A non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer and its preparation method

Abstract

This invention provides a non-isocyanate polyurethane acrylate-based flexible ion-conducting elastomer and its preparation method, relating to the field of ion-conducting flexible materials. The main components of this flexible ion-conducting elastomer are non-isocyanate polyurethane acrylate, reactive diluent, photoinitiator, lithium salt, and additives. The method provided by this invention successfully prepares a non-isocyanate polyurethane acrylate-based flexible ion-conducting elastomer with a wide operating temperature range and free of any liquid. The preparation process of this flexible ion-conducting elastomer involves no toxic monomers, it has a wide operating temperature range (0℃~80℃), and after curing, it contains no liquid and will not leak due to compression.

Description

Technical Field

[0001] This invention relates to the field of ion-conducting flexible materials, specifically to a non-isocyanate polyurethane acrylate-based flexible ion-conducting elastomer and its preparation method. Background Technology

[0002] Conductive flexible materials are the core components of flexible sensors. Early methods often involved adding conductive fillers and particles to obtain electronically conductive flexible materials. However, these materials suffer from uneven filler distribution and short circuits under high stress, limiting their application in flexible sensors. Ionically conductive flexible materials, on the other hand, solve these problems by using a cross-linked network to accommodate freely moving ions, offering advantages such as high transparency and high flexibility. Ionically conductive flexible materials mainly include hydrogels, ionogels, and flexible ionically conductive elastomers. Hydrogels have poor mechanical strength and flexibility, and are prone to freezing at low temperatures and dehydration at high temperatures, limiting their application environments. Ionogels, however, suffer from the problem of leakage when ionic liquids are compressed. Flexible ionically conductive elastomers, due to their absence of liquid and high stability, overcome these problems, offering a wide operating temperature window, good flexibility, and preventing leakage during compression.

[0003] Polyurethane acrylate is an important photocurable resin. Its molecules contain acrylic functional groups and urethane bonds, giving it excellent flexibility, abrasion resistance, adhesion, and low-temperature resistance after curing, making it suitable for preparing flexible ion-conductive elastomers. Typically, the preparation of polyurethane acrylate requires monomers containing isocyanates, such as diphenylmethane diisocyanate and hexamethylene diisocyanate. However, isocyanate groups are highly toxic and harmful to the environment and human health. Therefore, this patent uses isocyanate-free monomers to prepare polyurethane acrylate. A non-isocyanate polyurethane is prepared by reacting ethylene carbonate and diamine to produce urethane diol, followed by transesterification with a polyol. This non-isocyanate polyurethane acrylate is then synthesized by reacting with acrylic anhydride compounds.

[0004] Based on the above, a non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer was prepared. Summary of the Invention

[0005] In view of the above, the purpose of this invention is to provide a non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer and its preparation method. This flexible ion-conductive elastomer has a wide operating temperature range, contains no liquid, and does not use toxic isocyanates in the preparation process.

[0006] A method for preparing a non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer includes the following preparation steps:

[0007] Step 1: Add ethylene carbonate and aliphatic diamine to a flask and react at 80℃~120℃ for 4~6h at a rotation speed of 200r / min. Then recrystallize with deionized water to obtain urethane diol.

[0008] Step 2: Add urethane diol, polycarbonate diol or polyether diol with a molecular weight of 400-5000 to a flask and mix them evenly at 100°C. Then, react them under vacuum (pressure less than 500Pa) at 180°C at a rotation speed of 200r / min for 1h to obtain non-isocyanate polyurethane.

[0009] Step 3: Add acrylic anhydride compounds, triethylamine, polymerization inhibitor, and catalyst to the non-isocyanate polyurethane obtained in Step 2 and mix them evenly in the solvent. Then react at room temperature for 48 hours at a speed of 200 r / min. After purification, dry in a vacuum oven at 80℃ for 24 hours to remove the solvent and obtain the reaction product, non-isocyanate polyurethane acrylate.

