Association of Amino-Terminated Polystyrenes. 2. Dynamic Light Scattering of Associating Linear Chains

Dynamic light scattering was used to study the associating coupling process of amino-terminated polystyrene chains with monofunctional and bifunctional dinitrophenol reagents. The tertiary amino end group and the end group which results from association with monofunctional dinitrophenol were found to have no effect on the solution behavior in good solvents. The interaction with the coupling reagent caused a decrease in the mutual diffusion coefficients D c with increasing polymer concentration. Translational diffusion coefficients D z °(c) of the associating polymers at each concentration c with a corresponding molecular weight M w (c) were determined from D c and its concentration dependence which is expressed by the k D parameter. The molecular weight dependence of the k D parameter was obtained from experimental values of linear polystyrenes in toluene. On the time scale of these experiments, the associates were found to show a diffusion behavior that corresponds to covalently linked chains. Apparently the lifetime of a complex is longer than the measurement time in typical experiments.