Abstract:
Epoxy/cnts nanocomposites were prepared using pristine and functionalized multiwalled
carbon nanotubes (p-MWCNTs and f-MWCNTs). The functionalization of
MWCNTs was done by COOH groups and FT-IR analysis was performed to confirm
successful attachment of COOH groups to MWCNTs. The different concentrations of
Epoxy/CNTs nanocomposites were prepared by solution mixing and resin casting
method. A comparison study was carried out between both types of nanocomposites to
investigate the change in morphology, mechanical, thermal, thermo-mechanical and
dielectric properties. Structure and morphology of the epoxy/cnts nanocomposites were
studied using sem. SEM images revealed better dispersion of f-MWCNTs than p-
MWCNTs into the epoxy matrix with nanofillers threshold concentration at 0.5%wt.
ratio and at higher wt% the CNTs were agglomerated in the epoxy matrix. Good and
uniform dispersion of nanofillers lead to polymer chain wrapping/adherence which in
turn enhanced the tensile strength and modulus of epoxy/f-MWCNTs as compared to
epoxy/p-MWCNTs. The mechanical properties were improved at the expense of strain at
break and maximum increase in modulus was 21% and 64% whereas enhancement in
tensile strength was 100% and 105% for epoxy/p-MWCNTs and epoxy/f-MWCNTs
nanocomposites, respectively. The glass transition temperature (Tg) was measured by
DMA and it was decreased by increasing the wt% of MWCNTs and the effect of
decrease in Tg was higher in case of f-MWCNTs. The thermal stability was determined
by TGA and it was also decreased by increasing the wt% of MWCNTs, the effect of
decrease was higher in p-MWCNTs. Moreover, impedance analysis confirmed that
dielectric properties and ac conductivity were improved by addition of MWCNTs into
epoxy matrix.
