A main chain containing a thioester group polyamide and a method for synthesizing the same

Abstract

The application discloses a main-chain sulfur ester group-containing polyamide and a synthesis method thereof. The main-chain sulfur ester group-containing polyamide has a structural general formula as shown in the following formula (I) or (II). In the formula, n is selected from 1 to 200. The polymer product disclosed by the application has a definite structure, the main-chain repeating unit has the structures of sulfur ester and amide, simultaneously contains different functional groups, and the end groups have further reactivity. The main-chain sulfur ester group-containing polyamide also has a high molecular mass and excellent mechanical properties.

Description

Technical Field

[0001] This invention relates to the technical field of polymer materials, and in particular to a polyamide with a main chain containing sulfur ester groups and its synthesis method. Background Technology

[0002] Sulfur-containing polymers, due to the introduction of sulfur atoms, generally possess excellent mechanical properties, thermal stability, optical functionality, biocompatibility, and strong ionic binding capacity, making them widely used in general-purpose, engineering, and functional materials. Compared to polyesters, polysulfides often exhibit better crystallinity, superior optical properties, and degradability and recyclability. Polyamide materials containing sulfur ester groups combine sulfur ester bonds and amide bonds, possessing both the degradability and excellent optical properties of sulfur ester compounds and retaining the superior mechanical properties of amide compounds, leading to their widespread application in biomaterials, optical materials, and biodegradable materials.

[0003] However, the simple and controllable introduction of thioester and amide bonds remains a challenging problem in the field of synthesis, especially the synthesis of polymers with both thioester and amide groups in the main chain. Currently, the synthesis of polythioesters mainly relies on the condensation polymerization of dicarboxylic acids and dithiols, which suffers from problems such as the unpleasant odor of dithiols, high energy consumption, and the release of water byproducts.

[0004] Chinese patent document CN 113943485 A discloses a method for preparing polysulfides, which involves ring-opening polymerization of thiolactide monomers under the catalysis of an organic base to obtain polysulfide compounds. However, this ring-opening polymerization method is limited by the types of reactants, resulting in a polymer with a simple structure containing only thiolactide groups, making it difficult to introduce amide groups.

[0005] Chinese patent document CN 116640308 A discloses a method for preparing polythioesteramide and its depolymerization method. The preparation method includes adding a co-catalyst and an initiator containing thiourea and an organic base to a thiazine dione monomer solution to induce ring-opening polymerization of the thiazine dione monomer, thereby obtaining a polythioesteramide polymer. This technical solution claims to avoid the thioester exchange side reaction through a two-component catalytic system and to prepare depolymerizable polythioesteramide with a narrow molecular weight distribution. However, this ring-opening polymerization method is limited by the limited types of reactants, and the preparation, storage, and transportation of thiazine dione monomers are difficult, resulting in a relatively simple structure and type of polythioesteramide, and a low monomer conversion rate, with a maximum of only 73%. In addition, the polythioesteramide polymer prepared by this technical solution has a narrow molecular weight distribution, not exceeding 1.13, but the number average molecular weight range is only 4000-8000 g / mol. Summary of the Invention

[0006] To address the problems of existing technologies, this invention discloses a polyamide with a main chain containing thioester groups and its synthesis method. This polyamide possesses a well-defined structure, with repeating main chain units containing both thioester and amide structures, and includes various functional groups, with end groups exhibiting further reactivity. Furthermore, this thioester-containing polyamide has a high molecular weight and excellent mechanical properties, showing broad application prospects in food packaging, coatings, biotechnology, and electronics. Simultaneously, based on the stepwise polymerization mechanism, this method achieves high monomer conversion rates, with near-complete conversion in the initial stage, resulting in high monomer utilization. The synthesis process of this invention requires only one step, uses inexpensive and readily available raw materials, is time-efficient, and eliminates the need for cumbersome post-processing purification steps, facilitating industrial-scale production.

[0007] The specific technical solution is as follows:

[0008] A polyamide with a main chain containing sulfur ester groups has the following general structural formula (I) or (II):

[0009]

[0010] In the formula, n is selected from 1 to 200;

[0011] R1 is selected from C2 to C. 22 Alkylene, terephthalamide, 2,5-furandimethyl, 1,4-cyclohexylene, (CH2CH2O) m CH2CH2, m=1~3;

[0012] R2 is selected from H or methyl;

[0013] R3 is selected from C2 to C3. 12 Alkylene, (CH2)3Si(CH3)2OSi(CH3)2(CH2)3, (CH2)2O(CH2)2O(CH2)2, isophorone, 1,4-phenylene, 1,3-phenylene, 1,2-phenylene, terephthalimide, o-phenylene, iso-phenylene, 1,4-cyclohexyl, 1,2-cyclohexyl, 1,3-cyclohexyl, CH2C(CH3)2CH2;

[0014] R4 is selected from H, methyl, ethyl, n-propyl, and isopropyl.

[0015] Tests have shown that the polyamide with thioester groups in the main chain prepared by this invention has a number average molecular weight of 1-200 kg / mol and a molecular weight distribution of 1.1-2.5, specifically 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 or any value within the above range.