[0010] Step 4: Add the reactive diluent, photoinitiator, lithium salt, and additives to the non-isocyanate polyurethane acrylate reaction product obtained in Step 3. Stir at room temperature for 1 hour at 200 r / min to mix evenly and obtain the final product, a flexible ion-conductive elastomer precursor solution. Then, perform photopolymerization reaction under 3W ultraviolet light to obtain the flexible ion-conductive elastomer.

[0011] Further supplementary information to the above steps:

[0012] In step 1, the molar ratio of ethylene carbonate to aliphatic diamine is 2–2.5:1. The aliphatic diamine includes one or more of 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, isophoronediamine, and 4,4-diaminodicyclohexylmethane.

[0013] In step 2, the molar ratio of urethane diol to medium molecular weight diol is 2–7:1. The polycarbonate diol and polyether diol include one or more of polypropylene carbonate diol, polyethylene carbonate diol, polyethylene glycol, polypropylene glycol, and polytetrahydrofuran diol.

[0014] In step 3, the mass ratio of non-isocyanate polyurethane, solvent, acrylic anhydride compound, triethylamine, polymerization inhibitor, and catalyst is 50:40:(4-8):(2-6):0.1:0.1. The acrylic anhydride compound includes one or more of acrylic anhydride and methacrylic anhydride; the solvent is one or more of N,N-dimethylformamide and dichloromethane; the polymerization inhibitor is one or more of hydroquinone and p-hydroxyanisole; and the catalyst is 4-dimethylaminopyridine.

[0015] In step 4, the mass ratio of non-isocyanate polyurethane acrylate, reactive diluent, photoinitiator, lithium salt, and additive is (15-65):(15-65):(2-4):(5-15):(10-20). The reactive diluent includes one or more of isoborneol methacrylate, isoborneol acrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, 1,6-hexanediol diacrylate, diethylene glycol ethyl ether acrylate, and trimethylolpropane triacrylate. The photoinitiator is one or more of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxymethylphenylpropane-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, benzophenone, 2-phenyl-2,2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, and 1-hydroxycyclohexylphenylacetone. The lithium salt is one or more of lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, and lithium perchlorate. The additive is one or more of succinic anionyl, tributyl citrate, and fumed silica.

[0016] Beneficial effects:

[0017] This invention utilizes a ring-opening reaction between ethylene carbonate and an aliphatic diamine to obtain an urethane diol, which is then subjected to transesterification with the diol to yield a non-isocyanate polyurethane. Finally, an esterification reaction with acrylic anhydride compounds yields a non-isocyanate polyurethane acrylate. The synthesis process of this non-isocyanate polyurethane acrylate does not use highly toxic chemicals or expensive materials, is energy-saving and emission-reducing, and is environmentally friendly. It can be used to prepare flexible ion-conductive elastomers. Adding reactive diluents, photoinitiators, lithium salts, and additives to this non-isocyanate polyurethane acrylate, followed by UV curing, produces a liquid-free elastomer with excellent ionic conductivity (2.7 × 10⁻⁶). -3 ~4.1×10 -3 It features high S / m, high flexibility (tensile strength <1.5MPa, elongation at break >200%), high transparency (visible light transmittance >80%), wide operating temperature range (0℃~80℃), and is a liquid-free flexible ion-conductive elastomer that can be applied to flexible sensors and electrolytes. Detailed Implementation

[0018] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0019] Example 1

[0020] This embodiment provides a non-isocyanate polyurethane acrylate, prepared by the following method:

[0021] Step 1: Add 73.92g of ethylene carbonate (EC) and 46.4g of 1,6-hexanediamine (1,6-HDA) to a flask and react at 100℃ for 6 hours at 200 rpm. Then add 120g of deionized water to the flask and mix at 80℃ for 30 minutes at 200 rpm. After recrystallization twice, the product is dried to obtain the final product, urethane diol (ECUD).

