Method for synthesizing thermoplastic polyurethane elastomer fluorescent material based on water-saturated dichloromethane acyl chloride solution
Chemically bonding the fluorescent molecules to thermoplastic polyurethane elastomers by water-saturated dichloromethane solution, solving the stability and cost problems in fluorescent polyurethane synthesis, achieving efficient preparation of fluorescent materials, and promoting industrial application.
Patent Information
- Application Number
- CN202510576175.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2025-08-08
AI Technical Summary
In the prior art, fluorescent polyurethane synthesis methods have problems such as poor stability, high cost and reduced mechanical properties of fluorescent molecules, which limit their industrial applications.
Water-saturated dichloromethane chloride solution is used to connect the fluorescent molecules with thermoplastic polyurethane elastomers through amide bonds to generate imides to achieve chemical bonding, simplifying operations and increasing the load of fluorescent molecules.
It realizes rapid reaction and low-cost fluorescent molecular bonding, improves the fluorescent and mechanical properties of the materials, and promotes industrial applications.
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Figure CN120441806A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of material chemistry, and in particular to a method for synthesizing a thermoplastic polyurethane elastomer fluorescent material by using water-saturated dichloromethane to prepare an acyl chloride solution. Background Art
[0002] Thermoplastic polyurethane (TPU) elastomers are common polymer materials with excellent tensile properties, a certain degree of toughness and strength, and controllable hard and soft segments. They are highly adaptable materials with a wide range of applications. Fluorescent polyurethanes are widely used in fields such as information encryption, sensors, bioimaging, and wearable devices, such as fluorescence flaw detection and live cell fluorescence staining imaging. Traditional fluorescent polyurethane synthesis mainly involves physical blending and chemical bonding. The fluorescent polyurethane materials obtained through physical blending have poor stability and poor dispersion on the surface of fluorescent molecules, and are prone to self-aggregation, leading to fluorescence quenching. Chemical bonding, primarily through block copolymerization, chemically connects the polymer raw material to the fluorescent molecule. The fluorescent molecule is generally modified to react with the polyurethane raw material. This method results in a more stable polyurethane molecular structure and fluorescent properties, and a longer lifespan. However, modification of the fluorescent molecule is difficult, resulting in high preparation costs. Furthermore, the fluorescent molecule has high steric hindrance, making it difficult to bond to the polyurethane chain. This also results in reduced mechanical properties of the synthesized thermoplastic polyurethane elastomer, restricting its industrial application. Acid chlorides react violently with water to produce carboxylic acid and hydrogen chloride. Typically, anhydrous dichloromethane solutions are used to synthesize acyl chlorides. However, these solutions are expensive and difficult to store, limiting the industrial production of fluorescent polyurethane elastomers. These issues represent pressing technical challenges in this field. Summary of the Invention
[0003] The present invention aims to provide a method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution. The method bonds fluorescent molecules to the surface of a polymer material, greatly shortens the reaction time, has a fast reaction speed, loads a large number of fluorescent molecules, has low requirements for fluorescent molecule modification, is simpler to operate than block copolymerization, and can quickly screen other fluorescent substances.
[0004] To this end, the technical solution of the present invention is: a method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane acyl chloride solution, wherein a thermoplastic polyurethane elastomer is immersed in a fluorescent molecule acyl chloride solution for reaction, so that the amide bonds on the polyurethane main chain connect to the fluorescent molecules in the acyl chloride solution, generating imides to achieve chemical bond connection between the fluorescent molecules and the polyurethane, thereby obtaining the thermoplastic polyurethane elastomer fluorescent material; the fluorescent molecule acyl chloride solution is obtained by dispersing the fluorescent molecule acyl chloride in a water-saturated dichloromethane solution.
[0005] A further improvement of the present invention is that the water-saturated dichloromethane solution is prepared at 15-30°C, preferably at 20°C.
[0006] A further improvement of the present invention is that the concentration of the fluorescent molecular acyl chloride solution for impregnating the thermoplastic polyurethane elastomer molecules is 0.01 to 0.6 mol / L.
[0007] A further improvement of the present invention is that the fluorescent molecular acyl chloride is 2-anthracenecarbonyl chloride, 9-anthracenecarbonyl chloride, anthracene-1-chloride or 9-fluorenecarbonyl chloride.
[0008] A further improvement of the present invention is that the fluorescent molecular acyl chloride is 2-anthracenecarbonyl chloride, 9-anthracenecarbonyl chloride, anthracene-1-chloride or 9-fluorenecarbonyl chloride.
