Preparation method of double-bond-containing piperidine functional monomer and cationic resin thereof

Abstract

The invention belongs to the field of high polymer materials, and relates to a double-bond-containing piperidine functional monomer and a preparation method of cationic resin thereof. The method comprises the following steps: reacting a monomer reagent with a tertiary amine piperidine monomer to generate a double bond-containing piperidine functional monomer; mixing an initiator, a dispersing agent and the prepared one or more double-bond-containing piperidine functional monomers to obtain a mixed solution, and preparing the homopolymerized cationic resin containing the double-bond-containing piperidine functional monomers or the blended cationic resin containing the double-bond-containing piperidine functional monomers through a polymerization reaction method. The obtained double-bond piperidine functional monomer can be subjected to homopolymerization reaction to obtain piperidine cationic resin, and the problems of compatibility of different monomers and monomer activity difference do not need to be solved; the obtained resin has relatively high chemical stability and good ionic conductivity, an electron donating group can further improve the stability of a six-membered ring piperidine cation group, the service life of the material is prolonged, and an important raw material is provided for further research and application of anion exchange membranes AEMs.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high polymer materials, and relates to a preparation method of a kind of double bond piperidine functional monomer and its cationic resin. BACKGROUND

[0002] Cationic resin is a kind of high polymer functional material capable of conducting and exchanging anion groups, one of important uses is to prepare anion exchange membrane (AEM) for fuel cell, electrodialysis, bipolar membrane, hydrogen production by electrolysis of water, catalytic reduction of carbon dioxide and high-efficiency separation field in chemical industry. The cationic group in cationic resin is the key to ion conduction, and the stability of its structure plays a decisive role in the stability and effectiveness of AEM. However, most of the cationic groups, such as quaternary amine groups, imidazole groups, pyridine groups, etc. are easily attacked by OH- or OH free radicals, thereby aggravating the degradation of the resin (Energy Environ. Sci., 2014, 7, 3135). Therefore, the research direction of AEM has shifted to polymers containing stable cationic group structures.

[0003] In recent years, piperidine cationic groups have attracted widespread attention in the field of AEMs due to their unique six-membered ring structure and steric hindrance effect (Angew. Chem. Int. Ed. 2023, e202307690; Acc. Chem. Res. 2025, 58, 688−702). This is because the low ring strain of piperidine cation and the conformational constraint imposed by the ring structure increase the transition state energy of substitution and elimination reactions during degradation, resulting in higher chemical stability.

[0004] Currently, the common synthesis strategy for piperidine-containing cationic resins is to perform polycondensation or copolymerization of piperidine-containing tertiary amine monomers with other monomers, and then perform post-modification to obtain the target product. For example, Chinese patent CN114524912A copolymerizes biphenyl with -methyl piperidone, and then performs quaternization reaction to obtain a piperidine cationic resin; Chinese patent CN112175217A copolymerizes arylidene piperidine with diketone monomers, and then performs quaternization reaction with iodomethane to obtain a cationic resin. However, there are great differences in reaction activity, physical compatibility and initiator matching among the various monomers involved in the polycondensation or copolymerization process, resulting in great difficulties in reaction kinetics control, molecular weight distribution and process control; in addition, multiple chemical reactions and the use of toxic and harmful reagent iodomethane are often required in the post-modification process, which further increases the promotion and application of piperidine cationic resin and AEMs. Therefore, how to solve this trade-off dilemma is an important content of the research on piperidine cationic resin and AEMs. SUMMARY

[0005] In order to overcome the defects of the prior art, the application provides a preparation method of a double-bond-containing piperidine functional monomer and a cationic resin thereof.

[0006] The object of the application can be achieved by the following technical solutions. A double-bond-containing piperidine functional monomer has a structural formula as follows:

[0007] Formula (I) The structure of formula (I) comprises a double-bond structure unit of an A unit, an electron-donating linking unit of a B unit and a piperidine cation unit of a C unit.

[0008] n is an integer of 0-5; preferably, n is 0 or 1; n represents the number of double-bond piperidine functional groups connected after Ar2. In particular, when n is 0, it means that only one double-bond piperidine functional monomer is contained; Y is one of F, Cl, Br and I.