[0016] This invention discloses a polyamide with a main chain containing thioester groups. The main chain repeating unit has a structure of thioester and amide, has a well-defined structure, contains different functional groups, and the end groups have further reactivity. This polyamide containing thioester groups also has high molecular weight, low molecular weight distribution, and excellent mechanical properties, and has broad application prospects in food packaging, coatings, biotechnology, and electronics.

[0017] The present invention also discloses a method for synthesizing the above-mentioned polyamide with a main chain containing sulfur ester groups, wherein the raw materials include a carbon-carbon double bond monomer with electron-withdrawing groups, a diamino monomer and a cyclic monothioic anhydride monomer, which are polymerized under autogenous pressure.

[0018] The structural formula of the carbon-carbon double bond monomer with electron-withdrawing groups is shown in formula (Ⅲ) below:

[0019]

[0020] The structural formula of the diamino monomer is shown in formula (Ⅳ) below:

[0021]

[0022] The cyclic monothioic anhydride monomer has the following structural formulas (V) to (VI):

[0023]

[0024] In the formula, R1 is selected from C2 to C3. 22 Alkylene, terephthalamide, 2,5-furandimethyl, 1,4-cyclohexylene, (CH2CH2O) m CH2CH2, m=1~3;

[0025] R2 is selected from H or methyl;

[0026] R3 is selected from C2 to C3. 12 Alkylene, (CH2)3Si(CH3)2OSi(CH3)2(CH2)3, (CH2)2O(CH2)2O(CH2)2, isophorone, 1,4-phenylene, 1,3-phenylene, 1,2-phenylene, terephthalimide, o-phenylene, iso-phenylene, 1,4-cyclohexyl, 1,2-cyclohexyl, 1,3-cyclohexyl, CH2C(CH3)2CH2;

[0027] R4 is selected from H, methyl, ethyl, n-propyl, and isopropyl.

[0028] Based on extensive experimental research, the inventors discovered a rapid addition reaction between thioester anions and double-bonded compounds, leading to the development of a novel one-step polymerization reaction for di-double-bonded monomers, diamino monomers, and cyclic monothioic anhydrides. Due to the strong nucleophilicity of nitrogen (N), it preferentially and rapidly reacts with cyclic monothioic anhydrides to form… The group, under the action of other amino groups, generates a sulfide anion, which can undergo a nucleophilic addition reaction with the double bond group to form a sulfide ester compound. The double bond monomer is a carbon-carbon double bond compound with an electron-withdrawing group. This electron-withdrawing group enhances the electrophilicity of the double bond functional group, thus favoring the reaction. Therefore, this invention, through a stepwise polymerization mechanism, can synthesize high molecular weight products under catalyst-free conditions. Based on the above mechanism discovery, the inventors developed this invention through extensive experimental research.

[0029] The synthesis process of this invention requires only one step, the raw materials are cheap and readily available, the time is short, and there is no need for complicated post-processing purification steps, which is conducive to industrial production. At the same time, based on the stepwise polymerization mechanism, the method has a high monomer conversion rate, and can be basically completely converted in the early stage, resulting in a high monomer utilization rate.

[0030] The synthesis process of this invention is selective for cyclic monothioic anhydride monomers. Experiments have shown that the suitable cyclic monothioic anhydride monomers are selected from monothiosuccinic anhydride and / or monothioglutaric anhydride. If the cyclic monothioic anhydride monomers are replaced with monothiophthalic anhydride with similar structure, polymerization cannot be carried out.

[0031] Preferred:

[0032] The electron-withdrawing carbon-carbon double bond monomer is selected from ethylene glycol diacrylate, 1,3-propanediol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, neopentanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, 1,12-dodecanediol diacrylate, 1,14-tetradecanediol diacrylate, 1,16-hexadecanediol diacrylate, 1,18-octadecanediol diacrylate, 1,20-eicosenediol diacrylate, 1,22-eicosenediol diacrylate, terephthalic acid diacrylate, 2,5-furan One or more of the following: 1,4-cyclohexanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,3-propanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,5-pentanediol dimethacrylate, neopentanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, 1,12-dodecanediol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and tetraethylene glycol dimethacrylate;

[0033] The diamino monomer is selected from C2-C3. 12 The alkyl diamine, p-phenylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, o-phenylenediamine, m-phenylenediamine, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,8-diamino-3,6-dioxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, dimethylpropylenediamine, isophorone diamine, N,N′-dimethylethylenediamine, N,N′-diisopropylethylenediamine, N,N′-dimethyl-1,3-propanediamine, N,N′-dimethyl-1,6-hexanediamine, N,N′-dimethyl-1,8-octanediamine, N,N′-diethylethylenediamine, N,N′-diethyl-1,3-propanediamine.

[0034] The synthesis method disclosed in this invention has good universality for monomers and is applicable to diamino monomers with different structures and properties. This makes it possible to prepare polymers with different properties simply by changing the type of diamino monomer.

