) and DBTDL (0.073g, 0.5%), adding N, N-dimethylformamide (20.2g) to adjust the total solid content to 40%, reacting at 60 ℃ for 2h under the protection of nitrogen, adding compound 4(2.02g, 4.5mmol), performing crosslinking reaction for 0.5h, performing vacuum defoaming, pouring the solution into a tetrafluoro mold, putting the solution into an oven, gradually increasing the temperature from 50 ℃ to 100 ℃ within 24h, then putting the solution into a vacuum oven, and standing at 80 ℃ for 24h to remove residual solvent to obtain a dynamic covalent polyurethane film, namely the polyurethane elastomer.
Example 6
A process for the preparation of polyfunctional azine derivatives comprising the steps of:
to a 500mL four-necked flask equipped with a stirrer, reflux condenser, thermometer was added 4-hydroxybenzaldehyde (122.12g, 1mol) and poured 300mL of ethanol to dissolve, warmed to 40 deg.C, slowly added dropwise (30.9g, 0.525mol) hydrazine hydrate solution (85%), the reaction was exothermic, the temperature was controlled at 50 deg.C and the reaction was continued for 1h, filtered and the ethanol was distilled to give a yellow powder (4-hydroxybenzaldehyde azine, 115g) with a yield of 95.7%.
To a 250mL four-necked flask equipped with a stirrer, reflux condenser, and thermometer was added 4-hydroxybenzaldehyde azine (12.01g, 0.05mol), 1.2g tetrabutylammonium bromide (TBAB), and 115.6g (1.25mol) of epichlorohydrin was poured, and the mixture was heated to 80 ℃ under nitrogen atmosphere and reacted for 2 hours. Cooling to room temperature in a water bath, dropwise adding 15g of 40% sodium hydroxide aqueous solution within 30 minutes, adding 20mL of chloroform after the dropwise adding is completed, continuing to react for 5h, washing the reaction solution with water for three times, dropwise adding petroleum ether for precipitation to obtain a white solid, and drying in a vacuum oven at 80 ℃ for 12h to obtain 4-glycidyl ether benzaldehyde azine, 14.1g, and the yield is 80.1%.
To a 250mL four-necked flask equipped with a stirrer, reflux condenser, and thermometer was added 4-glycidyl ether benzaldehyde azine (14.09g, 0.04mol), thioglycerol 10.38g (0.096mol), and catalyst N, N, N ', N' -tetramethyl-1, 8-naphthalenediamine 0.291g, and 36.7g of N, N-dimethylacetamide (30% solid content) was poured in, and the mixture was heated to 80 ℃ under nitrogen protection, reacted overnight, poured in ether for precipitation, and dried in a vacuum oven at 75 ℃ for 24h to obtain a pale yellow powder, Compound 5(17.3g, 76.2% yield).
The nuclear magnetic data for compound 5 is:1H NMR(400MHz,DMSO)δ8.63(s,1H),7.87–7.74(m,2H),7.13–7.01(m,2H),5.26(dd,J＝5.0,1.2Hz,1H),4.79(d,J＝5.1Hz,1H),4.62–4.51(m,1H),4.14–3.91(m,3H),3.58(dp,J＝6.8,5.3Hz,1H),3.36(t,J＝5.3Hz,2H),2.82–2.61(m,3H),2.57–2.51(m,1H).
adding compound 1(1.97g, 6mmol), polytetrahydrofuran 1000(6g, 6mmol), isophorone diisocyanate (4.67g, 21mmol) and DBTDL (0.072g, 0.5%), adding N, N-dimethylformamide (20.2g) to adjust the total solid content to 40%, reacting at 60 ℃ for 2h under the protection of nitrogen, adding compound 5(1.71g, 3mmol) to perform crosslinking reaction for 0.5h, performing vacuum defoamation, pouring the solution into a tetrafluoro mold, putting into an oven, gradually increasing the temperature from 50 ℃ to 100 ℃ within 24h, then putting into a vacuum oven, standing at 80 ℃ for 24h, and removing residual solvent to obtain a dynamic covalent polyurethane film, namely the polyurethane elastomer.
