Abstract:
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 signifcantly 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 signifcantly and
hence can be used for automotive and aerospace engine
parts where loading frequencies are high and temperature
conditions are variable.
