  PMMA and Poly carbonate (PC) are wonderful low cost materials which can be
easily tailored and shaped. However they have poor mechanical, thermal and
electrical properties which are required to be enhanced in several applications
where along with high strength, a quick heat transfer becomes a necessity.
Carbon nanotubes (CNT) are excellent new materials having extraordinary
mechanical and transport properties. In this paper we report results of
fabricating composites of varying concentrations of CNTs with PMMA and PC and
measurements of thermal conductivity data by a simple transient heat flow. The
samples in disk shapes of around 2 cm diameters and 0.2 cm thickness with CNT
concentrations varying up to 10 wt percent were fabricated. By keeping one end
of the discs at steam temperature, the temperature of the other end was noted
for each sample after 10 s. The rise in temperature was correlated with thermal
conductivity which was appropriately calibrated. We found that both PMMA and PC
measured high thermal conductivity with increase in the concentration of CNTs.
The thermal conductivity of PMMA rose from about 0.2 W/mK to 0.4 W/mK at 10
wtpercent of CNT whereas for PC, it rose from about 0.2 W/mK to 0.9 W/mK at 10
wt percent of CNT. It is thus observed that modification in thermal properties
is easily achieved by making CNT based composites using only up to 10 wt
percent of CNTs in PMMA and PC and enabling quicker heat dissipation in these
materials.
