A review of recent progress in improving the fracture toughness of epoxy‐based composites using carbonaceous nanofillers

Abstract

Epoxy resins (EPs) exhibit various extraordinary properties, including significant mechanical and thermal properties, low shrinkage, and high chemical resistance, opening a wide window of different applications such as adhesives, paints, coatings, etc. By contrast, EPs also have the undesirable behavior of being brittle and cannot sufficiently resist against the initiation and growth of cracks. Efforts are being made to enhance the toughening of EPs without sacrificing their other desirable properties. With the advent of nanotechnology, improving the toughening of EPs has gained momentum by incorporating different modified and unmodified nanofillers into these polymers. Since the discovery of carbonaceous nanofillers, especially carbon nanotubes (CNTs) and graphene (Gr), significant progress has been made in the development of EP‐based composites incorporating these nanofillers and their hybrids. The current review presents research progress during the last six years on the toughening of EPs using CNTs, Gr, and CNT‐Gr hybrids. Special attention is given to the chemical functionalization of these nanofillers, which has been demonstrated over and over again to significantly affect nanofiller dispersion in the EP matrix and subsequently its fracture properties. Details on the various toughening mechanisms of EP‐based composites are further provided.

Effect of MWNT Functionalization with Tunable-Length Block Copolymers on Dispersity of MWNTs and Mechanical Properties of Epoxy/MWNT Composites

“…To put the mechanical properties‘ results in the perspective of published studies of tensile strength and fracture toughness in epoxy/CNT nanocomposites, we find that the introduction of organic molecules in the functionalized CNTs improved either tensile strength or fracture toughness to a certain extent at 0.2–1 wt% loadings [ 40 , 41 ]. In this work, bc@ f MWNT only required loading of 0.05 wt% to obtain a similar improvement in strength, K IC , or G IC , indicating our interfacial design works.…”

Ionic liquid‐functionalized reinforcements in epoxy‐based composites: A systematic review

“…As a consequence, epoxy nanocomposites, obtained by the incorporation of an organic or inorganic component, have recently gained attention as a means to produce high performance nanocomposites. [ 9 ]…”

“…As a consequence, epoxy nanocomposites, obtained by the incorporation of an organic or inorganic component, have recently gained attention as a means to produce high performance nanocomposites. [9] In this sense, not only nano-materials, but several types of reinforcements have been used as a second phase in composites. Some examples include carbon, [10,11] glass [12,13] vegetable fibers, [14,15] clays, [16] carbonaceous (e.g., carbon nanotubes and graphene nanoplatelets [17][18][19][20] ) and polysaccharide (e.g., micro cellulose and chitin nano-whiskers [21][22][23][24] ) particulates, among others.…”

Evaluating the mechanical, thermal, and antibacterial properties of poly (lactic acid)/silicone rubber blends reinforced with (3‐aminopropyl) triethoxysilane‐functionalized titanium dioxide nanoparticles

“…To cope with this issue, nanomaterials are usually used. [36][37][38][39][40] However, the compatibility threshold is a vital subject that must be considered during the blending process. In other words, to enhance the effective interactions between the polymer phases in the interface region, there is a limit to the amount of compatibilizer used.…”