[0035] For example, when the diamino monomer is selected from alkyl diamine, p-phenylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, o-phenylenediamine, and m-phenylenediamine, the prepared polymer has obvious crystallinity and is a crystalline polymer;

[0036] When the diamino monomer is selected from flexible chains of length such as 1,8-diamino-3,6-dioxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, isophorone diamine, secondary amine diamino monomers (such as N,N′-dimethylethylenediamine), cyclohexane diamino monomers, etc., the polymer prepared is a thermoplastic elastomer or thermoplastic plastic.

[0037] Further optimization:

[0038] The electron-withdrawing carbon-carbon double bond monomers are selected from one or more of ethylene glycol diacrylate, 1,3-propanediol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, neopentanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, 1,12-dodecanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, and terephthalic acid diacrylate. Further preferred electron-withdrawing carbon-carbon double bond monomers are inexpensive, readily available, and easy to store and transport; most importantly, they exhibit good reactivity and excellent performance.

[0039] The diamino monomer is selected from C2-C3. 12 One or more of the following: alkyl diamines, 1,8-diamino-3,6-dioxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, isophorone diamine, N,N′-dimethylethylenediamine, N,N′-diisopropylethylenediamine, N,N′-dimethyl-1,3-propanediamine, N,N′-dimethyl-1,6-hexanediamine, N,N′-dimethyl-1,8-octanediamine, N,N′-diethylethylenediamine, and N,N′-diethyl-1,3-propanediamine; further preferred diamino monomers exhibit excellent reaction efficiency.

[0040] Preferred:

[0041] The molar ratio of the carbon-carbon double bond monomer with electron-withdrawing groups to the diamino monomer is 1:

[0042] (0.2 to 5.0); specifically, it can be 1:0.2, 1:0.5, 1:1.0, 1:1.5, 1:2.0, 1:2.5, 1:3.0, 1:3.5, 1:4.0, 1:4.5, 1:5.0, or any ratio within the above range. Further preferred is 1:(0.5 to 2.0); more preferably, it is 1:1.

[0043] Preferred:

[0044] The molar ratio of the carbon-carbon double bond monomer with electron-withdrawing groups to the cyclic monothioic anhydride is 1:

[0045] (1.5 to 5.0); specifically, it can be 1:1.5, 1:1.8, 1:2.0, 1:2.5, 1:3.0, 1:3.5, 1:4.0, 1:4.4, 1:5.0 or any ratio within the above range. Further preferred is 1:(2 to 5); more preferably 1:(2 to 4).

[0046] More preferably, the molar ratio of the carbon-carbon double bond monomer with electron-withdrawing groups, the diamino monomer, and the cyclic monothioic anhydride is 1:1:(2.0 to 4.0); most preferably, the molar ratio is 1:1:2.

[0047] Experiments have shown that by using the continuously optimized raw material molar ratios described above, polymers with higher molecular weights can be prepared.

[0048] The polymerization reaction of the present invention is carried out under autogenous pressure. The polymerization can be bulk polymerization or solution polymerization. Studies have found that the generated thioester groups can reach saturation after 55 minutes of reaction. This shows that the reaction system of the present invention still has an extremely high monomer conversion rate under relatively mild reaction conditions without the addition of a catalyst.

[0049] The polymerization temperature is 25–160°C, specifically 25°C, 40°C, 60°C, 80°C, 100°C, 120°C, 140°C, 160°C, or any value within the above range. Preferably, the polymerization temperature is 40–90°C; more preferably, the polymerization temperature is 60–90°C.

[0050] The polymerization time is 0.5 to 120 hours, specifically 0.5 hours, 2 hours, 6 hours, 12 hours, 24 hours, 48 ​​hours, 72 hours, 96 hours, 120 hours, or any value within the above range. Preferably, the polymerization time is 55 minutes to 12 hours.

[0051] If solution polymerization is used, the solvent is selected from one or more of N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, phenol, dichloromethane, chloroform, tetrahydrofuran, toluene, trichlorobenzene, o-dichlorobenzene, m-dichlorobenzene, and p-dichlorobenzene.

[0052] Preferably, the solvent is selected from one or more of N,N-dimethylformamide, N-methylpyrrolidone, and dimethyl sulfoxide. Experiments have shown that, under the same other process conditions, polymers prepared using this solvent have higher molecular weights.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] (1) Based on extensive experimental research, this invention proposes for the first time a one-step reaction of a carbon-carbon double bond compound with electron-withdrawing group, a diamino monomer and a cyclic monothioic anhydride to obtain a polymer with controllable end groups, whose main chain contains both thioester groups and amide groups. The raw materials are cheap and readily available, and the reaction conditions are simple. It is a new polymerization reaction with complete atom economy.

[0055] (2) In this invention, a rapid reaction can be achieved without a catalyst. Basically, the thioester groups generated after 55 minutes of reaction can reach saturation. The monomer conversion rate is high, and a clear structure, no metal residue, colorless, main chain repeating unit containing thioester groups and amide groups, clear end group structure is obtained. There is no need for complicated post-processing purification steps.

