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CN-122012012-A - High-strength low-temperature-resistant recyclable adhesive and preparation method thereof

CN122012012ACN 122012012 ACN122012012 ACN 122012012ACN-122012012-A

Abstract

The invention relates to the technical field of low-temperature adhesive materials, and discloses a high-strength low-temperature-resistant recyclable adhesive and a preparation method thereof, wherein the method comprises the steps of dissolving DL-alpha-lipoic acid and N, N' -carbonyl diimidazole in a polar organic solvent, then reacting with ethylenediamine, and purifying to obtain a comonomer SNH; dissolving benzo-21-crown-7 derivative B21C7-N and 1, 2-dithiavaleryl-3-pentanoic acid succinimide ester in acetone, adding triethylamine for reaction, purifying to obtain a comonomer SC, uniformly mixing the comonomer SC and SNH, and polymerizing under an ultraviolet light source to obtain the adhesive. The invention reasonably designs molecular structure from chemical angle, synthesizes the adhesive in one step under room temperature environment by lipoic acid photoinitiation polymerization, has excellent room temperature scene adhesive strength, has best adhesive strength at about 25 ℃ and meets the conventional use, and in addition, has excellent liquid nitrogen temperature adhesive strength, and has excellent recycling property and complete closed loop recovery characteristic.

Inventors

  • LI YIWEN
  • SONG YUXIAN
  • LI ZHAN
  • LIU PENGYU

Assignees

  • 四川大学

Dates

Publication Date
20260512
Application Date
20260126

Claims (10)

  1. 1. The preparation method of the high-strength low-temperature-resistant recyclable adhesive is characterized by comprising the following steps of: s1, dissolving DL-alpha-lipoic acid and N, N' -carbonyl diimidazole in a polar organic solvent, then dropwise adding the polar organic solvent into methylene dichloride solution of ethylenediamine for reaction, extracting reaction liquid by using aqueous phase after the reaction is finished, merging organic phases, concentrating, and purifying by silica gel column chromatography to obtain a comonomer SNH with the following structure: ; S2, dissolving potassium carbonate and potassium fluoborate in anhydrous acetonitrile, adding hexaethyleneglycol di-p-toluenesulfonate and N- (tert-butoxycarbonyl) dopamine, heating and refluxing at 70-90 ℃, cooling to room temperature after the reaction is completed, performing suction filtration, adding saturated sodium chloride solution into the obtained concentrated solution for extraction, combining organic phases, drying by anhydrous sodium sulfate, performing suction filtration, concentrating to obtain a crude product, and purifying by silica gel column chromatography to obtain a benzo-21-crown-7 derivative B21C7-boc with the following structure: ; s3, dissolving the benzo-21-crown-7 derivative B21C7-boc in dichloromethane, adding trifluoroacetic acid (TFA) for reaction, and concentrating under reduced pressure after the reaction is finished to obtain the benzo-21-crown-7 derivative B21C7-N with the following structure: ; S4, dissolving benzo-21-crown-7 derivative B21C7-N and 1, 2-dithialane-3-pentanoic acid succinimidyl ester in acetone, adding triethylamine for reaction, filtering after the reaction is finished, concentrating under reduced pressure to obtain a crude product, and purifying by silica gel column chromatography to obtain a comonomer SC with the following structure: ; S5, uniformly mixing the comonomer SC and the SNH according to the molar ratio of 1:0.5-2.5, and carrying out photoinitiated polymerization under an ultraviolet light source to obtain the high-strength low-temperature-resistant recyclable adhesive.
  2. 2. The method for preparing a high-strength low-temperature-resistant recyclable adhesive according to claim 1, wherein the reaction in step S1 is performed under an inert atmosphere at room temperature, and the reaction in step S4 is performed at room temperature.
  3. 3. The method for preparing the high-strength low-temperature-resistant recyclable adhesive according to claim 1, wherein in the step S1, the DL-alpha-lipoic acid is used in an amount of 14.5 mmol, the N, N' -carbonyldiimidazole is used in an amount of 10-20 mmol, and the ethylenediamine is used in an amount of 80-200 mmol.
  4. 4. The method for preparing the high-strength low-temperature-resistant recyclable adhesive according to claim 1, wherein in the step S2, 15-mmol mmol of potassium carbonate, 5-10 mmol of potassium fluoborate, 2-7 mmol of hexaethylene glycol di-p-toluenesulfonate and 2-7 mmol of N- (tert-butoxycarbonyl) dopamine are adopted.
  5. 5. The method for preparing the high-strength low-temperature-resistant recyclable adhesive according to claim 1, wherein in the step S4, 15-30 mmol of the benzo-21-crown-7 derivative B21C 7-N10.01 mmol, 15-30 mmol of 1, 2-dithialane-3-pentanoic acid succinimide ester and 10-50 mmol of triethylamine are used.
  6. 6. The method for preparing the high-strength low-temperature-resistant recyclable adhesive according to claim 1, wherein in the step S1, the eluent adopts dichloromethane and methanol in a volume ratio of 1-5:1, and/or in the step S2, the eluent adopts methanol and dichloromethane in a volume ratio of 20-40:1, and/or in the step S4, the eluent adopts dichloromethane and methanol in a volume ratio of 10-30:1.
  7. 7. The method for preparing a high-strength low-temperature-resistant recyclable adhesive according to claim 1, wherein the ultraviolet light source has a wavelength of 365nm.
  8. 8. A high strength low temperature resistant recyclable adhesive prepared by the method of any one of claims 1-7.
  9. 9. The high strength, low temperature resistant, recyclable adhesive of claim 8 wherein in use, the adhesive is applied to the bond by heating to a flowable state and cooling to room temperature to effect bonding.
  10. 10. The method for recycling the high-strength low-temperature-resistant recyclable adhesive according to claim 8, which is characterized in that sodium borohydride is used as a reducing agent in a methanol solvent to carry out selective depolymerization on the adhesive, then silicon powder is added for spin drying, and after separation and purification, comonomers SC and SNH are obtained through recycling.

