Enhanced Shape Memory Metal-Coordinated Poly(aryl ether ketone)s with Tunable Gradient-Deformation Behaviors as well as Self-Healing and Reprocessing Abilities

Reversible dynamic bonds are able to crack and recombine upon external stimuli, which endow polymers with exceptional self-healing, reprocessing, and reversible deformation ability. In this paper, we integrated the metal coordination bonds into shape memory poly(aryl ether ketone) (PAEK) to fabricate smart materials with multifunctionalities. Through tuning the metal ion content and species, the enhancement of shape memory behaviors was achieved, including the high recovery ratio (over 98%) and fixity ratio (over 98%), which was closely related to the synergic effect of the intrinsic motion ability of PAEK matrix and the cracking-recombination of coordination bonds. Besides, through the combination of the components with different Cu2+ contents, in addition to the components with Fe2+ coordination bonds, we fabricated the gradient shape memory structures with controllable shape memory and recovery behaviors. The manipulation of gradient coordination bonds resulted in different shape recovery speeds and directions. Furthermore, due to the dynamic cracking-recombination of coordination bonds, the metal-coordinated PAEK material exhibited the great self-healing and reprocessing performances, which were significant for largely extending its application range.