Imine-based thermoplastic polymers, methods of making and using the same

Abstract

The present application relates to an imino-based thermoplastic polymer and its preparation method and application. The imino-based thermoplastic polymer is obtained by the reaction of at least one aldehyde-based monomer as shown in formula (1) and formula (2) and at least one crosslinking agent as shown in formula (3) and formula (4), the imino-based thermoplastic polymer has excellent mechanical properties, thermal properties, solvent resistance and reworkability, and the hot processing type crosslinked hot melt adhesive material prepared by using the imino-based thermoplastic polymer can not only be hot processed and easily implemented, but also has high bonding efficiency and can be recycled.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to an imino-based thermoplastic polymer, its preparation method, and its applications. Background Technology

[0002] Hot melt adhesive is a type of malleable adhesive whose physical state changes with temperature within a certain temperature range, while its chemical properties remain unchanged. It is non-toxic, odorless, and considered an environmentally friendly chemical product. Its popularity stems from its solid nature, facilitating packaging, transportation, and storage; its solvent-free, pollution-free, and non-toxic properties; and its simple production process, high added value, strong bonding strength, and fast processing speed. Currently, hot melt adhesive materials are widely used in our lives, primarily composed of thermoplastic resins. When heated to a certain temperature, hot melt adhesive transforms from a solid to a molten state. After being applied to the surface of engineered wood substrates or edge banding materials, it cools and solidifies, bonding the material to the substrate.

[0003] However, thermoplastic hot melt adhesives also have some drawbacks: 1. They have limitations in performance, such as insufficient heat resistance, limited bonding strength, and poor chemical resistance; 2. Manual application is not effective, wastes adhesive material, and is difficult to control. Therefore, special equipment such as hot melt glue guns are required for melting and applying the adhesive, which is inconvenient to use and thus limits its use and promotion. Summary of the Invention

[0004] Therefore, it is necessary to provide an imino-based thermoplastic polymer, its preparation method, and its application to address the above-mentioned problems. The imino-based thermoplastic polymer has excellent mechanical properties, thermal properties, solvent resistance, and reprocessability. The hot-processable cross-linked hot melt adhesive material prepared using it is not only heat-processable and easy to implement, but also has high bonding efficiency and can be repeatedly recycled.

[0005] An imino thermoplastic polymer is obtained by reacting at least one aldehyde monomer as shown in formulas (1) and (2) with at least one crosslinking agent as shown in formulas (3) and (4).

[0006]

[0007] R5 is selected from aldehyde, hydroxyl, and epoxy groups;

[0008] R6 is selected from

[0009] R1, R1′, R2, R2′, R3, and R3′ are each independently selected from H, hydroxyl, methyl, ethyl, n-propyl, isopropyl, or butyl.

[0010] R4 is selected from H, hydroxyl, C1-C8 straight-chain or branched alkyl, and C1-C8 straight-chain or branched heteroalkyl.

[0011] R7 is selected from C2-C15 straight-chain or branched alkylene groups, C6-C20 aryl groups, and straight-chain or branched groups of length 2-70 formed by combining at least one of oxygen atom, sulfur atom, silicon atom, and nitrogen atom with carbon atom.

[0012] R 11 Selected from amino, Wherein, L1 is selected from C1-C15 alkylene or C1-C15 heteroalkylene, and L2 is selected from C1-C15 alkyl or C1-C15 heteroalkyl.

[0013] R 12 Selected from Among them, R8, R9, R 10 R is independently selected from substituted or unsubstituted alkylene groups and C1-C15 substituted or unsubstituted heteroalkylene groups. 13 Selected from nitrogen atoms or R c Selected from H, -OC2H3, C1-C15 substituted or unsubstituted alkyl groups, and C1-C15 substituted or unsubstituted heteroalkyl groups.

[0014] In one embodiment, R7 is selected from straight-chain alkylene groups having 2-15 carbon atoms, -C2H4-O-C2H4-, -C2H4-O-C2H4-O-C2H4-, ...

[0015] Where, k = 2-34, n = 2-34, m = 2-34, x = 1-10, y = 1-66.

[0016] In one embodiment, when R 11 Selected from In this case, R7 is selected from straight-chain alkylene groups having 2-15 carbon atoms, -C2H4-O-C2H4-, -C2H4-O-C2H4-O-C2H4-, or... Where k = 2 - 34.

