Effects of Nanosilica on the Mechanical Properties and Swelling Resistance of EPDM/NBR Nanocomposites

The final performance of polymer-based composites is greatly influenced by the surface modification of fillers, filler dispersion, and interfacial adhesion. In this contribution, silica is modified by polymethylhydrosiloxane (PMHS) using a quick and effective tris(pentafluorophenyl)borane-catalyzed functionalization that can be finished at room temperature in a few minutes. The modified silica exhibits both unaltered reactivity and a highly hydrophobic surface. A comparison of composites containing extracted silica and modified silica reveals that the PMHS modification can improve silica dispersibility by lowering the interfacial energy, as well as enhance interfacial interaction due to the reactivity of the remaining Si-H bonds. The modified composite shows remarkable improvements in mechanical properties with a PMHS grafting percentage as low as 1.5 wt% (63% increase in tensile strength, 12% increase in elongation at break, and 23% increase in modulus). We believe that the hydrosilane-modified silica offers enormous promise for the creation of high-performance polymer composites, owing to the improved overall performance of the modified composites and the ease and speed of the modification process.