Repairable supramolecular plastics with high mechanical strength and high environmental stability and methods of making the same

Abstract

This invention discloses a self-healing supramolecular plastic with high mechanical strength and high environmental stability, and its preparation method. The supramolecular plastic is prepared by polycondensation of a uniform mixture of 1,4-butanediol-bis(3-aminopropyl) ether and isophorone diisocyanate in a specific ratio. The self-healing supramolecular plastic of this invention not only possesses high strength and high hardness, but also good ductility, superior to that of ordinary plastics. Furthermore, the supramolecular plastic of this invention also exhibits excellent thermal stability and resistance to moisture.

Description

Technical Field

[0001] This invention relates to a repairable supramolecular plastic with high mechanical strength and high environmental stability, and its preparation method, belonging to the field of polymer materials. Background Technology

[0002] Supramolecular polymers utilize supramolecular interactions for self-assembly, exhibiting high sensitivity and faster network reconstruction speeds. Furthermore, the entire process requires no catalyst, significantly reducing side reactions and ensuring the stability of mechanical and chemical properties during use. However, the rapid dissociation-exchange-recombination kinetics of non-covalent bonds and the relatively low bond energy greatly affect the mechanical robustness and durability of supramolecular materials, making them incomparable to conventional commercial thermoplastics.

[0003] Sun et al. prepared super-strong PAA-polyvinylpyrrolidone (PVPON) by complexing it through hydrogen bonding based on a complexation strategy and then compressing the resulting product into the desired shape. The glassy PAA-PVPON composite exhibited ultra-high tensile strength of ~81.1 MPa and very high Young's modulus of ~4.5 GPa. Due to reversible hydrogen bonding, the broken PAA-PVPON composite can recover its original mechanical properties at ~45 °C (N.An,X.Wang,Y.Li,L.Zhang,Z.Lu,J.Sun.Healable and mechanically super-strong polymeric composites derived from hydrogen-bonded polymeric complexes[J].Advanced Materials,2019,31(41):1904882). Aida used a polymer building block strategy to stack low molecular weight polyether thiourea through hydrogen bonding interactions to form an amorphous glassy polymer. This polymer exhibits high tensile strength (~45 MPa) and high Young's modulus (~1.4 GPa). When an external pressure (1.0 MPa) is applied at 24 °C, it can be completely repaired within 6 hours (Y. Yanagisawa, Y. Nan, K. Okuro, T. Aida. Mechanically robust, readily repairable polymers via tailored noncovalent cross-linking[J]. Science, 359(6371), 72-76). Although some results have been achieved, supramolecular materials still face the following problems: (1) Achieving high hardness and high strength in materials means that the movement of molecular chains is greatly restricted, resulting in high brittleness of the materials and greatly increasing the possibility of danger during use. Therefore, developing supramolecular polymers with both high hardness and high toughness is an urgent problem to be solved in engineering applications. Moreover, the high restriction on chain segments also seriously hinders the repair efficiency. (2) Non-covalent bonds are sensitive to external stimuli such as heat, humidity, solvents, acids, and alkalis. These stimuli can cause a significant reduction in the mechanical properties of materials, greatly limiting their application range. Improving the environmental stability of polymers is also a concern. Therefore, constructing repairable supramolecular polymers with high mechanical strength and high environmental stability is an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide a repairable supramolecular plastic with high mechanical strength and high environmental stability, and a method for preparing the same.

[0005] The technical solution for achieving the objective of this invention is as follows:

[0006] A repairable supramolecular plastic with high mechanical strength and high environmental stability has the following structural formula:

[0007] n≥50.

[0008] The above-mentioned method for preparing repairable supramolecular plastics with high mechanical strength and high environmental stability involves the polycondensation of 1,4-butanediol-bis(3-aminopropyl) ether and isophorone diisocyanate. The synthetic route is as follows:

[0009] The specific steps are as follows:

[0010] Step 1: Under a nitrogen atmosphere, isophorone diisocyanate is dissolved in N,N'-dimethylformamide (DMF) to prepare solution I, and solution I is stirred in an ice bath;

[0011] Step 2: Dissolve 1,4-butanediol-bis(3-aminopropyl) ether in N,N'-dimethylformamide to prepare solution II. Then, add solution II dropwise to solution I and stir vigorously in an ice bath to prepare initial product solution III, wherein the molar ratio of isophorone diisocyanate to 1,4-butanediol-bis(3-aminopropyl) ether is 1 to 1.05:1.

