selfpolishing

Self-polishing refers to a property or process in which a surface becomes smoother or cleaner over time through an internal mechanism, rather than by external polishing methods. This can occur through controlled chemical reactions, such as hydrolysis or dissolution, or through mechanical wear that continually reveals a fresh layer. The goal is to reduce roughness, fouling, or drag without repeated manual treatment.

In marine coatings, self-polishing coatings are a notable application. Self-polishing copolymers (SPCs) are designed to slowly hydrolyze in seawater, causing the coating to erode at a predictable rate. This gradual wear exposes a new surface and allows a steady release of biocides or other active agents. The combination of surface renewal and controlled chemical activity helps minimize biofouling and can contribute to lower hydrodynamic drag on ships. Formulation factors such as the ratio of hydrolyzable units, binder chemistry, pigment content, and seawater conditions determine the polishing rate and biocide release profile.

Outside marine uses, the term can describe coatings or finishes intended to maintain a smooth appearance or low-friction surface through self-renewing mechanisms. However, the term is not universally standardized across industries, and “self-polishing” may be used loosely to describe surfaces that gradually improve with use. Environmental considerations, including the impact of released substances in SPCs, influence the adoption and regulation of these materials. See also antifouling coatings and polymer coatings.