Synergistic Antifouling and Robust Protection Enabled by a Main-Chain Capped Castor Oil-Based Polyurea Coating

Traditional antifouling coatings primarily rely on organic fluorine reagents, which are costly, poorly biodegradable, and potentially toxic. These drawbacks limit their applications in high-safety and environmental-standard scenarios, creating an urgent need for antifouling coatings. To address this, a fluorine-free, environmentally friendly castor oil-based polyurea coating (BPAE-X) was developed. Renewable castor oil as the soft segment enhances substrate adhesion, while poly(aspartic ester) F524 enables controlled curing for a smoother surface and optimized mechanical properties. The core innovation is a main-chain capping strategy that integrates the low-surface-energy silane coupling agent BTMSPA into the polyurea matrix, avoiding BTMSPA migration and preserving the antifouling performance. Performance tests confirm BPAE-X’s superior antifouling capability (contact angle >90°, no residue after wiping), excellent durability (low wear index after 1000 Taber abrasion cycles), grade 0 substrate adhesion, 19.06 MPa tensile strength, and corrosion protection for metal substrates. This work provides an effective solution for antifouling applications in sensitive fields.