Thermo‐adjusted self‐healing epoxy resins based on Diels–Alder dynamic chemical reaction

Abstract

Micro‐damage in materials could be repaired by endowing materials with self‐healing performance. Herein, an epoxy resin with excellent self‐healing performance grounded on thermo‐reversible Diels–Alder dynamic chemical reaction was developed. Results showed that the bending strength and adhesive behavior of epoxy resin were influenced dramatically upon treatment with various temperatures. More importantly, damages created in epoxy resin could be repaired completely after suitable heat treatments. What is more, the healed epoxy resin exhibited much higher bending strength and adhesive performance than the pristine one did. The materials could be damaged and then repaired repeatedly. Meanwhile, the as‐prepared self‐healing epoxy resin exhibited excellent thermal reversibility and controllable adhesion. The thermo‐adjusted self‐healing performance endowed epoxy resin with recyclable and reusable performance. Therefore, the research made it possible of recycling waste epoxy resins.

Diels–Alder Augmented Epoxies with Plasmonic Nanoparticle Fillers for Efficient Photothermal Depolymerization

“…Similarly, T g increases from −25 °C of FA6 to 0 °C of FA6-MPM(0.4) to 20 °C of FA6-MPM(1.0) as a crosslinking network forms and the crosslinking density increases. The DSC thermograms have features corresponding to an endothermic reaction around 100–130 °C, which is consistent with previous reports in the literature ,,− There are two peaks corresponding to the rDA reaction. The first at ∼100 °C is the rDA of the endo-isomer of the DA cycloadduct.…”

“…The DA-epoxies have been used for self-healing materials through a thermal cycle of heating and cooling. The rDA fills out the crack at a high temperature, and the fDA forms new bonds across the crack at a low temperature. , In a paper by Zhang et al, a crack was created on DA-epoxy samples. After a thermal cycle at 140 °C for 40 min and at 80 °C for 24 h, these DA-epoxy samples exhibited 1.3 times improved bending strength compared to the control sample without a crack or a thermal cycle for the self-healing process.…”

Improved tribological performance of epoxy composites containing core–shell PE wax@SiO2 nanoparticles

“…Epoxy resin (EP) is a widely used and indispensable thermosetting plastic for modern industry because of its excellent moldability, thermal, mechanical, anti-corrosion, and chemical resistant properties. [1][2][3] However, as a brittle polymer with three dimensions crosslinked structure inside, it lacks self-lubricating properties for being used in friction and wears protection. [4][5][6] To improve the lubricating and anti-wear properties of traditional epoxy resin, researchers have made great efforts, such as mixing lubricating secondary polymer (polytetrafluoroethylene (PTFE), [7,8] rubber, [9] polyurethane (PU) [10] ), incorporating anti-wear fillers (fibers [11][12][13] and inorganic particles [14,15] ) and doping nanofillers (nanosheets, [6,16,17] nanotubes [18,19] and nanoparticles [5,20] ) with both functions.…”

Mechanically robust and self‐healing waterborne polyurethane nanocomposites based on inorganic organic hybrid materials and reversible covalent interaction

“…It possesses the repeated self‐healing properties owing to the repeatability of the dynamic bond breakage/recombination. These reversible chemistries include dynamic covalent bonding, such as Diels‐Alder (DA) cycloaddition reactions, 29,30 disulfide exchange 31,32 and boroxine/boronic acid equilibrium process 33,34 ; Or non‐covalent interactions such as hydrogen bonds, 35,36 metal–ligand coordination 37,38 and redox‐triggered host‐guest complexations 39,40 . Among these reactions, the DA reaction is considered to be most attractive types owing to its mild reaction conditions.…”