Supramolecular Transparent Plastic Engineering via Covalent-and-Supramolecular Polymerization

Abstract

Supramolecular glass and plastic are a new generation of artificial transparent materials with exhibit excellent optical behavior and processability. However, owing to congenital deficiencies in the mechanical toughness and long-term stability, supramolecular materials lack the potential for functionalization and application. Inspired by the toughening phenomena in biological systems, a synergistic covalent-and-supramolecular polymerization strategy is applied to construct plastic-like supramolecular material with high transmittance via the solvent-free one-pot amidation of thioctic acid and (poly)amines. Covalent amide linkers, dynamic disulfide bonds, and hydrogen bond significantly enhance the mechanical toughness and hardness of supramolecular plastic. Benefitting greatly from covalent-and-supramolecular polymerization, supramolecular plastic not only exhibits high mechanical strength (45.51 MPa) and rigidity (74.0 HD), but is also highly resistant to mechanical impact (34.47 KJ/m2). Experimental and theoretical investigations demonstrate that polymeric structures connected by amide units are responsible for the tough mechanical properties, whereas the dynamic and reversible bonding/debonding of disulfide and hydrogen bonds favor energy dissipation, which together convert supramolecular transparent plastic into a rigid and tough material.