Synergistic effect on static and dynamic mechanical properties of carbon fiber-multiwalled carbon nanotube hybrid polycarbonate composites

Carbon fiber (CF) and multiwalled carbon nanotube (MWCNT)-reinforced hybrid micro-nanocomposites are prepared through melt mixing followed by injection moulding. The synergistic effect on both the static and dynamic mechanical properties with MWCNT/aMWCNT and CF reinforcement in a polycarbonate matrix is investigated by utilizing dynamic mechanical analysis, and flexural and tensile measurements. The enhancement in the flexural modulus and strength of the composite specimens as compared to pure PC for maximum loading of CF is 128.40% and 39.90%, respectively, which further improved to 142.94% and 42.60%, respectively, for CF-functionalized MWCNTs. Similarly, the storage modulus of the composite specimens reinforced with a maximum loading of CF and CF-functionalized MWCNTs show an increment of 176.57% and 203.33%, respectively over pure PC at 40 degrees C. Various types of parameter such as the coefficient C factor, degree of entanglement and adhesion factor have been calculated to analyze the interaction between fillers and the polymer matrix. Composite specimens containing 2 wt% of functionalized MWCNTs show a lower C value than the as-synthesized MWCNTs, which is indicative of a higher effectiveness of functionalized MWCNT-containing composite specimens. These results are well supported by optical microscopy and Raman spectroscopy by confirming the distribution of reinforcements and the interaction to PC, respectively.