Effects of temperature and water absorption on the interfacial mechanical properties of carbon/glass-reinforced thermoplastic epoxy hybrid composite rods

•Fracture process changes from brittle to ductile as the temperature increased.•Interfacial strength decreases with increasing temperature and water immersion time.•Interfacial strength restores after drying.•Temperature dependence could be estimated via DMA and/or microindentation.•Water absorption dependence could be determined using the mass uptake behavior. The effects of temperature and water absorption on the mechanical properties at the interface of a two-phase hybrid carbon/glass fiber reinforced thermoplastic epoxy composite rods were investigated. The push-out tests were performed on three types of these hybrid composite rods, with different carbon/glass ratios, at various temperatures and water immersion times to investigate their interfacial shear strength and fracture mechanism. Debonding occurred at the interface between glass fiber bundles and thermoplastic epoxy, followed by sinusoidal behavior during sliding, as revealed by the load–displacement curve. The interfacial debonding and sliding strengths decreased with increasing the temperature. The interfacial strengths also decreased with increasing water immersion time, but they were both restored after drying, for all the samples tested. In addition, the effects of temperature and water absorption on the thermoplastic epoxy matrix were also evaluated and the interfacial shear properties of hybrid composite rods were estimated.