Hydrodynamic and dynamo-optical properties of molecules of an aromatic polyester with para- and meta-phenyl rings in the main chain

Abstract

The hydrodynamic and optical properties of molecules of an aromatic polyester (PE) dissolved in dichloroacetic acid have been investigated by the methods of translational diffusion, viscometry and flow birefringence. The chain of the PE investigated contains one phenyl ring in the meta-position alternating with three phenyl rings in the para-position. The Mark-Kuhn equations relating intrinsic viscosity and the translational diffusion coefficient to molecular weight have been obtained: [ η] = 2.6 × 10 −3 M 1.1 cm 3 g −1 and D = 5.6 × 10 −5 M −0.70 cm 2 sec −1. The results are interpreted in terms of theories of hydrodynamic and dynamo-optical properties of wormlike chains. It is shown that the PE macromolecules in solution exhibit equilibrium rigidity determined by the length of the Kuhn statistical segment A = 120 ± 20 A ̊ and the anisotropy of unit chain length β = 5 × 10 −17 cm 2.