[0017] In one embodiment, when R8, R9, R 10 When R8, R9, and R are independently selected from substituted alkylene groups or substituted heteroalkylene groups of C1-C15, respectively... 10 The number of substituents in the middle is independently selected from 1 to 3, R8, R9, R 10 The substituents are independently selected from C1-C10 alkyl, C2-C10 alkenyl, C1-C10 heteroalkyl or C2-C10 heteroalkenyl;

[0018] And / or, L1 is selected from -CH2-O-C2H4-, -CH2-O-C3H6-, -CH2-O-C4H8-, -CH2-O-C5H 10 -,-CH2-O-C6H 12 -、-CH2-O-C7H 14 -,-CH2-O-C8H 16 -、-CH2-O-C9H 18 -, -CH2-OC 10 H 20 -, -CH2-OC 11 H 22 -, -CH2-OC 12 H 24 -, -CH2-OC 13 H 26 -or -CH2-O-C2H4-O-C2H4-.

[0019] In one embodiment, the imino thermoplastic polymer has at least one of the structures shown in formula (I), formula (II), and formula (III):

[0020]

[0021]

[0022] Among them, R1, R1′, R2, R2′, R3, and R3′ are independently selected from H, hydroxyl, methyl, ethyl, n-propyl, isopropyl, or butyl, respectively;

[0023] R4 is selected from H, hydroxyl, and C1-C6 straight-chain or branched alkyl groups;

[0024] R5′ is selected from -O-,

[0025] R6 is selected from

[0026] R7 is selected from -C2H4-O-C2H4-O-C2H4-, Where, k = 2-34, n = 2-34, m = 1-10, x = 1-10, y = 1-66;

[0027] R8, R9, R 10 Each is independently selected from ethylidene or propyleneide;

[0028] R 11 Selected from amino or

[0029] A method for preparing the imine-based thermoplastic polymer as described above includes the following steps:

[0030] An aldehyde monomer, a crosslinking agent, and a solvent are pre-reacted at 60°C-140°C and then cured at 80°C-180°C to obtain an imino thermoplastic polymer, wherein the aldehyde monomer is at least one of the above formulas (1) and (2), and the crosslinking agent is at least one of the above formulas (3) and (4).

[0031] In one embodiment, the molar ratio of the crosslinking agent to the aldehyde monomer is 1:2-5:2.

[0032] In one embodiment, the aldehyde monomer is selected from at least one of terephthalaldehyde, o-phthalaldehyde, isophthalaldehyde, pyromellitic trialdehyde, vanillin, vanillin-derived trialdehyde compounds, vanillin epoxy, 2-hydroxy-1-naphthaldehyde, 2,5-dihydroxybenzaldehyde, 5-aldehyde-2-methoxyphenylboronic acid, and 3-fluoro-4-aldehyde-phenylboronic acid.

[0033] And / or, the crosslinking agent is selected from at least one of polyetheramine D230, polyetheramine D400, polyetheramine D2000, UPy-polyetheramine, hexamethylenediamine, octyldiamine, decanediamine, poly(dimethylsiloxane) bis(3-aminopropyl)-terminated (Mn = 1000, 2000 or 5000), 4,4-diaminodiphenylmethane, melamine, tris(2-aminoethyl)amine, and TUGE3 diamine monomers containing SH bonds prepared from 1,1-thiocarbonyldiimidazole and 2,2′-(ethylenedioxy)bis(ethylamine).

[0034] In one embodiment, the pre-reaction time is 1-5 hours;

[0035] And / or, the curing time is 2h-6h;

[0036] And / or, the heating method for the curing process is selected from gradient heating.

[0037] An imine-based thermoplastic polymer as described above is used to prepare a heat-processable crosslinked hot melt adhesive material.

[0038] The imine-based thermoplastic polymer described in this invention possesses a dynamic imine bond (-C=N-) covalent crosslinking network, resulting in excellent dynamic properties, thermal properties, and solvent resistance. Its Young's modulus reaches 5 MPa-20 MPa, tensile strength reaches 1 MPa-15 MPa, and elongation at break reaches 4%-500%. It can undergo rapid exchange at high temperatures, making it reprocessable and recyclable. Furthermore, the imine-based thermoplastic polymer contains various types of hydrogen bonds, resulting in high surface energy and excellent adhesive properties. Simultaneously, the dynamic characteristics of the imine bonds give the polymer excellent replasticity, thereby achieving thermal bonding.