[0012] Step 3: Heat-treat the initial product solution III at 50-80℃ for 8-9 hours to obtain the final polymer solution IV;

[0013] Step 4: Dry the polymer solution IV to remove the solvent, and obtain a repairable supramolecular plastic with high mechanical properties and high environmental stability.

[0014] Preferably, in step 1 or 2, the ice bath temperature is 0–4°C.

[0015] Preferably, in step 1, the concentration of isoflurane diisocyanate in solution I is 0.5–1 mmol / mL.

[0016] Preferably, in step 2, the solubility of 1,4-butanediol-bis(3-aminopropyl) ether in solution II is the same as the concentration of isophorone diisocyanate in solution I.

[0017] Preferably, in step 2, the dropping rate is 200 μL / min.

[0018] Preferably, in step 2, the stirring time is 1 hour.

[0019] Preferably, in step 4, the drying method is to first dry at 90°C for 48 hours, and then continue drying under vacuum at 90°C for 24 hours.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) The self-healing supramolecular plastic with high mechanical strength and high environmental stability of the present invention not only has high strength (>60MPa) and high hardness (~1GPa), but also has good ductility (>60%), which is superior to general plastics such as polymethyl methacrylate, polyethylene, etc.

[0022] (2) The self-healing supramolecular plastic of the present invention, which has high mechanical strength and high environmental stability, has excellent thermal stability. When the temperature reaches 90°C, its mechanical properties hardly change. In addition, it has excellent resistance to moisture. After being placed at 65% humidity for 4 weeks, its mechanical properties remain almost unchanged.

[0023] (3) The preparation method of the present invention is simple, has good repeatability, and is suitable for large-scale production. Attached Figure Description

[0024] Figure 1 The infrared spectrum of the supramolecular plastic prepared in Example 1.

[0025] Figure 2 The stress-strain diagram is for the supramolecular plastic prepared in Example 1.

[0026] Figure 3 The stress-strain curves of the supramolecular plastic prepared in Example 1 at different temperatures.

[0027] Figure 4 The stress-strain curves of the supramolecular plastic prepared in Example 1 after being placed at 65% humidity for different times.

[0028] Figure 5 The stress-strain curve of the supramolecular plastic prepared in Example 1 under the assistance of isopropanol for repair.

[0029] Figure 6 Stress-strain diagrams of the supramolecular plastics prepared in Example 1 and Comparative Example 2.

[0030] Figure 7 The images show the water vapor adsorption-desorption isotherms of the supramolecular plastics prepared in Example 1 and Comparative Example 3. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0032] Example 1

[0033] The preparation method of self-healing supramolecular plastics with high mechanical strength and high environmental stability includes the following specific steps:

[0034] Step 1: Under a nitrogen atmosphere, isophorone diisocyanate was dissolved in N,N'-dimethylformamide solvent to prepare solution I with a concentration of 0.5 mmol / mL. Solution I was stirred in an ice bath (0-4℃).

[0035] Step 2: Dissolve 1,4-butanediol-bis(3-aminopropyl) ether in N,N'-dimethylformamide to prepare solution II, which has the same concentration as solution I. Then, add solution II dropwise to solution I at a rate of 200 μL / min and stir vigorously for 1 h in an ice bath to obtain the initial product solution III, in which the molar ratio of isophorone diisocyanate to 1,4-butanediol-bis(3-aminopropyl) ether is 1.05:1.

[0036] Step 3: Heat-treat the initial product solution III at 50°C for 9 hours to obtain the final polymer solution IV;

[0037] Step 4: Dry the polymer solution IV to remove the solvent, and obtain a repairable supramolecular plastic with high mechanical properties and high environmental stability.

[0038] Example 2

[0039] The preparation method of self-healing supramolecular plastics with high mechanical strength and high environmental stability includes the following specific steps:

[0040] Step 1: Under a nitrogen atmosphere, isophorone diisocyanate was dissolved in N,N'-dimethylformamide solvent to prepare solution I with a concentration of 1.0 mmol / mL. Solution I was stirred in an ice bath (0-4℃).

[0041] Step 2: Dissolve 1,4-butanediol-bis(3-aminopropyl) ether in N,N'-dimethylformamide to prepare solution II, which has the same concentration as solution I. Then, add solution II dropwise to solution I at a rate of 200 μL / min and stir vigorously for 1 h in an ice bath to obtain the initial product solution III, in which the molar ratio of isophorone diisocyanate to 1,4-butanediol-bis(3-aminopropyl) ether is 1.05:1.

