Composite Materials Research Progress

An Experimental and Analytical Study of Unidirectional Carbon Fiber… 139
Figure 9. Nano-phased unidirectional laminate.
Figure 10. Consolidation cycle for laminates.
Experimental Results and Discussion
Differential Scanning Calorimetry
The Differential Scanning calorimetric (DSC) studies have been carried out to understand the
effect of nanoparticles on glass transition temperature of cured carbon-epoxy prepregs based
on consolidated samples. Figure 11 represents the DSC curve of as-fabricated neat system.
The curve exhibits an endothermic baseline shift at about 220 0 C and highly exothermic peak
at about 390 0 C. The baseline shift at 220 0 C is assigned to the glass transition temperature
and exothermic peak at 390 0 C is assigned to the decomposition temperature of the epoxy
resin. These results match well with the supplier materials data sheet. Figure 12 represents the
DSC curve of as-fabricated 1.5 wt.% SiC nano-phased system. The curve showed only one
exothermic peak at about 397 0 C which is assigned to the decomposition temperature of the
cured epoxy resin. The baseline shift corresponding to glass transition temperature was
almost disappeared. This clearly indicated that the epoxy was highly cross-linked due to
catalytic effect caused by SiC nanoparticles. The shift was not observed, we believe, because
of the equipment sensitivity to the higher cross-linked polymers. To further validate the