We compare the experimental relaxation times against theoretical relaxation times for a single PII-2T polymer. To estimate the relaxation time, we use the relation for Zimm relaxation time as well as the rotational diffusion coefficient for wormlike chains . The Zimm relaxation time is given by (5) Where is the intrinsic viscosity, is the molecular weight, is the solvent viscosity, is the gas constant, is the temperature, and is the universal ratio of the characteristic relaxation time to the longest relaxation time. depends on the relaxation spectrum of the constitutive model and has values of 2.39 for theta solvents and 1.8 for good solvents and so for the purpose of estimation we use a value of 2. For the rotational diffusion method, we estimate the rotational diffusion of our polymer using the expression for rods by Broersma then we calculate the deviation from this value using the results of Hagerman and Zimm which depends on the ratio between the contour length and the persistence length. We find that both methods yield a relaxation time of approximately 0.1 to 1 µs for individual PII-2T polymers (depending on the number-averaged or weight-averaged molecular weight). This would require an extensional strain rate >10 6 s -1 to align the individual polymer chains, which is greater than the extensional strain rates explored in this work. Although we have characterized the radius of the PII-2T fibril aggregates in CB through SAXS (~10 nm), their lengths are not determinable from SAXS.