Light-induced optical anisotropy have been studied by laser grating inscription method within the group of novel azobenzene functionalized polymers. Undergoing light-induced trans-cis-trans photoisomerisations azo-benzene groups were covalently bonded to the main chains of polymers. Two-wave mixing technique was employed to inscribe the amplitude and phase gratings in these polymers. Using two light polarization geometries s-s an s-p we were able to study differences in grating properties as well as ability of surface relief grating formation in studied class of polymers. The supplementary technique of moving grating was used as a tool for obtaining information on contribution of various reorientations of chromophores and main chains to light diffraction on the obtained periodic structures.
Novel azobenzene functionalized poly(amide-imide)s (PAIs) having azo-benzene group in side chain of polymers were prepared. FTIR spectroscopy and elemental analyses confirm structure and the existence of azo-benzene chromophores in obtained polymers. The relationship between structure of polymers and their physical and optical properties was studied. Thermal behaviour such as glass transition temperature and thermal stability were measured. The influence of the main chain structure of poly(amide-imide)s on polarization gratings recording using standard degenerate two-wave mixing technique with 514.5 nm Ar+ laser line has been investigated.
A series of 5 conjugated aromatic polyimines (Schiff-base polymers), containing -C=N- linkages in the backbone
and various side-group substitutions, has been synthesized, characterized, and used to investigate the effects of molecular
structure on the electronic structure and properties of these polymers. In this paper we report the photophysical behaviour of
the Schiff-base polymers and their diluted solutions in DMA. The fluorescence excitation and emission spectra of these
compounds were measured. These compounds show no evidence of excimer formation under these conditions and their
fluorescence exhibits in solid state and in solution first-order decay behaviour.
Bis [((omega) -(4'-cyanobiphenyl)-4-yl)oxy-n- alkyl]norborn-5-ene-2,3-dicarboxylate was polymerized via ring opening metathesis polymerization. Two distributed polynorbornene derivatives, both of cis configuration, with different length of side-chain were studied. The influence of thermal history on the smectic phase stabilization, position and shape of the glass transition with temperature and on the relaxation process is shown. Glass transition temperatures enthalpies of isotropization and average layer spacing were calculated. Although, the rather flexible spacer between the mesogenic group and the main chain seems to be sufficient to partially decouple the mobility of the main chain from that of the mesogenic group, the influence of a backbone chain structure is still significant for polymer properties, especially in bulk. The measured layer spacing doe not correspond to double length of the side chain which suggests that either the side chains are not fully extended or some overlapping of CN tails occurs.