Bio-Inspired Self-Healing Polyurethanes with Multiple Stimulus Responsiveness
writer：Yang,Z.J.; Wang, F. F.; Zhang, C.; Li, J.; Zhang, R. C.*; Wu, Q.;Chen, T.H. and Sun, P.C.*
keywords：Bio-Inspired, Self-Healing,Polyurethanes,Stimulus Responsiveness
source：期刊
specific source：Polymer Chemistry, 2019, in press
Issue time：2019年
High-performance
stimuli-responsive polymers that possess spontaneous, sophisticated and
reversible responses to a wide range of external stimuli are highly desirable
for applications in diverse fields and have attracted dramatic attention in
recent decades. However, it still remains a great challenge to precisely design
molecular architectures which can integrate multi-stimuli responsive functions
into one structure in polymeric materials. In this study, we reported the
synthesis and preparation of a novel multi-responsive self-healing polyurethane
with superior mechanical properties by adapting a stimuli-responsive dynamic
covalent chemical crosslinker and a biomimetic modular polymer design. This unique
crosslinker was synthesized through the Michael addition reaction between
thiols and bismaleimides, imparting the chemically crosslinked polyurethanes
healable and recyclable at an elevated temperature as well as
stimuli-responsive to heat, pH and ammonia gas. A visible color change can be
clearly observed when the polymer is in the base or ammonia gas environment,
rendering the sample a great potential for being a gas or pH sensor.
Furthermore, the incorporation of self-complementary quadruple hydrogen bonding
interactions between 2-ureido-4-[1H]-pyrimidione (UPy) motifs in the PU
backbone chains enables the formation of modular hydrogen bonding domains, rendering
the material with enhanced mechanical properties.