The understanding of mechanisms involved in the controlled release of active molecules from the polymer matrix requires the study of hydration phenomenon. Fluorescence and attenuated total reflection Fourier transform infrared (ATR−FTIR) spectroscopies were used to analyze the earlier steps of hydration in acrylic copolymers. The effect of hydration on the anisotropy of the PRODAN fluorescent probe showed a change in the dynamics of the macromolecular chains. By using ATR−FTIR spectroscopy, the structure of dissolved water in polymers was studied. The evolution of this structure was performed as hydration proceeds by band decomposition of the νOH vibration on the basis of the four-state model which allows discriminating bound from free molecules:  in the “early” stages of hydration, the water network appears drastically perturbed as compared to that of bulk pure water, this perturbation vanishing in the “later” stages of hydration. Besides, this study reveals that the polymer carbonyl groups constitutes the major water binding sites as it was deduced from their progressive engagement in H bonds in the time course of hydration. The rate and extent of this process was observed to be correlated with the hydrophobicity of polymers. The present findings, obtained on similar time scales from noninvasive techniques, indicate that both dynamic and structural consequences of hydration are correlated in most of the polymers here studied.

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To produce ecological marine paints, it is necessary to understand the phenomena involved in antifouling activity. Due to the multivariable components which have to be taken into account and due to their analytical intricacy, only studies based on selected properties are conceivable. In this study, four properties have been chosen, viz. erosion, biocide release, roughness and the physicochemical characteristics of the film surface. A principal-component analysis (PCA) of the experimental data has shown that, among the selected properties, only erosion affected antifouling efficiency. A more detailed investigation of erosion by quantifying global hydration and hydrolysis of immersed paints revealed the difficulty in linking the chemical structure of binders to the final erosion properties. Biocide release from paints, quantified by chromatographic methods coupled with UV detection, was inferior to the doses stated by the paint producers. These observations allowed the conceiving of formulations with reduced amounts of active molecules. The development of erodable, biodegradable binders associated with non toxic compounds is a promising way to obtain efficient antifouling paints compatible with existing, preventive systems.

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