Ionic polymer adhesive prepared based on pet degradation and preparation method thereof

Abstract

The application discloses an ionic polymer adhesive prepared based on PET degradation and a preparation method thereof, and comprises the following steps: an amine group or a hydroxyl group is arranged at one end of a small molecule with an organic cation precursor, and the other end of the small molecule is arranged with the organic cation precursor; an intermediate is obtained by carrying out an aminolysis or an ester exchange reaction on the small molecule and PET; an ionization reaction is carried out on the intermediate and a halogenated hydrocarbon to obtain an organic ionic compound; an anion exchange reaction is carried out by mixing a solution of the organic ionic compound with a salt solution containing a target anion to obtain an organic ionic monomer compound; and the organic ionic monomer compound is heated to carry out a polymerization reaction to obtain the ionic polymer adhesive prepared based on PET degradation. The PET is converted into a small molecule compound through the aminolysis / ester exchange reaction, the organic ionic monomer compound is prepared through the ionization reaction and the anion exchange reaction, the three-dimensional polymer network is formed by dehydration and polymerization and cross-linking, the ionic polymer adhesive has excellent adhesion, and meanwhile, the ionic polymer adhesive can be recycled and repeatedly bonded under specific conditions.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, specifically to an ionomer adhesive prepared based on PET degradation and its preparation method. Background Technology

[0002] Polyethylene terephthalate (PET) is one of the most widely used plastics, especially in beverage bottles, food packaging, and textiles. Its lightweight, durable, and low-cost properties make it dominant in the packaging industry. However, its recycling rate is severely inadequate, consistently below 30%. An imperfect recycling system, high sorting costs, and low economic viability of recycled materials collectively hinder the recycling of PET.

[0003] Adhesives, as key materials in modern industry, have permeated numerous fields such as electronic equipment, automobile manufacturing, aerospace, and everyday consumer goods, playing an irreplaceable role in bonding and sealing. However, traditional adhesives are difficult to separate and degrade at the end of their product lifespan, exacerbating resource waste and environmental pollution. Developing recyclable adhesives that are reusable, easy to separate, or degradable under specific conditions has become an important focus of research and development in both academia and industry.

[0004] Organic ionic polymers, due to their electrical conductivity, electrochemical stability, and non-flammability, can effectively compensate for the performance deficiencies of traditional adhesives in specific applications. However, traditional ionic compounds typically exist in liquid or crystalline states at room temperature and pressure. If used directly as adhesives, they are theoretically difficult to meet bonding requirements, as neither of these states can balance the contradiction between cohesive energy and interfacial adhesion energy.

[0005] Therefore, the degradation of waste PET into high-performance adhesives that are reusable, easy to separate, and recyclable has great application potential. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing an ionic polymer adhesive based on PET degradation and its preparation method. PET is converted into small molecule compounds via anamine hydrolysis / ester exchange reaction, and further organic ionic monomer compounds are prepared through ionization and anion exchange reactions. These organic ionic monomer compounds cross-link with each other through dehydration to form a three-dimensional polymer network, thereby exhibiting excellent adhesion in macroscopic bonding performance tests. Furthermore, the adhesive can be recycled and reused under specific conditions, allowing the performance of the organic ionic polymer adhesive to meet specific production requirements.

[0007] To address the aforementioned technical problems, the first aspect of this invention provides a method for preparing ionomer adhesives based on PET degradation, comprising the following steps:

[0008] S1. In an organic solvent, a small molecule with an amino or hydroxyl group at one end and an organic cationic precursor at the other end undergoes an aminolysis or transesterification reaction with PET to obtain an intermediate.

[0009] S2. In an organic solvent, the intermediate and the haloalkane undergo an ionization reaction to obtain an organic ionic compound;

[0010] S3. Mix the organic ionic compound solution with a salt solution containing the target anion to carry out anion exchange reaction, thereby obtaining an organic ionic monomer compound; wherein the target anion is selected from CH3COO. － CF3COO － BF4 － PF6 － OTf － NCN2 － and NTF2 － One or more of them;

[0011] S4. The organic ionic monomer compound is heated to carry out a polymerization reaction to obtain an ionic polymer adhesive based on PET degradation.