[0042] Step 3: Heat-treat the initial product solution III at 50°C for 9 hours to obtain the final polymer solution IV;

[0043] Step 4: Dry the polymer solution IV to remove the solvent, and obtain a repairable supramolecular plastic with high mechanical properties and high environmental stability.

[0044] Example 3

[0045] The preparation method of self-healing supramolecular plastics with high mechanical strength and high environmental stability includes the following specific steps:

[0046] Step 1: Under a nitrogen atmosphere, isophorone diisocyanate was dissolved in N,N'-dimethylformamide solvent to prepare solution I with a concentration of 0.5 mmol / mL. Solution I was stirred in an ice bath (0-4℃).

[0047] Step 2: Dissolve 1,4-butanediol-bis(3-aminopropyl) ether in N,N'-dimethylformamide to prepare solution II, which has the same concentration as solution I. Then, add solution II dropwise to solution I at a rate of 200 μL / min and stir vigorously for 3 h in an ice bath to obtain the initial product solution III, in which the molar ratio of isophorone diisocyanate to 1,4-butanediol-bis(3-aminopropyl) ether is 1.05:1.

[0048] Step 3: Heat-treat the initial product solution III at 50°C for 9 hours to obtain the final polymer solution IV;

[0049] Step 4: Dry the polymer solution IV to remove the solvent, and obtain a repairable supramolecular plastic with high mechanical properties and high environmental stability.

[0050] Example 4

[0051] The preparation method of self-healing supramolecular plastics with high mechanical strength and high environmental stability includes the following specific steps:

[0052] Step 1: Under a nitrogen atmosphere, isophorone diisocyanate was dissolved in N,N'-dimethylformamide solvent to prepare solution I with a concentration of 0.5 mmol / mL. Solution I was stirred in an ice bath (0-4℃).

[0053] Step 2: Dissolve 1,4-butanediol-bis(3-aminopropyl) ether in N,N'-dimethylformamide to prepare solution II, which has the same concentration as solution I. Then, add solution II dropwise to solution I at a rate of 200 μL / min and stir vigorously for 1 h in an ice bath to obtain the initial product solution III, in which the molar ratio of isophorone diisocyanate to 1,4-butanediol-bis(3-aminopropyl) ether is 1.05:1.

[0054] Step 3: Heat-treat the initial product solution III at 60°C for 8 hours to obtain the final polymer solution IV;

[0055] Step 4: Dry the polymer solution IV to remove the solvent, and obtain a repairable supramolecular plastic with high mechanical properties and high environmental stability.

[0056] Example 5

[0057] The preparation method of self-healing supramolecular plastics with high mechanical strength and high environmental stability includes the following specific steps:

[0058] Step 1: Under a nitrogen atmosphere, isophorone diisocyanate was dissolved in N,N'-dimethylformamide solvent to prepare solution I with a concentration of 0.5 mmol / mL. Solution I was stirred in an ice bath (0-4℃).

[0059] Step 2: Dissolve 1,4-butanediol-bis(3-aminopropyl) ether in N,N'-dimethylformamide to prepare solution II, which has the same concentration as solution I. Then, add solution II dropwise to solution I at a rate of 200 μL / min and stir vigorously for 1 h in an ice bath to obtain the initial product solution III, in which the molar ratio of isophorone diisocyanate to 1,4-butanediol-bis(3-aminopropyl) ether is 1.05:1.

[0060] Step 3: Heat-treat the initial product solution III at 70°C for 9 hours to obtain the final polymer solution IV;

[0061] Step 4: Dry the polymer solution IV to remove the solvent, and obtain a repairable supramolecular plastic with high mechanical properties and high environmental stability.

[0062] Example 6

[0063] The preparation method of self-healing supramolecular plastics with high mechanical strength and high environmental stability includes the following specific steps:

[0064] Step 1: Under a nitrogen atmosphere, isophorone diisocyanate was dissolved in N,N'-dimethylformamide solvent to prepare solution I with a concentration of 0.5 mmol / mL. Solution I was stirred in an ice bath (0-4℃).

[0065] Step 2: Dissolve 1,4-butanediol-bis(3-aminopropyl) ether in N,N'-dimethylformamide to prepare solution II, which has the same concentration as solution I. Then, add solution II dropwise to solution I at a rate of 200 μL / min and stir vigorously for 1 h in an ice bath to obtain the initial product solution III, in which the molar ratio of isophorone diisocyanate to 1,4-butanediol-bis(3-aminopropyl) ether is 1.05:1.

