Insights into the effect of fiber-matrix interphase physiochemical-mechanical properties on delamination resistance and fracture toughness of hybrid composites

The characteristics of the formed fiber-matrix interphase play a decisive role during fracture of fiber reinforced composites. Herein, we experimentally investigate the influence of fiber-matrix interphase on the fracture toughness of fiber-reinforced composites. Carbon fiber is modified with nanoparticles having different physical and chemical features, including functionalized carbon nanotubes (fCNTs), cellulose nanocrystals (CNCs), and hybrid CNC-CNT, and the effect of chemical and mechanical properties of the fiber-matrix interphase and fiber surface topology on the mode I and mode II delamination resistance of carbon fiber/epoxy composites is studied. The objective of this study is to fundamentally understand the relationship of fiber-matrix interphase properties and fracture toughness. It is observed that fiber-matrix interfacial strength depends on the width and chemical properties of the interphase zone. CNC-CNT spans the interfacial zone enhancing the interfacial strength by 76%, allowing the matrix to have a more effective contribution during the fracture. The stronger interphase subse-quently results in 183% improvement in mode I and 75% improvement in mode II interlaminar fracture toughness of the composite.

Automated summary

This study experimentally investigates the influence of the fiber-matrix interphase on the fracture toughness of fiber-reinforced composites. The width and chemical properties of the interphase zone are found to significantly affect the interfacial strength. By modifying the fiber surface with nanoparticles, the interfacial strength is improved by 76%, resulting in a more effective contribution of the matrix during fracture. This stronger interphase leads to a 183% improvement in mode I and 75% improvement in mode II interlaminar fracture toughness of the composite.