Comparative example 1
A preparation method of a 4, 4' -bis-hydroxyethoxy bisphenol A chain extender comprises the following steps:
bisphenol A (22.83g, 0.1mol), ethylene carbonate (19.37g, 0.22mol), potassium carbonate (0.422g, 1%), N, N-dimethylacetamide (98.5g) were added to a 250mL four-neck flask equipped with a stirring, reflux condenser and thermometer, and reacted at 130 ℃ for 5 hours under nitrogen protection, after the reaction was completed, the solution was precipitated in 0.5M sodium hydroxide solution, the unreacted phenol was washed off, filtered, the filter cake was washed with water to neutrality and then filtered, and the product was dried under vacuum at 80 ℃ for 24 hours to remove water, to obtain a white powder, comparative compound 1(4, 4' -bis (hydroxyethoxy) bisphenol A, 30.1g, yield 91.8%).
The nuclear magnetic data for comparative compound 1 is:1H NMR(400MHz,DMSO)δ7.18–7.02(m,2H),6.90–6.71(m,2H),4.83(t,J＝5.5Hz,1H),3.94(t,J＝5.1Hz,2H),3.69(q,J＝5.2Hz,2H),1.58(s,3H).
a100 mL four-neck flask is added with a comparative compound 1(1.90g, 6mmol), polytetrahydrofuran 1000(6g, 6mmol), isophorone diisocyanate (4.67g, 21mmol) and DBTDL (0.067g, 0.5%), N-dimethylformamide (20.2g) is added to adjust the total solid content to 40%, the mixture is reacted at 60 ℃ for 2h under the protection of nitrogen, trimethylolpropane (0.805g, 6mmol) is added to perform crosslinking reaction for 1h, vacuum defoaming is performed, the solution is poured into a tetrafluoro mold and placed into an oven, the temperature is gradually increased from 50 ℃ to 100 ℃ within 24h, then the solution is placed into a vacuum oven, and the solution is placed at 80 ℃ for 24h to remove residual solvent, so that a yellow transparent polyurethane film is obtained.
Comparative example 2
A preparation method of a cross-linking agent comprises the following steps:
a250 mL four-neck flask equipped with a stirring reflux condenser and a thermometer was charged with bisphenol A (11.42g, 0.05mol), tetrabutylammonium bromide (TBAB)1.14g (10%), and 92.5g (1mol) of epichlorohydrin was poured in, heated to 80 ℃ under nitrogen protection, reacted for 2h, cooled to room temperature in a water bath, and 15g of 40% aqueous sodium hydroxide solution was added dropwise over 30 minutes. After the dropwise addition, 20mL of chloroform was added, the reaction was continued for 5 hours, the reaction solution was washed with water three times, washed with saturated brine, and dried in a vacuum oven at 80 ℃ for 12 hours to obtain 13.1g of 4-glycidyl ether bisphenol A in a yield of 77.0%.
To a 250mL four-necked flask equipped with a stirring, reflux condenser and thermometer was added 4-glycidyl ether bisphenol A (10.2g, 0.03mol), mercaptoethanol 5.16g (0.066mol), and N, N, N ', N' -tetramethyl-1, 8-naphthalenediamine (catalyst) 0.21g, and 35.8g N, N-dimethylacetamide (solid content 30%) was poured in, and the mixture was heated to 80 ℃ under nitrogen protection, reacted overnight, poured in ether for precipitation, and dried in a vacuum oven at 75 ℃ for 24 hours to obtain comparative compound 2.
A100 mL four-neck flask is added with comparative compound 1(1.90g, 6mmol), polytetrahydrofuran 1000(6g, 6mmol), isophorone diisocyanate (4.67g, 21mmol) and DBTDL (0.075g, 0.5%), N-dimethylformamide (20.2g) is added to adjust the total solid content to 40%, the mixture is reacted for 2h at 60 ℃ under the protection of nitrogen, comparative compound 2(2.24g, 4.5mmol) is added for crosslinking reaction for 0.5h, vacuum defoaming is carried out, the solution is poured into a tetrafluoro mold and placed into an oven, the temperature is gradually increased to 100 ℃ from 50 ℃ within 24h, then the solution is placed into a vacuum oven, and the solution is placed at 80 ℃ for 24h to remove residual solvent, so that a polyurethane yellow transparent film is obtained.
