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

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 degrees C. Owing to the toughnessenhancement 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.