[0056] (3) The polymer prepared by this invention has a high molecular weight and does not contain metal ions. Moreover, by controlling the type and ratio of raw materials and process conditions in the synthesis method, the number average molecular weight and main chain repeating units of the prepared polymer products can be controlled over a wide range. Thus, products with completely different properties such as crystalline polymers, thermoplastic plastics, and thermoplastic elastomers can be prepared by the same method. They have excellent mechanical properties and have broad application prospects in food packaging, coatings, biology and electronics. Attached Figure Description

[0057] Figure 1 The copolymerized product prepared in Example 1 1 H NMR spectrum;

[0058] Figure 2 The copolymerized product prepared in Example 1 13 C NMR spectrum;

[0059] Figure 3 The copolymerized product prepared in Example 22 1 H NMR spectrum;

[0060] Figure 4 The copolymerized product prepared in Example 22 13 C NMR spectrum;

[0061] Figure 5 The copolymerized product prepared in Example 26 1 H NMR spectrum;

[0062] Figure 6 The copolymerized product prepared in Example 26 13 C NMR spectrum;

[0063] Figure 7 The copolymerized product prepared in Example 27 1 H NMR spectrum;

[0064] Figure 8 The copolymerized product prepared in Example 27 13 C NMR spectrum;

[0065] Figure 9 The copolymerized product prepared in Example 28 1 H NMR spectrum;

[0066] Figure 10 The copolymerized product prepared in Example 28 13 C NMR spectrum;

[0067] Figure 11 The copolymerized product prepared in Example 30 1 H NMR spectrum;

[0068] Figure 12 The copolymerized product prepared in Example 30 13 C NMR spectrum;

[0069] Figure 13 The copolymerized product prepared for Comparative Example 1 1 H NMR spectrum. Detailed Implementation

[0070] To make the objectives, features, and advantages of this invention more apparent, further embodiments are provided below to illustrate the invention in detail. These embodiments are for illustrative purposes only and should not be construed as limiting the scope of protection of this invention. Any non-essential improvements and adjustments made by those skilled in the art based on the principles described herein are within the scope of protection of this invention.

[0071] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0072] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0073] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0074] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. Where the terms "first," "second," etc., are used throughout the text, they are used only to distinguish similar objects and should not be construed as indicating or implying their relative importance, order of precedence, or implicitly specifying the number of technical features indicated. It should be understood that the data in the descriptions of "first," "second," etc., can be interchanged where appropriate.

[0075] In the following examples, the raw material monomers, monothiosuccinic anhydride, monothioglutaric anhydride, and monothiophthalic anhydride, were prepared in-house. Taking monothiosuccinic anhydride as an example, the preparation steps are as follows:

[0076] 100.07 g of succinic anhydride was dissolved in 400 mL of tetrahydrofuran, and 270 g of a 14.5 wt% sodium sulfide aqueous solution was added. The mixture was reacted at room temperature for 4 hours. The tetrahydrofuran was removed under vacuum, and the mixture was extracted three times with methyl tert-butyl ether. The methyl tert-butyl ether was removed under vacuum, and the mixture was sublimated.

[0077] When preparing monothioglutaric anhydride and monothiophthalic anhydride, succinic anhydride is replaced with equimolar amounts of glutaric anhydride and phthalic anhydride, respectively.

[0078] Example 1: 1,4-Butanediol diacrylate / 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane / monothiosuccinic anhydride reaction to generate a polyamide with a repeating main chain unit containing a thioester group.

[0079] Before polymerization, a 15 mL pressure-resistant tube was dried at 110 °C for 2 hours to remove moisture and then cooled to room temperature in a glove box. 0.3871 g of monothiosuccinic anhydride dissolved in 1.5 mL of DMF, 0.3304 g of 1,4-butanediol diacrylate, and 0.4142 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane were added sequentially to the reactor. The molar ratio of 1,4-butanediol diacrylate, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane to monothiosuccinic anhydride was 1 / 1 / 2. The reaction was carried out at 60 °C under autogenous pressure for 2 hours. After the reaction, the crude product was dissolved in chloroform, and the polymer was precipitated in 200 mL of methyl tert-butyl ether. This washing process was repeated three times, and the product was dried under vacuum to constant weight. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the results are shown in Table 1.

[0080] Figure 1 , 2 The polymers prepared in this embodiment are respectively 1 H NMR spectrum and 13 The C NMR spectrum and the structural formula of the polymer are shown below:

[0081]

[0082] Examples 2-5

[0083] The preparation process was basically the same as in Example 1, except that the polymerization temperature was changed sequentially to 25℃, 90℃, 120℃, and 160℃. The molecular weight and molecular weight distribution of the polymers prepared in each example were determined by gel permeation chromatography, and the test results are shown in Table 1.

[0084] Examples 6-9

[0085] The preparation process was basically the same as in Example 1, except that the polymerization reaction time was successively replaced with 6h, 12h, 24h, and 120h. The molecular weight and molecular weight distribution of the polymers prepared in each example were determined by gel chromatography, and the test results are shown in Table 1.

[0086] Examples 10-13

[0087] The preparation process is basically the same as in Example 1, except that the mass of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane added is different, specifically:

[0088] The molar ratios of 1,4-butanediol diacrylate, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and monothiosuccinic anhydride were successively replaced with 1 / 0.2 / 2, 1 / 0.5 / 2, 1 / 2 / 2, and 1 / 5 / 2.