Comparative example 3
A preparation method of a cross-linking agent comprises the following steps:
a250 mL four-neck flask provided with a stirring reflux condenser tube and a thermometer is added with bisphenol A (11.42g, 0.05mol) and tetrabutylammonium bromide (TBAB) with the concentration of 1.14g (10%), 92.5g (1mol) of epichlorohydrin is poured in, the temperature is raised to 80 ℃ under the protection of nitrogen, the reaction is carried out for 2h, the water bath is cooled to the room temperature, 15g of 40% sodium hydroxide aqueous solution is dripped in 30min, 20mL of chloroform is added after the dripping is finished, the reaction is continued for 5h, the reaction solution is washed with water for three times, washed with saturated brine and dried in a vacuum oven at 80 ℃ for 12h, so that 4-glycidyl ether bisphenol A, 13.1g and the yield of 77.0 percent are obtained.
To a 250mL four-necked flask equipped with a stirring, reflux condenser and thermometer was added 4-glycidyl ether bisphenol A (10.2g, 0.03mol), thioglycerol 7.14g (0.066mol), and catalyst N, N, N ', N' -tetramethyl-1, 8-naphthalenediamine 0.21g, and 40.5g N, N-dimethylacetamide (30% solid content) was poured in under nitrogen protection, and the mixture was allowed to rise to 80 ℃ for overnight reaction, poured in ether for precipitation, and dried in a vacuum oven at 75 ℃ for 24 hours to obtain comparative compound 3.
Adding a comparative compound 1(1.90g, 6mmol), polytetrahydrofuran 1000(6g, 6mmol), isophorone diisocyanate (4.67g, 21mmol) and DBTDL (0.071g, 0.5%), adding N, N-dimethylformamide (20.2g) to adjust the total solid content to 40%, reacting at 60 ℃ for 2h under the protection of nitrogen, adding a comparative compound 3(1.67g, 3mmol) for crosslinking, continuing to react for about 0.5h, carrying out vacuum defoamation, pouring the solution into a tetrafluoro mold, putting the solution into an oven, gradually increasing the temperature from 50 ℃ to 100 ℃ within 24h, then putting the solution into a vacuum oven, and standing at 80 ℃ for 24h to remove residual solvent to obtain the dynamic covalent polyurethane film.
Test example:
(1) tensile property: GB/T528-2009; the results of mechanical property measurements of the dynamic covalent polyurethane elastomers obtained in examples 1 and 2 and comparative example 1 are shown in table 1. It can be seen from Table 1 that the tensile strengths of the polyurethane elastomers prepared from azine derivatives are all greater than those of the comparative examples, presumably because the carbon-nitrogen bonds in the azine groups form conjugated structures with the benzene rings, giving the elastomers excellent mechanical properties. FIG. 5 shows the tensile properties of the sample of example 2 after three times of recovery, and it can be seen that the tensile strength can be maintained above 20MPa, and the sample has good mechanical properties.
(2) Creep resistance test: test using a DMA Q800 dynamic thermomechanical analyzer, bars with dimensions of about 20mm (length) x 5mm (width) x 0.5mm (thickness) were mounted on a jig, set at a tensile stress of 0.1MPa, and when the temperature was raised to the test temperature, held constant for 5 minutes, initially stretched at a stress of 0.1MPa for 30 minutes, then the stress was removed and held for 40 minutes. The creep resistance of the product of example 1 is shown in FIG. 1, and it can be seen from FIG. 1 that the tensile strain of the sample strip gradually increases with the temperature, and at a temperature below 100 ℃, the sample strip can return to the initial state after the tensile stress is removed, and at a temperature above 120 ℃, the sample strip can not return after the tensile stress is removed, and has a large residual strain. Indicating that the sample has better creep resistance at 100 ℃. The creep resistance test of example 2 is shown in FIG. 2, and it can be seen from FIG. 2 that the tensile strain of the sample strip gradually increases with the increase of temperature, and at a temperature of 100 ℃ or lower, the sample strip can return to the initial state after the tensile stress is removed, and at a temperature of 120 ℃ or higher, the sample strip cannot return after the tensile stress is removed, and still has a large residual strain. Indicating that the sample has better creep resistance at 100 ℃.