[0009] M1-M3 are independently selected from one of -H, -OH, -CH3, -OCH3, -Ph (Ph represents a benzene ring), -OPh, -Cl, -CH2Cl and -CH2CH3; Ar1 is one of a cycloalkyl group composed of 4-7 carbon atoms, an alkyl group containing 1-20 carbon atoms, a hydrocarbon group containing 1-20 carbon atoms, and a completely or partially fluorinated alkyl group containing 1-6 carbon atoms; Ar2 contains one or more piperidine cation groups.

[0010] Preferably, when n=0, the monomer has a structural formula as follows: ; Formula (II) When n=1, the monomer has a structural formula as follows:

[0011] Formula (III).

[0012] Preferably, the structure of the piperidine cation group is as shown in formula IV.

[0013] Formula (IV).

[0014] Further preferably, the structure of the piperidine cation group is selected from one of formula V:

[0015] Formula (V).

[0016] The application also provides a preparation method of the above-mentioned double-bond-containing piperidine functional monomer, which comprises the following steps: reacting a monomer reagent containing a double bond and a halomethyl group -CH2Y with a tertiary amine piperidine monomer in a solvent, washing the unreacted monomer in a precipitant multiple times after the reaction is completed, and drying to obtain the target product shown in formula (I).

[0017] Preferably, the solvent is a mixture of one or more of water, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, ethanol, isopropanol, acetonitrile, dimethyl sulfoxide or ethyl acetate; and the precipitant is a mixture of one or more of diethyl ether, chloroform, acetone, cyclohexane, n-hexane or ethyl acetate.

[0018] Preferably, Y in the halomethyl group in the monomer reagent is one of F, Cl, Br and I.

[0019] Preferably, the molar ratio of the monomer reagent to the tertiary amine piperidine monomer is 1-20:1-20, preferably 1-5:1-10; and the mass-volume ratio of the monomer reagent to the solvent is 1:1-35 g / mL, further preferably 1:1-25 g / mL, and most preferably 1:1-20 g / mL.

[0020] Preferably, the reaction requires a temperature of 0-150°C, further preferably 0-50°C, and a reaction time of 1-48 hours, further preferably 1-15 hours.

[0021] Preferably, the tertiary amine piperidine monomer contains one or more tertiary amine piperidine structures, which are shown in formula VI.

[0022] Formula (VI) Further preferably, the tertiary amine piperidine structure is selected from one of the structures shown in formula VII.

[0023] Formula (VII).

[0024] The application also provides a preparation method of a cationic resin containing a piperidine group, which comprises mixing an initiator, a dispersant and the above-mentioned double-bond-containing piperidine functional monomer to obtain a mixed solution, and preparing the cationic resin containing the piperidine group through a polymerization reaction.

[0025] Preferably, in the preparation method, the double-bond-containing piperidine functional monomer can be one or more, wherein the initiator, the dispersant and one double-bond-containing piperidine functional monomer are mixed to prepare a homopolymer cationic resin containing the piperidine group; and the initiator, the dispersant and multiple double-bond-containing piperidine functional monomers are mixed to prepare a blended cationic resin containing the piperidine group.

[0026] According to the present application, the number average molecular weight of the cationic resin containing piperidine group is preferably 1.2-12 million, further preferably 2.5-6 million, and most preferably 2.5-3.5 million; the ion exchange capacity is 0.5-4.0 mmol / g, further preferably 0.8-2.5 mmol / g, and most preferably 0.90-2.3 mmol / g.

[0027] Preferably, the mass ratio of the double-bonded piperidine functional monomer to the dispersant is 1:1-35; further preferably 1:1-25; and most preferably 1:1-20; and the mass ratio of the double-bonded piperidine functional monomer to the initiator is 1-100:1; and most preferably 50-80:1.

[0028] Preferably, the initiator comprises one or more of benzoyl peroxide, azo compounds, and persulfate.

[0029] Preferably, the dispersant is at least one of N,N-dimethylformamide, deionized water, an alcohol / water mixed solvent, N,N-dimethylacetamide, N-methylpyrrolidone, toluene, dichloromethane, trichloromethane, tetrahydrofuran, ethanol, n-propanol, isopropanol, dimethyl sulfoxide, or ethyl acetate.