[0089] The molecular weight and molecular weight distribution of the polymers prepared in each example were determined by gel chromatography, and the test results are shown in Table 1.

[0090] Examples 14-18

[0091] The preparation process is basically the same as in Example 1, except that the mass of monothiosuccinic anhydride added is different, specifically:

[0092] The molar ratios of 1,4-butanediol diacrylate, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and monothiosuccinic anhydride were successively replaced with 1 / 1 / 1.5, 1 / 1 / 1.8, 1 / 1 / 4.0, 1 / 1 / 4.4, and 1 / 1 / 5.0.

[0093] The molecular weight and molecular weight distribution of the polymers prepared in each example were determined by gel chromatography, and the test results are shown in Table 1.

[0094] Examples 19-21

[0095] The preparation process was basically the same as in Example 1, except that the solvents for the polymerization reaction were successively replaced with NMP, DMSO, and CHCl3. The molecular weight and molecular weight distribution of the polymers prepared in each example were determined by gel permeation chromatography, and the test results are shown in Table 1.

[0096] Example 22: 1,4-Butanediol diacrylate / N,N′-dimethyl-1,6-hexanediamine / monothiosuccinic anhydride reaction to generate a polyamide with a repeating main chain unit containing a thioester group.

[0097] Before polymerization, a 15 mL pressure-resistant tube was dried at 110 °C for 2 hours to remove moisture, and then cooled to room temperature in a glove box. 0.3871 g of monothiosuccinic anhydride dissolved in 1.5 mL of DMF, 0.3304 g of 1,4-butanediol diacrylate, and 0.2404 g of N,N′-dimethyl-1,6-hexanediamine were added sequentially to the reactor. The molar ratio of 1,4-butanediol diacrylate, N,N′-dimethyl-1,6-hexanediamine, and monothiosuccinic anhydride was 1 / 1 / 2. The reaction was carried out at 60 °C under autogenous pressure for 2 hours. After the reaction, the crude product was dissolved in chloroform, and the polymer was precipitated in 200 mL of methyl tert-butyl ether. This washing process was repeated three times, and the product was dried under vacuum to constant weight. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the results are shown in Table 1.

[0098] Figure 3 , 4 The polymers prepared in this embodiment are respectively 1 H NMR spectrum and 13 The C NMR spectrum and the structural formula of the polymer are shown below:

[0099]

[0100] Example 23: 1,4-Butanediol diacrylate / 1,6-hexanediamine / monothiosuccinic anhydride reaction to generate a polyamide with a repeating main chain unit containing a thioester group.

[0101] Before polymerization, a 15 mL pressure-resistant tube was dried at 110 °C for approximately 2 hours to remove moisture, and then cooled to room temperature in a glove box. 0.3871 g of monothiosuccinic anhydride dissolved in 1.5 mL of DMF, 0.3304 g of 1,4-butanediol diacrylate, and 0.1937 g of 1,6-hexanediamine were added sequentially to the reactor. The molar ratio of 1,4-butanediol diacrylate, 1,6-hexanediamine, and monothiosuccinic anhydride was 1 / 1 / 2. The reaction was carried out at 90 °C under autogenous pressure for 2 hours. After the reaction, the crude product was dissolved in chloroform, and the polymer was precipitated in 200 mL of methyl tert-butyl ether. This washing process was repeated three times, and the product was dried under vacuum to constant weight. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the results are shown in Table 1.

[0102] The structural formula of the polymer prepared in this embodiment is shown below:

[0103]

[0104] Example 24: 1,9-Nonadiol diacrylate / 1,8-diamino-3,6-dioxaoctane / monothiosuccinic anhydride reaction to generate a polyamide with a repeating main chain unit containing a thioester group.

[0105] Before polymerization, a 15 mL pressure-resistant tube was dried at 110 °C for 2 hours to remove moisture and then cooled to room temperature in a glove box. 0.3871 g of monothiosuccinic anhydride dissolved in 1.5 mL of DMF, 0.4473 g of 1,9-nonanediol diacrylate, and 0.2470 g of 1,8-diamino-3,6-dioxane were added sequentially to the reactor. The molar ratio of 1,9-nonanediol diacrylate, 1,8-diamino-3,6-dioxane, and monothiosuccinic anhydride was 1 / 1 / 2. The reaction was carried out at 60 °C under autogenous pressure for 2 hours. After the reaction, the crude product was dissolved in chloroform, and the polymer was precipitated in 200 mL of methyl tert-butyl ether. This washing process was repeated three times, and the product was dried under vacuum to constant weight. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the results are shown in Table 1.

[0106] The structural formula of the polymer prepared in this embodiment is shown below:

[0107]

[0108] Example 25: 1,10-Decanediol diacrylate / isophorone diamine / monothiosuccinic anhydride reaction to generate a polyamide with a repeating main chain unit containing a thioester group.