(3) Recovery experiments: cutting the sample into small pieces, hot pressing for 20min at 150 ℃ and 10MPa by using a flat vulcanizing machine, and cooling to room temperature. The recovery test results of the product of example 2 are shown in FIG. 3. after the sample was cut into small pieces and hot-pressed at 150 ℃ and 10MPa for 20 minutes, the azine groups in the elastomer were exchanged, and the sample was recovered and reused. Example 2 Infrared spectrum of sample recovered three times is shown in FIG. 4, and azine groups (1624 cm) of the sample can be seen-1) The quilt is well reserved, and the whole structure is unchanged.
(4) Antibacterial property: GB/T21866-2008. FIG. 6 shows the antibacterial properties of the sample of example 2, and it can be seen that the sample has excellent antibacterial activity against Escherichia coli.
TABLE 1
Claims (10)
1. A polyfunctional azine derivative, characterized in that the structure of the azine derivative is represented by the general formula (1):
in the general formula (1), R represents hydrogen or C1-6One of alkyl and phenyl of (1);
R1、R2each independently represents hydrogen, hydroxy, -O- (CH)2)2-OH、-O-CH2CHOHCH2S(CH2)2-OH、-O-CH2CHOHCH2SCH2CHOHCH2One of OH.
2. An azine derivative according to claim 1, wherein the structure of the azine derivative is represented by any one of general formula (1-1) to general formula (1-5):
the meaning of R is defined in claim 1.
3. An azine derivative according to claim 1, characterized in that the structure of the azine derivative is any of the following structures:
4. use of the polyfunctional azine derivative according to claim 1 as a chain extender or cross-linker for the preparation of polyurethane elastomers.
5. A polyurethane elastomer prepared from the polyfunctional azine derivative according to claim 2, wherein the polyurethane elastomer is prepared by reacting an azine derivative represented by the general formula (1-1) as a chain extender, a polyol, and an isocyanate terminal-blocking agent, and then continuing the reaction with a crosslinking agent; the cross-linking agent is one or more of trimethylolpropane, triethanolamine and glycerol.
6. A polyurethane elastomer prepared from the polyfunctional azine derivative according to claim 2, wherein the polyurethane elastomer is prepared by subjecting an azine derivative represented by the general formula (1-1) as a chain extender, a polyol, and an isocyanate to a terminal-capping reaction, and then subjecting the resultant mixture to a crosslinking reaction with a structure represented by any one of the general formulae (1-2) to (1-5) as a crosslinking agent.
7. A polyurethane elastomer according to claim 5 or 6 characterised in, that said isocyanate is one or more of isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), Hexamethylene Diisocyanate (HDI); the polyol is one of polyether polyol, polyester polyol and polycarbonate polyol.
8. The polyurethane elastomer according to claim 5 or 6, wherein the temperature of the end-capping reaction is 40 to 100 ℃.
9. The polyurethane elastomer according to claim 5 or 6, wherein the solvent for the reaction is one of N, N-dimethylformamide, N-dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, acetone, and toluene; the catalyst for the reaction is one of an organic tin catalyst, an organic bismuth catalyst, an organic zinc catalyst and a tertiary amine catalyst.
10. The polyurethane elastomer according to claim 5 or 6, wherein the molar ratio of the azine derivative represented by the general formula (1-1) to the isocyanate is from 0.1 to 0.9: 1; the molar ratio of the polyol to the isocyanate is 0.1-0.9: 1; the dosage of the catalyst is 0.1-1% of the total mass of the isocyanate, the polyol, the chain extender and the cross-linking agent.
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