[0066] Step 3: Heat-treat the initial product solution III at 80°C for 9 hours to obtain the final polymer solution IV;

[0067] Step 4: Dry the polymer solution IV to remove the solvent, and obtain a repairable supramolecular plastic with high mechanical properties and high environmental stability.

[0068] Comparative Example 1

[0069] This comparative example is basically the same as Example 1, except that in step 2, the mixture is stirred vigorously at room temperature for 1 hour. The specific steps are as follows:

[0070] Step 1: Under a nitrogen atmosphere, isophorone diisocyanate was dissolved in N,N'-dimethylformamide solvent to prepare solution I with a concentration of 0.5 mmol / mL. Solution I was stirred at room temperature.

[0071] Step 2: Dissolve 1,4-butanediol-bis(3-aminopropyl) ether in N,N'-dimethylformamide solvent to prepare solution II, with the same concentration as solution I. Then, add solution II dropwise to solution I at 200 μL / min and stir vigorously at room temperature for 1 h to obtain the initial product solution III, in which the molar ratio of isophorone diisocyanate to 1,4-butanediol-bis(3-aminopropyl) ether is 1.05:1.

[0072] Step 3: Heat-treat the initial product solution III at 50°C for 9 hours to obtain the final polymer solution IV;

[0073] Step 4: Dry the polymer solution IV to remove the solvent and obtain the supramolecular plastic.

[0074] The supramolecular plastics prepared in this comparative example have poor mechanical properties.

[0075] Comparative Example 2

[0076] This comparative example is basically the same as Example 1, except that in step 2, 1,4-butanediol-bis(3-aminopropyl) ether is replaced with 1,12-diaminododecane. The specific steps are as follows:

[0077] Step 1: Under a nitrogen atmosphere, isophorone diisocyanate was dissolved in N,N'-dimethylformamide to prepare solution I with a concentration of 0.5 mmol / mL. Solution I was stirred in an ice bath at room temperature (0-4℃).

[0078] Step 2: Dissolve 1,12-diaminododecane in N,N'-dimethylformamide to prepare solution II, which has the same concentration as solution I. Then, add solution II dropwise to solution I at a rate of 200 μL / min and stir vigorously for 1 h in an ice bath to obtain the initial product solution III, in which the molar ratio of isophorone diisocyanate to 1,12-diaminododecane is 1.05:1.

[0079] Step 3: Heat-treat the initial product solution III at 50°C for 9 hours to obtain the final polymer solution IV;

[0080] Step 4: Dry the polymer solution IV to remove the solvent and obtain the supramolecular plastic.

[0081] The supramolecular plastic prepared in this comparative example has poor mechanical properties.

[0082] Comparative Example 3

[0083] This comparative example is basically the same as Example 1, except that in step 2, 1,4-butanediol-bis(3-aminopropyl) ether is replaced with 3,3-(butane-1,4-imidedi(oxo))di(propane-1-ol). The specific steps are as follows:

[0084] Step 1: Under a nitrogen atmosphere, isophorone diisocyanate was dissolved in N,N'-dimethylformamide to prepare solution I with a concentration of 0.5 mmol / mL. Solution I was stirred in an ice bath at room temperature (0-4℃).

[0085] Step 2: Dissolve 3,3-(butane-1,4-imidene di(oxo))di(propane-1-ol) in N,N'-dimethylformamide to prepare solution II, with the same concentration as solution I. Then, add solution II dropwise to solution I at 200 μL / min and stir vigorously for 1 h in an ice bath to obtain the initial product solution III, in which the molar ratio of isophorone diisocyanate to 3,3-(butane-1,4-imidene di(oxo))di(propane-1-ol) is 1.05:1.

[0086] Step 3: Heat-treat the initial product solution III at 50°C for 9 hours to obtain the final polymer solution IV;

[0087] Step 4: Dry the polymer solution IV to remove the solvent and obtain the supramolecular plastic.

[0088] The supramolecular plastic prepared in this comparative example has poor environmental stability.

[0089] The self-healing supramolecular plastics prepared in Examples 1-6 are essentially the same, with similar properties, including comparable mechanical strength and environmental stability. The following description uses the self-healing supramolecular plastic prepared in Example 1, which exhibits high mechanical strength and high environmental stability, as a representative example, to present its specific characterization and performance testing results.

