Multifunctional CoO-ZnO/Mica pigments: A synergistic approach to anticorrosive coatings and activated SBR composites

Advancing multifunctional pigments that combine low-cost processing with the high-value performance of engineered materials represents a frontier in materials science. In this study, next-generation pearlescent CoO-ZnO/Mica pigments (Co.Zn/M) were engineered through a sol-gel process and designed to deliver dual functionality in two significant technological fields: anticorrosive coatings and as an activator in styrene-butadiene rubber (SBR). Two tailored compositions, 1Co.9Zn/M and 3Co.7Zn/M, were synthesized and rigorously characterized by using several spectroscopic techniques, confirming their structural integrity and compositional precision. When integrated as pearlescent pigments into epoxy resins with three ratios (e.g., 5, 10, and 15%), these pigments exhibited inherent bright colors and anticorrosive behavior, underscoring their potential as versatile materials for next-generation coatings. The corrosion measurements revealed that 3Co.7Zn/M is more protective than 1Co.9Zn/M, and the ratio of 10% is the best. Moreover, these pigments were introduced with three ratios of loading (e.g., 1, 2, and 3 phr) in SBR formulations as alternative activators to partially or entirely replace the conventional ZnO-stearic acid. The Co.Zn/M/SBR composites accelerated curing behavior and a slight reduction in tensile strength of (1.86%) compared with the blank composite, but a pronounced enhancement in elongation compared with the blank composite. Furthermore, the pigments also improved swelling resistance, cross-link efficiency, while simultaneously promoting a more uniform additive dispersion within SBR matrix.