A High Strength PH Responsive Supramolecular Copolymer Hydrogel

In this work,we proposed a simple and very convenient approach to fabricate high strength pH responsive supramolecular polymer(SP)hydrogels by one-pot copolymerization of N-acryloyl glycinamide(NAGA)and 2-vinyl-4,6-diamino-1,3,5-triazine(VDT),two feature hydrogen bonding monomers.In these PNAGA-PVDT SP hydrogels obtained,the hydrogen bonding of NAGA was shown to play a dominant role in reinforcing strength,while the hydrogen bonding of diaminotriazine served as a pH sensitive moiety.At pH3,the mechanical properties of PNAGA-PVDT hydrogels decreased to a different extent due to the breakup of hydrogen bonding;in contrast,the hydrogel resumed the original strength while pH was raised to pH7.4 because of reconstruction of hydrogen bonding.Over the selected pH range,the PNAGA-PVDT hydrogels exhibited up to 1.25 MPa tensile strength,845% breaking strain,69 kPa Young's modulus and 21 MPa compressive strength.This novel high strength pHresponsive SP hydrogels may find applications in biomedical and industrial fields.