[0009] A further improvement of the present invention is that the hard segment content of the thermoplastic polyurethane elastomer is 30%-45%.
[0010] A further improvement of the present invention is that the thermoplastic polyurethane elastomer is an IPDI polyurethane elastomer, an MDI polyurethane elastomer, an HDI polyurethane elastomer, a TDI polyurethane elastomer or an XDI polyurethane elastomer.
[0011] The thermoplastic polyurethane elastomer of the present invention may be an isocyanate-terminated thermoplastic polyurethane elastomer, and its preparation method comprises the following steps:
[0012] S1. Dehydrate the polyether or polyester diol at 120° C. and -0.08 MPa to -0.1 MPa under vacuum conditions for 2-4 hours and set aside;
[0013] S2. Add the dehydrated polyether or polyester diol, aliphatic or aromatic diisocyanate and catalyst into a reaction kettle, control the molar ratio of isocyanate group to hydroxyl group in the reaction system to be 1.0-1.5, heat to 70-85°C, stir for 2-3h, cool to 55°C, add chain extender and stir for 0.5h;
[0014] S3. The reaction materials were poured into a polytetrafluoroethylene mold, placed at room temperature for 24 h, placed in a 60° C. oven for 24 h, and placed in a 100° C. vacuum drying oven for 10 h to obtain an isocyanate-terminated thermoplastic polyurethane elastomer.
[0015] Furthermore, the polyether or polyester diol is at least one of polyethylene adipate diol, polypropylene adipate diol, polypropylene glycol, polycaprolactone diol, polycarbonate diol, polyethylene glycol, and polytetrahydrofuran having a number average molecular weight of 1000-4000.
[0016] Furthermore, the catalyst is at least one of dibutyltin laurate, stannous octoate, dimethylcyclohexylamine or N-ethylmorpholine.
[0017] Furthermore, the isocyanate is any one of 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, isofluorodione diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate or p-phenylene diisocyanate, or a combination thereof.
[0018] The present invention has the beneficial effect of utilizing the rapid reaction between the amide bond in the polyurethane molecule and the acyl chloride in the fluorescent molecule to connect the two molecules, thereby achieving fluorescent functionalization of the thermoplastic polyurethane elastomer. The specific operation is simple: simply immerse the prepared thermoplastic polyurethane elastomer in a solution of fluorescent molecules to achieve fluorescent functionalization of the material. This method, which bonds the fluorescent molecules to the surface of the polymer material, significantly shortens the reaction time, has a fast reaction speed, can load a large number of fluorescent molecules, and requires less modification of the fluorescent molecules. It is simpler to operate than block copolymerization and can quickly screen for other fluorescent substances. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is the fluorescence emission spectrum of polyurethane and polyurethane fluorescent materials.
[0020] Figure 2 This is the excitation spectrum of polyurethane and polyurethane elastomer fluorescent materials.
[0021] Fluorescence spectrum analysis showed that the polyurethane material treated with fluorescent group loading achieved a transition from non-fluorescent properties to significant fluorescent properties. DETAILED DESCRIPTION
[0022] Example 1:
[0023] Preparation of water-saturated dichloromethane solution: Add excess water to the dichloromethane solution at 20°C, shake for 15 minutes, and then let it stand for 1 hour to separate the layers in a separatory funnel. The lower dichloromethane solution is the water-saturated dichloromethane solution prepared.
[0024] Thermoplastic polyurethane elastomers can be prepared according to methods reported in the literature. For example, Reactive and Functional Polymers 192(2023)105736 describes a detailed method for preparing thermoplastic polyurethane elastomers by polymerizing isophorone diisocyanate, polytetramethylene ether, and 1,4-butanediol. Thermoplastic polyurethane elastomers can also be purchased as a finished product from a reagent company (CAS number: 9009-54-5).
[0025] 2-Anthracenecarbonyl chloride (CAS No.: 16331-51-4) can be prepared by refluxing 5 g of 2-anthracenecarboxylic acid (CAS No.: 613-08-1) in 150 mL of thionyl chloride and water-saturated dichloromethane solution, and then evaporating the excess thionyl chloride water-saturated dichloromethane solution.
