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Adaptable Strategy to Fabricate Self-Healable and Reprocessable Poly(thiourethane-urethane) Elastomers via Reversible Thiol–Isocyanate Click Chemistry
journal contribution
posted on 2020-05-28, 13:36 authored by Cheng-Jie Fan, Zhi-Bin Wen, Zhi-Yuan Xu, Yi Xiao, Di Wu, Ke-Ke Yang, Yu-Zhong WangCurrently, a variety of elastomers
with a self-healing capacity
and reprocessability have been developed by dynamic chemistry to extend
the service life, increase the reliability of polymeric materials,
and reduce the waste. However, it is still a large challenge to seek
an appropriate dynamic interaction that may perfectly match the general
performance of the target polymeric materials such as polyurethane.
Herein, we report a poly(thiourethane-urethane) (PTUU–Nx) elastomer containing dynamic thiourethane
bonds prepared via a thiol–isocyanate click reaction, which
is stable at room temperature, healable at moderate temperature, and
reprocessable at high temperature. Importantly, it exhibits a mechanical
strength similar to the polyurethane because of a very similar structure.
The dynamic feature of PTUU–Nx is
demonstrated theoretically and experimentally to originate from the
exchange of thiourethane bonds via the reversible generation of isocyanates
and thiols. Most importantly, the thiourethane bond possesses a much
lower bond dissociation energy than the urethane bond, which not only
makes PTUU–Nx elastomers easier
to be reprocessed but also endows them with a desirable self-healing
ability under moderate conditions. In addition, the optimized sample
PTUU–N2 is utilized to fabricate a conductive device
by coating Ag glue on the elastomer surface and inserting the coated
elastomer into a circuit, which displays a high self-healing efficiency,
as the material recovers to its original mechanical property and conductivity.
Therefore, these results not only indicate that the PTUU–Nx elastomers have considerable potential for
applications in intelligent electronic devices but also provide new
ideas for developing new self-healing materials by applying the adaptable
dynamic bond to the target polymers.