CN-121427060-B - Epoxy polymer containing dynamic reversible polysulfide bond, and preparation method and application thereof

Abstract

The invention discloses an epoxy polymer containing dynamic reversible polysulfide bonds, a preparation method and application thereof, and relates to the technical field of polymer materials. The preparation method comprises the steps of mixing 1, 2-dithiolane glycol with elemental sulfur, heating for reaction to obtain a linear polysulfide prepolymer, adding an alkaline catalyst and an epoxy monomer into the linear polysulfide prepolymer, and continuing heating for reaction to obtain the epoxy polymer containing dynamic reversible polysulfide bonds. The epoxy polymer containing the dynamic reversible polysulfide bond prepared by the invention contains two polar groups, namely hydroxyl and ether bond, can form hydrogen bonds with the polar groups on the surface of the plate to provide stronger binding force, and the contained dynamic reversible polysulfide bond endows the material with excellent reworkability and reusability, so that the material has good recoverability and wide application prospect. The preparation method of the invention does not need to use organic solvents, has mild conditions and is simple to operate.

Inventors

• CHEN JIZHONG
• DUAN ZONGLIN
• YANG WEISHU
• ZHANG ZHEN

Assignees

• 广东工业大学

Dates

Publication Date

20260508

Application Date

20251226

Claims (4)

1. 1. An epoxy polymer containing dynamic reversible polysulfide bond, which is characterized in that the structural formula of the epoxy polymer containing dynamic reversible polysulfide bond is that ; Wherein x=1 to 7, n=5 to 50, and r includes And One or two of the following components; The preparation method of the epoxy polymer containing the dynamic reversible polysulfide bond comprises the following steps: Adding an alkaline catalyst and an epoxy monomer into the linear polysulfide prepolymer, and continuing the heating reaction to obtain the epoxy polymer containing dynamic reversible polysulfide bonds; The structural formula of the linear polysulfide prepolymer is Wherein x=1 to 7, n=5 to 50; The epoxy monomer comprises one or two of bisphenol A diglycidyl ether and 2,2' - [ oxybis (2, 1-ethyleneoxymethylene) ] bisoxirane; mixing 1, 2-dithiolane glycol and elemental sulfur, and then heating to react for 12-24 hours at a temperature of 100-120 ℃; and after adding an alkaline catalyst and an epoxy monomer into the linear polysulfide prepolymer, continuously heating to react at a temperature of 90-120 ℃ for 12-24 hours.
2. 2. The epoxy polymer containing a dynamically reversible polysulfide linkage of claim 1 wherein said basic catalyst comprises imidazole.
3. 3. The dynamic reversible polysulfide-bond-containing epoxy polymer of claim 1, wherein the molar ratio of elemental sulfur, 1, 2-dithiolane diol, epoxy monomer, and basic catalyst is 0.5-2:2:0.25-4:0.01.
4. 4. Use of an epoxy polymer containing dynamically reversible polysulfide linkage according to claim 1 as an adhesive.

Description

Epoxy polymer containing dynamic reversible polysulfide bond, and preparation method and application thereof Technical Field The invention relates to the technical field of high polymer materials, in particular to an epoxy high polymer containing dynamic reversible polysulfide bonds, and a preparation method and application thereof. Background Epoxy resin is an important thermosetting polymer material, and is widely applied to the fields of structural adhesives, coatings, composite material matrixes, electronic packaging materials and the like due to excellent bonding strength, mechanical properties, chemical resistance, electrical insulation and dimensional stability. However, conventional epoxy systems generally achieve excellent strength and stability through a three-dimensional network structure of high crosslink density, which simultaneously results in materials that exhibit significant brittleness and irreversible characteristics during use, i.e., low fracture toughness, poor impact resistance, internal stress concentrations, and inability to be thermally repaired or reworked. This irreversible structural feature greatly limits further applications of epoxy materials in the fields of sustainable manufacturing, resource recovery and smart materials. To overcome the limitations of conventional epoxy systems that "deactivate once cured", researchers have attempted to introduce dynamic reversible chemical bonds (Dynamic Covalent Bonds) into the epoxy network system, thereby imparting self-repairability, reworkability, and recyclability to materials. Typical types of dynamic bonds include disulfide bonds (S-S), transesterification bonds (C-O), schiff base bonds (c=n), thioester interchange bonds (C-S), and the like. The disulfide bond and the polysulfide bond have high chemical reactivity, can realize reversible fracture and recombination under the medium temperature condition, and are considered as ideal candidates for realizing dynamic modification of the thermosetting material. For example, patent application publication No. CN114686149A reports a dynamic disulfide-bond epoxy resin constructed by reacting 5,5' -dithiobis (2-nitrobenzoic acid) with an epoxy monomer, the material being reversibly crosslinked and reusable to some extent. However, this method relies on expensive aromatic disulfide reagents, and the preparation process requires the use of organic solvents, and is complex in process and less environmentally friendly. In recent years, the preparation of a polymer material containing polysulfide bonds by a reverse vulcanization reaction (Inverse Vulcanization) using elemental sulfur (S8) as an inexpensive sulfur source has become a research hotspot in the field of reversible network construction. The polysulfide bond not only can realize dynamic exchange under the medium temperature condition, but also can provide a flexible chain segment, thereby obviously improving the toughness and the reconfigurable performance of the material. In epoxy systems, some progress has been made in the research by introducing olefin-sulfur copolymers or polysulfide prepolymers as crosslinking agents. However, the prior art scheme has the common problems that firstly, the reaction needs to be carried out at a high temperature of more than 160 ℃, secondly, the high-temperature reaction condition limits the applicability of the monomer, and only the high-boiling-point olefin monomer can be adapted, thirdly, the reaction is assisted by an organic solvent, the process complexity is increased, and fourthly, the adhesive property and the reusability of the existing epoxy polymer containing the polysulfide bond still need to be improved. Therefore, the development of the epoxy polymer which takes elemental sulfur as a sulfur source, does not need to use an organic solvent, has low reaction temperature, mild condition and strength and repeatability and the preparation method thereof become the research key and technical difficulty in the field of the current polymer materials. Disclosure of Invention The invention aims to provide an epoxy polymer containing dynamic reversible polysulfide bond, and a preparation method and application thereof, so as to solve the problems in the prior art. The preparation method is simple, and the prepared epoxy polymer containing the dynamic reversible polysulfide bond has adjustable chemical structure, good repeatable processing performance and wide application prospect. In order to achieve the above object, the present invention provides the following solutions: One of the technical proposal of the invention is that the epoxy polymer containing dynamic reversible polysulfide bond has the structural formula of ; Wherein x=1 to 7 (specifically, an integer of 1 to 7), n=5 to 50, and r includes(Abbreviated as structural unit a) and(Abbreviated as structural unit b). The epoxy polymer containing the dynamic reversible polysulfide bond contains two polar groups, namely hydroxyl and ether bond,