Proceedings of the XIIIth International Congress on Rheology edition:Vol. 1 pages:408-410
XIIIth International Congress on Rheology edition:XIII location:Cambridge, UK date:20-25 August 2000
In addition to rheo-mechanical shear and oscillation measurements, recent years have also seen the parallel determination of rheo-optical material functions, such as flow birefringence and flow dichroism, used in order to investigate macroscopic viscoelastic flow behaviour at a molecular level. Apart from determining these moduli, which are proportional to rheo-mechanical parameters, it was also possible to determine the orientation of polymer segments and aggregated structures. In particular, it became possible to explain aggregation behaviour during the sol-gel transition and during temperature-induced phase separation on a molecular level. In addition to native polysaccharides, investigations also included chemically modified celluloses and fermentation polymers. The overriding aim was to establish structure-property relationships for rheo-optical material functions in homogeneous solutions to determine deviations in Solutions with associates and aggregates.