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Photoresponsive Liquid Crystalline Epoxy Networks with Shape Memory Behavior and Dynamic Ester Bonds
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posted on 2016-06-01, 00:00 authored by Yuzhan Li, Orlando Rios, Jong K. Keum, Jihua Chen, Michael R. KesslerFunctional
polymers are intelligent materials that can respond to a variety of
external stimuli. However, these materials have not yet found widespread
real world applications because of the difficulties in fabrication
and the limited number of functional building blocks that can be incorporated
into a material. Here, we demonstrate a simple route to incorporate
three functional building blocks (azobenzene chromophores, liquid
crystals, and dynamic covalent bonds) into an epoxy-based liquid crystalline
network (LCN), in which an azobenzene-based epoxy monomer is polymerized
with an aliphatic dicarboxylic acid to create exchangeable ester bonds
that can be thermally activated. All three functional building blocks
exhibited good compatibility, and the resulting materials exhibits
various photomechanical, shape memory, and self-healing properties
because of the azobenzene molecules, liquid crystals, and dynamic
ester bonds, respectively.