TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Strelina, Irina A.
A1  - Okatova, Olga V.
A1  - Schulz, Burkhard
T1  - Orientation of naphthylene ring in the new poly(naphthylen-1,3,4-oxadiazole)s molecules
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Schulz, Burkhard
A1  - Strelina, Irina A.
A1  - Okatova, Olga V.
T1  - Synthesis and molecular properties of new poly(naphthalene-1,3,4-oxadiazole)s
N2  - Poly[(1,4-naphthalene)-2,5-diyl-1,3,4-oxadiazole] and poly[(2,6-naphthalene)-2,5-diyl-1,3,4-oxadiazole] have been synthesized and investigated in conc. H2S04, by the flow birefringence method in comparison with poly(1,4- phenylene)-2,5-diyl-1,3,4-oxadiazole]. Changes in conformation parameters and optical anisotropy of a chain unit induced by incorporation of the naphthalene groups into the macromolecule backbone have been evaluated.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Strelina, Irina A.
A1  - Schulz, Burkhard
T1  - Dynamo-optical properties of poly(naphthylene oxadiazole)s in sulfuric acid
N2  - Flow birefringence induced in dilute solutions of poly[(1,4-naphthylene)-2,5-diyl-1,3,4-oxadiazole] and poly[2,6-naphthylene)-2,5-diyl-1,3,4-oxadiazole] in conc. sulphuric acid has been investigated. The shear optical coefficient was found for these polymers to be approximately double the value of that obtained in the same solvent for poly[(para-phenylene) -2,5-diyl-1,3,4-oxadiazole]. Rigid-chain behaviour of the polymers was characterized by hydrodynamic and dynamo-optical parameters evaluated with application of the worm-like chain model and the "method of similar structures". Change in optical anisotropy of a chain unit induced by incorporation of naphthylene groups into the main chain has been evaluated.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Okatova, Olga V.
A1  - Schulz, Burkhard
A1  - Andreeva, Katharina A.
A1  - Strelina, Irina A.
T1  - Hydrodynamic and dynamo-optical properties of poly(1,3-phenylene-1,3,4-oxadiazole) molecules in sulphuric acid
N2  - Translational diffusion of the macromolecules, intrinsic viscosity and flow birefringence induced in dilute solutions of poly(1,3-phenylene-1,3,4-oxadiazole) (PMOD) in conc. sulphuric acid has been investigated. Molecular-weight dependences of hydrodynamic and dynamo-optical properties are established over the M range from 8.1  103 to 87  103. Experimental data agree well with the theories developed for translational friction and intrinsic viscosity of the wormlike chains with the following molecular parameters: mass per chain unit ML = 22.7 Dalton/Å, the Kuhn segment length A = 59 ± 4 Å, the chain diameter d = 4 ± 1.5 Å. Hindrance to intramolecular rotation is characterized by the parameter s = 1.7. The shear optical coefficient was found to be approximately 1.7 times lower the value of that obtained in the same solvent for the para-phenylene isomer of this polymer, being in good agreement with higher equilibrium flexibility of the PMOD molecule chains in solutions as determined herein from the hydrodynamic data.
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Andreeva, Katharina A.
A1  - Strelina, Irina A.
A1  - Garmonova, Tatjana I.
A1  - Schulz, Burkhard
T1  - Optical anisotropy and flexibility of poly(m-phenylene oxadiazole) in sulfuric acid
Y1  - 1999
ER  -