[0012] This invention uses waste PET as raw material to prepare organic ionic monomer compounds through PET degradation, ionization reaction, and anion exchange reaction. The organic ionic monomer compounds cross-link with each other through dehydration to form a three-dimensional polymer network. The ionic polymers exhibit excellent macroscopic bonding performance when used in adhesives. At the same time, they can be recycled and reused under specific conditions, allowing the performance of organic ionic polymer adhesives to meet specific production needs.

[0013] Furthermore, in S1, the small molecule is selected from one or more of the following compounds: .

[0014] Furthermore, in S2, the haloalkane is selected from one or more of the following compounds: .

[0015] This invention utilizes the self-assembly of specific small molecules and halogenated hydrocarbons through multiple hydrogen bonds. The resulting ionic polymers can form internal aggregate structures, not only forming strong hydrogen bonds with various substrate materials, thus generating excellent interfacial adhesion, but also constructing a rich dynamic non-covalent cross-linked network within the material. This network, synergistically with electrostatic interactions, significantly enhances the cohesive energy of the adhesive. This interfacial-bulk interaction mechanism enables the prepared ionic polymers to exhibit superior macroscopic adhesive properties when used in adhesives.

[0016] Furthermore, the type of end group selected during the ionization reaction and the target anion chosen in the anion exchange step both affect the water solubility and glass transition temperature of the ionic compound. Therefore, the physicochemical properties of ionomer adhesives can be controlled and adjusted by flexibly combining cations with different end groups and different types of anions.

[0017] Furthermore, in S1, the temperature of the aminolysis or transesterification reaction is 70-100°C, and the time is 20-30 h.

[0018] Furthermore, in S2, the conditions for the ionization reaction are: inert atmosphere protection, temperature 25-110℃, and time 5-72h.

[0019] Furthermore, in S4, the polymerization reaction is carried out at a temperature of 50-200°C for a time of 1-24 hours.

[0020] Furthermore, in S1 and S2, the organic solvent is independently selected from one or more of anhydrous ethanol, methanol, tetrahydrofuran, ethyl acetate, acetonitrile, toluene, acetone, dichloromethane, chloroform, and N,N-dimethylformamide.

[0021] Furthermore, in S3, the solvents for the organic ionic compound solution and the salt solution containing the target anion are independently selected from one or more of deionized water, acetone, and tetrahydrofuran.

[0022] The second aspect of the present invention provides an adhesive prepared by the method described in the first aspect.

[0023] Furthermore, the adhesive is degummed and recovered by rinsing or soaking with small molecule alcohol solvents.

[0024] The beneficial effects of this invention are:

[0025] This invention converts PET into small molecule compounds through aminolysis / ester exchange reactions, and prepares organic ionic monomer compounds through ionization and anion exchange reactions. These organic ionic monomer compounds crosslink with each other through dehydration to form a three-dimensional polymer network. Through the self-assembly of multiple hydrogen bonds, the ionic polymers can form internal aggregate structures, which not only form strong hydrogen bonds with the surfaces of various substrate materials, thus generating excellent interfacial adhesion, but also construct a rich dynamic non-covalent crosslinked network within the material. This network, in synergy with electrostatic interactions, significantly enhances the cohesive energy of the adhesive, resulting in excellent macroscopic bonding properties and superior adhesion in adhesives.

[0026] The adhesive obtained by this invention can be recycled and reused under specific conditions, enabling the performance of organic ion polymer adhesives to meet specific production needs. In addition, using waste PET as raw material is of great significance in solving environmental pollution and resource recycling. Attached Figure Description

[0027] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is the infrared absorption spectrum of the adhesive obtained in Example 1 of the present invention;

[0029] Figure 2 This is the infrared absorption spectrum of the adhesive obtained in Example 2 of the present invention;

[0030] Figure 3 These are the shear strength test results of the adhesive obtained in Example 1 of the present invention on different substrates;

[0031] Figure 4 This is a macroscopic weighing test of the adhesive obtained in Example 1 of the present invention after bonding the substrate;

[0032] Figure 5 These are the shear strength data of the adhesive obtained in Example 1 of the present invention on ceramic and stainless steel substrates after ethanol solvent recovery. Detailed Implementation

[0033] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This embodiment relates to a method for preparing ionomer adhesives based on PET degradation, including the following steps:

[0035] S1. In an organic solvent, a small molecule with an amino or hydroxyl group at one end and an organic cationic precursor at the other end undergoes an aminolysis or transesterification reaction with PET to obtain an intermediate.

