Control of basic aggregate structure: Application and mechanism analysis in nitrile rubber composite materials

Abstract This paper investigated the dispersion of silica exhibiting different specific surface areas in nitrile rubber (NBR) matrices and the interactions between fillers, filled rubber, and rubber networks by regulating the aggregate size. To better characterize and leverage the filler network structure, a comprehensive analysis was conducted using linear and nonlinear rheological tests based on the equilibrium solvation theory and pipe models. The results demonstrated that the incorporation of fillers formed an island‐like network structure. With high specific surface area, the concurrent use of high and low specific surface area silica fillers improved the filler‐rubber interactions and hindered filler‐filler interactions, decreased the filler aggregate size, and enhanced the dispersion. Furthermore, we analyzed the mechanism of the filler network structural enhancement and its relationship with the specific surface area by regulating the filler ratios to adjust the polymer size. Highlights Control of Filler Network Structure: Ratio adjustment strengthens interactions. Large silica surface enhances F‐R interaction, small surface improves dispersion. Mixing ratios favor robust filler interconnection or dispersion. Reveals strong correlation of filler network strength with F‐F interactions. Highlighted effective eco‐friendly means of adjusting filler Mixing ratios.