Ultrafast Self-Healing Fiber/Matrix Composite with Single-Component Microcapsules Loaded with Cationic Catalyst

Abstract

In this study, ultrafast self-healing of different damage modes in resin and fiber/matrix composites was achieved by incorporating single-component double-shell microcapsules loaded with a cationic catalyst. The formation of stable and size-controllable inner microcapsules was achieved using hydrophilic metal−organic frameworks (MOFs) as stabilizers for the Pickering emulsion. With adjustable nanospaces, MOFs served as a good platform for host− guest interactions, providing an ideal environment for capturing and storing the cationic catalyst. Unlike traditional two-component microcapsule systems, the cationic catalyst could be loaded relatively easily into the double-shell microcapsules. More importantly, a singlecomponent microcapsule system could achieve immediate repair of microcracks in situ as the agents could immediately react with the cationic catalyst upon the rupturing of microcapsules. A satisfactory healing efficiency was achieved along with outstanding mechanical properties of the composite. For example, epoxy resin with 15 wt % microcapsules loading showed 95% healing efficiency within 10 min at room temperature, and the interlaminar shear strength of the composite reached 92% in 5 min.

Self-Healing Nanocomposites—Advancements and Aerospace Applications

“…Here, healing agent can be mixed with a catalyst and included in polymers for better recovery properties. Sometimes, catalysts can also be filled in microcapsules or hollow fibers along with the healing agents [169].…”

“…Here, healing agent can be mixed with a catalyst and included in polymers for better recovery properties. Sometimes, catalysts can also be filled in microcapsules or hollow fibers along with the healing agents [169]. When any damage occurs to an aerospace structure, these microcapsules or hollow fibers break down to release the encapsulated healing agent and catalyst.…”

The mechanochemical synthesis of environmentally benign fully biobased 4th generation benzoxazines and their polymers: mechanistic insights into the catalytic activity of latent catalysts

“…47 Biomass-derived derivatives of phenols and amines have proven successful as renewable resources, offering excellent opportunities to synthesize sustainable polymers capable of partially or fully replacing petroleum-based PBZs. 22,25,30,34,48,49 Biobased PBZs have demonstrated their utility in several applications including high-performance anticorrosive coatings, 50 superparamagnetic materials, 51 cathode materials in next-generation batteries beyond Li-ions, 52,53 antibacterials, 54,55 and as potential flameretardant materials. 36,56,57 Recently, the replacement of formaldehyde with other aldehydes has also been employed to form 4 th generation BZs.…”

Preparation and Application of Latent Microcapsule Catalysts in One-Component Silicone Rubber Curing

“…However, the former approach necessitates substantial amounts of compound (ranging from 20 to 100 equiv relative to the catalyst) to achieve moderate latency, which may still lack controllability and exhibits relatively short room temperature latency. Conversely, the use of LMCs offers a solution to these issues, providing enhanced control over latency and prolonged room temperature stability, thereby facilitating the preparation of one-component silicone rubbers with improved efficiency and performance. − In LMCs, the inclusion of metal catalysts, such as the Karstedt catalyst, within the wall material serves to isolate them from direct contact with the silicone rubber during storage, effectively preventing premature curing reactions. Upon the need for curing, the catalyst is released by rupturing the microcapsules, typically achieved by elevating the temperature or pressure.…”