New polyamides with azo-chromophore groups

A series of four novel polyamides with semiflexible main chains were prepared from two azo-chromophore diamines: 2,4-diamino-4'-nitroazobenzene and 2,4-diamino-4-azo-(4'-nitroazobenzene)benzene. Polymers were obtained from diacid chlorides by the polycondensation reaction in DMA solution. The polymers were identified by infrared, H-1 NMR spectroscopy and elemental analysis. The thermal properties of these polymers were investigated using differential scanning calorimetry (DSC) method and thermogravimetric analysis. The presence of photoisomerisable azobenzene groups makes them interesting for the optical information storage and processing. We have checked that thin films casted on glass plates from these polymers are suitable substrates for holographic polarization grating recording realized by laser light of 514.5-nm wavelength. The kinetics of gratina recording observed within the studied group of polymers is discussed in relation to structural properties of the polymers. Such type of materials could find potential applications in photonics. (C) 2003 Elsevier B.V. All rights reserved.