Dynamic mechanical characterization of PC/MWCNT composites under variable temperature conditions

A dynamic mechanical analysis has been performed on composite materials of polycarbonates (PC) and multi-walled carbon nanotubes (MWCNT) for evaluation of their mechanical hardness and storage modulus under the combined effects of variable loading frequencies and temperature conditions. The PC-based engineering machine components that are subjected to variable external loads and temperature conditions are not durable owing to the viscoelastic properties of PC. Composites of PC with MWCNT (2, 5 and 10 wt%) were fabricated and their mechanical characterization tests revealed that with increase in MWCNT composition both storage modulus and hardness enhanced significantly in comparison to pure PC. For 10 wt% PC/MWCNT composite, the average storage modulus increased in the range of 40–92%, while the average hardness was enhanced in a range of 88–121% for the combined effect of temperature range of 30–90 °C and loading frequency range of 30–230 Hz. With increase in temperature, the maxima of storage moduli and hardness for these composites shifted toward higher loading frequencies, indicating that these composites can be used for wider loading frequency range. Therefore, the experimental results of this paper have shown that the mechanical properties of PC-based composite materials with minor MWCNT compositions are enhanced significantly and hence can be used for automotive and aerospace engine parts where loading frequencies are high and temperature conditions are variable.