[0039] Therefore, the hot-processable cross-linked hot melt adhesive material prepared using the imino-based thermoplastic polymer is stable at ambient temperature, and is not only hot-processable and easy to implement, but also has high bonding efficiency and can be repeatedly recycled. Attached Figure Description

[0040] Figure 1 The infrared spectrum of the imino-based thermoplastic polymer prepared in Example 1 of this invention. Detailed Implementation

[0041] To facilitate understanding of the present invention, it will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. Rather, these embodiments or examples are provided to make the disclosure of the present invention more thorough and complete.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments or examples only and is not intended to be limiting of the invention.

[0043] This invention provides an imino-based thermoplastic polymer, obtained by reacting at least one aldehyde monomer as shown in formulas (1) and (2) with at least one crosslinking agent as shown in formulas (3) and (4).

[0044]

[0045] R5 is selected from aldehyde, hydroxyl, and epoxy groups;

[0046] R6 is selected from

[0047] R1, R1′, R2, R2′, R3, and R3′ are each independently selected from H, hydroxyl, methyl, ethyl, n-propyl, isopropyl, or butyl.

[0048] R4 is selected from H, hydroxyl, C1-C8 straight-chain or branched alkyl, and C1-C8 straight-chain or branched heteroalkyl.

[0049] R7 is selected from C2-C15 straight-chain or branched alkylene groups, C6-C20 aryl groups, and straight-chain or branched groups of length 2-70 formed by combining at least one of oxygen atom, sulfur atom, silicon atom, and nitrogen atom with carbon atom.

[0050] R 11 Selected from amino, Wherein, L1 is selected from C1-C15 alkylene or C1-C15 heteroalkylene, and L2 is selected from C1-C15 alkyl or C1-C15 heteroalkyl.

[0051] R 12 Selected from Among them, R8, R9, R 10 R is independently selected from substituted or unsubstituted alkylene groups and C1-C15 substituted or unsubstituted heteroalkylene groups. 13 Selected from nitrogen atoms or R c Selected from H, -OC2H3, C1-C15 substituted or unsubstituted alkyl groups, and C1-C15 substituted or unsubstituted heteroalkyl groups.

[0052] The aforementioned imine-based thermoplastic polymer possesses a dynamic imine bond (-C=N-) covalent crosslinking network, resulting in excellent dynamic properties, thermal properties, and solvent resistance. Its Young's modulus reaches 5MPa-20MPa, tensile strength reaches 1MPa-15MPa, and elongation at break reaches 4%-500%. It can undergo rapid exchange at high temperatures, making it reprocessable and recyclable. Furthermore, the imine-based thermoplastic polymer contains various types of hydrogen bonds, resulting in high surface energy and excellent adhesive properties. Simultaneously, the dynamic characteristics of the imine bonds give the polymer excellent replasticity, thereby achieving thermal bonding.

[0053] It should be noted that when R7 is selected from at least one of oxygen atom, sulfur atom, silicon atom, and nitrogen atom combined with carbon atom to form a straight-chain or branched group with a length of 2-70, the degree of polymerization of the polymer chain segment formed by the combination of at least one of oxygen atom, sulfur atom, silicon atom, and nitrogen atom with carbon atom corresponds to one length of R7.

[0054] Preferably, R7 is selected from straight-chain alkylene groups having 2-15 carbon atoms, -C2H4-O-C2H4-, -C2H4-O-C2H4-O-C2H4- Wherein, k = 2-34, including but not limited to k = 2, k = 8, k = 12, k = 16, k = 20, k = 24, k = 28, k = 32, k = 34; n = 2-34, including but not limited to n = 2, n = 8, n = 12, n = 16, n = 20, n = 24, n = 28, n = 32, n = 34; m = 2-34, including but not limited to m = 2, m = 8, m = 12, m = 16, m = 20, m = 24, m = 28, m = 32, m = 34; x = 1-10; y = 1-66, including but not limited to y = 8, y = 12, y = 16, y = 20, y = 24, y = 30, y = 36, y = 42, y = 48, y = 54, y = 60, y = 64, y = 66.

[0055] As a preferred option, when R 11 Selected from In this case, R7 is selected from straight-chain alkylene groups having 2-15 carbon atoms, -C2H4-O-C2H4-, -C2H4-O-C2H4-O-C2H4-, or... Where k = 2 - 34.