[0030] Further preferably, the dispersant is one of N,N-dimethylformamide, N,N-dimethylacetamide, ethanol, and n-propanol; and the alcohol / water mixed solvent, in which the alcohol is one of ethanol, n-propanol, and isopropanol, and the volume ratio of the alcohol / water mixed solvent is 1:1-3.

[0031] Preferably, the polymerization reaction comprises emulsion polymerization, suspension polymerization, and aqueous solution polymerization.

[0032] Further preferably, the aqueous solution polymerization method uses deionized water as the dispersant, and specifically comprises: slowly heating the mixed solution of step (2) to 45-135℃, and reacting for 1-48 hours under mechanical stirring; after the reaction is completed, cooling to room temperature and performing post-treatment, and drying to obtain the double-bonded piperidine cationic resin.

[0033] Further preferably, the emulsion polymerization method specifically comprises: adding an emulsifier to the mixed solution of step (2) and slowly heating to 45-80℃, and the mass ratio of the emulsifier to the monomer is 1-20 wt%; and reacting for 1-48 hours under mechanical stirring; after the reaction is completed, the emulsion is washed in acetone or ethanol to break the emulsion, remove the emulsifier and unreacted monomers, and dry to obtain the double-bonded piperidine cationic resin.

[0034] More preferably, the emulsifier is one or more of ammonium perfluorooctanoate, sodium dodecyl sulfate, and cetyltrimethylammonium bromide.

[0035] The application also provides a cationic resin containing a piperidyl group prepared according to the above method, having a structure shown in formula (VIII) or formula (IX):

[0036] Formula (VIII)

[0037] Formula (IX) wherein Y is one of F, Cl, Br and I, and m is a natural number greater than or equal to 50; M1-M3 are independently selected from one of -H, -OH, -CH3, -OCH3, -Ph, -OPh, -Cl, -CH2Cl and -CH2CH3; Ar1 is one of a cycloalkyl group containing 4 to 7 carbon atoms, an alkyl group containing 1 to 20 carbon atoms, a hydrocarbon group containing 1 to 20 carbon atoms, and a completely or partially fluorinated alkyl group containing 1 to 6 carbon atoms; Ar2 contains one or more piperidyl cation groups; Formula (VIII) is a structure formula of a homopolymer cationic resin prepared using a double-bond-containing piperidyl functional monomer and when n in the structure formula of the monomer is 0; Formula (IX) is a structure formula of a homopolymer cationic resin prepared using a double-bond-containing piperidyl functional monomer and when n in the structure formula of the monomer is 1.

[0038] Preferably, the obtained monomer or the obtained ion resin is selected to be subjected to an alkali treatment to complete ion exchange according to the type of counter ion carried by the cationic unit. When the type of counter ion is F-, Cl-, Br- or I-, the alkali treatment can be performed to exchange OH-; the alkali treatment process is to immerse the obtained ion resin in a 2M KOH solution for 24 to 48 hours to completely convert the counter ion into OH-.

[0039] The application also provides application of the above cationic resin in one or more of the following: 1) application in manufacturing fuel cells; 2) application in preparing membrane electrodes for alkaline electrolytic water; 3) application in electrodialysis; 4) application in seawater desalination; 5) application in antibacterial materials; and 6) application in sewage treatment.

[0040] Compared with the prior art, the application has the following beneficial effects: (1) The double-bond-containing piperidyl functional monomer contains a double-bond active functional group, an electron-donating linking group and a piperidyl cation group, and compared with the existing synthesis process of a piperidyl cation resin, the obtained double-bond piperidyl functional monomer can be subjected to a homopolymerization reaction to obtain a piperidyl cation resin, and there is no need to deal with the compatibility of different monomers and the difference in monomer activity.

[0041] (2) The resin prepared by the method of the present application does not need a post-modification reaction, avoids the use of toxic solvents such as methyl iodide, and does not use a catalyst in the reaction process, so that the introduction of cations is more effective, green and environmentally friendly, and the synthesis process is simple and effective. The obtained resin has high chemical stability and good ionic conductivity, and the electron-donating group can further improve the stability of the six-membered ring piperidine cation group and prolong the service life of the material, providing important raw materials for the further research and application of AEMs.

