Photoresponsive behaviour of “T-type” azopolyimides. The unexpected high efficiency of diffraction gratings, modulations and stability of the SRG in azopoly(ether imide)

The goal of the studies was to compare the light-induced properties of three “T-type“ polyimide containing azobenzene chromophores (PI-Az-1, PI-Az-2, PI-Az-3) with the properties of their structural counterparts containing azopyridine moieties (PI-AzPy-1, PI-AzPy-2, PI-AzPy-3). The data set includes files:1H NMR in DMSO-d6 for new polyimides (PI-Az-3 and PI-AzPy-3) FTIR in KBr pallets for PI-Az-3 and PI-AzPy-3.studies of physicochemical properties for PI-Az-3 and PI-AzPy-3 (DSC, TGA)thermal cis-trans isomerization in the solid-state for azobenzene and azopyridine functionalized polyimides. Cis isomer generated by 405 nm diode laser (P= 80mW).chemical structures of PI-AzPy-1, PI-AzPy-2 and PI-AzPy-3 determined by DFT calculations with an exchange-correlation hybrid functional B3LYP and the basis 6-31G++ for all atoms.photoinduced birefringence for PI-Az-2 and PI-Az-3 generated by a 405nm laser light ( I= 100mW/cm2).the modulation of the surface profile for PI-Az-2. The grating was inscribed using coherent excitation light from a 442 nm He-Cd laser. In the arranged geometry the two beams crossed on the polymer layer at 7°. The intensity of each 442 nm beam at the sample plane was ca. 50 mW/cm2.