Fouling Release Property of Polydimethylsiloxane-Based Polyurea with Improved Adhesion to Substrate

Polydimethylsiloxane (PDMS)-based coatings are environment-friendly systems for marine fouling release. However, they usually exhibit low adhesion to substrate and poor mechanical properties, which limits their applications. We have developed polyurea (PUa) with PDMS as soft segments and 1,6-hexanediamine as hard segments via a polycondensation reaction. Such polyurea (PDMS-PUa-<i>x</i>) is hydrophobic with water contact angle above 90° and has low surface energy (25–29 mJ·m^–2). In particular, its adhesion to the substrate (>1.0 MPa) and modulus (>80.0 MPa) are significantly improved in comparison with those of PDMS coatings. Laboratory bioassay and marine field tests demonstrate that PDMS-PUa-<i>x</i> has good fouling release performance

Biodegradable Polymer with Hydrolysis-Induced Zwitterions for Antibiofouling

Persistent protein resistance is critical for marine antibiofouling. We have prepared copolymer of 2-methylene-1,3-dioxepane (MDO), tertiary carboxybetaine ester (TCB), and 7-methacryloyloxy-4-methylcoumarin (MAMC) via radical ring-opening polymerization, where MDO, TCB, and MAMC make the polymer degradable, protein resistible, and photo-cross-linkable, respectively. Our study shows that the polymer can well adhere to the substrate with controlled degradation and water adsorption rate in artificial seawater (ASW). Particularly, the polymer film can generate zwitterions via surface hydrolysis in ASW. Quartz crystal microbalance with dissipation measurements reveal that such hydrolysis-induced zwitterionic surface can effectively resist nonspecific protein adsorption. Moreover, the surface can inhibit the adhesion of marine bacteria <i>Pseudomonas</i> sp. and Vibrio alginolyticus as well as clinical bacterium Escherichia coli

Poly(dimethylsiloxane)-Based Polyurethane with Chemically Attached Antifoulants for Durable Marine Antibiofouling

Marine biofouling is a problem for marine industry and maritime activities. We have prepared polyurethane with poly­(dimethylsiloxane) (PDMS) main chains and <i>N</i>-(2,4,6-trichlorophenyl) maleimide (TCM) pendant groups via a combination of a thiol–ene click reaction and a condensation reaction and studied its properties. The polymer has low surface energy and a high water contact angle. When TCM content in bulk is high enough, sufficient antifoulant groups can be exposed on the surface. Our study reveals that such polymeric surface can effectively inhibit the adhesion and colonization of marine organisms such as bacteria (<i>Micrococcus luteus</i>), diatom Navicula, and barnacle cyprids. Particularly, marine field tests demonstrate that the polymer has excellent antibiofouling performance in 110 days

Inhibition of Marine Biofouling by Use of Degradable and Hydrolyzable Silyl Acrylate Copolymer

Silyl acrylate copolymers are promising materials for marine antibiofouling. However, their structures need optimizing to improve their erosion and mechanical properties. We have prepared copolymer of 2-methylene-1,3-dioxepane (MDO), tributylsilyl methacrylate (TBSM) and methyl methacrylate (MMA) via radical ring-opening copolymerization. Such polymer has a degradable backbone and hydrolyzable side groups. Our study demonstrates that as the ester units in the backbone increase, the degradation rate increases but the swelling decreases in seawater. The degradation is controlled by the polymer composition or the molar ratio of the ester units in the backbone to the silyl ester side groups. Moreover, such polymer can serve as a carrier and controlled release system for organic antifoulants. Marine field tests show that the system consisting of the copolymer and organic antifoulant has good antifouling performance depending on the polymer composition. It can effectively inhibit the colonization and growth of marine organisms when MDO content is above 20 wt %