Autonomous self‐healing based on epoxy resin–imidazole chemistry in carbon fiber‐reinforced polymer composites

Abstract

Epoxy resin-imidazole chemistry is used as a new autonomous self-healing system for unidirectional fiber-reinforced polymers and tested for its efficiency in recovery of fracture properties in laminated carbon fiber-reinforced polymers. The dual microcapsule approach is utilized to store and distribute the reactive chemistries in the structure. Microcapsules were located in possible damage regions using polymeric interleaves. Microcapsules containing separately the epoxy resin (EPIDIAN 52-ethyl phenylacetate) and imidazole hardener (1-benzyl-2-methylimidazole) are prepared with poly(urea-formaldehyde) and PMMA shell wall, respectively. Mode I fracture toughness tests are used to evaluate the recovery of the material mechanical properties. At optimized conditions, 117.5% of the interlaminar fracture toughness (G IC ) was recovered after heat treatment at 100 C for 24 h. Furthermore, it is demonstrated that the self-healing efficiency is strongly dependent on the load of microcapsules with the imidazole hardener and that the microcapsules' presence in the laminate has a detrimental effect on the material's mechanical performance.

Investigation on microcapsule self‐healing mechanism of polymer matrix composites based on numerical simulation

“…Jony et al [ 20 ] studied the bio‐mimetic repeatable self‐healing capability of thermoplastic healing agent poly‐caprolactone together with shape memory polymer in thermosetting fiber reinforced polymer composites. Bolimowski et al [ 21 ] investigated the behavior of self‐healing microcapsules separately containing the epoxy resin and imidazole hardener in CFRP composites.…”

Comparative Study of the Reinforcement Type Effect on the Thermomechanical Properties and Burning of Epoxy-Based Composites

“…They are not only resistant to stress corrosion and stress rupture failures like glass fibers but gain an advantage over other used reinforcements by additional functionality such as good electrical and heat conductivity [16]. This translates directly to the beneficial properties of composites developed with their participation [17][18][19]. Although basalt fibers (BF), similar to GF, often have more than 50% SiO 2 , their properties are much superior.…”

Synthesis and application of thermal latent initiators of epoxy resins: A review

“…On the other hand, in the catalytic curing agent system, epoxide groups in the epoxy resin are initiated and cured by ion polymerization. [56][57][58][59][60][61][62][63][64] The latent initiator is a relatively stable curing agent that can be stored for an extended period at room temperature, after being mixed with an epoxy resin. When external conditions (such as heat and light) are applied, curing of the epoxy resin can be promoted by the initiator.…”