Fracture Behaviors of TRGO-Filled Epoxy Nanocomposites with Different Dispersion/Interface Levels

Abstract

In this work, we investigate mechanical properties and fracture behaviors of thermally reduced graphene oxide (TRGO)-filled epoxy composites with two different dispersion/ interface levels. The amphiphilic surfactant treatment of TRGO was found to promote the dispersion in both water and epoxy, but also produced improved TRGO/epoxy interface. As expected, incorporation of untreated or treated TRGO sheets into epoxy increases the storage modulus and the glass transition temperature. In particular, significant improvements in both tensile strength and fracture toughness (K IC ) of the TRGO/epoxy composites were also obtained after the surfactant treatment processing. For example, at a very low loading of 0.20 wt.-%, the surfactant-treated TRGO enhances the tensile strength and K IC of epoxy by $51 and$65%, respectively; while the corresponding untreated TRGO results in almost unchanged strength and produces $52% improvement in the K IC value. Based on the fractography observation and analysis, several failure mechanisms, e.g., crack bridging, pull-out/debonding, and fracture of TRGO as well as matrix plastic deformation, were identified and correlated to the increased fracture toughness of the two composite systems studied.

Study on epoxy resin-based thermal adhesive filled with hybrid expanded graphite and graphene nanoplatelet

“…It has been observed that the smooth surface of fractured neat epoxy composite was changed to rough surface after the incorporation of single and hybrid fillers. There were small solid lines in the region of cracks, showing brittle nature and low resistance toward propagation of stress fractures [10,13,[44][45][46].…”

Chitin nano-whiskers (CNWs) as a bio-based bio-degradable reinforcement for epoxy: evaluation of the impact of CNWs on the morphological, fracture, mechanical, dynamic mechanical, and thermal characteristics of DGEBA epoxy resin

“…40,41 In contrast, CNTs and Graphenes have been shown to reinforce through mechanisms like crack bridging behind the crack tip. [42][43][44][45][46] The aspect ratio of CNWs is between that of spherical nanoparticles and carbon nanotubes. This results in the possibility of hybridizing the reinforcement effects from both these types of nanoparticles (promotion of matrix plastic deformation and crack bridging) through the addition of CNWs.…”

Tailored interphase and thermal interface resistance of self‐assembled thermally reduced graphene oxide–polyamide hybrid/epoxy composites with enhanced thermal conductivity

“…However, the thermal transfer properties of graphene‐reinforced epoxy composites can be severely weakened by the agglomeration of graphene, which would result in poor dispersion of graphene in the epoxy matrix and high thermal interface resistance ( R TIM ) in the resulting composites . Therefore, graphene dispersion in an epoxy matrix and interface compatibility between graphene and the epoxy matrix are the key issues for the application of thermally conductive composites …”

“…7,8 Therefore, graphene dispersion in an epoxy matrix and interface compatibility between graphene and the epoxy matrix are the key issues for the application of thermally conductive composites. 9,10 Many methods have been attempted to facilitate graphene dispersion in an epoxy (EP) matrix, such as mechanical blending with ultrasonication and high-shear mixing, [11][12][13][14] which was able to break the van der Waals interactions among graphene nanosheets and retain the distinct structure of graphene. However, the enhancement in phonon scattering and mismatch led to a increase in the thermal interface resistance of the resulting composites.…”