[0056] As a preferred option, when R8, R9, R 10 When R8, R9, and R are independently selected from substituted alkylene groups or substituted heteroalkylene groups of C1-C15, respectively... 10 The number of substituents in the middle is independently selected from 1 to 3, R8, R9, R 10 The substituents are independently selected from C1-C10 alkyl, C2-C10 alkenyl, C1-C10 heteroalkyl or C2-C10 heteroalkenyl.

[0057] Preferably, L1 is selected from -CH2-O-C2H4-, -CH2-O-C3H6-, -CH2-O-C4H8-, and -CH2-O-C5H. 10 -,-CH2-O-C6H 12 -、-CH2-O-C7H 14 -,-CH2-O-C8H 16 -、-CH2-O-C9H 18 -, -CH2-OC 10 H 20 -, -CH2-OC 11 H 22 -, -CH2-OC 12 H 24 -, -CH2-OC 13 H 26 -or -CH2-O-C2H4-O-C2H4-.

[0058] The aldehyde groups in formulas (1) and (2) can bond with the amino groups in formulas (3) and (4) to form various imine covalent cross-linked network structures. In one embodiment, the imine thermoplastic polymer has at least one of the structures shown in formulas (I), (II), and (III):

[0059]

[0060]

[0061] Among them, R1, R1′, R2, R2′, R3, and R3′ are each preferably H, hydroxyl, methyl, ethyl, n-propyl, isopropyl, or butyl, and are more preferably H.

[0062] R4 is preferably H, hydroxyl, or a straight-chain or branched alkyl group of C1-C6, and is more preferably H.

[0063] R5′ is preferably -O-, Further preferred

[0064] R6 is selected from

[0065] R7 is preferably -C2H4-O-C2H4-O-C2H4-, Where, k = 2-34, n = 2-34, m = 1-10, x = 1-10, y = 1-66.

[0066] R8, R9, R 10 Ethylene or propylene is preferred, each independently.

[0067] R 11 Preferably amino or

[0068] Furthermore, when R 11 Preferred At that time, R7 is more preferred.

[0069] The present invention also provides a method for preparing the imino-based thermoplastic polymer as described above, comprising the following steps:

[0070] An aldehyde monomer, a crosslinking agent, and a solvent are pre-reacted at 60°C-140°C and then cured at 80°C-180°C to obtain an imino thermoplastic polymer, wherein the aldehyde monomer is at least one of the above formulas (1) and (2), and the crosslinking agent is at least one of the above formulas (3) and (4).

[0071] Preferably, the molar ratio of the crosslinking agent to the aldehyde monomer is 1:2-5:2, more preferably 1.5:2-3:2, calculated by reactive groups, which can make the imino thermoplastic polymer have better bonding properties.

[0072] Specifically, the aldehyde monomer is preferably at least one of terephthalaldehyde, o-phthalaldehyde, isophthalaldehyde, trimesonaldehyde, vanillin, vanillin-derived trialdehyde compounds, vanillin epoxy, 2-hydroxy-1-naphthaldehyde, 2,5-dihydroxybenzaldehyde, 5-aldehyde-2-methoxyphenylboronic acid, and 3-fluoro-4-aldehyde-phenylboronic acid, and more preferably at least one of terephthalaldehyde, trimesonaldehyde, vanillin, vanillin-derived trialdehyde compounds, and vanillin epoxy.

[0073] It should be noted that derivatives of terephthalaldehyde, o-phthalaldehyde, iso-phthalaldehyde, vanillin, 2-hydroxy-1-naphthaldehyde, 2,5-dihydroxybenzaldehyde, 5-aldehyde-2-methoxyphenylboronic acid, 3-fluoro-4-aldehyde-phenylboronic acid, and other derivatives containing aldehyde functional groups can all be used as aldehyde monomers.

