Synthesis and characterization of waterborne polyurethane‐based marine antifouling coating modified via glycerol laurate

Abstract Marine biofouling is a major international challenge since it is responsible for several environmental problems and economic losses. Developing a novel antifouling coating with good water resistance, adhesion, and controlled degradation performance is crucial to solving the problem. Herein, a series of waterborne polyurethane emulsions were synthesized using the prepolymerization chain expansion and self‐emulsification method, with varying contents of glycerol laurate (GL) as the post‐chain extender. The findings demonstrated a notable enhancement in the controllable degradation performance, adhesion, marine antifouling properties, and water resistance with an increase in the concentration of GL. In particular, the film exhibited the most optimal overall properties when the introduction amount of GL was 2 wt%. The absorption rate of the artificial seawater (ASW) reached a state of equilibrium when GWPU2 was immersed in ASW for 60 days, with a final value of approximately 18.5%. The release rates of the GWPU2 antifouling coatings were observed to be the lowest at approximately 120 days, with a rate of approximately 37.59 μg/cm 2 /day. The long‐term antifouling capability of the GWPU resins was demonstrated in marine field tests, wherein they exhibited sustained antifouling activity for a period exceeding 9 months. In particular, GWPU2 exhibited noteworthy antifouling performance.