[0022] Step 2: Add 10g of urethane diol (ECUD) and 42.8g of polypropylene carbonate diol (PPCD) to a flask and mix well. React at 200r / min under vacuum (pressure less than 500pa) at 180℃ for 1h to obtain non-isocyanate polyurethane (NIPU).

[0023] Step 3: Add 50g of the non-isocyanate polyurethane obtained in step (2) to a flask and mix it evenly with 40g of N,N-dimethylformamide (DMF). Add 0.1g of hydroquinone (HQ), 0.1g of 4-dimethylaminopyridine (DMAP), 4.53g of triethylamine (HEA), and 5.92g of methacrylic anhydride (MAAH) and mix evenly. React at room temperature for 48h at a speed of 200r / min. After purification, dry in a vacuum oven at 80℃ for 24h to remove the solvent and obtain the reaction product, non-isocyanate polyurethane acrylate (NIPUA).

[0024] Example 2

[0025] This embodiment provides a flexible ion-conducting elastomer, the preparation method of which is as follows:

[0026] (1) Take 14g of non-isocyanate polyurethane acrylate (NIPUA) and 6g of hydroxyethyl acrylate (HEMA) and add them to a beaker. Mix at 200r / min and 60℃ for 1h. Then add 0.8g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and continue stirring for 30min to mix evenly to obtain photosensitive resin.

[0027] (2) Take 5g of the photosensitive resin obtained in step (1) and add it to a beaker. Add 0.6g of lithium bis(trifluoromethanesulfonylimide) (LiTFSI) and 1.25g of succinate (SN) and sonicate for 30min to mix the liquid evenly to obtain a flexible ion-conductive elastomer precursor solution.

[0028] (3) Pour the precursor solution obtained in step (2) into a rectangular strip-shaped polytetrafluoroethylene mold (60×10×1mm). 3In the process, a photopolymerization reaction was carried out by irradiating the solution with a UV lamp with a wavelength of 365nm and a power of 3W for 5 minutes to obtain a flexible ion-conductive elastomer.

[0029] Example 3

[0030] This embodiment provides a flexible ion-conducting elastomer, the preparation method of which is as follows:

[0031] (1) Take 10g of non-isocyanate polyurethane acrylate (NIPUA) and 10g of hydroxyethyl acrylate (HEMA) and add them to a beaker. Mix at 200r / min and 60℃ for 1h. Then add 0.8g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and continue stirring for 30min to mix evenly to obtain photosensitive resin.

[0032] (2) Take 5g of the photosensitive resin obtained in step (1) and add it to a beaker. Add 0.6g of lithium bis(trifluoromethanesulfonylimide) (LiTFSI) and 1.25g of succinate (SN) and sonicate for 30min to mix the liquid evenly to obtain a flexible ion-conductive elastomer precursor solution.

[0033] (3) Pour the precursor solution obtained in step (2) into a rectangular strip-shaped polytetrafluoroethylene mold (60×10×1mm). 3 In the process, a photopolymerization reaction was carried out by irradiating the solution with a UV lamp with a wavelength of 365nm and a power of 3W for 5 minutes to obtain a flexible ion-conductive elastomer.

[0034] Example 4

[0035] This embodiment provides a flexible ion-conducting elastomer, the preparation method of which is as follows:

[0036] (1) Take 6g of non-isocyanate polyurethane acrylate (NIPUA) and 14g of hydroxyethyl acrylate (HEMA) and add them to a beaker. Mix at 200r / min and 60℃ for 1h. Then add 0.8g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and continue stirring for 30min to mix evenly to obtain photosensitive resin.

[0037] (2) Take 5g of the photosensitive resin obtained in step (1) and add it to a beaker. Add 0.6g of lithium bis(trifluoromethanesulfonylimide) (LiTFSI) and 1.25g of succinate (SN) and sonicate for 30min to mix the liquid evenly to obtain a flexible ion-conductive elastomer precursor solution.

