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CN-121975469-A - High-toughness epoxy resin adhesive and preparation method thereof

CN121975469ACN 121975469 ACN121975469 ACN 121975469ACN-121975469-A

Abstract

The invention relates to the technical field of adhesives, in particular to a high-toughness epoxy resin adhesive and a preparation method thereof. The epoxy resin DYD-128 comprises epoxy resin DYD-128, a curing agent and a toughening system, wherein the toughening system comprises modified polysulfone, modified graphene oxide and pyrenyl-terminated polydimethylsiloxane. The modified polysulfone grafted polyethylene glycol reduces the viscosity, and the amino group of the modified graphene oxide simultaneously reacts with the epoxy group and the epoxy resin of the modified polysulfone, so that the compatibility of the polysulfone and the epoxy resin matrix is improved. The modified graphene oxide realizes simultaneous anchoring of two heterogeneous interfaces of aluminum alloy and CFRP through double-function modification of dopamine and phosphonic acid, and primary amino is converted into ketimine, so that amino and epoxy resin are prevented from pre-reaction. Pyrene groups of pyrene-terminated polydimethylsiloxane grasp graphene sheets through strong interaction, and migrate towards the CFRP interface together through the low surface energy of the polydimethylsiloxane, so that the modified graphene oxide accurate positioning interface is realized.

Inventors

  • GUAN HONGYU
  • ZHAO WENSHUI
  • BI CHANGCHENG

Assignees

  • 大连聚砜塑料有限公司

Dates

Publication Date
20260505
Application Date
20260212

Claims (6)

