Evaluation of mechanical properties and damage sensing performance of functionalized carbon nanotube modified epoxy-carbon fiber

Uniform distribution and strong interaction of carbon nanotubes in a polymer matrix have resulted in improved performance of the pure polymer. In this work, MWCNTs (CNTs) and carboxylic acid functionalized MWCNTs (CNTs-COOH) were dispersed into the epoxy resin to improve the intrinsic damage sensing property of woven carbon fiber reinforced epoxy (CFRP) composite laminates. We prepared the MWCNT-modified CFRP composites (CNT_CFRP and CNT-COOH_CFRP) with varying MWCNT concentrations (0.25 wt% - 1 wt%) and studied the effect of functionalization and concentration of MWCNTs on the mechanical, and electrical properties of CFRP laminates. A pronounced increase in the tensile strength and tensile modulus of CFRP laminate was achieved with the introduction of 0.5 wt% CNTs and CNTs-COOH. The damage sensing capability of modified CFRP laminate was investigated by measuring electrical resistance upon loading.