SELF-HEALABLE COPOLYMERS VIA VAN DER WAALS INTERACTIONS

摘要

In these studies we developed fluoro-containing copolymers that for well-defined monomer molar ratios exhibit autonomous self-healing. This behavior is attributed to inter-digitated copolymer topologies facilitated by van der Waals (vdW) interactions. The main feature of vdW interactions is large polarizability (hydrophobicity) which in thermoplastic polymers leads to non-directional interactions between neighboring macromolecular segments. However, dipole-dipole directionality of the side groups can be enhanced by alternating/random copolymer compositions resulting from inter-chain vdW forces. Upon mechanical damage macromolecular segments will energetically favor original inter-chain conformations and return to original conformations, thus self-heal. Using chemical imaging (IR) and ~1H NMR spectroscopy (NOESY, COSY) through-space and through-bond interactions were identified and used as input to molecular dynamic (MD) simulations in an effort to identify molecular events governing self-healing behavior.