writer：Zhengzheng Wang, Huiqi Zhang*
keywords：Photodeformable azobenzene polymers, main-chain azobenzene polymers, physically cross-linked, Michael addition polymerization, Fibers
source：期刊
specific source：Chinese Journal of Polymer Science 2020, 38(1), 37-44.
Issue time：2020年
The synthesis of a new azobenzene (azo)-containing main-chain crystalline polymer with reactive secondary amino groups in its backbone and photodeformation behaviors of its supramolecular hydrogen-bonded fibers are described. This main-chain azo polymer (namely Azo-MP6) was prepared via first the synthesis of a diacrylate-type azo monomer and its subsequent Michael addition copolymerization with trans-1,4-cyclohexanediamine under a mild reaction condition. Azo-MP6 was found to have a linear main-chain chemical structure instead of a branched one, as verified by comparing its H-1-NMR spectrum with that of the azo polymer prepared via the polymer analogous reaction of Azo-MP6 with acetic anhydride. The thermal stability, phase transition behavior, and photoresponsivity of Azo-MP6 were characterized with TGA, DSC, POM, XRD, and UV-Vis spectroscopy. The experimental results revealed that it had good thermal stability, low glass transition temperature, broad crystalline phase temperature range, and highly reversible photoresponsivity. Physically crosslinked supramolecular hydrogen-bonded fibers with good mechanical properties and a high alignment order of azo mesogens were readily fabricated from Azo-MP6 by using the simple melt spinning method, and they could show "reversible" photoinduced bending under the same UV light irradiation and good anti-fatigue properties.