Flow birefringence behavior of some amylopectins and limit dextrins

The flow birefringence behavior of some amylopectins and their limit dextrins are reported. Though no quantitative interpretation is possible due to the great heterogeneity and their probable deformation in the flow gradient, several characteristics seem quite general. The extinction angle is relatively independent of the flow gradient. The gradient range over which observations could be made was limited at the lower end by lack of precision and at the higher end by precipitation which invariably occured. The birefringence curves characteristically showed a saturation behavior. Possible qualitative explanations for the observed behavior are discussed.