Physically cross-linked starch/hydrophobically-associated poly(acrylamide) self-healing mechanically strong hydrogel

Mechanically tough self-healing hydrogels have attracted tremendous attraction in recent years owing to their flexibility and excellent deformation-resistance. Herein, we synthesized a bio-based self-healing hydrogel by incorporating starch onto a hydrophobically associated (HA) domain. The inclusion of physically cross-linked starch onto the HA-poly(acrylamide) (PAM) chain enhanced the mechanical strength of the hydrogel and this enhancement depends on dose level of starch. The ductile and tough HA-PAM network could bear stress and recombine the damage zones within a short time, and hence exhibit noteworthy self-healing ability. Moreover, the introduction of the reversible and physically cross-linked starch network was unable to eliminate self-healing attribute of the HA-PAM network completely. Most importantly, synthesized hydrogel was dimensionally stable after swelling and exhibited noteworthy mechanical strength under such conditions. Thus, this work provides a novel starch incorporated mechanically tough, self-healing hydrogel that can hopefully enrich the current hydrogel research and expand its practical application spectrum.