Packing and permeability properties of E-glass fibre reinforcements functionalised with capsules for self-healing applications

Self-healing polymer nanocomposite materials: A review

“…The release of these nanocapsules was attributed to the thin microcapsule walls along with the hydrophobic-hydrophobic interactions among the cracked surface and nanoparticles. Microcapsules based self-healing polymer composites have been extensively studied and reported [98][99][100][101][102]. However limited information is available on nanocapsules based self-healing composites.…”

Progress in Self‐Healing Fiber‐Reinforced Polymer Composites

“…Indeed, woven reinforcements have been used in many healing studies, rather than unidirectional arrays, because resin rich areas are found between crossing warp and fill yarns where the capsules can be naturally stored without affecting the intrinsic waviness of the fiber reinforcement, if their size is lower than the resin rich gaps . The introduction of extrinsic systems, which have a dimension comparable to or larger than the natural void space in the reinforcement will generate distortions, and in turn modify the achievable V f as well as initial (mostly compressive and interlaminar, as well as fatigue) properties …”

“…In general, low‐pressure consolidation techniques are required, so as to preserve the microcapsules or hollow fibers from breaking during processing. As an example, in the work of Manfredi et al, urea–formaldehyde capsules, which were shown to rupture under a force of 4–6 mN could be successfully introduced into glass fiber composites (with fiber volume fractions around 40%) only with an adapted VARIM process, with 0.3 bars as pressure difference, instead of a full vacuum as usually employed. The microcapsules used for self‐healing studies in FRPs were typically of 200 µm diameter, which is around 20 times larger than single glass or carbon fibers (8–16 µm).…”

“…For extrinsic systems containing microcapsules, the viscosity of the polymer is greatly increased if the capsules are mixed into the flowing polymer; aggregation of the particles might severely limit the flow of liquid through the reinforcement. One solution to this problem, which does not change the resin permeability (and can even increase it), is to functionalize the reinforcement prior to infusion as demonstrated by Manfredi et al However, in that case, the choice of epoxy resin system remains limited to resins with relatively low cure temperature, so as to remain within the stability range of the capsules (in terms of capsule shell stability and breaking strength above room temperature). In general, room temperature or low cure temperature (around 35 °C) are selected to demonstrate the principle.…”

Experimental characterization of polydisperse particle‐loaded flow for linear resin transfer molding injections

“…Remarkable features of this process are the possibility of producing composite parts of complex shapes with high quality and strength, along with a strong dimensional stability, in addition to its potential of introducing inserts. [1] For some RTM applications, particles are added to provide functional properties to the finished part, [2,3] such as electrical [4,5] and thermal conductivity, [6][7][8][9] flame retardancy, [8,[10][11][12] self-healing properties, [13] enhancement of mechanical properties, [14][15][16][17] and weight saving. [18][19][20] Recent developments [13,21] have introduced several methods for particle addition to composite materials such as the deposition of inclusions on the preform surface or the addition of particles to the liquid resin.…”