[0026] 2 grams of thermoplastic polyurethane elastomer (TPE) were immersed in 10 mL of a 0.25 mol / L water-saturated dichloromethane solution of 2-anthracenecarbonyl chloride. After magnetic stirring (800 rpm) at room temperature (25°C) for 1 hour, the reaction solution was transferred to a centrifuge tube and centrifuged. The supernatant was diluted to 20 mL with chloroform. The 2-anthracenecarbonyl chloride concentration was measured using a UV-visible spectrophotometer, and the consumed 2-anthracenecarbonyl chloride was calculated based on this. This indirectly determined the fluorescent group density of the TPE fluorescent material to be 0.22 mmol / g. The residue was rinsed with deionized water into a small beaker, and any residue remaining on the reaction tube walls during the transfer process was also rinsed into the beaker. The deionized water was then poured off, and the beaker was placed in a vacuum desiccator and vacuum-dried at 80°C for 3 hours. The solid, i.e., the TPE fluorescent material, was collected. The fluorescence emission spectra of the TPE before and after treatment are shown in the attached figure. Figure 1 The fluorescence excitation spectra of thermoplastic polyurethane elastomer before and after treatment are shown in the attached figure. Figure 2 As shown. Figure 1 It can be seen that after the thermoplastic polyurethane elastomer is loaded with fluorescent groups, the fluorescence emission is greatly enhanced. Figure 2 It can be seen that the fluorescence excitation of thermoplastic polyurethane elastomer is enhanced after loading fluorescent groups. Figure 1 Figure 2 This proves that the fluorescent group was loaded successfully.
[0027] Example 2:
[0028] Other conditions were the same as in Example 1. The surface treatment was performed using a 0.25 mol / L fluorescent molecule acyl chloride solution synthesized using a water-saturated dichloromethane solution prepared at 5-40° C. The results are shown in Table 1 below:
[0029] Table 1 Experimental results of preparing thermoplastic polyurethane elastomer fluorescent materials by synthesizing fluorescent molecules at different temperatures
[0030]
[0031] As shown in the table above, the preparation temperature of the water-saturated dichloromethane solution is preferably 15-30°C, and most preferably 20°C. The higher the temperature, the higher the water content in the water-saturated dichloromethane solution, which is more likely to cause side reactions. The lower the temperature, the lower the water content in the water-saturated dichloromethane solution, which is insufficient to promote the main reaction.
[0032] Therefore, using a water-saturated dichloromethane solution prepared at 30°C to prepare a fluorescent acid chloride solution is beneficial for increasing the density of fluorescent groups on the thermoplastic polyurethane elastomer fluorescent material. 20°C is a preferred value.
[0033] Example 3:
[0034] Other conditions were the same as in Example 1, and fluorescent molecules with different molecular structures were used as the fluorescence source. The results are shown in Table 2 below:
[0035] Table 2 Experimental results of preparing thermoplastic polyurethane elastomer fluorescent materials using different fluorescent molecules as fluorescence sources
[0036] serial number Fluorescent molecules Fluorophore density (mmol / g) 1 2-Anthracenecarbonyl chloride (CAS No.: 16331-51-4) 0.22 (Example 1) 2 9-Anthracenecarbonyl chloride (CAS No.: 16331-52-5) 0.20 3 Anthracene-1-yl chloride (CAS No. 42442-96-6) 0.21 4 9-Fluorenylcarbonyl chloride (CAS No.: 24168-51-2) 0.23 5 3-Phenanthroline carboxylic acid (CAS No. 7470-14-6) 0.17 6 9-Phenanthrenecarboxylic acid (CAS No.: 837-45-6) 0.13 7 1-Pyrenecarboxylic acid (CAS No.: 19694-02-1) 0.17 8 9-Fluorenone-4-carbonyl chloride (CAS No.: 7071-83-2) 0.15
[0037] As shown in the table above, the fluorescent molecular acyl chloride can be selected from 2-anthracenecarbonyl chloride, 9-anthracenecarbonyl chloride, anthracene-1-yl chloride or 9-fluorenecarbonyl chloride, and the obtained thermoplastic polyurethane elastomer fluorescent material has a higher density of fluorescent groups.
[0038] Example 4:
[0039] Other conditions were the same as in Example 1. Water-saturated dichloromethane solutions with different concentrations of fluorescent molecules were used for immersion. The results are shown in Table 3 below:
[0040] Table 3 Experimental results of preparing fluorescent thermoplastic polyurethane elastomer materials using different concentrations of fluorescent molecules
[0041]
[0042]
[0043] As shown in the table above, the concentration of the fluorescent molecule has little effect on the density of the fluorescent groups. However, considering cost and efficiency, a concentration of 0.25 mol / L is optimal.