  1. 1. The high-toughness epoxy resin adhesive is characterized by comprising the following components of epoxy resin DYD-128, a curing agent and a toughening system; the curing agent is 20-35% of the mass of the epoxy resin DYD-128, and the toughening system is 25-50% of the mass of the epoxy resin; The toughening system comprises, by weight, 15-35 parts of modified polysulfone, 0.5-3 parts of modified graphene oxide and 5-15 parts of pyrenyl-terminated polydimethylsiloxane; The modified polysulfone is grafted with polyethylene glycol and epoxy groups are introduced; The surface of the modified graphene oxide is coated with a dopamine layer and connected with a phosphonic acid group.
  2. 2. The high-toughness epoxy resin adhesive according to claim 1, wherein the curing agent is one or more of diaminodiphenyl sulfone, 4' -diaminodiphenyl methane or m-phenylenediamine.
  3. 3. The high-toughness epoxy resin adhesive according to claim 1, wherein the preparation method of the modified polysulfone comprises the following steps: S11, dissolving polysulfone in anhydrous 1, 2-dichloroethane, stirring for dissolving, adding anhydrous zinc chloride, continuously stirring for dissolving, slowly dripping chloromethyl methyl ether, stirring for reacting, slowly pouring the obtained reaction solution into methanol for precipitating, filtering, collecting solid, washing with methanol, and drying in vacuum to obtain chloromethylated polysulfone; S12, dissolving mPEG-OH in anhydrous DMF, cooling in ice bath, adding NaH, stirring for reaction to obtain mPEG-ONa, dissolving chloromethylated polysulfone in the anhydrous DMF, stirring for dissolving, slowly dropwise adding mPEG-ONa, stirring for reaction, cooling, pouring into methanol for precipitation, filtering, collecting solid, washing with methanol and deionized water, and vacuum drying to obtain polyethylene glycol grafted chloromethyl polysulfone; S13, dissolving glycidol in anhydrous DMF, cooling in an ice bath, slowly adding NaH, stirring for reaction to obtain glycidol sodium salt, dissolving polyethylene glycol grafted chloromethyl polysulfone in the anhydrous DMF, dripping the glycidol sodium salt, stirring for reaction, cooling, pouring into methanol for precipitation, filtering, collecting solid, washing with methanol, and drying in vacuum to obtain modified polysulfone.
  4. 4. The high-toughness epoxy resin adhesive according to claim 1, wherein the preparation method of the modified graphene oxide comprises the following steps: S21, adding graphite into concentrated sulfuric acid and phosphoric acid, stirring under ice bath cooling, adding potassium permanganate, removing the ice bath, slowly heating, stirring for reaction, pouring the obtained reaction solution into ice water, slowly dripping H 2 O 2 , standing for layering, washing and centrifuging the obtained solid with hydrochloric acid and deionized water respectively, re-dispersing in the deionized water, and freeze-drying to obtain graphene oxide; s22, dissolving tris (hydroxymethyl) aminomethane in deionized water, regulating the pH value by using hydrochloric acid, adding graphene oxide, performing ultrasonic dispersion, adding dopamine hydrochloride, stirring for reaction, centrifugally collecting precipitate, washing with deionized water, and performing freeze drying to obtain polydopamine-coated graphene oxide; S23, dispersing polydopamine coated graphene oxide in anhydrous DMF, performing ultrasonic dispersion, adding 2-carboxyethyl phosphonic acid, stirring for dissolution, adding EDC and HCl for stirring for activation, adding NHS, stirring for reaction, centrifuging the obtained reaction solution, collecting precipitate, washing with DMF, ethanol and deionized water in sequence, and performing freeze drying to obtain phosphonic acid modified polydopamine coated graphene oxide; S24, ultrasonically dispersing the phosphonic acid modified polydopamine coated graphene oxide in absolute ethyl alcohol, adding an activated 4A molecular sieve, heating in an oil bath, adding methyl isobutyl ketone and paratoluenesulfonic acid monohydrate, carrying out reflux reaction under stirring, cooling the obtained reaction liquid, centrifuging, collecting precipitate, washing with absolute ethyl alcohol, carrying out vacuum drying, and grinding to obtain the modified graphene oxide.
  5. 5. The high-toughness epoxy resin adhesive according to claim 1, wherein the preparation method of the pyrenyl-terminated polydimethylsiloxane comprises the following steps: S31, dissolving hydroxyl-terminated polydimethylsiloxane and 1-pyrene butyric acid in anhydrous dichloromethane, adding 4-dimethylaminopyridine, stirring, cooling in an ice bath, adding N, N' -dicyclohexylcarbodiimide, removing the ice bath, stirring at room temperature for reaction, filtering and collecting filtrate, concentrating by a rotary evaporator, dripping into N-hexane for precipitation, filtering and collecting precipitate, washing by ethyl acetate, and drying in vacuum to obtain pyrene-terminated polydimethylsiloxane.
  6. 6. A method for preparing a high-toughness epoxy resin adhesive, which is applied to preparing the high-toughness epoxy resin adhesive according to any one of claims 1-5, and is characterized by comprising the following steps: s1, dispersing modified graphene oxide in pyrenyl-terminated polydimethylsiloxane, and performing ultrasonic dispersion to obtain a first mixture; s2, adding the modified polysulfone into epoxy resin DYD-128, and stirring and dissolving to obtain a second mixture; s3, cooling the second mixture, adding the first mixture, and stirring to obtain a third mixture; S4, adding the curing agent into the third mixture, and performing vacuum defoaming to obtain the adhesive.

