Synthesis and Characterization of Zwitterionic Polyurethane with Self-healing Properties

Abstract

A new zwitterionic polyurethane prepared by blending method (bZPU) is synthesized and its self-healing properties are characterized in this study. To synthesize bZPU, a polyol and a zwitterionic polyol are blended and the blended polyols are reacted with crosslinker containing isocyanate groups. In comparison with bZPU based on blend system, a polyurethane with randomly distributed zwitterions (rZPU) from one-pot synthesis and conventional polyurethane with no zwitterions (PU) are prepared. A self-healing test under dry and wet condition reveals that bZPU shows better self-healing performances than rZPU and PU while rZPU exhibit similar self-healing efficiency compared with PU. Interestingly, even though rZPU also has zwitterions, only bZPU shows significant improvement of self-healability in the presence of water. All of these results demonstrate that the zwitterion-based self-healing material can maximize its self-healability by concentration of zwitterions into a local domain as opposed to random distribution.