[0044] Example 4:
[0045] Other conditions were the same as in Example 1. Different types of polyurethane elastomers were surface treated in a 0.25 mol / L dichloromethane solution of fluorescent molecules. The results are shown in Table 4:
[0046] serial number Types of polyurethane elastomers Fluorophore density (mmol / g) 1 IPDI type polyurethane elastomer 0.25 2 MDI type polyurethane elastomer 0.28 3 HDI type polyurethane elastomer 0.27 4 TDI type polyurethane elastomer 0.22 5 XDI type polyurethane elastomer 0.20
[0047] As shown in the table above, using MDI-type polyurethane elastomer or HDI-type polyurethane elastomer as the matrix is beneficial to increasing the density of fluorescent groups on the thermoplastic polyurethane elastomer fluorescent material.
[0048] Example 5:
[0049] The preparation of the isocyanate-terminated thermoplastic polyurethane elastomer is carried out as follows:
[0050] Dehydrate polyethylene adipate at 120°C and -0.1 MPa vacuum for 2-4 hours and set aside; control the molar ratio of isocyanate group to hydroxyl group in the reaction system to be 1.0-1.5, add dehydrated polytetrahydrofuran ether (Mn=1000), isofluorodione diisocyanate and dibutyltin dilaurate into the reaction kettle, and heat to 85 ℃ , stirred for 3 hours, and cooled to 55 ℃ , add 1,4-butanediol, stir for 0.5h, pour into a polytetrafluoroethylene mold, place at room temperature for 24h, place in a 60℃ oven for 24h, and place in a 100℃ vacuum drying oven for 10h to obtain a thermoplastic polyurethane elastomer.
[0051] Polyethylene adipate can be replaced by other polyether or polyester diols with a number average molecular weight of 1000-4000, such as at least one of polypropylene adipate diol, polypropylene glycol, polycaprolactone diol, polycarbonate diol, polyethylene glycol, and polytetrahydrofuran.
[0052] The catalyst is replaced by at least one of stannous octoate, dimethylcyclohexylamine or N-ethylmorpholine.
[0053] The isofluorodione diisocyanate may be replaced by other isocyanates, for example, any one of 2,4-toluene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, or p-phenylene diisocyanate, or a combination thereof.
[0054] In summary, the thermoplastic polyurethane elastomer is an isocyanate-terminated thermoplastic polyurethane elastomer, and its preparation method may include the following steps:
[0055] S1. Dehydrate the polyether or polyester diol at 120° C. and -0.08 MPa to -0.1 MPa under vacuum conditions for 2-4 hours and set aside;
[0056] S2. Add the dehydrated polyether or polyester diol, aliphatic or aromatic diisocyanate and catalyst into a reaction kettle, control the molar ratio of isocyanate group to hydroxyl group in the reaction system to be 1.0-1.5, heat to 70-85°C, stir for 2-3h, cool to 55°C, add chain extender and stir for 0.5h;
[0057] S3. The reaction materials were poured into a polytetrafluoroethylene mold, placed at room temperature for 24 h, placed in a 60° C. oven for 24 h, and placed in a 100° C. vacuum drying oven for 10 h to obtain an isocyanate-terminated thermoplastic polyurethane elastomer.
[0058] By changing the molar ratio of isocyanate groups to hydroxyl groups, polyurethane elastomers with different hard segment contents can be obtained. Increasing the proportion of isocyanate will increase the hard segment content, while reducing the proportion of polyol will also reduce the soft segment content.
[0059] The obtained isocyanate-terminated thermoplastic polyurethane elastomer was subjected to the following experiment:
[0060] Other conditions were the same as in Example 1. Polyurethanes with different hard segment contents were surface treated in a 0.25 mol / L water-saturated dichloromethane solution of fluorescent molecules. The results are shown in Table 5.
[0061] serial number Thermoplastic polyurethane elastomer hard segment content (%) Fluorophore density (mmol / g) 1 30 0.21 2 35 0.23 3 40 0.27 4 45 0.20
[0062] As shown in the table above, using different hard segment contents of thermoplastic polyurethane elastomer as the matrix, the fluorescent group density on the thermoplastic polyurethane elastomer fluorescent material has a peak. The thermoplastic polyurethane elastomer with a hard segment content of 40% is the best.
