Mesoporous Polydopamine Nanoparticles: Unlocking Their Potential for Thermo‐Oxidative Stabilization of Polypropylene

ABSTRACT Biobased nanoparticles offer sustainable alternatives for polymer stabilization, but optimizing their anti‐aging efficiency remains challenging due to structural limitations. We report the synthesis of mesoporous polydopamine (MPDA) nanoparticles via a facile supramolecular assembly process using templates. Compared to conventional nonporous polydopamine (NPDA) nanoparticles, MPDA exhibits a 23% higher specific surface area (32.8 m 2 /g), resulting in superior performance when incorporated into polypropylene (PP). PP/MPDA composites demonstrate a 376% increase in oxidation induction time and a 16°C higher initial degradation temperature ( T 5% ) versus neat PP, significantly outperforming PP/NPDA composites (111% and 9°C improvements, respectively). Mechanistic investigations reveal that MPDA's enhanced performance stems from its superior free radical scavenging and metal ion chelation capacities. This study establishes structure–function relationships for MPDA and demonstrates its potential as an effective, sustainable stabilizer for enhancing polymer durability across diverse applications.