The thermal degradation and dynamic mechanical properties modeling of MWCNT/glass fiber multiscale filler reinforced polypropylene composites

The present work is focused to explore the influence of multiscale fillers (nano scale multiwalled carbon nanotubes (MWCNTs) and micro scale Glass fibers) on the thermal degradation and dynamic mechanical properties of polypropylene (P). MWCNTs weight fraction was varied up to 5 wt% for a fixed glass fiber fraction of 20 wt% and the resultant composite was characterized using X-ray diffraction, Scanning and Transmission Electron Microscopy. Hybrid composites with 2 wt% MWCNTs presented 101% increase in the activation energy for thermal degradation compared to the base matrix. The synergism of multiscale fillers could be clearly verified by the improved storage and loss modulus of the composite with 3 wt% MWCNT which is related to better interfacial interaction of fillers with the matrix. The lowering of tan delta peak suggested the rise in entanglement density of polymer chains on the fillers and decrease in the damping behavior of the composites was observed till 3 wt% of MWCNTs both by experimental and theoretical model values. Beyond 3 wt% of MWCNTs agglomeration effects caused decline in the dynamic mechanical properties.