Cellulose nanofibre enabled natural rubber composites: Microstructure, curing behaviour and dynamic mechanical properties

Traditional rubber industries rely heavily on petroleum-based materials, such as carbon black (CB). The present study aims at mitigating the environmental challenges, through partial replacement of CB, while simultaneously consuming an easily accessible agricultural waste. Accordingly, cellulose nanofibre (CNF) was extracted from wheat-straw using chemo-mechanical process, which in-turn was used for fabrication of CNF enabled rubber nanocomposites. Microstructural observation of CNF confirmed nanometric defibrillation of cellulose. A variety of tests were performed on the nanocomposites towards exploring their structure-property correlations, curing-behaviour, thermal degradability and mechanical (static and dynamic) properties. Overall, considerable enhancement in properties such as tensile strength and strain energy density could be realized, owing to synergistic use of CNF and CB in rubber, allowing for replacement of up to 15 phr CB. These were further augmented by significant improvements in dynamic rolling-resistance, traction and stress-softening behaviour. The results were especially significant, considering that the improvements could be achieved without any modification of CNF surface, thereby establishing its potential for development of environment friendly rubber nanocomposites.