Influence of Modified Nanosilica on the Performance of NR/EPDM Blends: Cure Characteristics, Mechanical Properties and Swelling Resistance

In this study, the influence of modified nanosilica on the curing, mechanical, and swelling resistance properties of natural rubber and ethylene-propylene-diene monomer blends (NR/EPDM; 70/30 phr/phr) was examined. The composites were developed using the melt compounding method, with nanosilica derived from rice husk ash serving as the reinforcing nanofiller in NR/EPDM composites. Two modifiers were employed in this study: a 2:1 ratio of TESPT (bis(3-triethoxysilylpropyl)tetrasulfide) to TWEEN-20 (polyoxyethylene (20) sorbitan monolaurate) (Modifier 1), and thioctic acid (TA) (Modifier 2). In comparison to pure NR/EPDM blends, the inclusion of TA-modified nanosilica significantly enhanced tensile and tear strength by up to 76% and 48%, respectively. Moreover, NR/EPDM nanocomposites filled with TA-modified nanosilica exhibited reduced swelling at a given loading when compared to their counterparts filled with TESPT/TWEEN-20-modified nanosilica.