Diffusion of Polyisobutylene in Very Dilute Solutions

The diffusion of polyisobutylene in very dilute solutions was investigated. With the interferometric method used the maximum error in D was 2%. Diffusion coefficients of the fractions were measured as a function of molecular weight and concentration down to 0.02 g./dl. The hydrodynamical parameters of the coil were determined. A comparison of molecular weights of fractions measured by light scattering and computed from intrinsic viscosity and D was given. It was possible to characterize the polydispersity of polymers on the basis of diffusion measurements.