Effects of carboxyl functionalized MWCNTs on the cure behavior of epoxy
resin (EPIKOTETM resin 862 and EPICURETM curing agent W) were investigated
by using differential scanning calorimeter in dynamic scan mode. Results indicated
that nanotubes could initiate cure reaction at lower temperature while only 0.1
wt% samples were able to suppress the peak temperature (Tp) consistently regardless of different heating rate
due to their higher reaction rate, other two batches (0.2 wt%and 0.3 wt% CNT)
showed hardly any change in Tp compared to neat samples. Furthermore, addition of small amount (0.1 wt%) of
CNTs significantly reduced the activation energy of the system but further
addition elevated that due to their retarding effect. Also, a correlation was
established between the dispersion state of CNTs in epoxy and total heat of
reaction (ΔH) where lower ΔH was considered as an indication of better
interfacial interaction of CNTs with matrix and hence, better dispersion. The
difference in curing behavior of three different CNT percentages was discussed
in terms of their steric hindrance and state of dispersion in the matrix.
Cite this paper
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