Analysis of self-polishing antifouling paints using rotary experiments andmathematical modeling

A detailed mathematical model for a self-polishing antifouling paint has be en developed. The important rate-influencing steps, dissolution of pigment particles, hydrolysis and erosion of the active polymer binder, effective d iffusion in the leached layer, and external mass transport of relevant spec ies, were all included. The aims have been to produce a tool for estimating paint lifetimes at various seawater conditions and paint compositions, for possible product optimizations, and for supporting the development of nove l and environmentally friendly antifouling paints. Experimental data for mo del verification, such as polishing rates and extent of pigment leaching, w ere obtained using a laboratory rotor. Simulations performed for different rotary speeds and temperatures matched experimental data for two of the thr ee paints investigated. In the last case, the disagreement between model an d experiment was explained by significant water swelling of the hydrolyzed polymer. The modeling tools developed are applicable to other types of self -polishing antifouling paints than the ones investigated here.