Hydrodynamic, dynamo-optical and conformational characteristics of molecules of phenyl-substituted para-aromatic polyesters

Hydrodynamic, optical and conformational properties of mono-phenyl-substituted para-aromatic polyester (PAPE) in tetrachloroethane and dichloroacetic acid have been studied by sedimentation-diffusion analysis, viscometry and flow birefringence. The effect of phenyl side-groups on the equilibrium rigidity of PAPE chains was analysed. On the basis of these data, the energies of hindrance to intramolecular rotations about the ester bonds of various phenyl-substituted PAPEs were estimated.