[0036] S2. In an organic solvent, the intermediate and the haloalkane undergo an ionization reaction to obtain an organic ionic compound;

[0037] S3. Mix the organic ionic compound solution with a salt solution containing the target anion to carry out anion exchange reaction, thereby obtaining an organic ionic monomer compound; wherein the target anion is selected from CH3COO. － CF3COO － BF4 － PF6 － OTf － NCN2 － and NTF2 － One or more of them;

[0038] S4. The organic ionic monomer compound is heated to carry out a polymerization reaction to obtain an ionic polymer adhesive based on PET degradation.

[0039] This embodiment uses waste PET as raw material to prepare organic ionic monomer compounds through PET degradation, ionization reaction, and anion exchange reaction. The organic ionic monomer compounds cross-link with each other through dehydration to form a three-dimensional polymer network. The ionic polymer exhibits excellent macroscopic bonding performance when used as an adhesive. At the same time, it can be recycled and reused under specific conditions, allowing the performance of the organic ionic polymer adhesive to meet specific production needs.

[0040] In a preferred embodiment, in S1, the small molecule is selected from one or more of the following compounds: .

[0041] In a preferred embodiment, in S2, the haloalkane is selected from one or more of the following compounds: .

[0042] This embodiment utilizes specific small molecules and halogenated hydrocarbons. Through the self-assembly of multiple hydrogen bonds, the ionomer can form an internal aggregate structure, enabling it to form strong hydrogen bonds with various substrate materials, resulting in excellent interfacial adhesion. Simultaneously, these hydrogen bonds also construct a rich dynamic non-covalent cross-linked network within the material, synergistically enhancing the cohesive energy of the adhesive in conjunction with electrostatic interactions. This interfacial-bulk interaction mechanism allows the prepared ionomer to exhibit superior macroscopic adhesive properties when used in adhesives. Furthermore, the type of end group selected during the ionization reaction and the target anion used in the anion exchange step both affect the water solubility and glass transition temperature of the ionomer. Therefore, the physicochemical properties of ionomer adhesives can be controllably adjusted by flexibly combining cations with different end groups and different types of anions.

[0043] In a preferred embodiment, in S1, the temperature of the aminolysis or transesterification reaction is 70-100°C and the time is 20-30h; in S2, the conditions for the ionization reaction are: inert atmosphere protection, temperature 25-110°C, time 5-72h; in S4, the temperature of the polymerization reaction is 50-200°C and the time is 1-24h.

[0044] In a preferred embodiment, in S1 and S2, the organic solvent is independently selected from one or more of anhydrous ethanol, methanol, tetrahydrofuran, ethyl acetate, acetonitrile, toluene, acetone, dichloromethane, chloroform, and N,N-dimethylformamide; in S3, the solvents of the organic ionic compound solution and the salt solution containing the target anion are independently selected from one or more of deionized water, acetone, and tetrahydrofuran.

[0045] Another embodiment provides an adhesive prepared by the method described in the above embodiments, wherein the adhesive is degummed and recovered by rinsing or soaking in a small molecule alcohol solvent, wherein the small molecule alcohol solvent is selected from one or more of methanol, ethanol, and isopropanol.

[0046] Example 1

[0047] This embodiment relates to a method for preparing ionomer adhesives based on PET degradation, comprising the following steps:

[0048] (1) Weigh 1 mmol PET and 1 mmol 1-(3-aminopropyl)imidazolium and dissolve them in 20 ml ethyl acetate. Stir continuously at 80 °C for 24 h. After the reaction is complete, the product is obtained in the form of a precipitate. The product is collected directly and washed with ethyl acetate. After vacuum drying, the imidazolium-containing raw material is obtained with a yield of 87%.

[0049] (2) Weigh 2 mmol of 4-(bromomethyl)phenylboronic acid and 1 mmol of the PET degradation imidazole-containing raw material obtained in step (1) and dissolve them in 20 mL of acetonitrile. Under the condition of continuously purging inert gas Ar into the flask, the mixture is stirred continuously at 90 °C for 48 h. After the reaction is completed and cooled, the mixture is precipitated in ethyl acetate and the product is collected. After vacuum drying, an organic ionic compound with halogen anion is obtained with a yield of 71%.

