SYNTHESIS, CHARACTERIZATION AND PROPERTIES OF PROCESSABLE POLYAZOMETHINES FOR HIGH TEMPERATURE APPLICATIONS

Abstract

New dithiazole-diamine monomer containing cyclohexylidene ring and pendant methyl group i.e. 1,1-bis [4-(2- aminothiazole)-3-methyl phenyl] cyclohexane (BATMPC) was synthesized through various steps. The structure of new dithiazole amine monomer was confirmed by FT-IR, 1H NMR and 13CNMR Spectrometry. A series of polyazomethines containing cardo cyclohexane-thiazole unit have been incorporated by the polycondensation of a new diamine i.e. (BATMPC), with proportionate of aromatic dialdehydes. The impact of insertion of cardo cyclohexane, pendant methyl group and thiazole entity in the polyazomethine matrix with the dialdehydes [isophthalaldehyde (1,3 IPA) and terephthalaldehyde (1,4 TPA)], on solubility and thermal stability has been studied. All polyazomethines shown Tg in the range of 220-241ºC and T10% value of all thermally stable polyazomethines in nitrogen atmosphere was in between of 395-415ºC These polyazomethines exhibited solubility in various polar aprotic solvents such as NMP, DMSO, DMAc, DMF etc. However, these polyazomethines were insoluble in common solvents such as DCM and CHCl3. X-ray diffraction study confirms that all the polyazomethines are amorphous in nature having broad peak in the range of 2θ=20°. The UV absorption at 360 nm shows that there is a formation of imine (-C=N-) linkages in the polymer matrix which is helpful for the conduction of electron throughout. The structure-property correlation among these polyazomethines was studied, in view of their potential applications for high temperature applications.