Harnessing entropy to enhance toughness in reversibly-crosslinked polymer networks
By: Nicholas Tito
From: Department of Applied Physics, Eindhoven University of Technology
At: C1, Anfiteatro da FCiências.ID
[2018-03-26]
Materials composed of polymers that are permanently crosslinked into a network, such as gels and rubbers, eventually break if strained enough. This is because the network irreversibly ruptures once the local forces acting on the polymers and crosslinks become too large for the chemical bonds to withstand. Recent experiments have revealed that adding *reversible* crosslinks to the network allows the material to be strained to a much larger extent, yet without altering its elasticity [1]. In this talk we use theory, molecular simulation, and polymer self-consistent field theory for networks [2], to explore reversible crosslinking as a design paradigm for creating polymer networks that are tough but elastic. Emphasis will be placed on how entropy itself drives reversible crosslinks to toughen the material, while preserving its intrinsic elasticity.
[1] Kean, Z. S.; et al. Adv. Mat. 2014, 26, 6013.
[2] Tito, N. B.; Storm, C.; Ellenbroek, W. G. Macromolecules 2017, 50, 9788.
Project UID/FIS/00618/2013