Facile fabrication of fast recyclable and multiple self‐healing epoxy materials through diels‐alder adduct cross‐linker

Abstract

A reversibly cross‐linked epoxy resin with efficient reprocessing and intrinsic self‐healing was prepared from a diamine Diels‐Alder (DA) adduct cross‐linker and a commercial epoxy oligomer. The newly synthesized diamine cross‐linker, comprising a DA adduct of furan and maleimide moieties, can cure epoxy monomer/oligomer with thermal reversibility. The reversible transition between cross‐linked state and linear architecture endows the cured epoxy with rapid recyclability and repeated healability. The reversibly cross‐linked epoxy fundamentally behaves as typical thermosets at ambient conditions yet can be fast reprocessed at elevated temperature like thermoplastics. As a potential reversible adhesive, the epoxy polymer with adhesive strength values about 3 MPa showed full recovery after repeated fracture‐thermal healing processes. The methodology explored in this contribution provides new insights in modification of conventional engineering plastics as functional materials. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2094–2103

Recyclable biobased materials based on Diels–Alder cycloaddition

“…In addition, a number of thermally reversible healing materials and biological materials have been constructed based on this DA reaction . Modified epoxy resin was chosen by some researchers to construct DA reversible materials . Currently, most studies put emphasis on modifying the common epoxy monomer diglycidyl ether of bisphenol A (DGEBA) or changing the synthesis path to achieve epoxy healing materials, but ignore the improvement of the internal structure of epoxy materials.…”

Polyurethane adhesives containing Diels–Alder‐based thermoreversible bonds

“…Crosslinked polymers containing furfuryl and maleimide groups have been reported as well as linear alternatives but the synthetic routes are susceptible toward irreversible side‐reactions (particularly the Michael‐addition which occurs when maleimides are reacted in the presence of free nucleophiles at elevated temperature) or they involve the use maleimides that are not readily commercially available or the perspective is different from ours focusing on other applications including shape memory materials . An elegant approach is presented by Defize et al .…”

A review of shape memory polymers bearing reversible binding groups

“…The thermoreversible Diels–Alder (DA) bond has been used to prepare advanced functional materials such as self‐healing polymers and composites, reversible adhesives, gels, and self‐leveling materials making it one of the most highly utilized reversible covalent groups. Common examples include the furan‐maleimide (FUR/MAL), anthracene‐maleimide (ANTH/MAL), and dithioester diene DA adducts (Fig.…”