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Abstract
A new series of thermotropic polyazomethines (PAMs) containing flexible spacers in the main chain and side methoxy groups on the mesogenic core has been synthesised by solution polycondensation reaction of o-dianisidine with α,ω-bis(4-formylphenoxy)-alkanes. A model compound was also synthesised by condensation reaction of o-dianisidine with p-butoxybenzaldehyde, in order to accomplish the structural characterisation and for a better understanding of the polymer properties. Chemical structure of the studied polymers was confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy, and the supramolecular organisation was determined by powder wide angle X-ray diffraction measurements. The thermal properties of the polymers and model compound were investigated by thermogravimetry, polarised light microscopy and differential scanning calorimetry. The resulting data indicated high thermostability without significant weight loss up to 380°C and nematic liquid crystalline behaviour with large stability range (around 100°C) of the mesophase. Electronic UV–Vis absorption and light emitting ability were also investigated; these PAMs presented broad emission bands in the blue domain.