Preparation method of bio-based repairable flexible conductive organosilicon film

Abstract

The invention discloses a preparation method of a bio-based repairable flexible conductive organosilicon film. The preparation method comprises the following steps: firstly, reacting bio-based polyol PO3G (poly trimethylene ether glycol) with isophorone diisocyanate to obtain an isocyanate-terminated bio-based prepolymer; then, bis (3-aminopropyl) terminated polydimethylsiloxane (PDMS) and a mixed chain extender of 4, 4 '-(hexafluoroisopropylidene) diphenol and isophthaloyl hydrazine are sequentially used for two-step chain extension, and a bio-based organic silicon matrix with a repairable function is constructed; and finally, compounding with a multi-walled carbon nanotube to prepare the organic silicon film with flexibility, conductivity and self-repairing function. The material can be applied to manufacturing of flexible electronics and wearable equipment.

Description

Technical Field

[0001] This invention relates to a method for preparing a bio-based, self-healing, flexible, conductive organosilicon film. Specifically, the organosilicon film uses polydimethylsiloxane and bio-based polyol as the dual soft-segment structure basis. Through the synergistic mechanism of introducing FH bonds and constructing multi-level hydrogen bonds, a bio-based organosilicon matrix with self-healing properties is prepared. After further doping with multi-walled carbon nanotubes, a flexible composite film with both good conductivity and self-healing function can be obtained. Technical Background

[0002] The applications of elastomers have expanded from traditional fields to cutting-edge technologies such as flexible electronics, thanks to their flexibility, high designability, and multifunctional potential. With the development of flexible electronics, the demand for high-performance elastomer substrates is urgent. PDMS is an ideal substrate material due to its excellent biocompatibility, flexibility, and stability. However, pure PDMS suffers from poor strength and toughness due to its non-polar structure and weak intermolecular interactions, making it easily damaged and limiting its high-end applications. Therefore, simultaneously improving the strength, toughness, and tear resistance of silicon-based elastomers is a major challenge. If materials possess both repairability and recyclability, their lifespan will be extended and energy consumption and pollution reduced.

[0003] Thermoplastic polyurethane urea elastomers spontaneously form microphase separation structures due to the thermodynamic incompatibility between hard and soft segments. Hard segments aggregate through hydrogen bonding to form hard domains, while soft segments constitute soft domains, giving the material excellent designability and mechanical tunability. However, in polydimethylsiloxane (PDMS)-based polyurea elastomers, the incompatibility between the highly polar hard segments and the non-polar PDMS soft segments is too significant, easily leading to excessive microphase separation and impairing mechanical properties. To address this issue, polyether is introduced as a transition phase, with a polarity between PDMS and the hard segments. This effectively improves the interfacial compatibility between the hard and soft segments, thereby significantly enhancing the overall mechanical properties of the elastomer.

[0004] This invention uses polysiloxane and bio-based polyol as dual soft segments, and constructs a bio-based organosilicon matrix with repairable properties by introducing FH bonds and building a multi-level hydrogen bond synergistic mechanism; further, multi-walled carbon nanotubes are doped for functionalization, and a flexible composite film with both conductivity and repairability is successfully prepared. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a bio-based, self-healing, flexible, conductive silicone film, which aims to integrate excellent flexibility, conductivity, self-healing properties, and recyclability into the silicone film, thereby meeting the concepts of green, environmental protection, and sustainable development.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method for preparing a bio-based repairable flexible conductive organosilicon film. This method is based on a dual soft segment structure constructed from bio-based polyols and polysiloxanes. Through molecular structure design and functional doping, the organosilicon film is endowed with comprehensive properties including flexibility, conductivity, repairability, and recyclability.

[0007] The present invention provides a method for preparing a bio-based repairable flexible conductive organosilicon film, comprising the following steps:

[0008] (1) Mix 2-4 mmol of bio-based polyol PO3G (polytrimethylene ether glycol, number average molecular weight of 2000 g / mol), 4-8 mmol of isophorone diisocyanate and 10-15 mg of dibutyltin dilaurate, and react under N2 protection at 60-75°C for 1-2 h to obtain isocyanate-terminated bio-based prepolymer;

[0009] (2) Dissolve 1-2 mmol of bis(3-aminopropyl)-terminated poly(dimethylsiloxane) PDMS (number average molecular weight of 3000 g / mol) in 6-18 mL of NN-dimethylacetamide, and add it dropwise to the bio-based prepolymer prepared in (1) above. Continue the chain extension reaction at 60-75 °C for 1-2 h, and then cool to 50 °C to obtain an isocyanate-terminated bio-based organosilicon prepolymer solution.

