Synthesis of Zn/Mg oxide nanoparticles and its influence on sulfur vulcanization

To reduce the ZnO levels in rubber compounds, mixed metal oxide nanoparticles of zinc and magnesium (Zn_1-xMg_xO) have been synthesized and used as activator. The aim is to obtain better curing properties due to its nanosize and to take advantage of the behavior of both ZnO and MgO in sulfur vulcanization. The model compound vulcanization approach with squalene as a model molecule for NR and CBS as accelerator has been used to study the role of the mixed metal oxide along the reaction. The results found show that with Zn_1-xMg_xO nanoparticles the reaction of CBS becomes faster, higher amounts of MBT are formed at shorter reaction times, and the consumption of sulfur occurs faster in comparison with standard ZnO. Furthermore and more important, an increased crosslink degree calculated as the total amount of crosslinked squalene is obtained. All these findings indicate that Zn_1-xMg_xO is a promising candidate to reduce the ZnO levels in rubber compounds.