Highly tough and strain sensitive plasma functionalized carbon nanotube/epoxy composites

Abstract A highly tough and strain sensitive composite was manufactured by symmetric plasma functionalized CNT film and epoxy, considering the limited plasma permeability in a compact CNT assembly. Due to the homogeneously active chemical groups generated on CNTs, the composites demonstrated good resin infiltration and robust CNT-epoxy bonding, resulting in 220.1% improved peeling strength (331.2 N/m). Their tensile toughness reached 134.9 MJ/m 3 , which is around 5 times higher than other reported carbon based (CNT, Graphene, Carbon Fiber) composites. In addition, it showed excellent mechanical properties with tensile strength of 510.4 MPa and strain sensitivity with gage factor of ∼4.0 under a tensile strain above 40%. Our study for the first time revealed the improved interface interaction in a fiber-matrix system by uniform functionalized CNT film and created the tough and strain sensitive composites with good ductility. It can be applied as advanced composites in ballistic structure, aerospace field and some smart systems.