Influence of MWCNT modified epoxy matrix on hoop tensile performance of filament wound CFRP tubes

This study investigates the impact of the multi-walled carbon nanotube (MWCNT) modification of the epoxy matrix on the hoop tensile performance of the filament-wound carbon fiber reinforced polymer (CFRP) tubes. Five MWCNT concentrations (0–1.0 wt%) were dispersed into the epoxy using an acetone-assisted ultrasonic process to promote de-agglomeration and uniform nanotube distribution. The modified resins were used to fabricate the filament-wound tubes, which were machined into ASTM D2290 ring specimens for hoop tensile testing. The results show that MWCNT incorporation significantly enhances the hoop strength, with the highest value at 0.75 wt% (320 MPa) compared to 268 MPa for the unmodified matrix. The stress–strain behavior indicates improved stiffness and load transfer at moderate MWCNT levels. At 1.0 wt%, the performance decreased due to nanotube agglomeration and reduced impregnation quality. Post-failure morphology observed using Dino-Lite optical microscopy and scanning electron microscopy (SEM) confirmed stronger fiber matrix bonding at the optimal MWCNT concentration. These findings highlight the importance of controlled nanotube dispersion for improving the hoop tensile behavior of the filament-wound CFRP tubes.