Mode I and Mode II fracture energy of MWCNT reinforced nanofibrilmats interleaved carbon/epoxy laminates

Laboratory scale carbon/epoxy laminates were interleaved with electrospun Nylon 66 nanofibrilmat reinforced with multi wall carbon nanotubes (MWCNTs). The effect of the MWCNTs on the fracture energy was evaluated under Mode I and Mode II loading. It is shown that while nanofibrilmat interleaving resulted in a 3 times increase of the Mode I fracture energy compared to the non-interleaved laminates and the MWCNT reinforced nanofibrilmat interleaving resulted in a 4 times increase. Evaluation of the Mode II fracture energy indicated a 40% increase as a result of nanofibrilmats interleaving, while MWCNT reinforced nanofibrilmat interleaving resulted in a 60% increase. Mechanisms for the fracture energy increase of the MWCNT reinforced nanofibrilmats are suggested based on the test data and fractographic study of post-test specimen surfaces.