Molecular Crystals and Liquid Crystals, Vol.697, No.1, 85-96, 2020
Optical properties of azo-based poly(azomethine)s with aromatic fluorinated fragments, ether linkages and aliphatic units in the backbone
The aim of this work is to study the optical properties of the core-fluorinated azo-containing polyazomethines with 1,4-tetrafluorobenzene or 4,4 '-octafluorobiphenylene dioxyphenylene units and aliphatic fragments in the chain. Due to the reorganization process at the nanometer-scale under UV/Vis irradiation, azo-containing polymers (APs) have attracted much attention as materials for biology, optoelectronics, nano-manipulation field, etc. Moreover, the introduction of azomethine group into these polymers enhances not only their optical properties but also expands their practical application. APs polymers have the useful combination of chemical and physical properties such as liquid crystalline states, high nonlinearity and an ability to form metal complexes. It was shown that the optical properties of such polymers could be improved by the inclusion of fluorine. Fluorinated polymers demonstrate high thermal stability and have low dielectric constant and dielectric losses. It should be noted that the presence of flexible moieties in a polymer backbone allows regulating the different properties (solubility, thermostability, optical and liquid crystalline properties) of the final materials.
Keywords:Azo-containing poly(azomethine)s;azo-hydrazone tautomerism;fluorinated polymers;photoinduced dichroism;photoisomerization