Unveiling the molecular mechanism of self-healing in a telechelic, supramolecular polymer network

Sci Rep. 2016 Sep 1:6:32356. doi: 10.1038/srep32356.

Abstract

Reversible polymeric networks can show self-healing properties due to their ability to reassemble after application of stress and fracture, but typically the relation between equilibrium molecular dynamics and self-healing kinetics has been difficult to disentangle. Here we present a well-characterized, self-assembled bulk network based on supramolecular assemblies, that allows a clear distinction between chain dynamics and network relaxation. Small angle x-ray scattering and rheological measurements provide evidence for a structurally well-defined, dense network of interconnected aggregates giving mechanical strength to the material. Different from a covalent network, the dynamic character of the supramolecular bonds enables macroscopic flow on a longer time scale and the establishment of an equilibrium structure. A combination of linear and nonlinear rheological measurements clearly identifies the terminal relaxation process as being responsible for the process of self-healing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Barbiturates / chemistry
  • Nonlinear Dynamics
  • Polyenes / chemistry
  • Polymers / chemistry*
  • Rheology
  • Scattering, Small Angle
  • Time Factors

Substances

  • Barbiturates
  • Polyenes
  • Polymers
  • polyisobutylene
  • barbituric acid