[0042] (3) The resin obtained by the present application has a high ion exchange capacity (0.5-4.0 mmol / g); the cationic resin synthesized by the present application can control the ion exchange capacity of the resin by adjusting the structure of the double bond piperidine functional monomer.

[0043] (4) The cationic resin prepared by the present application has a retention rate of ion exchange capacity (IEC) of up to 93% or more after 600h of base decay test, proving that the obtained resin has a high ability to resist the attack of hydroxyl ions.

[0044] (5) The present application can control the n value of the monomer structure by controlling the molar ratio of the monomer reagent to the tertiary amine piperidine monomer, the reaction temperature and the reaction time; the ion exchange capacity of the resin can be controlled by selecting the values of m and n, the types of the monomer reagent and the tertiary amine piperidine monomer according to the performance requirements of the product.

[0045] (6) The monomer prepared by the present application can be directly subjected to bulk polymerization, effectively avoiding the complex problems caused by the copolymerization of multiple monomers. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 A is the nuclear magnetic spectrum of the target product A1 in Example 1; Figure 1 B is the nuclear magnetic spectrum of the target product A5 in Example 5. DETAILED DESCRIPTION

[0047] The present application will be described in detail below in conjunction with specific examples, which are only used to illustrate the present application and not to limit the protection scope of the present application. The present application is not limited to the following several embodiments, and other combination schemes derived from the present application also belong to the protection scope of the present application. The raw materials and reagents involved in the examples, if not specifically stated, are all ordinary commercially available products; the experimental methods involved in the examples, if not specifically stated, are all conventional technical means in the art.

[0048] The wavy line of the present application represents an alkyl chain or a perfluoroalkyl chain of any length, and the length is illustrative and does not represent the actual length; Ph in the present application represents a benzene ring.

[0049] In this embodiment, a 6M KOH attenuation experiment was used to accelerate the attack on the target product in order to examine its chemical stability. The chemical stability of the target product was evaluated by measuring the retention rate (RV%) of the ion exchange capacity (IEC) before and after the attenuation experiment.

[0050] The specific conditions for the alkali decay experiment were as follows: the target product was immersed in a 6M KOH solution and maintained at 80℃ for 500h. During this period, the KOH solution was replaced every 3h. After the experiment, the product was taken out and washed multiple times with deionized water, and finally dried at 60℃ for 4h.

[0051] Titration of ion exchange capacity (IEC): Accurately weigh a certain weight of the dry target product, then perform ion exchange with an aqueous solution of NaCl with a concentration of approximately 1M for more than 12 hours. Collect the solution after ion exchange, and titrate with 0.1M NaOH standard solution using phenolphthalein as an indicator until the solution turns pink. The ion exchange capacity (IEC) value of the target product can be calculated according to the following formula: IEC = (V) NaOH ×C NaOH ) / m In the formula: V NaOH —Volume of NaOH standard solution consumed, mL; C NaOH — Molar concentration of NaOH standard solution, mmol / mL; m — Mass of the target product, g.

[0052] Ion exchange capacity (IEC) retention rate: RV% = (IEC1 - IEC0) / IEC0 In the formula: IEC1 and IEC0 represent the ion exchange capacity (IEC) of the target product before and after the Fenton experiment, respectively.

[0053] Determination of the average molecular weight of resin: The average molecular weight was determined using a PL-220 high-temperature gel permeation chromatograph, and the average molecular weight was obtained by measuring the weight-average molecular weight of the polymer.

