Stiff, Self-Healable, Transparent Polymers with Synergetic Hydrogen Bonding Interactions

Macromolecular polymers with high mechanical strength usually have high crystallinity and tightly entangled segments, hindering the self-healing of fracture interfaces. In this work, we report stiff, self-healable, transparent polymer (SSHTP) materials made of hard and strong poly(acrylamide/choline chloride) and soft and reversible poly(acrylic acid/choline chloride) segments. SSHTPs can be easily fabricated in 1 min by photoinitiated copolymerization of two kinds of polymerizable deep eutectic solvent monomers, simultaneously obtaining high optical transmittance, superior mechanical strength, and self-healing capability. Due to the synergetic interactions of the high-density hydrogen bonds in the microphase-separated polymer matrix, damaged SSHTPs can autonomously self-heal fractures under moderate conditions, and healed SSHTPs can withstand greater than 500× their own weight without breakage. Our investigation provides a simple, feasible, and green methodology for the design of transparent healable stiff polymers which have promising applications in various industrial and technological fields.