Description

High-strength low-temperature-resistant recyclable adhesive and preparation method thereof Technical Field The invention relates to the technical field of low-temperature adhesive materials, in particular to a high-strength low-temperature-resistant recyclable adhesive and a preparation method thereof. Background As a key core material for realizing light weight, multifunctional integration and device miniaturization, the adhesive plays a vital role in promoting development and intelligent manufacturing development of high-performance materials. With the continuous expansion of human range of motion to extreme environments such as polar regions, deep spaces, and the like, adhesive materials are facing unprecedented performance challenges. The materials not only need to maintain mechanical integrity and interfacial stability under low temperature conditions, but also need to meet increasingly stringent requirements of recoverability, environmental compatibility and sustainability. Therefore, the development of the high-performance adhesive with high bonding strength, wide temperature range tolerance and closed loop recycling property has important scientific value and engineering significance. Although the traditional structural adhesive (such as epoxy resin and acrylic ester system) has excellent room temperature service performance, the removal and recovery difficulties are great on the premise of not damaging the substrate material. Low temperature adhesives (e.g., polyethersulfone, ethylene-vinyl acetate copolymer, polyamide, polyurethane, etc.) that have been commercially used tend to suffer from stress cracking, interfacial adhesion failure, and debonding when the temperature is reduced to about-50 ℃. The performance degradation phenomenon is caused by two core factors, namely, firstly, volume shrinkage of a polymer occurs in a low-temperature environment, movement of a frozen molecular chain is limited, internal generated stress cannot be released, embrittlement of the material is finally caused, stress cracking is caused, and secondly, free water molecules remained in an adhesive matrix are easy to form ice clusters which become stress concentration points under the low-temperature condition, so that interface bonding performance is seriously damaged. These limitations reveal an inherent contradiction in polymer molecular design that rigid molecular structures suitable for room temperature bonding tend to exacerbate material embrittlement at low temperatures, while flexible molecular chains that help to promote low temperature resistance generally sacrifice material load carrying capacity and bonding durability. Therefore, developing an adhesive with high adhesive strength, recoverability and wide-temperature-range stable service capability is still a very challenging task. Disclosure of Invention The invention aims to solve the problems of stress cracking, interface adhesion failure and debonding of the traditional adhesive material under the extremely low temperature condition, and provides a preparation method of a high-strength low-temperature-resistant recyclable adhesive. In order to achieve the above object, in a first aspect, the present invention provides a method for preparing a high-strength low-temperature-resistant recyclable adhesive, comprising the steps of: s1, dissolving DL-alpha-lipoic acid and N, N' -carbonyl diimidazole in a polar organic solvent, then dropwise adding the polar organic solvent into methylene dichloride solution of ethylenediamine for reaction, extracting reaction liquid by using aqueous phase after the reaction is finished, merging organic phases, concentrating, and purifying by silica gel column chromatography to obtain a comonomer SNH with the following structure: ; S2, dissolving potassium carbonate and potassium fluoborate in anhydrous acetonitrile, adding hexaethyleneglycol di-p-toluenesulfonate (HEDP) and N- (tert-butoxycarbonyl) dopamine (DA-Boc), heating and refluxing at 70-90 ℃, cooling to room temperature after the reaction is finished, suction-filtering, adding saturated sodium chloride solution into the obtained concentrated solution for extraction, merging organic phases, drying by anhydrous sodium sulfate, suction-filtering, concentrating to obtain a crude product, and purifying by silica gel column chromatography to obtain the benzo-21-crown-7 derivative B21C7-Boc with the following structure: ; s3, dissolving the benzo-21-crown-7 derivative B21C7-boc in dichloromethane, adding trifluoroacetic acid (TFA) for reaction, and concentrating under reduced pressure after the reaction is finished to obtain the benzo-21-crown-7 derivative B21C7-N with the following structure: ; S4, dissolving benzo-21-crown-7 derivative B21C7-N and 1, 2-dithialane-3-pentanoic acid succinimidyl ester in acetone, adding triethylamine for reaction, filtering after the reaction is finished, concentrating under reduced pressure to obtain a crude product, and purifying by silica g