Synthesis of the aureus nano-silica utilizing acid orange 7 for strengthening and coloring fluororubber

Fluororubber (FKM) has an important application in the industrial field. However, the coloring problem of FKM has been affecting the performance of its mechanical properties. Herein, a novel silicon dioxide (SiO₂) colored with acid orange 7 (AO7) was prepared by sol–gel method to ameliorate the mechanical properties and coloring property of FKM. Acid orange silica sol was prepared by adding AO7 to sodium silicate solution, and then colored SiO₂-AO7 was prepared by freeze drying. The effects of SiO₂-AO7 modified FKM on mechanical properties, thermal conductivity and coloring were systematically studied. The results show that SiO₂-AO7 has the advantage of enhancing the mechanical properties of FKM without affecting its color appearance. Relative to the unmodified FKM, the tensile strength and modulus at 300% elongation saw enhancements of 47.2% and 21.8% respectively. The SiO₂-AO7 offers exceptional coloration and mechanical reinforcement, showing strong suitability for industrial application.