Secondary‐Amine‐Terminated Siloxane‐Modified Polyaspartic Polyurea With Enhanced Durability and Corrosion Resistance

ABSTRACT To enhance the overall properties of polyaspartic polyurea (PAEU) coatings, a siloxane ‐modified PAEU (SiPU) series was synthesized using diethyl maleate‐alkylated aminopropylsilane (DM‐APTMDS) as a modifier. Systematic characterization and performance tests revealed that the incorporation of DM‐APTMDS improved thermal stability, lowered the glass transition temperature, and promoted microphase separation. These structural modifications resulted in significantly enhanced adhesion (up to 8.49 ± 0.44 MPa), flexibility (elongation at break of 149%), and hydrophobicity (water contact angle of 99.4°). Specifically, at 21 wt% DM‐APTMDS, the coating demonstrated superior durability against chemical attack, UV aging, freeze–thaw cycling, achieving the minimum corrosion current density (7.21 × 10 −8 A/cm 2 ) and highest protection efficiency (89.82%). This optimal formulation achieved a well‐balanced combination of toughness, hydrophobicity, adhesion, and anticorrosion performance. This work provides important theoretical and practical guidance for designing high‐performance, durable polyurea protective coatings.