[0063] Comparative Example 1
[0064] The difference from Example 1 is that the surface treatment was performed directly with an anthracenecarbonyl chloride solution synthesized from an anhydrous dichloromethane solution. The results are shown in Table 6.
[0065] serial number Fluorophore density (mmol / g) Example 1 0.22 Comparative Example 1 0.08
[0066] As shown in Table 6, the fluorescent group density of the anthracenecarbonyl chloride solution synthesized directly using an anhydrous dichloromethane solution is much lower than that of Example 1.
[0067] Comparative Example 2
[0068] The difference from Example 1 is that the polyurethane elastomer is directly added to anthracenecarboxylic acid for mechanical blending. The experimental results are shown in Table 7:
[0069] serial number Fluorophore density (mmol / g) Example 1 0.22 Comparative Example 2 0.13
[0070] As shown in Table 7, the density of fluorescent groups obtained by mechanically blending polyurethane elastomer with anthracenecarboxylic acid is lower than that in Example 1.
[0071] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some of the technical features therein according to the disclosed technical content without creative labor, and these substitutions and modifications are all within the protection scope of the present invention.
Claims
1. A method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution, characterized in that: The thermoplastic polyurethane elastomer is immersed in a fluorescent molecule acyl chloride solution for reaction, so that the amide bonds on the polyurethane main chain connect with the fluorescent molecules in the acyl chloride solution, generating imide to achieve chemical bond connection between the fluorescent molecules and the polyurethane, thereby obtaining the thermoplastic polyurethane elastomer fluorescent material; the fluorescent molecule acyl chloride solution is obtained by dispersing the fluorescent molecule acyl chloride in a water-saturated dichloromethane solution.
2. The method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution according to claim 1, characterized in that: The water-saturated dichloromethane solution is prepared at 15-35°C.
3. The method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution according to claim 1 or 2, characterized in that: The concentration of the fluorescent molecular acyl chloride solution for impregnating the thermoplastic polyurethane elastomer molecules is 0.01-0.6 mol / L.
4. The method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution according to claim 1 or 2, characterized in that: The fluorescent molecular acyl chloride is 2-anthracenecarbonyl chloride, 9-anthracenecarbonyl chloride, anthracene-1-chloride or 9-fluorenecarbonyl chloride.
5. The method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution according to claim 1 or 2, characterized in that: The thermoplastic polyurethane elastomer has a hard segment content of 30%-45%.
6. The method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution according to claim 1 or 2, characterized in that: The thermoplastic polyurethane elastomer is an IPDI type polyurethane elastomer, an MDI type polyurethane elastomer, an HDI type polyurethane elastomer, a TDI type polyurethane elastomer or an XDI type polyurethane elastomer.
7. The method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution according to claim 1 or 2, characterized in that: The thermoplastic polyurethane elastomer is an isocyanate-terminated thermoplastic polyurethane elastomer, and its preparation method comprises the following steps: S1. Dehydrate the polyether or polyester diol at 120°C and a vacuum condition of -0.08 MPa to -0.1 MPa for 2-4 hours and set aside. S2. Add the dehydrated polyether or polyester diol, aliphatic or aromatic diisocyanate and catalyst into a reactor, control the molar ratio of isocyanate group to hydroxyl group in the reaction system to be 1.0-1.5, raise the temperature to 70-85°C, stir for 2-3 hours, cool to 55°C, add the chain extender and stir for 0.5 hour; S3. The reaction materials were poured into a polytetrafluoroethylene mold, placed at room temperature for 24 h, placed in a 60°C oven for 24 h, and placed in a 100°C vacuum drying oven for 10 h to obtain an isocyanate-terminated thermoplastic polyurethane elastomer.
8. The method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution according to claim 7, characterized in that: The polyether or polyester diol is at least one of polyethylene adipate diol, polypropylene adipate diol, polypropylene glycol, polycaprolactone diol, polycarbonate diol, polyethylene glycol, and polytetrahydrofuran with a number average molecular weight of 1000-4000.
9. The method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution according to claim 7, characterized in that: The catalyst is at least one of dibutyltin dilaurate, stannous octoate, dimethylcyclohexylamine or N-ethylmorpholine.
10. The method for synthesizing a thermoplastic polyurethane elastomer fluorescent material based on a water-saturated dichloromethane chloride solution according to claim 7, wherein: The isocyanate is any one of 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, isofluorodione diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate or p-phenylene diisocyanate, or a combination thereof.