[0038] (3) Pour the precursor solution obtained in step (2) into a rectangular strip-shaped polytetrafluoroethylene mold (60×10×1mm). 3In the process, a photopolymerization reaction was carried out by irradiating the solution with a UV lamp with a wavelength of 365nm and a power of 3W for 5 minutes to obtain a flexible ion-conductive elastomer.

[0039] Example 5

[0040] This embodiment provides a flexible ion-conducting elastomer, the preparation method of which is as follows:

[0041] (1) Take 10g of non-isocyanate polyurethane acrylate (NIPUA) and 10g of hydroxyethyl acrylate (HEMA) and add them to a beaker. Mix at 200r / min and 60℃ for 1h. Then add 0.8g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and continue stirring for 30min to mix evenly to obtain photosensitive resin.

[0042] (2) Take 5g of the photosensitive resin obtained in step (1) and add it to a beaker. Add 0.45g of lithium bis(trifluoromethanesulfonylimide) (LiTFSI) and 1.25g of succinate (SN) and sonicate for 30min to mix the liquid evenly to obtain a flexible ion-conductive elastomer precursor solution.

[0043] (3) Pour the precursor solution obtained in step (2) into a rectangular strip-shaped polytetrafluoroethylene mold (60×10×1mm). 3 In the process, a photopolymerization reaction was carried out by irradiating the solution with a UV lamp with a wavelength of 365nm and a power of 3W for 5 minutes to obtain a flexible ion-conductive elastomer.

[0044] Example 6

[0045] This embodiment provides a flexible ion-conducting elastomer, the preparation method of which is as follows:

[0046] (1) Take 10g of non-isocyanate polyurethane acrylate (NIPUA) and 10g of hydroxyethyl acrylate (HEMA) and add them to a beaker. Mix at 200r / min and 60℃ for 1h. Then add 0.8g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and continue stirring for 30min to mix evenly to obtain photosensitive resin.

[0047] (2) Take 5g of the photosensitive resin obtained in step (1) and add it to a beaker. Add 0.75g of lithium bis(trifluoromethanesulfonylimide) (LiTFSI) and 1.25g of succinate (SN) and sonicate for 30min to mix the liquid evenly to obtain a flexible ion-conductive elastomer precursor solution.

[0048] (3) Pour the precursor solution obtained in step (2) into a rectangular strip-shaped polytetrafluoroethylene mold (60×10×1mm). 3In the process, a photopolymerization reaction was carried out by irradiating the solution with a UV lamp with a wavelength of 365nm and a power of 3W for 5 minutes to obtain a flexible ion-conductive elastomer.

[0049] The performance test results of Examples 2 to 6 are shown in the table, see Table 1 for details.

[0050] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

[0051] Table 1. Room temperature performance tests of non-isocyanate polyurethane acrylate-based flexible ion-conducting elastomers.

[0052]

[0053] Table 2 Performance tests at different temperatures in Example 3

[0054]

Claims

1. A non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer, characterized in that, The raw material components include the following parts by weight: 15-65 parts of non-isocyanate polyurethane acrylate, 15-65 parts of reactive diluent, 2-4 parts of photoinitiator, 5-15 parts of lithium salt, and 10-20 parts of additives; The preparation steps of the non-isocyanate polyurethane acrylate are as follows: Step 1: Add ethylene carbonate and aliphatic diamine to a flask and react at 80℃~120℃ for 4~6 hours at a speed of 200r / min. Then recrystallize from deionized water to obtain urethane diol. Step 2: Add urethane diol and polycarbonate diol or polyether diol with a molecular weight of 400~5000 to a flask and mix them evenly at 100°C. Then, react them under vacuum at 180°C for 1 hour at a speed of 200r / min to obtain non-isocyanate polyurethane. Step 3: Add acrylic anhydride compounds, triethylamine, polymerization inhibitor and catalyst to the non-isocyanate polyurethane obtained in step 2 and mix evenly in the solvent. Then react at room temperature for 48 hours at a speed of 200 r / min. After purification, dry in a vacuum oven at 80℃ for 24 hours to remove the solvent and obtain the reaction product non-isocyanate polyurethane acrylate. The additive is one or more of succinic anhydride, tributyl citrate, and fumed silica.

