Ecofriendly silicon-poly(lactic acid) hybrid antifouling coatings

Societal and environmental constraints have led to changes in international and European regulations to limit the use of biocides in antifouling paints. In this context, coatings combining fouling release properties and leaching of active molecules are sought. The objectives of this study are to conceive a hybrid system for antifouling paint and to observe the influence of the physio-chemical properties of the binders on its antifouling activity. Poly(lactic acid) (PLA) and poly(dimethylsiloxane) (PDMS) homopolymers have already been used as binders for different antifouling strategies. The use of a block copolymer based on PLA and PDMS is likely to allow the design of paint with biocides release associated to fouling release properties in order to be more efficient with a lower environmental impact. Triblock copolymers with different molar compositions have been synthesized. The properties of the corresponding films have been determined in distilled water (adhesion to the support, hydrophobicity). Then formulated paints have been immersed in Lorient harbor to evaluate their erosion, degradation and antifouling efficacy. Furthermore, their biocide release kinetics were studied in artificial seawater to evaluate their environmental impact. The silicon-poly(lactic acid) paints have shown an efficiency superior to a commercial paint during their in situ immersion (19 months) with a lower biocides amount (14 %).