[0054] Example 1 The synthesis of a piperidine functional monomer containing a double bond involves reacting 4-chloromethylstyrene with a tertiary amine piperidine monomer (N-methylpiperidine) to synthesize the target product. The specific steps are as follows: After cleaning a 100mL sealed reaction vessel, evacuating it three times with high-purity nitrogen, add 1.0g of 4-chloromethylstyrene and 20mL of acetonitrile. Turn on the stirrer and wait until the mixture is completely dissolved. Then add 3.2g of N-methylpiperidine, with a molar ratio of approximately 1:5 between 4-chloromethylstyrene and N-methylpiperidine. After the addition is complete, the reaction is carried out at 0℃ with stirring. The reaction is completed after 6 hours. The unreacted monomer is removed by washing repeatedly in diethyl ether, and the product is dried at room temperature to obtain the target product, denoted as A1. The reaction formula is as follows:

[0055] The target product was subjected to NMR spectroscopy to confirm its structural composition. Figure 1 A1 in this invention ( Figure 1 The proton NMR spectrum of A) shows that for A1, the chemical shifts at 7.0–8.0 ppm are attributed to the proton characteristic peaks of the benzene ring in the product; 5.0–7.0 ppm are attributed to the characteristic peaks of the double bond; 4.3 ppm is the -CH2 proton on the chloromethyl group; and 1.0–4.0 ppm are the proton peaks on the piperidine ring. These positions are attributed to the reference European Polymer Journal 173 (2022) 111271. The above results prove that the target monomer A1 was successfully synthesized through the reaction.

[0056] Example 2 The synthesis of a piperidine functional monomer containing a double bond involves reacting 4-chloromethylstyrene with a tertiary amine piperidine monomer (1,4-dimethylpiperazine) to synthesize the target product. The specific steps are as follows: After cleaning a 100mL sealed reaction vessel, evacuating it three times with high-purity nitrogen, add 1.0g of 4-chloromethylstyrene and 20mL of acetonitrile. Turn on the stirrer and wait for complete dissolution. Then add 4.5g of 1,4-dimethylpiperazine, with a molar ratio of approximately 1:6 between 4-chloromethylstyrene and 1,4-dimethylpiperazine. After the addition is complete, the reaction is carried out at 0℃ with stirring. The reaction is completed after 6 hours. Unreacted monomers are removed by washing repeatedly in diethyl ether, and the product is dried at room temperature to obtain the target product, denoted as A2. The reaction formula is as follows:

[0057] Example 3 The synthesis of a piperidine functional monomer containing a double bond involves reacting allyl chloride as a monomeric reagent with a tertiary amine piperidine monomer (N-methylpiperidine) to synthesize the target product. The specific steps are as follows: A sealed 100 mL reactor was washed, vacuumed and filled with high purity nitrogen three times, then 1 g of allyl chloride and 20 ml of ethanol were added, the stirring device was turned on, and after complete dissolution, 6.48 g of N-methylpiperidine was added, the molar ratio of allyl chloride to N-methylpiperidine was about 1:5; after the addition was completed, the reaction was carried out at 0°C under stirring, and after 6 h, the reaction was completed, unreacted monomers were removed by washing in acetone multiple times, and the target product was obtained by drying at room temperature, which was recorded as A3, and the reaction formula was as follows:

[0058] Example 4 A kind of double bond piperidine functional monomer containing synthesis, allyl chloride and tertiary amine piperidine monomer (1,4-dimethylpiperazine) were selected to react to synthesize target product, and the specific steps were as follows: A sealed 100 mL reactor was washed, vacuumed and filled with high purity nitrogen three times, then 1.0 g of allyl chloride and 25 ml of acetonitrile were added, the stirring device was turned on, and after complete dissolution, 11.9 g of 1,4-dimethylpiperazine was added, the molar ratio of allyl chloride to 1,4-dimethylpiperazine was about 1:8; after the addition was completed, the reaction was carried out at 0°C under stirring, and after 10 h, the reaction was completed, unreacted monomers were removed by washing in diethyl ether multiple times, and the target product was obtained by drying at room temperature, which was recorded as A4, and the reaction formula was as follows:

[0059] Example 5 A kind of double bond piperidine functional monomer containing synthesis, allyl chloride and tertiary amine piperidine monomer (A5) were selected to react to synthesize target product, and the specific steps were as follows: First, a sealed 100 mL reactor was washed, vacuumed and filled with high purity nitrogen three times, then 10.5 g of 1-methylpiperazine and 25 ml of acetonitrile were added, the stirring device was turned on, and after complete dissolution, 1,6-hexanediamine was added, the molar ratio of 1-methylpiperazine to 1,6-hexanediamine was about 8:1; after the addition was completed, the reaction was carried out at 60°C for 12 h, and then the reaction was completed, unreacted monomers were removed by washing in diethyl ether multiple times, and the tertiary amine piperidine monomer A5 was obtained by drying at room temperature; then, the target product was synthesized according to the steps of Example 4, except that A5 was used instead of 1,4-dimethylpiperazine to react, and the reaction formula was as follows:

[0060] Example 6 A kind of synthesis of homopolymer cationic resin containing piperidine group, 100mL closed reaction kettle is washed and vacuumed and replaced by high-purity nitrogen three times, then 50ml of deionized water is added, and 5g A1, 0.5g benzoyl peroxide initiator is added, after completing feeding, temperature is raised to 60℃, and 10 hours are reacted by aqueous solution polymerization under mechanical stirring. After the reaction is finished, it is cooled to room temperature, and a resin solution is obtained by washing with acetone to remove unreacted monomer and initiator, and a cationic resin based on double bond piperidine functional monomer is obtained by drying, which is denoted as A7, and the reaction formula is as follows:

[0061] The target product is tested by nuclear magnetic test to confirm the structure composition, Figure 1 The hydrogen nuclear magnetic spectrum of A5 (B) in the application, Figure 1 Compared with monomer A1, A5 shows obvious polymer nuclear magnetic characteristic bulge peak, the characteristic peak of the protons of the polymer main chain is attributed to the chemical shift at 6.0~7.0 ppm; 7.0~8.0 ppm is attributed to the characteristic peak of benzene ring on the side chain; the -CH2 protons on the chloromethyl are at 4.3 ppm; 1.0~4.0 ppm is the proton peak on the piperidine ring; the above results prove that the target resin A5 is successfully synthesized by polymerization reaction.

[0062] Through ion exchange capacity (IEC) determination, the IEC of the obtained target product A5 resin is 1.40 mmol / g. The molecular weight is 250,000. After the obtained resin is tested by base attenuation test for 600h, the ion exchange capacity retention rate is 93.6%, which proves that the obtained ion resin has high resistance to hydroxyl attack.

[0063] Example 7 A kind of synthesis of homopolymer cationic resin containing piperidine group, the operation process and method of this embodiment refer to example 6, the difference is only that: A2 monomer in example 2 is selected to carry out polymerization reaction, in addition, initiator uses azo compound, and polymerization reaction is maintained at 75℃, and the resin as shown in A8 structure can be obtained, and the reaction formula is as follows:

[0064] Through IEC determination, the IEC of the obtained target resin is 1.80 mmol / g. The molecular weight is 270,000. After the obtained resin is tested by base attenuation test for 600h, the ion exchange capacity retention rate is 93.5%.

[0065] Example 8 A homopolymer cation resin containing a piperidine group was synthesized according to the procedure and method of Example 6, except that the A3 monomer of Example 3 was used for the polymerization reaction, and ammonium perfluorooctanoate was added as an emulsifier for emulsion polymerization, with a mass ratio of emulsifier to monomer of 2 wt%, and the polymerization reaction was maintained at 75°C. After the reaction was completed, the emulsion was broken by an ethanol solution, washed, and the emulsifier and unreacted monomer were removed, and the product was recorded as A9, and the reaction formula is as follows:

[0066] The IEC of the target resin obtained was 2.20 mmol / g by IEC determination. The molecular weight was 300,000. The ion exchange capacity retention rate of the obtained resin was 93.7% after 600 h of base decay test.

[0067] Example 9 A homopolymer cation resin containing a piperidine group was synthesized according to the procedure and method of Example 6, except that the A4 monomer of Example 4 was used for the polymerization reaction, and one time the mass of A4 monomer was added after 10 h of polymerization reaction, and the polymerization time was extended to 20 h, to obtain the product shown as A10, and the reaction formula is as follows:

[0068] The IEC of the target resin obtained was 2.50 mmol / g by IEC determination. The molecular weight was 360,000. The ion exchange capacity retention rate of the obtained resin was 93.3% after 600 h of base decay test.

