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Structurally Dynamic Hydrogels Derived from 1,2-Dithiolanes
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posted on 2015-05-06, 00:00 authored by Gregg
A. Barcan, Xiangyi Zhang, Robert M. WaymouthThe
design and generation of adaptable materials derived from structurally
dynamic polymers provides a strategy for generating smart materials
that can respond to environmental stimuli or exhibit self-healing
behavior. Herein we report an expedient organocatalytic ring-opening
polymerization of cyclic carbonates containing pendant dithiolanes
(trimethylene carbonate/dithiolane, TMCDT) from poly(ethylene oxide)
diols to generate water-soluble triblock (ABA) copolymers containing
a central poly(ethylene oxide) block and terminal dithiolane blocks.
Hydrogels generated from the triblock copolymers and a cross-linking
dithiol exhibited dynamic behavior as a result of the reversible ring
opening of the pendant 1,2-dithiolanes. These materials exhibit self-healing
behavior, can be injected through a syringe, and rapidly recover their
mechanical properties after a severe strain deformation. The dynamic
properties of these gels can be modulated with the number of dithiolane
units, pH, and temperature.