[0109] Before polymerization, a 15 mL pressure-resistant tube was dried at 110 °C for approximately 2 hours to remove moisture, and then cooled to room temperature in a glove box. 0.3871 g of monothiosuccinic anhydride dissolved in 1.5 mL of DMF, 0.4706 g of 1,10-decanediol diacrylate, and 0.2838 g of isophorone diamine were added sequentially to the reactor. The molar ratio of 1,10-decanediol diacrylate, isophorone diamine, and monothiosuccinic anhydride was 1 / 1 / 2. The reaction was carried out at 60 °C under autogenous pressure for 2 hours. After the reaction, the crude product was dissolved in chloroform, and the polymer was precipitated in 200 mL of methyl tert-butyl ether. This washing process was repeated three times, and the product was dried under vacuum to constant weight. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the results are shown in Table 1.

[0110] The structural formula of the polymer prepared in this embodiment is shown below:

[0111]

[0112] Example 26: Reaction of 1,5-pentanediol diacrylate / 1,7-heptanediamine / monothioglutaric anhydride to generate a polyamide with a repeating main chain unit containing a thioester group.

[0113] Before polymerization, a 15 mL pressure-resistant tube was dried at 110 °C for approximately 2 hours to remove moisture, and then cooled to room temperature in a glove box. 0.4339 g of monothioglutaric anhydride dissolved in 1.5 mL of DMF, 0.3538 g of 1,5-pentanediol diacrylate, and 0.2171 g of 1,7-heptanediamine were added sequentially to the reactor. The molar ratio of 1,5-pentanediol diacrylate, 1,7-heptanediamine, and monothioglutaric anhydride was 1 / 1 / 2. The reaction was carried out at 90 °C under autogenous pressure for 2 hours. After the reaction, the crude product was dissolved in chloroform, and the polymer was precipitated in 200 mL of methyl tert-butyl ether. This washing process was repeated three times, and the product was dried under vacuum to constant weight. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the results are shown in Table 1.

[0114] Figure 5 , 6 The polymers prepared in this embodiment are respectively 1 H NMR spectrum and 13 The C NMR spectrum and the structural formula of the polymer are shown below:

[0115]

[0116] Example 27: Reaction of diethylene glycol diacrylate / 1,8-diamino-3,6-dioxane / monothioglutaric anhydride to generate polyamide with thioester groups in the main chain repeating unit.

[0117] Before polymerization, a 15 mL pressure-resistant tube was dried at 110 °C for approximately 2 hours to remove moisture, and then cooled to room temperature in a glove box. 0.4339 g of monothioglutaric anhydride dissolved in 1.5 mL of DMF, 0.3570 g of diethylene glycol diacrylate, and 0.2470 g of 1,8-diamino-3,6-dioxane were added sequentially to the reactor. The molar ratio of diethylene glycol diacrylate, 1,8-diamino-3,6-dioxane, and monothioglutaric anhydride was 1 / 1 / 2. The reaction was carried out at 60 °C under autogenous pressure for 2 hours. After the reaction, the crude product was dissolved in chloroform, and the polymer was precipitated in 200 mL of methyl tert-butyl ether. This washing process was repeated three times, and the product was dried under vacuum to constant weight. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the results are shown in Table 1.

[0118] Figure 7 , 8 The polymers prepared in this embodiment are respectively 1 H NMR spectrum and 13 The C NMR spectrum and the structural formula of the polymer are shown below:

[0119]

[0120] Example 28: Reaction of tetraethylene glycol diacrylate / 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane / monothioglutaric anhydride to generate a polyamide with a repeating main chain unit containing a thioester group.

[0121] Before polymerization, a 15 mL pressure-resistant tube was dried at 110 °C for approximately 2 hours to remove moisture, and then cooled to room temperature in a glove box. 0.4339 g of monothioglutaric anhydride dissolved in 1.5 mL of DMF, 0.5039 g of tetraethylene glycol diacrylate, and 0.4142 g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane were added sequentially to the reactor. The molar ratio of tetraethylene glycol diacrylate, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and monothioglutaric anhydride was 1 / 1 / 2. The reaction was carried out at 60 °C under autogenous pressure for 2 hours. After the reaction, the crude product was dissolved in chloroform, and the polymer was precipitated in 200 mL of methyl tert-butyl ether. This washing process was repeated three times, and the product was dried under vacuum to constant weight. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the results are shown in Table 1.

[0122] Figure 9 , 10 The polymers prepared in this embodiment are respectively 1H NMR spectrum and 13 The C NMR spectrum and the structural formula of the polymer are shown below:

[0123]

[0124] Example 29: 1,6-Hexanediol diacrylate / isophorone diamine / monothioglutaric anhydride reaction to generate a polyamide with a repeating main chain unit containing a thioester group.

[0125] Before polymerization, a 15 mL pressure-resistant tube was dried at 110 °C for approximately 2 hours to remove moisture, and then cooled to room temperature in a glove box. 0.4339 g of monothioglutaric anhydride dissolved in 1.5 mL of DMF, 0.3771 g of 1,6-hexanediol diacrylate, and 0.2838 g of isophorone diamine were added sequentially to the reactor. The molar ratio of 1,6-hexanediol diacrylate, isophorone diamine, and monothioglutaric anhydride was 1 / 1 / 2. The reaction was carried out at 60 °C under autogenous pressure for 2 hours. After the reaction, the crude product was dissolved in chloroform, and the polymer was precipitated in 200 mL of methyl tert-butyl ether. This washing process was repeated three times, and the product was dried under vacuum to constant weight. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the results are shown in Table 1.

