Dynamics of Polymer Solutions. 1. Theory for an Instrument

We present the theory for an instrument which can measure several parameters of the viscoelasticity of dilute solutions of very large polymer molecules. In previous work on solutions of large DNA molecules, we used retardation times, measured by creep recovery, to get the molecular weight of the largest such molecules in solution. We have now added the capability to measure stress relaxations, the theory for which is described here. In the following paper, we show that by combining creep-recovery and strain-relaxation measurements it is possible to get information about the molecular-weight distribution of large polymer molecules in the solution.