Strategies for Preparing Migration-Resistant Macromolecular Antioxidants

Polymeric materials are susceptible to thermo-oxidative degradation during melt processing and usage, which can be prevented using antioxidants. However, conventional small-molecule antioxidants, such as phenolic antioxidants, are prone to migration, which compromises their long-term effectiveness. To address this, for crystalline/semicrystalline polymers, we propose a systematic design strategy for macromolecular antioxidants based on the "3C principle" (Compatibility, cocrystallization, and crosslinking) to construct novel stabilizers with enhanced antioxidant performance and migration resistance. For noncrystalline polymers, macromolecular antioxidants satisfying only two of these criteria can also provide good antioxidant performance. Based on these design principles, three different types of macromolecular antioxidants were developed with structures tailored to the characteristics of commodity plastics, including polyethylene, polymethyl methacrylate, and polystyrene. This work provides a new approach for enhancing the service stability of polymeric materials and offers a broad molecular design strategy for functionalized polymer materials.