CN-118206754-B - Polythioether type epoxy curing agent and synthesis method thereof

Abstract

The invention relates to the technical field of curing agents, and particularly discloses a polythioether type epoxy curing agent and a synthesis method thereof, wherein the epoxy curing agent comprises, by mass, 20-40% of olefin monomers, 20-50% of elemental sulfur, 20-40% of accelerators and 0.1-0.8% of catalysts, and the polythioether is synthesized by reacting the elemental sulfur with olefins. The method has the advantages of mild reaction conditions, wide adaptability of monomers, simple operation and lower cost. The prepared polythioether type epoxy curing agent has good chemical stability, the epoxy is cured through the dynamic exchange reaction of sulfur-sulfur bonds, the problem of peculiar smell of a mercaptan curing agent is avoided, the polythioether type epoxy curing agent is matched with epoxy resin, the low-temperature quick drying can be realized, the film hardness after curing is high, the adhesive force is good, and the polythioether type epoxy curing agent has excellent anti-corrosion performance and is suitable for outdoor packaging under the condition of room temperature. And the cured resin can be degraded and recycled, thereby providing convenience for updating and adjusting the packaging work.

Inventors

• ZHANG YE
• ZHANG JIKAI
• YANG HONGJUN
• JIANG LI
• HUANG WENYAN
• JIANG QIMIN

Assignees

• 常州大学

Dates

Publication Date

20260505

Application Date

20240412

Claims (4)

1. 1. The application of the polythioether type epoxy curing agent is characterized in that the polythioether type epoxy curing agent is used for curing epoxy resin, and comprises, by mass, 20-40% of olefin monomers, 20-50% of elemental sulfur, 20-40% of accelerators, wt% of catalysts, and 0.1-0.8% of wt%; The accelerator is one or more of triethylamine TEA, 2- (dimethylamino) ethyl acrylate DMAEA and dimethylaminopropyl acrylamide DMAPAA.
2. 2. The use of the polythioether type epoxy curing agent according to claim 1, wherein the olefin monomer is one or a mixture of more of ethyl acrylate EA, benzyl acrylate BA and N, N-dimethylacrylamide DMAA.
3. 3. The use of the polythioether type epoxy curing agent according to claim 1, wherein the catalyst is one of 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU), triethylenediamine DACH, sodium hydroxide, and potassium hydroxide.
4. 4. The application of the polythioether type epoxy curing agent according to claim 1, wherein the mass ratio of the polythioether type epoxy curing agent to the epoxy resin is 1:2-1:6 when the epoxy resin is cured, and the curing condition is that the epoxy resin is cured at room temperature of 12-36 h.

Description

Polythioether type epoxy curing agent and synthesis method thereof Technical Field The invention relates to the technical field of curing agents, and particularly discloses a polythioether type epoxy curing agent and a synthesis method thereof. Background Epoxy resin (epoxy resin) refers to a generic term for compounds which contain two or more epoxy groups in one molecule and which form a three-dimensional crosslinked network with a curing agent. The uncured epoxy resin is a high molecular prepolymer, has thermoplasticity, has little use value, and cannot be directly used. Only after the three-dimensional cross-linked insoluble infusible thermosetting polymer is formed by the cross-linking reaction with different curing agents at room temperature or under the heating condition, the material can be used as an application material, and has a use value. Epoxy resin has the advantages of electrical insulation, high cohesiveness, dimensional stability (small shrinkage rate in curing reaction), corrosion resistance, excellent mechanical properties and the like after curing, and is widely used as a coating, an adhesive, an electronic and electrical appliance material, a civil engineering material and the like in the fields of mechanical electronics, aerospace, chemistry and chemical industry, ship building, automobile military industry, metallurgy and light industry and the like. Amine, anhydride, thiol and the like are the most common and effective curing agents for epoxy resins, wherein the amine, anhydride and the like can achieve the curing of epoxy at a moderate and high temperature, but often face the problem of severe heat release due to the reaction characteristics of the amine. Thiols are effective in achieving low temperature curing, but are expensive to prepare relative to the former, and have a large odor generated during actual production, resulting in production safety and environmental pollution. Therefore, there is a need for a new epoxy curing agent that is efficient, convenient, easy to operate, and inexpensive. Disclosure of Invention In order to solve the defects of the existing epoxy curing agent, the invention provides a simple synthesis method for directly preparing a polythioether epoxy resin curing agent from elemental sulfur and the curing agent thereof. The obtained curing agent can cure epoxy resin at room temperature, has simple synthesis method, can be stored for a long time, has no pungent smell, and adopts low-cost elemental sulfur as a raw material. Avoids the complex process of synthesizing sulfhydryl monomer, and is a novel efficient curing agent for curing epoxy at room temperature. In order to achieve the above purpose, the invention is realized by the following technical scheme: The polythioether type epoxy curing agent comprises, by mass, 20-40% of olefin monomers, 20-50% of elemental sulfur, 20-40% of accelerators and 0.1-0.8% of catalysts. The olefin monomer is one or more of Ethyl Acrylate (EA), benzyl Acrylate (BA) and N, N-Dimethylacrylamide (DMAA). The promoter is one or more of Triethylamine (TEA), ethyl 2- (dimethylamino) acrylate (DMAEA), dimethylaminopropyl acrylamide (DMAPAA). The catalyst is one of 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU), triethylene Diamine (DACH), sodium hydroxide (NaOH) and potassium hydroxide (KOH). The invention also provides a method for synthesizing the polythioether epoxy curing agent, which comprises the steps of fully stirring a dried olefin monomer, elemental sulfur, an accelerator and a catalyst in a dried reaction kettle, and then carrying out polymerization reaction for 12-24h at the copolymerization temperature higher than 25 ℃ to obtain the polythioether epoxy curing agent. The obtained product is directly packaged, dried and stored. The obtained polythioether type epoxy curing agent is used for curing epoxy resin, and the curing condition is that the epoxy resin is cured for 12-36 hours at room temperature. The mass ratio of the polythioether type epoxy curing agent to the epoxy resin is 1:2-1:6. The beneficial effects are that: The polythioether type epoxy curing agent provided by the invention is synthesized by a one-step method, has mild reaction conditions, does not release toxic gas, has low raw material price, is non-sulfhydryl type, does not have pungent smell, and is cured with epoxy resin through the dynamic exchange of sulfur-sulfur bonds. Greatly reduces the operation difficulty, time and economic cost of the synthesis of the curing agent. The polythioether type epoxy curing agent prepared by elemental sulfur is used for curing epoxy resin, can realize low-temperature quick drying, has high film hardness after curing, good adhesive force and excellent corrosion resistance, and is suitable for outdoor packaging work under room temperature conditions. The cured epoxy resin can be degraded and recovered through simple solvent treatment, thereby better providing convenience for packaging work. Description of the drawin