[0126] The structural formula of the polymer prepared in this embodiment is shown below:

[0127]

[0128] Example 30: Reaction of 1,4-butanediol diacrylate / 1,4-butanediamine / monothiosuccinic anhydride to generate polyamide with thioester groups in the main chain repeating unit.

[0129] Before polymerization, a 15 mL pressure-resistant tube was dried at 110 °C for approximately 2 hours to remove moisture, and then cooled to room temperature in a glove box. 0.3871 g of monothiosuccinic anhydride dissolved in 1.5 mL of DMF, 0.3304 g of 1,4-butanediol diacrylate, and 0.1469 g of 1,4-butanediamine were added sequentially to the reactor. The molar ratio of 1,4-butanediol diacrylate, 1,4-butanediamine, and monothiosuccinic anhydride was 1 / 1 / 2. The reaction was carried out at 60 °C under autogenous pressure for 2 hours. After the reaction, the crude product was dissolved in chloroform, and the polymer was precipitated in 200 mL of methyl tert-butyl ether. This washing process was repeated three times, and the product was dried under vacuum to constant weight. The molecular weight and molecular weight distribution of the polymer were determined by gel permeation chromatography, and the results are shown in Table 1.

[0130] Figure 11 , 12 The polymers prepared in this embodiment are respectively 1 H NMR spectrum and 13 The C NMR spectrum and the structural formula of the polymer are shown below:

[0131]

[0132] Comparative Example 1: Reaction of 1,4-Butanediol diacrylate / 1,4-Butanediamine / Monothiophthalic anhydride

[0133] The preparation process was basically the same as in Example 30, except that monothiosuccinic anhydride was replaced with an equimolar amount of monothiophthalic anhydride. The structure of the product was determined by NMR, and the test results are shown below. Figure 13 It can be seen that the monomer system in this comparative example cannot be polymerized and can only be used to prepare small molecules.

[0134] Table 1

[0135]

[0136]

[0137] Note: 1 Types of double bond monomers: BGDA is 1,4-butanediol diacrylate, PGDA is 1,5-pentanediol diacrylate, HGDA is 1,6-hexanediol diacrylate, NGDA is 1,9-nonanediol diacrylate, DGDA is 1,10-decanediol diacrylate, DEGDA is diethylene glycol diacrylate, and TEGDA is tetraethylene glycol diacrylate. 2 Types of diamino monomers: HMDA is 1,6-hexanediamine, DMDDA is N,N′-dimethyl-1,6-hexanediamine, DHA is 1,7-heptanediamine, BMDA is 1,4-butanediamine, DADOO is 1,8-diamino-3,6-dioxane, BAPTMDSi is 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and IPDA is isophorone diamine. 3 Types of cyclic monothioic anhydride monomers: STA is monothiosuccinic anhydride, GTA is monothioglutaric anhydride; 4 The molar ratio of double bond monomers, diamino monomers and cyclic monothioic anhydrides; 5 Reaction solvents: DMF is N,N-dimethylformamide, NMP is N-methylpyrrolidone, DMSO is dimethyl sulfoxide, and CHCl3 is chloroform; 6 M n Number-average molecular weight, determined by gel permeation chromatography; 7 PDI: Molecular weight distribution, determined by gel permeation chromatography.

[0138] Examples 1-30 show the copolymerization results of double-bonded monomers, diamino monomers, and cyclic monothioic anhydrides under catalyst-free conditions. It can be seen that this type of system has excellent reactivity and versatility.

[0139] The above description is only a few specific embodiments of the present invention. It should be noted that many variations and improvements can be made by those skilled in the art. All variations or improvements that do not exceed the scope of the claims should be considered as the protection scope of the present invention.

Claims

1. A polyamide with a main chain containing sulfur ester groups, characterized in that, The general structural formula is shown in equation (Ⅰ) or (Ⅱ) below: In the formula, n is selected from 1 to 200; R1 is selected from C2 to C. 22 Alkylene, terephthalamide, 2,5-furandimethyl, 1,4-cyclohexylene, (CH2CH2O) m CH2CH2, m=1~3; R2 is selected from H or methyl; R3 is selected from C2 to C3. 12 Alkylene, (CH2)3Si(CH3)2OSi(CH3)2(CH2)3, (CH2)2O(CH2)2O(CH2)2, isophorone, 1,4-phenylene, 1,3-phenylene, 1,2-phenylene, terephthalimide, o-phenylene, iso-phenylene, 1,4-cyclohexyl, 1,2-cyclohexyl, 1,3-cyclohexyl, CH2C(CH3)2CH2; R4 is selected from H, methyl, ethyl, n-propyl, and isopropyl.

2. The polyamide with a main chain containing sulfur ester groups according to claim 1, characterized in that, The number-average molecular weight is 1–200 kg / mol, and the molecular weight distribution is 1.1–2.

5.