[0069] Example 10 A homopolymer cation resin containing a piperidine group was synthesized according to the procedure and method of Example 6, except that the A6 monomer of Example 5 was used for the polymerization reaction, and two times the mass of A6 monomer was added after 10 h of polymerization reaction, and the polymerization time was extended to 20 h. The IEC of the target resin obtained was 3.00 mmol / g by IEC determination. The molecular weight was 300,000. The ion exchange capacity retention rate of the obtained resin was 93.6% after 600 h of base decay test.

[0070] Example 11 A blended cation resin containing a piperidine group was synthesized according to the procedure and method of Example 6, except that the A1 monomer of Example 1 and the A2 monomer of Example 2 were mixed for the polymerization reaction, and the molar mass ratio of A1 to A2 was 10:1. The monomers were mixed to carry out the polymerization reaction. The IEC of the target resin obtained was 1.60 mmol / g through IEC determination. The molecular weight was 260,000. The retention rate of ion exchange capacity of the resin obtained was 93.7% after 600 h of the base attenuation test.

[0071] Example 12 The synthesis of a blended cation resin containing a piperidine group, the operation process and method of the present example refer to Example 6, the only difference is that the A1 monomer in Example 1 and the A6 monomer in Example 5 are mixed to carry out the polymerization reaction, and the molar mass ratio of A1 to A6 is 10:2. The monomers were mixed to carry out the polymerization reaction. The IEC of the target resin obtained was 1.60 mmol / g through IEC determination. The molecular weight was 260,000. The retention rate of ion exchange capacity of the resin obtained was 93.7% after 600 h of the base attenuation test.

Claims

1. A class of piperidine functional monomers containing double bonds, characterized in that, The structural formula of the monomer is: Formula (I) The structure of formula (I) includes a double bond unit A, an electron-donating connection unit B, and a piperidine cation unit C. Where n is an integer from 0 to 5, and Y is one of F, Cl, Br, and I; M1 to M3 are independently selected from one of -H, -OH, -CH3, -OCH3, -Ph, -OPh, -Cl, -CH2Cl, and -CH2CH3; Ar1 is one of the following: a cycloalkyl group consisting of 4 to 7 carbon atoms, an alkyl group containing 1 to 20 carbon atoms, a hydrocarbon group containing 1 to 20 carbon atoms, or a fully or partially fluorinated alkyl group containing 1 to 6 carbon atoms; Ar2 contains one or more piperidine cationic groups.

2. The functional unit according to claim 1, characterized in that, The n is 0 or 1; Preferably, when n=0, the monomer structure is: Formula (II); When n=1, the monomer structure is: Formula (III); Preferably, the piperidine cationic group structure is shown in Formula IV: Formula (IV); More preferably, the piperidine cationic group structure is selected from one of formula V: Formula (V).

3. The method for preparing the functional monomer according to any one of claims 1 to 2, characterized in that, A monomeric reagent containing a double bond and a halomethyl group -CH2Y reacts with a tertiary amine piperidine monomer in a solvent. After the reaction is complete, the unreacted monomer is removed by washing repeatedly in a precipitant and then dried to obtain the target product shown in formula (I).

4. The method for preparing the functional monomer according to claim 3, characterized in that, The Y in the halomethyl group of the monomer reagent is one of F, Cl, Br, and I; the solvent is one or a mixture of water, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, ethanol, isopropanol, acetonitrile, dimethyl sulfoxide, or ethyl acetate; the precipitant is one or a mixture of diethyl ether, chloroform, acetone, cyclohexane, n-hexane, or ethyl acetate; the tertiary amine piperidine monomer contains one or more tertiary amine piperidine structures, the structure of which is shown in Formula VI: Formula (VI); Preferably, the tertiary amine piperidine structure is selected from one of the structures shown in Formula VII: Equation (VII).

5. The method for preparing the functional monomer according to claim 3, characterized in that, The molar ratio of the monomeric reagent to the tertiary amine piperidine monomer is 1~20:1~20, preferably 1~5:1~10; The reaction requires a temperature of 0~150℃, preferably 0~50℃; The reaction time is 1 to 48 hours, preferably 1 to 15 hours; The mass-to-volume ratio of the monomer reagent to the solvent is 1:1 to 35 g / mL; preferably 1:1 to 25 g / mL; and more preferably 1:1 to 20 g / mL.

