Hydrolyzable Additive-Based Silicone Elastomers: A New Approach for Antifouling Coatings.

Laure Gevaux,Marlène Lejars,Christine Bressy,Jean-François Briand,Robert Bunet,André Margaillan

doi:10.3390/polym11020305

Laure Gevaux, Marlène Lejars + Show 4 more

Open Access

https://doi.org/10.3390/polym11020305

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Journal: Polymers	Publication Date: Feb 12, 2019
Citations: 33	License type: CC BY 4.0

Affiliation: Université de Toulon, Institut Océanographique

Abstract

Fouling Release Coatings are marine antifouling coatings based on silicone elastomers. Contrary to commonly used biocide-based antifouling coatings, they do not release biocides into the marine environment, however, they suffer from poor antifouling efficacy during idle periods. To improve their antifouling performances in static conditions, various amounts of hydrolyzable polymers were incorporated within a silicone matrix. These hydrolyzable polymers were chosen for the well-known hydrolytic degradation mechanism of their main chain, e.g. poly(ε-caprolactone) (PCL), or of their ester pending groups, e.g. poly(bis(trimethylsilyloxy)methylsilyl methacrylate) (PMATM2). The degradation kinetics of such hydrolyzable silicone coatings were assessed by mass loss measurements during immersion in deionized water. Coatings containing PMATM2 exhibited a maximum mass loss after 12 weeks, whereas PCL-based coatings showed no significant mass loss after 24 weeks. Dynamic contact angle measurements revealed the modifications of the coatings surface chemistry with an amphiphilic behavior after water exposure. The attachment of macrofoulers on these coatings were evaluated by field tests in the Mediterranean Sea, demonstrating the short or long-term antifouling effect of these hydrolyzable polymers embedded in the silicone matrix. The settlement of A. amphitrite barnacles on the different coatings indicated inhospitable behaviors towards larval barnacles for coatings with at least 15 wt % of additives.

Highlights

The colonization of marine species such as algae and barnacles on ship hulls or any other artificial submerged surfaces causes serious impacts on the marine environment [1,2].It is noteworthy that such biofouling colonization on ship hulls increases their hydrodynamic drag leading to an increase in fuel consumption and greenhouse gases emission [3,4]
The use of biocides remains the most efficient way to prevent the settlement of marine species [5,6,7,8,9], the regulations around the world tend to drastically reduce over the years the number of harmful chemical substances authorized in antifouling paints [7,10]
Dioctyltin dilaurate (DOTDL) catalyst was kindly supplied by TIB Chemicals (Mannheim, Germany)

Summary

Introduction

The colonization of marine species such as algae (soft fouling) and barnacles (hard fouling) on ship hulls or any other artificial submerged surfaces causes serious impacts on the marine environment [1,2]. It is noteworthy that such biofouling colonization on ship hulls increases their hydrodynamic drag leading to an increase in fuel consumption and greenhouse gases emission [3,4]. During the past 10 years, more environmentally friendly antifouling coatings were developed, mainly by reducing the biocides content. The use of biocides remains the most efficient way to prevent the settlement of marine species [5,6,7,8,9], the regulations around the world tend to drastically reduce over the years the number of harmful chemical substances authorized in antifouling paints (e.g. the European Biocidal Product Regulation) [7,10].

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