Mechanochemical strengthening of a synthetic polymer in response to typically destructive shear forces.

Journal Article

High shear stresses are known to trigger destructive bond-scission reactions in polymers. Recent work has shown that the same shear forces can be used to accelerate non-destructive reactions in mechanophores along polymer backbones, and it is demonstrated here that such mechanochemical reactions can be used to strengthen a polymer subjected to otherwise destructive shear forces. Polybutadiene was functionalized with dibromocyclopropane mechanophores, whose mechanical activation generates allylic bromides that are crosslinked in situ by nucleophilic substitution reactions with carboxylates. The crosslinking is activated efficiently by shear forces both in solvated systems and in bulk materials, and the resulting covalent polymer networks possess moduli that are orders-of-magnitude greater than those of the unactivated polymers. These molecular-level responses and their impact on polymer properties have implications for the design of materials that, like biological materials, actively remodel locally as a function of their physical environment.

Full Text

Duke Authors

Cited Authors

  • Ramirez, ALB; Kean, ZS; Orlicki, JA; Champhekar, M; Elsakr, SM; Krause, WE; Craig, SL

Published Date

  • September 2013

Published In

Volume / Issue

  • 5 / 9

Start / End Page

  • 757 - 761

PubMed ID

  • 23965677

Electronic International Standard Serial Number (EISSN)

  • 1755-4349

Digital Object Identifier (DOI)

  • 10.1038/nchem.1720

Language

  • eng

Conference Location

  • England