Morphology correlated investigation on mechanical and dielectric properties of plasticized poly vinyl chloride/MWCNT nanocomposites

This paper investigates the correlation of morphologies with mechanical and dielectric properties of plasticized poly vinyl chloride/MWCNT (PPVCN) nanocomposites. Special focus is given to filler induced networking and its effect on the dielectric properties of nanocomposites. Mechanical properties with different MWCNT loadings from 0.25% to 5% are correlated with fracture morphologies to understand the fracture mechanism and factors influencing the mechanical properties of the nanocomposites. At 5% MWCNT loading, the nanocomposite shows improvement in strength with exceptional enhancement in modulus. The best mechanical properties of the nanocomposite at 5% MWCNT loading is supported by morphological features, such as matrix cracks and crack bridging by MWCNTs. These features also supported the enhancement in toughness of the nanocomposite imparted by better polymer/MWCNT interfacial interactions. The dielectric properties of nanocomposites increase with increasing MWCNT loading. The nanocomposite with 5% MWCNT loading shows a six times high filler contribution factor when the system reaches its percolation limit. This supports the idea that polymer bridged MWCNT network formation has a pronouncing effect on the permittivity of the nanocomposites. PPVCN nanocomposite with 5% MWCNT loading exhibits the best mechanical and dielectric properties.