6. A method for preparing a cationic resin containing piperidine groups, characterized in that, A mixed solution is prepared by mixing an initiator, a dispersant, and a piperidine functional monomer containing double bonds as described in any one of claims 1 to 5, and then a cationic resin containing piperidine groups is prepared by polymerization reaction.

7. The method for preparing the cation exchange resin according to claim 6, characterized in that, The mass ratio of the double-bonded piperidine functional monomer to the dispersant is 1:1 to 35; preferably 1:1 to 25; more preferably 1:1 to 20. The mass ratio of the double-bonded piperidine functional monomer to the initiator is 1~100:1; preferably 50~80:

1. The initiator includes one or more of benzoyl peroxide, azo compounds, and persulfates; The dispersant is at least one selected from N,N-dimethylformamide, deionized water, alcohol / water mixed solvent, N,N-dimethylacetamide, N-methylpyrrolidone, toluene, dichloromethane, chloroform, tetrahydrofuran, ethanol, n-propanol, isopropanol, dimethyl sulfoxide, or ethyl acetate; preferably, the dispersant is one selected from N,N-dimethylformamide, N,N-dimethylacetamide, ethanol, and n-propanol; the alcohol / water mixed solvent is one selected from ethanol, n-propanol, and isopropanol, and the volume ratio of the alcohol / water mixed solvent is 1:1~3; The polymerization reactions include emulsion polymerization, suspension polymerization, and aqueous solution polymerization; Preferably, the aqueous solution polymerization method uses deionized water as a dispersant. Specifically, the mixed solution is slowly heated to 45-135°C and reacted under mechanical stirring for 1-48 hours. After the reaction is completed, it is cooled to room temperature and post-treated. The product is then dried to obtain a cationic resin containing piperidine groups. The emulsion polymerization method specifically involves: adding an emulsifier to the mixed solution and slowly heating it to 45–80°C, with the mass ratio of emulsifier to monomer being 1–20 wt%; reacting under mechanical stirring for 1–48 hours; after the reaction is completed, the emulsion is demulsified and washed in acetone or ethanol to remove the emulsifier and unreacted monomer, and then dried to obtain a cationic resin containing piperidine groups. More preferably, the emulsifier is one or more of perfluorooctanoic acid ammonium, sodium dodecyl sulfate, and hexadecyltrimethylammonium bromide.

8. The cationic resin prepared according to any one of claims 6 or 7, characterized in that, The number-average molecular weight of the piperidine-containing cationic resin is 120,000 to 1,200,000, preferably 250,000 to 600,000, and more preferably 250,000 to 350,000; the ion exchange capacity is 0.5 to 4.0 mmol / g, preferably 0.8 to 2.5 mmol / g, and more preferably 0.90 to 2.3 mmol / g.

9. The cationic resin prepared according to any one of claims 6 or 7, characterized in that, It has the structure shown in formula (VIII) or formula (IX): Formula (VIII); Formula (IX); Where Y is one of F, Cl, Br, I, and m is a natural number ≥ 50; M1 to M3 are independently selected from one of -H, -OH, -CH3, -OCH3, -Ph, -OPh, -Cl, -CH2Cl, and -CH2CH3; Ar1 is one of the following: a cycloalkyl group consisting of 4 to 7 carbon atoms, an alkyl group containing 1 to 20 carbon atoms, a hydrocarbon group containing 1 to 20 carbon atoms, or a fully or partially fluorinated alkyl group containing 1 to 6 carbon atoms; Ar2 contains one or more piperidine cationic groups.

10. The use of the cation exchange resin prepared by the method of any one of claims 6 to 7 or the cation exchange resin of any one of claims 8 to 9 in one or more of the following: 1) use in the manufacture of fuel cells; 2) use in the preparation of membrane electrodes for alkaline water electrolysis; 3) use in electrodialysis; 4) use in seawater desalination; 5) use in antibacterial materials; 6) use in wastewater treatment.

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