[0050] (3) Weigh 1 mmol of the halogen anion obtained in step (2) and dissolve it in 100 ml of deionized water to obtain mixture A. Separately, weigh 1 mmol of lithium bis(trifluoromethanesulfonyl)imide (LiNTf2) and dissolve it in 150 ml of deionized water to obtain mixture B. Mixtures A and B are mixed at room temperature and stirred for about 12 h. The precipitate is collected and washed with deionized water, then vacuum dried to finally obtain the imidazole-type bis(trifluoromethanesulfonyl)imide salt ionic monomer compound with a yield of 93%. The structural formula is: .

[0051] The NMR characterization of ionic monomeric compounds is as follows: 1 H NMR (400 MHz, DMSO- d 6) δ 9.30 (d, J =1.8 Hz, 2H), 8.73 – 8.65 (m, 2H), 8.12 (s, 4H), 7.93 (s, 4H), 7.88 – 7.78 (m,8H), 7.36 (d, J = 7.8 Hz, 4H), 5.42 (s, 4H), 4.25 (t, J = 6.0 Hz, 4H), 3.30(t, J = 6.0 Hz, 4H), 2.09 (p, J = 6.8 Hz, 4H). 13 C NMR (100 MHz, DMSO- d 6) δ166.34, 137.07, 136.91, 136.80, 135.17, 127.65, 127.62, 123.37, 123.09,122.43, 119.95, 52.51, 47.50, 36.56, 30.04.

[0052] (4) Weigh 1 mmol of the ionic monomer compound obtained in step (3) and heat it to 60°C under vacuum for 30 minutes to obtain the ionic polymer adhesive PIL-1 with a yield of 100%.

[0053] Example 2

[0054] The difference between this embodiment and Example 1 is that step (2) 4-(bromomethyl)phenylboronic acid is replaced with 3-(bromomethyl)phenylboronic acid, while other steps and parameters remain unchanged. This prepares an ionic monomer compound and an ionic polymer adhesive PIL-2. The structural formula of the ionic monomer compound is: .

[0055] The NMR characterization of ionic monomeric compounds is as follows: 1 H NMR (400 MHz, DMSO- d 6) δ 9.31 (d, J=1.8 Hz, 2H), 8.70 – 8.65 (m, 2H), 8.14 (s, 4H), 7.90 (s, 4H), 7.85 – 7.70 (m,6H), 7.30-7.40 (m, 4H), 7.23-6.91 (m, 2H), 5.40 (s, 4H), 4.26 (t, J = 6.0 Hz, 4H), 3.31 (t, J = 6.0 Hz, 4H), 2.16 (p, J = 6.8 Hz, 4H). 13 C NMR (101 MHz, DMSO) δ 166.31, 138.31, 136.84, 136.02, 135.47, 135.15, 128.16, 127.59,123.38, 123.02, 122.31, 120.97, 119.95, 52.47, 47.44, 36.49, 30.48.

[0056] Example 3

[0057] The difference between this embodiment and Example 1 is that lithium bis(trifluoromethanesulfonyl)imide in step (3) is replaced with lithium hexafluorophosphate (LiPF6), while other steps and parameters remain unchanged. This prepares an ionic monomer compound and an ionic polymer adhesive PIL-3. The structural formula of the ionic monomer compound is: .

[0058] The NMR characterization of ionic monomeric compounds is as follows: 1 H NMR (400 MHz, DMSO- d 6) δ 9.31 (d, J =1.6 Hz, 2H), 8.72 – 8.63 (m, 2H), 8.12 (s, 4H), 7.93 (s, 4H), 7.88 – 7.78 (m,8H), 7.36 (d, J = 7.6 Hz, 4H), 5.42 (s, 4H), 4.25 (t, J = 6.0 Hz, 4H), 3.30(t, J = 6.0 Hz, 4H), 2.09 (p, J = 6.8 Hz, 4H). 13C NMR (101 MHz, DMSO) δ166.72, 137.45, 137.29, 137.18, 136.37, 135.55, 128.03, 128.01, 125.13,123.75, 123.47, 122.81, 52.89, 47.88, 36.93, 30.42.

[0059] Test case

[0060] Figure 1-2 The infrared absorption spectra of the ionic polymers obtained in Examples 1 and 2 are shown respectively, indicating that the cross-linked polymers were successfully obtained.

