Synthesis And Application Of Schiff Base Type Organic Silicon Polyurethane Liquid Crystalline Polymer As Chromatography Stationary Phase

Liquid crystal is a substance which is in the middle phase between the solid crystal and the liquid, not only has the liquid flow, but also some part has the order of the crystal. As the special structure of liquid crystal, when it is as a chromatographic stationary phase, it has great potential for the separation of complex samples. Propoxy hydroxyl benzene formaldehyde was synthesized by etherification reaction using p-hydroxy phenyl formaldehyde, 3-chloro-1-propanol. A new kind of schiff base liquid crystal unit which was called 1,4-two(4-oxypropyl group acohol phenylimino) benzene was synthesized using hydroxy-benzaldehyde, 3-chloro-1-propanol, p-phenylenediamine as raw materials. Schiff base organic silicon polyurethane liquid crystal polymer was synthesized by p-phenylene diisocyanate, 1,4-two(4-oxypropyl group acohol phenylimino) benzene and 1,3-bis(3-aminopropyl) tetramethyldisiloxane as raw materials. The structures of liquid crystal unit and polymer were characterized by Fourier transform infrared spectroscopy(FTIR), the decomposition temperature of liquid crystal unit and polymer were investigated by thermal analysis(TG-DSC), the liquid crystal range of liquid crystal unit and polymer were determined by thermal analysis(TG-DSC) and polarizing optical microscopy(POM), the crystal structure of liquid crystal unit and polymer were determined by X ray diffraction(XRD), the elemental composition of the liquid crystal polymer was determined by the X ray energy spectrum(EDS). The results showed that the liquid crystal polymer was smectic liquid crystal, the liquid crystal range was 103℃~150℃,the thermal decomposition temperature was 300℃, its element composition was C, O, N, Si, its content were 62.53%, 8.34%, 16.55%, 12.58% respectively.The gas chromatographic column was made by schiff base organic silicon polyurethane liquid crystal polymer as chromatography stationary phase, the relative polarity of the schiff base silicone polyurethane liquid crystal polymer as chromatographic stationary phase was determined by separating the mixed solution of benzene and hexane, the relative polarity of the chromatographic stationary liquid was 79(level was +4), it was strong polarity category, the separation tests of ether mixtures, alkane mixtures,benzene substituted mixtures, isomers mixtures, and benzene mixtures were tested. The results showed that the chromatographic stationary liquid had a certain ability of separation, the resolution of ether mixtures reached beyond 1.2, the resolution of alkane mixtures reached beyond 1.3, the resolution of benzene substituted mixtures reached beyond 1.5, the resolution of dichlorobenzene isomers mixtures reached beyond 1.2, the resolution of benzene mixtures reached beyond 1.4.