2. The non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer according to claim 1, characterized in that, The reactive diluent is one or more of isobornyl methacrylate, isobornyl acrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, 1,6-hexanediol diacrylate, diethylene glycol ethyl ether acrylate, and trimethylolpropane triacrylate; the photoinitiator is one or more of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxymethylphenylpropane-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, benzophenone, 2-phenyl-2,2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, and 1-hydroxycyclohexylphenylacetone; the lithium salt is one or more of lithium bis(trifluoromethanesulfonylimide), lithium bis(fluorosulfonylimide), and lithium perchlorate.

3. A method for preparing the non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer according to claim 1 or 2, characterized in that, The preparation steps include the following: Step 1: Add ethylene carbonate and aliphatic diamine to a flask and react at 80℃~120℃ for 4~6 hours at a speed of 200r / min. Then recrystallize from deionized water to obtain urethane diol. Step 2: Add urethane diol and polycarbonate diol or polyether diol with a molecular weight of 400~5000 to a flask and mix them evenly at 100°C. Then, react them under vacuum at 180°C for 1 hour at a speed of 200r / min to obtain non-isocyanate polyurethane. Step 3: Add acrylic anhydride compounds, triethylamine, polymerization inhibitor and catalyst to the non-isocyanate polyurethane obtained in step 2 and mix evenly in the solvent. Then react at room temperature for 48 hours at a speed of 200 r / min. After purification, dry in a vacuum oven at 80℃ for 24 hours to remove the solvent and obtain the reaction product non-isocyanate polyurethane acrylate. Step 4: Add the reactive diluent, photoinitiator, lithium salt, and additives to the non-isocyanate polyurethane acrylate reaction product obtained in Step 3. Stir at room temperature for 1 hour at 200 r / min to mix evenly and obtain the final product, a flexible ion-conductive elastomer precursor solution. Then, perform photopolymerization reaction under 3W ultraviolet light to obtain the flexible ion-conductive elastomer.

4. The method for preparing the non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer according to claim 3, characterized in that... : In step 1, the molar mass ratio of ethylene carbonate to aliphatic diamine is 2~2.5:1; the aliphatic diamine includes one or more of 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, isophoronediamine, and 4,4-diaminodicyclohexylmethane.

5. The method for preparing the non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer according to claim 3, characterized in that... : In step 2, the molar ratio of urethane diol to polycarbonate diol or polyether diol is 2 to 7:1; the polycarbonate diol and polyether diol include one or more of polypropylene carbonate diol, polyethylene carbonate diol, polyethylene glycol, polypropylene glycol, and polytetrahydrofuran diol.

6. The method for preparing the non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer according to claim 3, characterized in that... : In step 3, the mass ratio of non-isocyanate polyurethane, solvent, acrylic anhydride compound, triethylamine, polymerization inhibitor, and catalyst is 50:40:(4~8):(2~6):0.1:0.1; the acrylic anhydride compound includes one or more of acrylic anhydride and methacrylic anhydride; the solvent is one or more of N,N-dimethylformamide and dichloromethane; the polymerization inhibitor is one or more of hydroquinone and p-hydroxyanisole; and the catalyst is 4-dimethylaminopyridine.

7. The method for preparing a non-isocyanate polyurethane acrylate-based flexible ion-conductive elastomer according to claim 3, characterized in that... : In step 4, the mass ratio of non-isocyanate polyurethane acrylate, reactive diluent, photoinitiator, lithium salt, and additives is (15~65):(15~65):(2~4):(5~15):(10~20).

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