Environmentally friendly fluorine-free anti-fouling polyurea coatings with excellent abrasion resistance

Abstract

In conventional applications, organofluorine reagents are added to substrate coatings to provide anti-fouling properties. However, their high cost, poor biodegradability, and potential biotoxicity limit their widespread use. This study introduces a fluorine-free, environmentally friendly castor oil-based polyurea coatings (COP-X). Castor oil (CO), a renewable bio-based polyol, is used as a soft segment to increase the coating’s crosslink density. Polyaspartic ester F5240–3A is introduced as a secondary amine-based curing agent to slow down the curing time and improve the mechanical properties. By integrating PDMS as the low-surface-energy component and immobilizing it within the polyurea matrix through interpenetrating polymer network (IPN) technology, the coating benefits from both materials. The result showed that the COP-X coatings exhibited excellent overall performance in terms of mechanical properties, anti-fouling resistance, chemical resistance and abrasion resistance. Specifically, all coatings had an adhesion rating of 0 and a maximum tensile strength of 20.69 MPa. The coating effectively repelled common contaminants such as coffee, ink, orange soda and mud water, and provides excellent corrosion protection for the covered substrate. After 1000 abrasion cycles, the coatings maintain excellent liquid repellency with an abrasion index of less than 0.16. COP-X coatings demonstrate excellent antifouling performance and durability, highlighting their significant potential for engineering applications.