POLYETHER AZOMETHINES .1. SYNTHESIS AND CHARACTERIZATION

Six new polyether azomethines were synthesized by melt and solution polycondensation of six different diamines with 4,4'-[1,4-phenylene bis(oxy)]bisbenzaldehyde. The polymers synthesized by solution method are yellow to white in color and had inherent viscosities up to 0.59 dL/g in concentrated H2SO4. The polymers obtained by melt condensation show higher viscosity. Except polymer IV, others are insoluble in common organic solvents. The polymers were characterized by IR, x-ray, elemental analysis, and DSC study. The thermal stability of the polymers was evaluated by TGA and IGA study. Polymers I-III are highly thermally and thermooxidatively stable and exhibit no appreciable decomposition up to 420 degrees C both in air and nitrogen atmosphere. It was shown that the curing of the polyazomethines takes place by opening up of the -CH=N- linkages at higher temperature. the electrical conductivities of the virgin and iodine doped polymers were as high as 10(-11)-10(-16) and 10(-6)-10(-8) S cm(-1), respectively, at 30 degrees C. Electronic spectra of the undoped polymers (I-III) indicated a large bathochromic shift of the [GRAPHICS] absorptions band (376 nm) due to -C = N- bonds of the model compound. This can be attributed to extensive delocalization of the electrons along the polymer chain. (C) 1995 John Wiley and Sons, Inc.