Automated batch characterization of polymer solutions by static light scattering and viscometry

Using a programmable mixing pump, light scattering flow chamber, refractive index detector, and single capillary viscometer, the batch (unfractionated) characterization of polymers in solution has been automated. Three different schemes to produce polymer concentration gradients were used, and values for weight average mass Mw, root mean square radius of gyration 〈S2〉1/2, second virial coefficient A2, and intrinsic viscosity [η] were determined for a broad distribution sample of poly(vinyl pyrrolidone) (PVP) and a narrow fraction of poly(ethylene oxide) (PEO). High concentration experiments on the PVP also allowed determination of the third virial coefficient A3. The method has several advantages over traditional manual methods in terms of accuracy, sample preparation, and amount of labor required.