3. A method for synthesizing a polyamide with a main chain containing sulfur ester groups according to claim 1 or 2, characterized in that, The raw materials include carbon-carbon double bond monomers with electron-withdrawing groups, diamino monomers, and cyclic monothioic anhydride monomers, which are polymerized under autogenous pressure. The structural formula of the carbon-carbon double bond monomer with electron-withdrawing groups is shown in formula (Ⅲ) below: The structural formula of the diamino monomer is shown in formula (Ⅳ) below: The cyclic monothioic anhydride monomer has the following structural formulas (V) to (VI): In the formula, R1 is selected from C2 to C3. 22 Alkylene, terephthalamide, 2,5-furandimethyl, 1,4-cyclohexylene, (CH2CH2O) m CH2CH2, m=1~3; R2 is selected from H or methyl; R3 is selected from C2 to C3. 12 Alkylene, (CH2)3Si(CH3)2OSi(CH3)2(CH2)3, (CH2)2O(CH2)2O(CH2)2, isophorone, 1,4-phenylene, 1,3-phenylene, 1,2-phenylene, terephthalimide, o-phenylene, iso-phenylene, 1,4-cyclohexyl, 1,2-cyclohexyl, 1,3-cyclohexyl, CH2C(CH3)2CH2; R4 is selected from H, methyl, ethyl, n-propyl, and isopropyl.

4. The method for synthesizing polyamides with main chain containing sulfur ester groups according to claim 3, characterized in that: The electron-withdrawing carbon-carbon double bond monomer is selected from ethylene glycol diacrylate, 1,3-propanediol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, neopentanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, 1,12-dodecanediol diacrylate, 1,14-tetradecanediol diacrylate, 1,16-hexadecanediol diacrylate, 1,18-octadecanediol diacrylate, 1,20-eicosenediol diacrylate, 1,22-eicosenediol diacrylate, terephthalic acid diacrylate, 2,5-furan One or more of the following: 1,4-cyclohexanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,3-propanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,5-pentanediol dimethacrylate, neopentanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, 1,12-dodecanediol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and tetraethylene glycol dimethacrylate; The diamino monomer is selected from C2-C3. 12 The alkyl diamine, p-phenylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, o-phenylenediamine, m-phenylenediamine, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,8-diamino-3,6-dioxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, dimethylpropylenediamine, isophorone diamine, N,N′-dimethylethylenediamine, N,N′-diisopropylethylenediamine, N,N′-dimethyl-1,3-propanediamine, N,N′-dimethyl-1,6-hexanediamine, N,N′-dimethyl-1,8-octanediamine, N,N′-diethylethylenediamine, N,N′-diethyl-1,3-propanediamine.

5. The method for synthesizing polyamides with main chain containing sulfur ester groups according to claim 3, characterized in that: The molar ratio of the carbon-carbon double bond monomer with electron-withdrawing groups to the diamino monomer is 1: (0.2～5.0)； The molar ratio of the carbon-carbon double bond monomer with electron-withdrawing groups to the cyclic monothioic anhydride is 1: (1.5～5.0)。 6. The method for synthesizing polyamides with main chain containing sulfur ester groups according to claim 3, characterized in that: The polymerization is either bulk polymerization or solution polymerization, with a polymerization temperature of 25–160°C and a polymerization time of 0.5–120 h. The solvent used in the solution polymerization is selected from one or more of N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, phenol, dichloromethane, chloroform, tetrahydrofuran, toluene, trichlorobenzene, o-dichlorobenzene, m-dichlorobenzene, and p-dichlorobenzene.

7. The method for synthesizing polyamides with main chain containing sulfur ester groups according to claim 6, characterized in that, The solvent is selected from one or more of N,N-dimethylformamide, N-methylpyrrolidone, and dimethyl sulfoxide.

8. The method for synthesizing polyamides with main chain containing sulfur ester groups according to any one of claims 3 to 7, characterized in that: The carbon-carbon double bond monomer is selected from one or more of the following: ethylene glycol diacrylate, 1,3-propanediol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, neopentanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, 1,12-dodecanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, and terephthalic acid diacrylate. The diamino monomer is selected from C2-C3. 12 One or more of the following: alkyl diamines, 1,8-diamino-3,6-dioxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, isophorone diamine, N,N′-dimethylethylenediamine, N,N′-diisopropylethylenediamine, N,N′-dimethyl-1,3-propanediamine, N,N′-dimethyl-1,6-hexanediamine, N,N′-dimethyl-1,8-octanediamine, N,N′-diethylethylenediamine, and N,N′-diethyl-1,3-propanediamine; The molar ratio of the carbon-carbon double bond monomer with electron-withdrawing groups to the diamino monomer is 1: (0.5～2.0)； The molar ratio of the carbon-carbon double bond monomer with electron-withdrawing groups to the cyclic monothioic anhydride is 1: (2.0～5.0)。 9. The method for synthesizing polyamides with main chain containing sulfur ester groups according to claim 8, characterized in that, The molar ratio of the carbon-carbon double bond monomer with electron-withdrawing groups, the diamino monomer, and the cyclic monothioic anhydride is 1:1:(2.0–4.0).

10. The method for synthesizing polyamides with main chain containing sulfur ester groups according to claim 8, characterized in that, The polymerization temperature is 40–90°C.

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