[0061] Figure 3 The adhesive obtained in Example 1 was subjected to a single-lap shear test on copper, aluminum, stainless steel, ceramic, glass, epoxy resin, acrylic, and polytetrafluoroethylene substrates (adhesion area 1 cm²). 2 ), at room temperature for 100 mm min -1 The shear strength data of the bond was measured at the test speed. The data results show that PIL-1 has high bond strength, especially the highest bond strength on ceramic substrates.

[0062] Two stainless steel sheets were bonded together using the adhesive obtained in Example 1. A rope was fixed to one end of the bonded joint, and a weight was suspended from the other end. The bonding surface of the ceramic sheet was 0.5 cm in size. 2 After the adhesive has fully cured, the ceramic tile bonded surface can support a weight of 20kg, such as... Figure 4 As shown.

[0063] The adhesive obtained in Example 1 was degummed with ethanol, and the recovered solution was dried at 80°C. Single-lap shear tests were then performed on ceramic and stainless steel substrates. The shear strength at the bond joint was measured at room temperature. The results showed that the adhesive still exhibited high bonding strength on stainless steel and ceramic substrates after PIL-1 solvent recovery. Figure 5 As shown.

[0064] In summary, this invention converts PET into small molecule compounds through aminolysis / ester exchange reactions, and prepares organic ionic monomer compounds through ionization and anion exchange reactions. These organic ionic monomer compounds cross-link with each other through dehydration to form a three-dimensional polymer network. Through the self-assembly of multiple hydrogen bonds, the ionic polymers can form internal aggregate structures, not only forming strong hydrogen bonds with various substrate materials, thus generating excellent interfacial adhesion, but also constructing a rich dynamic non-covalent cross-linked network within the material. This network, synergistic with electrostatic interactions, significantly enhances the cohesive energy of the adhesive, resulting in superior macroscopic bonding properties and excellent adhesion. The adhesives obtained by this invention can be recycled and reused under specific conditions, allowing the performance of organic ionic polymer adhesives to meet specific production needs. Furthermore, using waste PET as a raw material is of great significance in addressing environmental pollution and resource recycling.

[0065] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A method for preparing an ionomeric adhesive based on PET degradation, characterized by, The method comprises the following steps: S1. In an organic solvent, aminolysis or transesterification reaction of a small molecule with amine group or hydroxyl group at one end and organic cation precursor at the other end with PET to obtain an intermediate; S2. In an organic solvent, ionization reaction of the intermediate and halogenated hydrocarbon to obtain an organic ionic compound; S3, mixing the organic ionic compound solution with a salt solution containing a target anion to perform an anion exchange reaction to obtain an organic ionic monomer compound; wherein the target anion is selected from one or more of CH3COO － , CF3COO － , BF4 － , PF6 － , OTf － , NCN2 － , and NTf2 － . S4. Polymerization reaction of the organic ionic monomer compound by heating to obtain an ionic polymer adhesive prepared based on PET degradation; In S1, the small molecule is selected from one or more of the following compounds: ; In S2, the halogenated hydrocarbon is selected from one or more of the following compounds: 。 2. The method for preparing an ionomeric adhesive based on PET degradation according to claim 1, characterized in that, In S1, the temperature of the aminolysis or transesterification reaction is 70-100℃, and the time is 20-30h.

3. The method for preparing an ionomeric adhesive based on PET degradation according to claim 1, wherein, In S2, the ionization reaction conditions are: inert atmosphere protection, temperature 25-110℃, and time 5-72h.

4. The method for preparing an ionomeric adhesive based on PET degradation according to claim 1, wherein, In S4, the temperature of the polymerization reaction is 50-200℃, and the time is 1-24h.

5. The method for preparing an ionomeric adhesive based on PET degradation according to claim 1, wherein, In S1 and S2, the organic solvent is independently selected from one or more of the following: anhydrous ethanol, methanol, tetrahydrofuran, ethyl acetate, acetonitrile, toluene, acetone, dichloromethane, chloroform, and N,N-dimethylformamide.

6. The method for preparing an ionomeric adhesive based on PET degradation according to claim 1, wherein, In S3, the solvents of the organic ionic compound solution and the salt solution containing target anions are independently selected from one or more of the following: deionized water, acetone, and tetrahydrofuran.

7. An adhesive obtained by the method of any one of claims 1-6.

8. The adhesive of claim 7, wherein The adhesive is degummed by flushing or soaking with a small-molecule alcohol solvent and recovered.

Images