Optimizing viscoelastic and mechanical properties of MWCNT/CF-epoxy nanocomposites

In the present investigation, optimization of the viscoelastic and mechanical properties of a functionalized multi-walled carbon nanotube (MWCNT) and carbon fiber-reinforced epoxy nanocomposite was carried out. The process parameters used in this investigation are MWCNT content (wt.%), sonication time (min), and ball milling duration (min). Taguchi orthogonal array (L9) was employed to design the experimental runs and study the effect of each parameter on the responses. Response variables used in this investigation are storage modulus, loss modulus, glass transition temperature (Tg), and tensile strength. A regression model in terms of process variables was developed and validated through confirmation experiments performed at the optimum conditions of 2 wt.% MWCNTs, 60 min of sonication, and 180 min of ball milling. The predicted and experimental values of storage modulus (41.815 against 38.2 ± 4.05 GPa), loss modulus (3.94 against 3.89 ± 0.15 GPa), Tg (138.81 against 135 ± 9.94°C), and tensile strength (941.45 against 942 ± 28.59 MPa) were found to be in close agreement, confirming the reliability of the developed models. Microstructural examination of the optimized composite using microscopy revealed a uniform dispersion of MWCNT’s within the epoxy matrix, contributing to the improved interfacial bonding and load transfer.