Masterbatch strategy for enhanced filler dispersion and reinforcement of zirconia-filled NBR composites

Abstract

The reinforcement of elastomeric composites by inorganic non-black fillers such as metal oxides is primarily governed by their shape, size, and state of dispersion. However, the filler incorporation technique can also play a critical role in this regard. This study investigates the efficacy of a masterbatch approach for in situ zirconia reinforced nitrile butadiene rubber (NBR) composites. A comprehensive characterization of all the composites is carried out, including evaluation of their rheological, thermal, mechanical, morphological and dynamic mechanical properties. This approach is found to be very efficient in strengthening composite properties, such as enhancements in their mechanical and thermal properties, along with other properties like aging resistance, viscoelastic behaviour and compression set. The masterbatch-derived 20 phr zirconia containing NBR composite shows better performance than externally filled zirconia-NBR composite at the same filler content. The masterbatch approach ensures superior filler dispersion and enhanced interfacial interaction. Beyond performance metrics, this method represents a greener approach by reducing solvent usage and energy input with respect to the purely sol–gel derived in situ filler incorporation method, aligning with sustainable development goals and promoting eco-friendly material processing.