Effect of ZnO nanoparticles on the simultaneous improvement in curing and mechanical properties of NR/ Recycled EPDM blends

Abstract

Recycling of rubber waste and searching for alternative routes to decreasing the loading of ZnO are of significant concern due to their input on environmental aspect. In this respect, recycled ethylene-propylene-diene (EPDM) rubber has been used in an attempt to create a value-added rubber material based on natural rubber/recycled EPDM blends. ZnO nanoparticles were also incorporated as a way to replace the conventional ZnO together with the aim of improving the curing and mechanical properties of the blends. Spherical and elongated shapes of ZnO nanoparticles were synthesised by a homogeneous precipitation method and were then characterised by Transmission Electron Microscopy (TEM) and X-Ray diffraction analysis. Synthesised ZnO nanoparticles were found to have no impurities and had a dimension ranging from 10-40 nm. The study confirmed that ZnO nanoparticles showed a better state of curing and higher maximum torque with a significant decrease in optimum curing time and scorching time. It was also observed that a low content of ZnO nanoparticles was sufficient to give higher mechanical properties compared to one containing a higher content of conventional ZnO.