Decoupling the roles of the catechol content from those of glass transition temperature and dynamic mechanical modulus in determining self-healing and anti-corrosion of mussel-inspired polymers

Abstract

Complex relationships between the catechol content, Tg, Young's modulus, and self-healability interweave and remain elusive in mussel-inspired polymers. We have developed a useful strategy, employing n-butyl acrylate, n-butyl methacrylate, and dopamine methacrylamide as co-monomers, to obtain ternary polymers. Altering their ratios generates certain polymers having the same catechol contents and Tg but different tensile moduli, or the same Tg and moduli but different catechol contents. This strategy allows one to examine how the catechol content or tensile modulus determined shear strength of adhesion, self-healing, and healable anti-corrosion, while other two parameters remained unaltered. An optimal catechol content or storage modulus seemed to exist for maximizing shear strength of adhesion. Self-healing exhibited insensitivity to the catechol content, when it was not too big. The ternary polymers showed self-healing under salty water to lead to anti-corrosion. A low catechol content or small storage modulus resulted in stronger anti-corrosion.