[0074] The crosslinking agent is selected from polyetheramine D230, polyetheramine D400, polyetheramine D2000, UPy-polyetheramine, hexamethylenediamine, octyldiamine, decanediamine, poly(dimethylsiloxane) bis(3-aminopropyl)-terminated (Mn = 1000, 2000 or 5000), 4,4-diaminodiphenylmethane, melamine, tris(2-aminoethyl)amine, or prepared from 1,1-thiocarbonyldiimidazole and 2,2′-(ethylenedioxy)bis(ethylamine). At least one of the TUGE3 diamine monomers containing SH bonds, more preferably at least one of the following: polyetheramine D400, UPy-polyetheramine, 4,4-diaminodiphenylmethane, poly(dimethylsiloxane) bis(3-aminopropyl)-terminated (Mn=1000), tris(2-aminoethyl)amine, and at least one of the TUGE3 diamine monomers containing SH bonds prepared from 1,1-thiocarbonyldiimidazole and 2,2′-(ethylenedioxy)bis(ethylamine).

[0075] The preparation method of the trialdehyde compound derived from vanillin includes: dissolving vanillin and triethylamine in chloroform (the concentration of vanillin in chloroform is 0.5 g / mL-0.6 g / mL, and the concentration of triethylamine in chloroform is 0.3 g / mL-0.4 g / mL), dissolving phosphorus oxychloride in chloroform (the concentration of phosphorus oxychloride in chloroform is 0.6 g / mL-0.7 g / mL), and then mixing and reacting the two mixed solutions at 40℃-60℃ for 5 h-7 h. After precipitation, a yellow solid is obtained, which is washed and dried to obtain the trialdehyde compound.

[0076] The preparation method of UPy-polyetheramine includes: reacting ethyl acetoacetate and guanidine carbonate suspension in ethanol at a mass ratio of 1:(1-1.2) under reflux, filtering and washing the reaction solution to obtain a white powdery first intermediate; reacting the first intermediate with N,N'-carbazide imidazole suspension at a mass ratio of 1:(1-2) at 70℃-90℃ for 2-3 hours, filtering and washing the reaction solution to obtain a white powdery second intermediate; and reacting the second intermediate with polyetheramine at a mass ratio of 1:(5-6) at 40℃-50℃ for 10-14 hours to obtain liquid UPy-polyetheramine. Depending on the type of polyetheramine raw material used (e.g., polyetheramine D230, polyetheramine D400, polyetheramine D2000), UPy-polyetheramine 230, UPy-polyetheramine 400, UPy-polyetheramine 2000, etc., can be prepared.

[0077] The preparation method of vanillin epoxy includes: reacting vanillin, epichlorohydrin and tetrabutylammonium bromide (the concentration of vanillin in epichlorohydrin is 0.1 g / mL-0.2 g / mL, and the concentration of tetrabutylammonium bromide in epichlorohydrin is 0.006 g / mL-0.007 g / mL) at 80℃-120℃ for 2h-3h, cooling, adding 50% NaOH aqueous solution dropwise, and then reacting in an ice bath for 3h-4h to obtain light yellow solid vanillin epoxy.

[0078] The preparation method of TUGE3 diamine monomer containing SH bonds prepared from 1,1-thiocarbonyldiimidazole and 2,2′-(ethylenedioxy)bis(ethylamine) includes: stirring 2,2′-(ethylenedioxy)bis(ethylamine) and 1,1′-thiocarbonyldiimidazole in an organic solvent at 25°C for 22-26 h in a mass ratio of 1:(1-1.2); redepositing the reactants twice in chloroform / ethanol; and drying to obtain TUGE3 diamine monomer containing SH bonds.

[0079] The solvent is selected from organic solvents, including but not limited to toluene, and preferably toluene.

[0080] Preferably, the temperature of the pre-reaction is 80℃-140℃, more preferably 100℃-120℃; the time of the pre-reaction is 1h-5h, more preferably 2h-3h.

[0081] In one embodiment, the pre-reaction effect is better when the temperature is preferably 95℃-115℃ and the time is preferably 1.5h-2h.

[0082] Preferably, the high-temperature curing treatment is performed at a temperature of 100℃-180℃ for 2 hours to 6 hours.

[0083] In one embodiment, the curing treatment heating method is selected from gradient heating, specifically including: curing the pre-reacted reaction system at 80℃-120℃ for 0.5h-4h, then curing at 120℃-160℃ for 1.5h-2.5h, and finally curing at 160℃-180℃ for 1.5h-2.5h.

[0084] The raw materials used in this invention are all commercially available raw materials or derivatives synthesized from commercially available raw materials. The entire preparation process is simple, has a short cycle, and is easy to industrialize.

[0085] The present invention also provides an imino-based thermoplastic polymer as described above for preparing a heat-processable crosslinked hot melt adhesive material.

