High-toughness CO 2 -sourced Ionic Polyurea Adhesives.
Xu OuJi PanQinbo LiuYajuan NiuYingjie ZhouFeng YanPublished in: Advanced materials (Deerfield Beach, Fla.) (2024)
Polyurea (PUa) adhesives are renowned for their exceptional adhesion to diverse substrates even in harsh environments. However, the presence of quadruple bidentate intermolecular hydrogen bonds in the polymer chains creates a trade-off between cohesive energy and interfacial adhesive energy. To overcome this challenge, a series of CO 2 -sourced ionic PUa adhesives with ultra-tough adhesion to various substrates were developed. The incorporated ionic segments within the adhesive serve to partially mitigate the intermolecular hydrogen bonding interactions while conferring unique electrostatic interactions, leading to both high cohesive energy and interfacial adhesive energy. The maximum adhesive strength of 10.9 MPa could be attained by ionizing the CO 2 -sourced PUa using bromopropane and subsequently exchanging the anion with lithium bis(trifluoromethylsulfonyl)imide. Additionally, these ionic PUa adhesives demonstrate several desirable properties such as low-temperature stability (-80°C), resistance to organic solvents and water, high flame retardancy, antibacterial activity, and UV-fluorescence, thereby expanding their potential applications. This study presents a general and effective approach for designing high-strength adhesives suitable for a wide array of uses. This article is protected by copyright. All rights reserved.