Preparation and properties of waterborne polyurethane-silane: A promising antifouling coating

Environmentally friendly waterborne polyurethane-silane (WBPUSi) resins were prepared through a prepolymer process using N-[3-(trimethoxysilyl)propyl]-ethylenediamine (TMSiP-EDA), which acted as both a chain extender and crosslinker. The TMSiP-EDA amine group reacted with the NCO group of the NCO-terminated prepolymer and the methoxy group induced branching with Si-O-Si via a hydrolysis and condensation reaction in water dispersion. The thermal stability, tensile strength and Young's modulus of the synthesized resins were superior to those of conventional WBPU. A selected WBPUSi-resin was used in foul release coating to protect the surface from marine fouling. The foul release property of the resin was examined after immersion in a marine environment for three months. WBPUSi showed improved protection against marine fouling.