Sterically Hindered Oleogel-Based Underwater Adhesive Enabled by Mesh-Tailoring Strategy

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Chemistry

Background:

• Underwater adhesives are crucial for various applications but developing high-performance, scalable options remains challenging.
• Existing underwater adhesives often struggle with stability in extreme conditions and broad substrate compatibility.

Purpose of the Study:

• To present a novel mesh-tailoring strategy for creating rapid, ultrastrong oleogel-based underwater adhesives (OUA).
• To investigate the mechanical properties, stability, and adhesion strength of the developed OUA under diverse conditions.

Main Methods:

• A highly crosslinked polyurethane network was synthesized with a specific mesh size to entrap epoxidized soybean oil (ESO) molecules via steric hindrance.
• The oleogel's mechanical properties, thermal and pressure stability, solvent resistance, hydrophobicity, and curing speed were evaluated.
• Underwater adhesion strength was measured across various substrates, and environmental adaptability in acidic, alkaline, saline, and extreme temperature solutions was assessed.

Main Results:

• The OUA demonstrated robust mechanical properties (≈35 MPa) and stability at 100°C and 30 MPa.
• Exceptional underwater adhesion strength (up to 2.13 MPa) was achieved with rapid curing and high hydrophobicity.
• The adhesive exhibited remarkable substrate universality and stability in harsh aqueous environments.

Conclusions:

• The novel mesh-tailoring strategy successfully produced a high-performance oleogel-based underwater adhesive.
• The OUA exhibits excellent mechanical strength, environmental adaptability, and adhesion, making it suitable for demanding underwater applications.
• This research provides a foundation for designing next-generation underwater adhesives and exploring oleogel-based materials.