Atactic polystyrene degradation

All the previous systems were polydisperse in nature, so that the coil-stretch transition was broad (because the relaxation time depends upon molecular weight). Also, only a part of the molecular weight distribution (the longest molecules) becomes stretched by the flow. It therefore proved impossible to determine the dependence of the coil-stretch or interaction behavior upon molecular weight. For these reasons, we examine the behavior of a model system, monodisperse atactic polystyrene (a-PS) in the 0 solvent decahydronaphthalene. We will explore separately, both by assessment of molecular strain and macrorheology, the onset of interaction behavior, particularly as a function of molecular weight, and the associated flow-induced degradation. 

Work by Jellinek and Igarashi should be noted here. The diffusion of NO2 into atactic polystyrene was studied. As Indicator of the progress of diffusion, the degree of degradation as a function of distance x from the polymer surface was chosen. Some data are presented in Figures 4 and 5. 

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