DESCRIPTION
This invention relates to a curable polyurethane coating composition incorporating amphiphilic additives synthesized from polyisocyanate, poly(ethylene glycol) methyl ether (mPEG), and monocarbinol-terminated polydimethylsiloxane (PDMS). The formulation leverages both hydrophilic and hydrophobic segments to create a surface that effectively reduces adhesion of marine organisms and improves biofouling release performance under hydrodynamic forces.
The key innovation lies in the inclusion of one or more amphiphilic PEG-PDMS isocyanate prepolymers, optionally added to further adjust the isocyanate/hydroxyl balance and surface properties. These prepolymers are designed with an excess of isocyanate groups to enable crosslinking and stable surface stratification.
The composition is highly customizable, with tunable ratios of mPEG to PDMS (including 10:90, 33:66, and 50:50), enabling formulators to fine-tune amphiphilicity for different marine environments or target organisms. The polyols used can include polyester, polyether, polycarbonate, or acrylic polyols, further enhancing mechanical durability and adhesion to substrates.
Preferred polyisocyanates include isophorone diisocyanate (IPDI) and its trimers, offering enhanced reactivity and stability. Molecular weights of PDMS (5000–10,000 g/mol) and mPEG (550–750 g/mol) are carefully selected to optimize the coating's hydrophobic and hydrophilic balance. The amphiphilic additive content can range from 0.1% to 40% by weight of the total formulation, providing flexibility in performance tuning.
The result is a non-toxic, biocide-free coating that resists biofilm formation, promotes fouling release, and remains durable in harsh marine environments. This technology is suitable for large-scale implementation due to its use of commercially available and easily synthesized components.
Benefits
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Non-toxic fouling-release alternative to traditional biocidal coatings
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Customizable amphiphilic balance using tunable PDMS:mPEG ratios
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Improved adhesion and mechanical durability through polyurethane matrix
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Stable surface performance due to excess isocyanate in prepolymer design
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Effective against a range of marine organisms, including barnacles, algae, and bacteria
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No tie-coat required due to strong adhesion of polyurethane systems
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Compatible with existing marine coating systems
Applications
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Ship hulls and naval vessels – reduce drag, improve fuel efficiency, lower maintenance
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Offshore infrastructure – wind turbines, oil platforms, submerged structures
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Aquaculture equipment – fish cages, nets, pipelines
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Marine sensors and monitoring equipment – prevent signal loss due to fouling
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Harbor assets – buoys, pilings, docks, and port equipment
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Recreational boats and yachts – long-lasting, eco-friendly antifouling protection
Patents
This technology is the subject of published US Patent Application US20210348021A1 and is available for licensing or partnering opportunities.
