Synthesis And Properties Research Of Star Liquid Crystalline Of Cyclotriphosphazene

The synthesized of new star-shaped compound with cyclotriphosphazene core havereceived increasing attention recently, and that factors of different center bridge bond andflexible chain length, which impacted on the liquid crystal behavior of thecyclotriphosphazene compounds, were investigated in many literature. Three new star-shapedcompounds with cyclotriphosphazene core, which respectively correspond to the mesogenic,were prepared in this paper. Fourier transform infrared spectroscopy(FTIR) and Nuclearmagnetic resonance spectroscopy were used to analysed the structure of the compounds, andthan the liquid crystal behavior of the compounds have been investigated by polarizing opticalmicroscopy(POM) and differential scanning calorimetry (DSC). These results which haveobtained from the paper could have a positive role in further expanding thecyclotriphosphazene derivatives. At the same time, some new liquid crystal materials withexcellent properties though the basic theory research were expected to find.1. The star amide compound with cyclotriphosphazene as a core have been synthesizedvis nucleophilic substitution reaction between the amide compound andhexachlorocyclohexane polyphosphazene. The structure of prepared compounds werecharacterized by FT-IR and~1H-NMR measurements and the liquid crystal characteristic ofthese compounds were tested by differential scanning calorimetery (DSC) and polarizingoptical microscopy (POM). It was found that the helium atom have been all replaced; The staramide compound and mesogenic unit both belong to nematic liquid crystal, and their liquidcrystal phase temperature range was respectively100℃~168℃、85℃~130℃.2. The star compounds containing thiadiazole ring with cyclotriphosphazene as a core(4a,4b) and mesogenic unit have been synthesized. The obtained compounds were characterizedby FT-IR and~1H-NMR measurements and the liquid crystal characteristic of thesecompounds were tested by differential scanning calorimetery (DSC) and polarizing optical microscopy (POM). The results showed that the compound4a,4b,5a revealed two differentliquid crystal texture during the heating process, with the liquid crystal phase transition(melting point~texture transition temperature~clearing point) and the liquid crystal texturewere:180℃~214℃~223℃, sheet, layer the status quo texture;185℃~167℃~270℃, thefocal conic, schlieren texture;148℃~167℃~183℃, the focal conic, schlieren texture; Theliquid crystal interval and liquid crystal texture of5b was:121℃~137℃, the texture layerstatus quo.In conclusion, the study showed that new star-shaped compounds of the liquid crystaltype were determined by their corresponding mesogenic; the melting point and the clearingpoint of them were higher than their corresponding mesogenic, and their liquid crystal phasetemperature range were wider than their corresponding mesogenic; the terminal alkyl chainlength have no impact on the liquid crystal type of compounds.