F127DA micelle cross-linked PAACA hydrogels with highly stretchable, puncture resistant and self-healing properties

Abstract

It is highly desirable to develop hydrogels that possess excellent mechanical properties and self-healing ability. In this study, a highly stretchable, puncture resistant and self-healing hydrogel is prepared, via in situ copolymerization of a functional monomer, N-acryloyl-6-aminocaproic acid (AACA), and Pluronic F127 diacrylate (F127DA) as macro-cross-linkers in aqueous solution at 50 °C. Owing to the toughness-enhancement mechanism induced by F127DA micelles, the elongation ratio and tensile strength at break of the optimal hydrogel reach up to 2500% and 69 kPa, respectively. Meanwhile, a stab test shows that the hydrogels can be stabbed by a steel needle without any damage. What's more, the hydrogels exhibit excellent self-healing ability, due to multiple hydrogen bonding between protonated PAACA groups. And the hydrogels show pH-responsive cyclic swelling and de-swelling behaviors because of the pH sensitivity of AACA. Thus, the present hydrogels would provide new opportunities with regard to the design and practical application of hydrogel systems.