Polymers with Underwater Self-healing Abilities

Abstract

For designing self-healing polymers which can be used under water with high durability, sufficient water resistance is required to suppress degradation of the materials by swelling. The hydrophobicity of polymer chains in water-triggered self-healing polymers has been considered to be important in suppressing the water uptake, but the effect of electrical nature of dynamic crosslinkers on the swelling behavior of network polymers has not been considered carefully. In this work, we demonstrated the crosslinker effect on water resistance and self-healing ability of network polymers. As a non-ionic crosslinker, tetrahedral boronate ester bearing B－N dative bond is incorporated into poly(butyl acrylate) polymer. The network polymer shows quantitative self-healing abilities under water with the water uptake of ~ 20 wt%. This property is unique compared to the network polymer with ionic crosslinker, Ca^2＋/catechol complexes, which showed lower self-healing ability with 6 times higher water uptake. The network polymer described here could afford a valuable design strategy for water-triggered self-healing bulk polymers used in underwater applications.