Enhanced Interfacial Compatibility and Dynamically Mechanical Properties of Nitrile Butadiene Rubber‐Polyoxymethlene Blends Fabricated by Two‐Stage Blending Approach

The present study prepared NBR/POM blends with varying rubber‐plastic ratios of 90/10, 80/20, 70/30 through a two‐stage blending approach involving internal/open‐mill blending and melt blending. The compatibilization performance of various compatibilizers polyether polyol (KGF‐400D), thermoplastic phenolic resin (PR‐12686E), thermosetting phenolic resin (SP‐1045), and epoxide resin (E51) was systematically evaluated at a fixed rubber/plastic ratio. Our findings demonstrated that all the investigated compatibilizers clearly improved the compatibility of the blends to varying degrees, among which SP‐1045 exhibited the most pronounced compatibilization effect. Both mechanical analysis and rubber process analysis (RPA) characterizations clearly indicated the mechanism of compatibility improvement. In the NBR/POM blend compatibilized with SP‐1045, the phenolic hydroxyl groups were found to in situ form hydrogen bonds with the ether oxygen in POM, enabling a considerable enhancement in compatibility with the POM phase. Meanwhile, the highly polar nitrile groups in NBR can interact strongly with the phenolic resin, further strengthening interfacial interactions. This work proposes an effective approach to enhance the compatibility of NBR/POM blends, which offers a promising strategy for developing high‐performance rubber‐plastic blends with tailored properties for demanding industrial applications.