[0086] The hot-processable cross-linked hot melt adhesive material prepared using the imino-based thermoplastic polymer described in this invention is stable at ambient temperature, and is not only heat-processable and easy to implement, but also has high bonding efficiency and can be repeatedly recycled.

[0087] In one embodiment, a method for applying an imino-based thermoplastic polymer in a thermoprocessable crosslinked hot melt adhesive material includes: spreading the imino-based thermoplastic polymer on the surface of the materials to be bonded, heating it for 3-5 minutes at a temperature higher than the glass transition temperature and lower than the decomposition temperature, and then rapidly cooling it at room temperature to achieve interfacial bonding.

[0088] The following specific examples will further illustrate the imino-based thermoplastic polymer, its preparation method, and its applications.

[0089] Example 1

[0090] 100.419 g of vanillin and 66.785 g of triethylamine were dissolved in 200 mL of chloroform, and 30.666 g of phosphorus oxychloride was dissolved in 50 mL of chloroform. The two mixed solutions were then added to a three-necked flask and reacted for 2 h, followed by 6 h at 50 °C. After cooling to room temperature, the mixture was precipitated with 1000 mL of petroleum ether, resulting in a yellow solid. The solid was washed with ethanol and dried in a vacuum oven at 70 °C to obtain a trialdehyde compound.

[0091] A suspension of 6.51 g of ethyl acetoacetate and 6.66 g of guanidine carbonate was refluxed overnight in 300 mL of ethanol. The reaction mixture was then cooled, the precipitate was filtered, and the product was washed with ethanol, water, and acetone to obtain a white powdery first intermediate. 8.00 g of the first intermediate and 14.58 g of N,N'-carbazyldiimidazole suspension were added to 400 mL of DMSO and stirred at 80 °C for approximately 15 min. The mixture was then reacted at 80 °C for approximately 2 h, and the precipitate was filtered, washed with ethanol, and dried at 80 °C for 4 h to obtain 9.31 g of a white powdery second intermediate. 2.00 g of the second intermediate and 10.92 g of polyetheramine D400 were combined in a 100 mL flask and stirred at 40 °C for 12 h to obtain liquid UPy-polyetheramine 400.

[0092] Take 5g (0.01mol) of a trialdehyde compound prepared from vanillin, 7.434g (0.0375mol) of 4,4-diaminodiphenylmethane, and 2.13g of UPy-polyetheramine 400, add 15mL of toluene as a solvent, mix and stir evenly, and pre-react at 100℃ for 2 hours. Then, allow some of the solvent to evaporate. After the viscosity of the system increases, spread it evenly in a mold and pre-cur it at 80℃ for 2 hours. Then, cure it sequentially at 100℃ for 2 hours, 120℃ for 2 hours, and 160℃ for 2 hours. After stepwise temperature curing, an imino thermoplastic polymer is obtained. The structure of the imino thermoplastic polymer obtained in this example is shown in formula (Ⅰ-1), where n≈6.

[0093]

[0094] The imide-based thermoplastic polymer prepared in this embodiment had an elongation at break of 325% and a tensile strength of 4 MPa, as tested. Its infrared spectrum is as follows: Figure 1 As shown, the imino-based thermoplastic polymer prepared in this example was hot-pressed for 10 minutes at 100°C and 5 MPa using a flat vulcanizing apparatus, resulting in a complete network structure with excellent performance. Furthermore, bonding at the material interface was achieved with excellent performance after heating at 160°C for 1 minute.

[0095] Example 2

[0096] 20 g (0.1314 mol) of vanillin, 150 mL of epichlorohydrin, and 1 g (3.2 mmol) of tetrabutylammonium bromide were mixed in a round-bottom flask equipped with a constant pressure funnel and a magnetic stirrer, and reacted at 120 °C for 2 h. After cooling, 13.2 g of 50% NaOH aqueous solution was added dropwise over a certain period of time, and the mixture was then reacted in an ice bath for 3 h. The resulting mixture was washed with water 6 times, dried with anhydrous magnesium sulfate, precipitated with petroleum ether, and dried at 80 °C to obtain a light yellow solid vanillin epoxy.