[0010] (3) Dissolve 0.5-1 mmol of 4,4'-(hexafluoroisopropylidene)diol and 0.5-1 mmol of isophthalohydrazide in 3-6 mL of NN-dimethylacetamide, and add them dropwise to the bio-based organosilicon prepolymer solution prepared in (2) above. Continue the chain extension reaction at 50 °C for 12-24 h, and dry to obtain bio-based repairable flexible organosilicon;

[0011] (4) Dissolve 15-20 mg of multi-walled carbon nanotubes and 30-40 mg of the bio-based repairable flexible organosilicon prepared in (3) above in 10-15 mL of tetrahydrofuran, mix thoroughly and uniformly, and obtain a flexible bio-based repairable conductive organosilicon film. The bio-based repairable flexible conductive organosilicon film is characterized by the fact that, when tested by an electrochemical workstation, the current passing through the film material is 10-11 mA when a constant voltage of 3V is applied.

[0012] Preferably, the molar ratio of the above-mentioned bio-based polyol PO3G, isophorone diisocyanate, bis(3-aminopropyl)-terminated poly(dimethylsiloxane) PDMS, 4,4'-(hexafluoroisopropylidene)diol and isophthalic acid hydrazide is 4:8:2:1:1.

[0013] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0014] (1) This method uses polysiloxane (PDMS) and bio-based polyol (PO3G) to construct a dual soft segment system. Among them, PO3G, as a polar transition phase, can improve the compatibility of soft and hard segments and effectively inhibit excessive microphase separation, thereby improving mechanical properties. At the same time, PO3G, as a bio-based raw material, replaces some petroleum-based derivatives, reducing dependence on fossil resources and carbon footprint from the source, so that the material has both high performance and green sustainability.

[0015] (2) The synergistic dynamic reversible effect of FH bond and multi-level hydrogen bond gives the material both high strength at room temperature and repairability when damaged (e.g., when heated), and endows it with recyclable properties. Attached Figure Description

[0016] Figure 1 Photograph of a bio-based, repairable, flexible, conductive silicone film. Detailed Implementation

[0017] The following embodiments illustrate the present invention in detail, but the present invention is not limited to these embodiments.

[0018] Unless otherwise specified, all raw materials and reagents used in the following implementation examples are commercially available.

[0019] Example 1

[0020] The specific preparation method is as follows: (1) 2 mmol of bio-based polyol PO3G (number average molecular weight of 2000 g / mol), 4 mmol of isophorone diisocyanate and 10 mg of dibutyltin dilaurate are mixed and reacted at 60 °C for 2 h under N2 protection to obtain isocyanate-terminated bio-based prepolymer.

[0021] (2) 1 mmol of bis(3-aminopropyl)-terminated poly(dimethylsiloxane) PDMS (number average molecular weight of 3000 g / mol) was dissolved in 6 mL of NN-dimethylacetamide and added dropwise to the bio-based prepolymer prepared in (1) above. The chain extension reaction was carried out at 60 °C for 2 h. After cooling to 50 °C, an isocyanate-terminated bio-based organosilicon prepolymer solution was obtained.

[0022] (3) Dissolve 0.5 mmol of 4,4'-(hexafluoroisopropylidene)diol and 0.5 mmol of isophthalohydrazide in 3 mL of N-N-dimethylacetamide, and add them dropwise to the bio-based organosilicon prepolymer solution prepared in (2) above. Continue the chain extension reaction at 50 °C for 12 h, and dry to obtain bio-based repairable flexible organosilicon;

[0023] (4) Dissolve 15 mg of multi-walled carbon nanotubes and 30 mg of the bio-based repairable flexible organosilicon prepared in (3) above in 10 mL of tetrahydrofuran, mix thoroughly and uniformly to obtain a flexible bio-based repairable conductive organosilicon film. The electrical performance of the obtained composite film is tested using an electrochemical workstation. When a constant voltage of 3 V is applied, the current passing through the film material is measured to be 10-10.5 mA.

[0024] Example 2

[0025] The specific preparation method is as follows: (1) 3 mmol of bio-based polyol PO3G (number average molecular weight of 2000 g / mol), 6 mmol of isophorone diisocyanate and 12 mg of dibutyltin dilaurate are mixed and reacted at 70 °C for 1.5 h under N2 protection to obtain isocyanate-terminated bio-based prepolymer;

[0026] (2) 1.5 mmol of bis(3-aminopropyl)-terminated poly(dimethylsiloxane) PDMS (number average molecular weight of 3000 g / mol) was dissolved in 12 mL of NN-dimethylacetamide and added dropwise to the bio-based prepolymer prepared in (1) above. The chain extension reaction was carried out at 70 °C for 1.5 h. After cooling to 50 °C, an isocyanate-terminated bio-based organosilicon prepolymer solution was obtained.

