Studies on the morphology and physico-mechanical properties of NBR/PVC hybrid nanocomposites

Abstract

In the present work, NBR/PVC conventional composite containing 70phr carbon black (CB) is taken for study. In order to reduce the utilization of CB, new hybrid nanocomposites containing a fixed content of 55phr (Parts by weight per hundred of rubber) CB and varied content of COOH functionalized graphene nanoplatelets (GNP) (3phr–9phr) were developed by melt-blending on a twin roll mill and their morphology and mechanical properties were tested and compared with conventional composite. The prepared composites were examined for their morphology and various physico-mechanical properties. Studies revealed that incorporation of GNP in NBR/PVC matrix resulted in superior mechanical properties and swelling resistance in comparison to NBR/PVC composites containing CB alone. Further NBR/PVC hybrid nanocomposites containing 55phr of CB and 6phr of GNP exhibited an improvement of 7%, 42%, 29% and 20% in stress at break, modulus at 100% elongation, tear strength and resistance to swelling in comparison to the conventional composite containing 70phr CB. The same composite also exhibits superior hardness and compression The better performance of NBR/PVC hybrid nanocomposites can be mainly ascribed attributed to immense surface area of functionalized GNP and its enhanced interactions with the NBR/PVC matrix, enhanced CB-GNP interactions, improved dispersion of graphene in the NBR/PVC matrix due the existence of carboxyl (COOH) group on the surface of graphene layers and formation of more cross-links between rubber and fillers with increase in nanofiller content. FESEM studies reveal the formation of exfoliated structures of GNP and local CB-GNP hybrid filler network. These studies prove that partial replacement of CB with GNP is a promising approach to produce NBR/PVC composites with superior mechanical properties and swelling resistance.