Description

High-toughness epoxy resin adhesive and preparation method thereof Technical Field The invention belongs to the technical field of adhesives, and particularly relates to a high-toughness epoxy resin adhesive and a preparation method thereof. Background Epoxy adhesives possess excellent adhesive strength, chemical resistance and dimensional stability, however, their inherent brittleness, internal stress greatly limit the wide application of epoxy adhesives. Polysulfone is a high-temperature-resistant and high-strength thermoplastic engineering plastic, and the inherent brittleness of epoxy resin can be obviously improved by introducing the polysulfone into an epoxy resin system, and meanwhile, the excellent bonding strength, heat resistance and modulus of the polysulfone are not sacrificed. However, the addition of the high molecular chain polysulfone can obviously increase the fluid resistance, so that the sizing is difficult, the high-viscosity glue solution is difficult to fully infiltrate the rough and multi-scale surfaces of the microporous anodic oxide layer of the aluminum alloy and the carbon fiber composite material, tight molecular-level contact cannot be formed, the interface bonding strength is directly reduced greatly, and the application of the high-molecular chain polysulfone in the key parts of high-end equipment such as aerospace, new energy automobiles and the like, which are light in weight (usually connected with the CFRP of the aluminum alloy and the carbon fiber composite material), is limited. Disclosure of Invention (1) Technical problem to be solved The invention aims to provide a high-toughness epoxy resin adhesive and a preparation method thereof, which are used for solving the technical problems that the polysulfone toughened modified epoxy resin adhesive is too high in viscosity, poor in interface wettability and difficult to achieve both high toughness and good workability. (2) Technical proposal In order to achieve the aim, in one aspect, the invention provides a high-toughness epoxy resin adhesive, which comprises the following components of epoxy resin DYD-128, a curing agent and a toughening system; the curing agent is 20-35% of the mass of the epoxy resin DYD-128, and the toughening system is 25-50% of the mass of the epoxy resin; The toughening system comprises, by weight, 15-35 parts of modified polysulfone, 0.5-3 parts of modified graphene oxide and 5-15 parts of pyrenyl-terminated polydimethylsiloxane; The modified polysulfone is grafted with polyethylene glycol and epoxy groups are introduced; The surface of the modified graphene oxide is coated with a dopamine layer and connected with a phosphonic acid group. Further, the curing agent is one or more of diamino diphenyl sulfone, 4' -diamino diphenyl methane or m-phenylenediamine. Further, the preparation method of the modified polysulfone comprises the following steps: S11, dissolving polysulfone in anhydrous 1, 2-dichloroethane, stirring for dissolving, adding anhydrous zinc chloride, continuously stirring for dissolving, slowly dripping chloromethyl methyl ether, stirring for reacting, slowly pouring the obtained reaction solution into methanol for precipitating, filtering, collecting solid, washing with methanol, and drying in vacuum to obtain chloromethylated polysulfone; S12, dissolving mPEG-OH in anhydrous DMF, cooling in ice bath, adding NaH, stirring for reaction to obtain mPEG-ONa, dissolving chloromethylated polysulfone in the anhydrous DMF, stirring for dissolving, slowly dropwise adding mPEG-ONa, stirring for reaction, cooling, pouring into methanol for precipitation, filtering, collecting solid, washing with methanol and deionized water, and vacuum drying to obtain polyethylene glycol grafted chloromethyl polysulfone; S13, dissolving glycidol in anhydrous DMF, cooling in an ice bath, slowly adding NaH, stirring for reaction to obtain glycidol sodium salt, dissolving polyethylene glycol grafted chloromethyl polysulfone in the anhydrous DMF, dripping the glycidol sodium salt, stirring for reaction, cooling, pouring into methanol for precipitation, filtering, collecting solid, washing with methanol, and drying in vacuum to obtain modified polysulfone. Further, the preparation method of the modified graphene oxide comprises the following steps: S21, adding graphite into concentrated sulfuric acid and phosphoric acid, stirring under ice bath cooling, adding potassium permanganate, removing the ice bath, slowly heating, stirring for reaction, pouring the obtained reaction solution into ice water, slowly dripping H 2O2, standing for layering, washing and centrifuging the obtained solid with hydrochloric acid and deionized water respectively, re-dispersing in the deionized water, and freeze-drying to obtain graphene oxide; s22, dissolving tris (hydroxymethyl) aminomethane in deionized water, regulating the pH value by using hydrochloric acid, adding graphene oxide, performing ultrasonic dispersion, adding dopamine