[0027] (3) Dissolve 0.75 mmol 4,4'-(hexafluoroisopropylidene)diol and 0.75 mmol isophthalohydrazide in 4 mL NN-dimethylacetamide, and add them dropwise to the bio-based organosilicon prepolymer solution prepared in (2) above. Continue the chain extension reaction at 50°C for 18 h, and dry to obtain bio-based repairable flexible organosilicon;

[0028] (4) Dissolve 18 mg of multi-walled carbon nanotubes and 35 mg of the bio-based repairable flexible organosilicon prepared in (3) above in 12 mL of tetrahydrofuran, mix thoroughly and uniformly to obtain a flexible bio-based repairable conductive organosilicon film. The electrical performance of the obtained composite film is tested using an electrochemical workstation. When a constant voltage of 3 V is applied, the current passing through the film material is measured to be 10-10.6 mA.

[0029] Example 3

[0030] The specific preparation method is as follows: (1) 4 mmol of bio-based polyol PO3G (number average molecular weight of 2000 g / mol), 8 mmol of isophorone diisocyanate and 15 mg of dibutyltin dilaurate are reacted at 75 °C for 1 h under N2 protection to obtain isocyanate-terminated bio-based prepolymer.

[0031] (2) 2 mmol of bis(3-aminopropyl)-terminated poly(dimethylsiloxane) PDMS (number average molecular weight of 3000 g / mol) was dissolved in 18 mL of NN-dimethylacetamide and added dropwise to the bio-based prepolymer prepared in (1) above. The chain extension reaction was carried out at 75 °C for 1 h. After cooling to 50 °C, an isocyanate-terminated bio-based organosilicon prepolymer solution was obtained.

[0032] (3) Dissolve 1 mmol of 4,4'-(hexafluoroisopropylidene)diol and 1 mmol of isophthalic hydrazide in 6 mL of NN-dimethylacetamide, and add dropwise to the bio-based organosilicon prepolymer solution prepared in (2) above. Continue the chain extension reaction at 50 °C for 24 h, and dry to obtain bio-based repairable flexible organosilicon.

[0033] (4) Dissolve 20 mg of multi-walled carbon nanotubes and 40 mg of the bio-based repairable flexible organosilicon prepared in (3) above in 15 mL of tetrahydrofuran, mix thoroughly and uniformly to obtain a flexible bio-based repairable conductive organosilicon film. The electrical performance of the obtained composite film is tested using an electrochemical workstation. When a constant voltage of 3 V is applied, the current passing through the film material is measured to be 10.5-11 mA.

Claims

1. A method for preparing a bio-based, repairable, flexible conductive organosilicon film, characterized in that, Includes the following steps: ① Mix 2-4 mmol of bio-based polyol PO3G (polytrimethylene ether glycol, number average molecular weight of 2000 g / mol), 4-8 mmol of isophorone diisocyanate and 10-15 mg of dibutyltin dilaurate, and react under N2 protection at 60-75 °C for 1-2 h to obtain isocyanate-terminated bio-based prepolymer; ② Dissolve 1-2 mmol of bis(3-aminopropyl)-terminated poly(dimethylsiloxane) PDMS (number average molecular weight of 3000 g / mol) in 6-18 mL of NN-dimethylacetamide, and add it dropwise to the bio-based prepolymer prepared in ① above. Continue the chain extension reaction at 60-75 °C for 1-2 h, and then cool to 50 °C to obtain an isocyanate-terminated bio-based organosilicon prepolymer solution. ③ Dissolve 0.5-1 mmol of 4,4'-(hexafluoroisopropylidene)diol and 0.5-1 mmol of isophthalohydrazide in 3-6 mL of NN-dimethylacetamide, and add them dropwise to the bio-based organosilicon prepolymer solution prepared in ② above. Continue the chain extension reaction at 50 °C for 12-24 h, and dry to obtain bio-based repairable flexible organosilicon; ④ Disperse 15-20 mg of multi-walled carbon nanotubes and 30-40 mg of the bio-based repairable flexible organosilicon prepared in ③ above in 10-15 mL of tetrahydrofuran, mix thoroughly and evenly, and composite to obtain a flexible bio-based repairable conductive organosilicon film. The molar ratio of the above-mentioned bio-based polyol PO3G, isophorone diisocyanate, bis(3-aminopropyl)-terminated poly(dimethylsiloxane) PDMS, 4,4'-(hexafluoroisopropylidene)diol and isophthalohydrazide is 4:8:2:1:

1.

2. The application of a bio-based repairable flexible conductive silicone film obtained by the preparation method of claim 1 in the preparation of flexible wearable electronic products, characterized in that, The bio-based repairable flexible conductive silicone membrane was tested with an electrochemical workstation and the current passing through the membrane material was 10-11 mA when a constant voltage of 3 V was applied.

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