[0090] Figure 1 The infrared spectrum of the supramolecular plastic prepared in Example 1. Wavelength: 3334 cm⁻¹ -1 It is the stretching vibration of -NH-, with wavelengths of 2935 and 2853 cm⁻¹. -1 It is the stretching vibration of -CH3, with a wavelength of 1634 cm. -1 It is a stretching vibration of C=O, with a wavelength of 1555 cm. -1 It is the bending vibration of -NH-, with a wavelength of 1364 cm. -1 It is a bending vibration of -CH3, with a wavelength of 124 cm. -1 It is a -CC- stretching vibration with a wavelength of 1098 cm. -1 It is the stretching vibration of -COC-.

[0091] Figure 2The stress-strain diagram shows the supramolecular plastic prepared in Example 1. The stress-strain diagram reveals that the material exhibits high strength (>60 MPa) and high hardness (~1 GPa), as well as good ductility (>60%).

[0092] Figure 3 The stress-strain curves of the supramolecular plastic prepared in Example 1 at different temperatures are shown. Figure 3 As shown, when stretched at 25℃, 60℃, 70℃, 80℃ and 90℃, the mechanical properties of the material hardly change even at 90℃, indicating that the material has excellent thermal stability.

[0093] Figure 4 The stress-strain curves of the supramolecular plastic prepared in Example 1 after being placed at 65% humidity for different times are shown. Figure 4 As shown, after being placed at 65% humidity for 1, 2, 3, and 4 weeks and then stretched, the mechanical properties of the material only changed slightly, indicating that the material has excellent resistance to moisture.

[0094] Figure 5 The repair curve of the supramolecular plastic prepared in Example 1 under isopropanol assistance is shown. The material was cut into test strips, severed with a blade, and then a small amount of IPA was applied to the fracture surface. The two surfaces were then joined together and repaired at 60°C for 1 hour. The repair effect was tested using a universal tensile testing machine. Figure 5 As shown, after repair, the material can basically fully recover its tensile length.

[0095] Figure 6 Stress-strain diagrams of the supramolecular plastics prepared in Example 1 and Comparative Example 2 are shown. Detailed mechanical properties such as Young's modulus, tensile strength, elongation, and toughness are shown below. Figure 6 As shown. The material of Example 1 has high hardness and strength, with a Young's modulus of approximately 0.95 GPa, which is much greater than that of Comparative Example 2. In addition, the toughness of the material of Example 1 is approximately 13 times that of Comparative Example 2.

[0096] Figure 7 The images show the water vapor adsorption-desorption isotherms of the supramolecular plastics prepared in Example 1 and Comparative Example 3. Comparative Example 3 absorbed approximately 4.1% water vapor at a maximum humidity of 95%, while Example 1 absorbed only 0.9%, indicating that the material of Example 1 has significantly better water vapor resistance than that of Comparative Example 3.

Claims

1. A repairable supramolecular plastic with high mechanical strength and high environmental stability, characterized in that, The structure is as follows: ，n≥50； Prepared by the following steps: Step 1: Under a nitrogen atmosphere, isophorone diisocyanate is dissolved in N,N-dimethylformamide to prepare solution I, and solution I is stirred in an ice bath; Step 2: Dissolve 1,4-butanediol-bis(3-aminopropyl) ether in N,N-dimethylformamide to prepare solution II. Then add solution II dropwise to solution I and stir vigorously in an ice bath to prepare initial product solution III, wherein the molar ratio of isophorone diisocyanate to 1,4-butanediol-bis(3-aminopropyl) ether is 1~1.05:

1. Step 3: Heat-treat the initial product solution III at 50-80℃ for 8-9 hours to obtain the final polymer solution IV; Step 4: Dry the polymer solution IV to remove the solvent, and obtain a repairable supramolecular plastic with high mechanical properties and high environmental stability.

2. The repairable supramolecular plastic according to claim 1, characterized in that, In step 1 or 2, the ice bath temperature is 0~4℃.

3. The repairable supramolecular plastic according to claim 1, characterized in that, In step 1, the concentration of isophorone diisocyanate in solution I is 0.5~1 mmol / mL.

4. The repairable supramolecular plastic according to claim 1, characterized in that, In step 2, the solubility of 1,4-butanediol-bis(3-aminopropyl) ether in solution II is the same as the concentration of isophorone diisocyanate in solution I.

5. The repairable supramolecular plastic according to claim 1, characterized in that, In step 2, the dropping rate is 200 μL / min.

6. The repairable supramolecular plastic according to claim 1, characterized in that, In step 2, the stirring time is 1 hour.

7. The repairable supramolecular plastic according to claim 1, characterized in that, In step 4, the drying method is to first dry at 90℃ for 48 hours, and then continue drying under vacuum at 90℃ for 24 hours.

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