Achieving Pseudo‐Ductile Behavior of Carbon Fiber Reinforced Polymer Composites via Interfacial Engineering

This article presents an investigation of the properties of interfacial engineered carbon fiber (CF) reinforced polymer (CFRP) composites. Poly(ϵ‐caprolactone) (PCL) is used as an interface engineering/interlayer material to modify the interfacial shear strength (IFSS) between the phases, with which it is aimed to increase the pseudo‐ductility of CFRPs. A stable crack propagation behavior can be achieved through interfacial engineering due to the locally weakened connection between the resin and the fiber reinforcement. Various grid patterns of PCL interfacial additive are designed, and 3D printed on the unidirectional (UD) CF (UDCF) surfaces by fused deposition modeling (FDM) and the UDCF is infiltrated with an amine‐cured epoxy (EP). The resulting composites are subjected to mechanical tests. In each case, the PCL‐rich interphase increases ductile pseudo‐behavior, and the type of grid affects the mechanical response.