Chemical hybrid of nanoclay (NC)/carbon nanotube (CNT) was synthesized via growth of CNTs by
chemical vapor deposition. The cure kinetics of epoxy resin
in the presence of novel chemical hybrid of NC/CNT
(CNC) was studied by non-isothermal differential scanning
calorimetry. The effect of the CNC on cure kinetics was
compared with conventional nanofillers such as CNTs, NC,
and physical mixture of them (PNC). The kinetic parameters of the cure reaction were determined by iso-conversional method. The accelerating effect of CNT, CNC, and
PNC in initial stage of cure reaction was related to the high
thermal conductivity of CNTs, while the decelerating
effect of nanofillers as the cure proceeded can be attributed
to the reduction of polymer molecules motion caused by
enhanced viscosity. The apparent activation energy (Ea) as
the function of conversion (a) was calculated by five
methods categorized into two different types: (1) conversion-dependent methods: Kissinger–Akahira–Sunose
(KAS), Ozawa–Flynn–Wall (OFW), and Friedman; (2)
conversion-independent methods: Kissinger and Augis.
The accelerating effect of CNT, PNC, and CNC was
observable as the reduced Ea values in low conversion only
with KAS and OFW methods. The reverse trend of Ea
values was observed with the introduction of these
nanofillers at high conversions. The uniqueness of the CNC
was more marked in increasing Ea values of epoxy after
initial stage due to its special 3D structure of CNC. Calculated data using KAS and OFW methods showed the best
agreement with the obtained experimental data.