[0097] Take 1.664g of vanillin epoxy and 6g of poly(dimethylsiloxane) bis(3-aminopropyl) end-capped (Mn=1000), add 15mL of toluene as solvent, mix and stir evenly, pre-react at 100℃ for 2 hours, then allow some solvent to evaporate, wait for the viscosity of the system to rise, spread it evenly in a mold and pre-cur it at 80℃ for 2 hours, then cure it sequentially at 100℃ for 2 hours, 120℃ for 2 hours, and 160℃ for 2 hours, that is, after step temperature curing, an imino-based thermoplastic polymer is obtained. The imino-based thermoplastic polymer obtained in this example is shown in the following formula (Ⅱ-1).

[0098]

[0099] Testing showed that the imino-based thermoplastic polymer obtained in this embodiment had an elongation at break of 70% and a tensile strength of 1.5 MPa. Using a flat vulcanizing apparatus, the imino-based thermoplastic polymer obtained in this embodiment was hot-pressed for 10 minutes at 100°C and 5 MPa to re-obtain the complete network structure, exhibiting excellent performance. Furthermore, bonding at the material interface was achieved with excellent performance after heating at 160°C for 1 minute.

[0100] Example 3

[0101] Take 3.35g (0.025mol) of terephthalaldehyde, 4g (0.01mol) of polyetheramine D400, and 1.46g (0.01mol) of tris(2-aminoethyl)amine, add 10mL of toluene as a solvent, mix and stir evenly, and pre-react at 100℃ for 2 hours. Then, allow some of the solvent to evaporate and wait for the viscosity of the system to increase. Spread it evenly in a mold and pre-cur it at 80℃ for 2 hours. Then, cure it sequentially at 100℃ for 2 hours, 120℃ for 2 hours, and 160℃ for 2 hours. After stepwise temperature curing, an imino-based thermoplastic polymer is obtained. The imino-based thermoplastic polymer obtained in this example is shown in formula (Ⅲ-1) below, where n≈6.

[0102]

[0103] Testing showed that the imino-based thermoplastic polymer obtained in this embodiment had an elongation at break of 230% and a tensile strength of 4 MPa. Using a flat vulcanizing apparatus, the imino-based thermoplastic polymer obtained in this embodiment was hot-pressed for 10 minutes at 100°C and 5 MPa to re-obtain the complete network structure, exhibiting excellent performance. Furthermore, bonding at the material interface was achieved with excellent performance after heating at 160°C for 1 minute.

[0104] Example 4

[0105] Take 4.0239 g (0.03 mol) of terephthalaldehyde, 4 g (0.01 mol) of polyetheramine D400, 1.46 g (0.01 mol) of tris(2-aminoethyl)amine, and 2.83 g of UPy-polyetheramine 400 prepared by the same method as in Example 1. Add 15 mL of toluene as a solvent, mix and stir evenly, and pre-react at 100 °C for 2 hours. Then, allow some of the solvent to evaporate and wait for the viscosity of the system to increase. Spread it evenly in a mold and pre-cur it at 80 °C for 2 hours. Then, cure it sequentially at 100 °C for 2 hours, 120 °C for 2 hours, and 160 °C for 2 hours. After stepwise temperature curing, an imino-based thermoplastic polymer is obtained. The imino-based thermoplastic polymer obtained in this example is shown in the following formula (Ⅲ-2), where n≈6.

[0106]

[0107] Testing showed that the imino-based thermoplastic polymer obtained in this embodiment had an elongation at break of 450% and a tensile strength of 3.2 MPa. Using a flat vulcanizing apparatus, the imino-based thermoplastic polymer obtained in this embodiment was hot-pressed for 10 minutes at 100°C and 5 MPa to re-obtain the complete network structure, exhibiting excellent performance. Furthermore, bonding at the material interface was achieved with excellent performance after heating at 160°C for 1 minute.

[0108] Example 5

[0109] 17.8 g of 1,1′-thiocarbonyldiimidazole was added to a 50 mL LMF solution containing 17.71 g of 2,2′-(ethylenedioxy)bis(ethylamine), and the mixture was stirred at 25 °C for 24 h. Chloroform was added to the solution, and the diluted mixture was poured into ethanol. The mixture was redeprecipitated twice from the chloroform / ethanol mixture, and the precipitate was dried at 140 °C for 12 h to obtain the TUGE3 diamine monomer containing SH bonds.

