Fluorine-Containing Polyurethane Prepolymers to UV-Curable Elastomeric Coatings for the Anti-Corrosion Application
摘要
The development of high-performance flexible coatings is crucial for protecting flexible printed circuit boards (FPCs) and other bendable electronic components from corrosion. Herein, a novel fluorinated urethane oligomer (HTPUF) with varying fluorine contents was synthesized and formulated into UV-curable coatings. The chemical structures of the synthesized HTPUF were confirmed by FTIR spectroscopy. The effects of fluorine content on the properties of the cured coatings, including water contact angle, water absorption, gel content, mechanical properties, and anti-corrosion performance, were systematically investigated. Results demonstrated that the incorporation of fluorine significantly enhanced the coating properties. The HTPUF-0.9 coating (0.9 wt.% fluorine) exhibited optimal performance, characterized by a high water contact angle, low water absorption, and superior corrosion resistance, with a low corrosion current density of 3.41 × 10−7 A·cm−2 and a high charge transfer resistance of 4.64 × 105 Ω·cm2. Notably, it maintained excellent corrosion protection (9.01 × 10−7 A·cm−2) even after 72 h of immersion in a 3.5 wt.% NaCl solution. The coating’s robustness was further confirmed by accelerated tests. Thin coatings with a thickness of 10 μm on Q235 steel resisted salt spray (5 wt.% NaCl) for over 72 h and, in a bending state under a 1.5 V electric field in 60 °C artificial sweat, prevented copper corrosion for more than 24 h. This work provides a promising candidate for high-performance protective coatings in flexible electronics.