[0110] Take 2g (0.004mol) of the trialdehyde compound prepared by the same method as in Example 1, 8.94g (containing 0.12mol of NH2) of TUGE3 diamine monomer containing SH bonds, add 15mL of toluene as solvent, mix and stir evenly, pre-react at 100℃ for 2 hours, then allow some solvent to evaporate, wait for the viscosity of the system to rise, spread it evenly in a mold and pre-cur it at 80℃ for 2 hours, then cure it sequentially at 100℃ for 2 hours, 120℃ for 2 hours, and 160℃ for 2 hours, that is, after stepwise temperature curing, an imino thermoplastic polymer is obtained. The imino thermoplastic polymer obtained in this example is shown in the following formula (Ⅰ-2), where n≈5.

[0111]

[0112] Testing showed that the imino-based thermoplastic polymer obtained in this embodiment had an elongation at break of 170% and a tensile strength of 12 MPa. Using a flat vulcanizing apparatus, the imino-based thermoplastic polymer obtained in this embodiment was hot-pressed for 10 minutes at 100°C and 5 MPa to re-obtain the complete network structure, exhibiting excellent performance. Furthermore, bonding at the material interface was achieved with excellent performance after heating at 160°C for 1 minute.

[0113] Example 6

[0114] Take 0.649 g (0.004 mol) of pyromellitic trimethylolpropoxide and 8.94 g (containing 0.12 mol of NH2) of TUGE3 diamine monomer containing SH bonds prepared by the same method as in Example 5. Add 15 mL of toluene as a solvent, mix and stir evenly, and pre-react at 100 °C for 2 hours. Then, allow some of the solvent to evaporate and wait for the viscosity of the system to increase. Spread it evenly in a mold and pre-cur it at 80 °C for 2 hours. Then, cure it sequentially at 100 °C for 2 hours, 120 °C for 2 hours, and 160 °C for 2 hours. After stepwise temperature curing, an imino-based thermoplastic polymer is obtained. The imino-based thermoplastic polymer obtained in this example is shown in the following formula (Ⅰ-3), where n≈5.

[0115]

[0116] Testing showed that the imino-based thermoplastic polymer obtained in this embodiment had an elongation at break of 232% and a tensile strength of 10.6 MPa. Using a flat vulcanizing apparatus, the imino-based thermoplastic polymer obtained in this embodiment was hot-pressed for 10 minutes at 100°C and 5 MPa to re-obtain the complete network structure, exhibiting excellent performance. Furthermore, bonding at the material interface was achieved with excellent performance after heating at 160°C for 1 minute.

[0117] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments. For example, they used any one or more combinations of polyetheramine D230, polyetheramine D400, polyetheramine D2000, hexamethylenediamine, octanediamine, decanediamine, poly(dimethylsiloxane) bis(3-aminopropyl)-terminated (Mn = 1000, 2000, 5000), 2,4-diaminodiphenylmethane, melamine, and tri(2-aminoethyl)amine as crosslinking agents, and monomers such as terephthalaldehyde, o-phthalaldehyde, isophthalaldehyde and their derivatives, vanillin and its derivative monomer pyromellitic aldehyde as aldehyde monomers, and obtained relatively ideal results in all cases.

[0118] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0119] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An imino thermoplastic polymer, characterized by, The imino-based thermoplastic polymer has a structure as shown in formula (I) or formula (II): 、 ； R1´, R2´, and R3´ are each independently selected from H, hydroxyl, methyl, ethyl, n-propyl, isopropyl, or butyl; R5' is selected from -O-, ; R6is selected from or ; R7 is selected from -C2H4-O-C2H4-O-C2H4-, , , Where, k=2-34, n=2-34, m=1-10, x=1-10, y=1-66; R 11 selected from amino or .

2. A process for the preparation of the imino thermoplastic polymer according to claim 1, characterized in that, Includes the following steps: The aldehyde monomer, crosslinking agent, and solvent are pre-reacted at 60℃-140℃, and then cured at 80℃-180℃ to obtain an imino thermoplastic polymer.

3. The method of preparing an imine-based thermoplastic polymer according to claim 2, wherein The molar ratio of the crosslinking agent to the aldehyde monomer is 1:2-5:

2.

4. The method of preparing an imine-based thermoplastic polymer according to claim 2, wherein The pre-reaction time is 1-5 hours; And / or, the curing time is 2h-6h; And / or, the heating method for the curing process is selected from gradient heating.

5. The application of the imino-based thermoplastic polymer as described in claim 1 in the preparation of a heat-processable crosslinked hot melt adhesive material.

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