Electro‐optic birefringence and scattering of concentrated solutions of ethylcellulose

Photon correlation spectroscopy (PCS) at small scattering vector (kR G ≃ ) and the same is true for the broadening parameters of the decay and rise transients (β r ≃ β d ). The β values were found to decrease with increasing concentration. The experimental results are in qualitative agreement with the theoretical prediction of Doi and Edwards but in quantitative disagreement; thus implying that idealised models are far from describing the true observation. The semi-empirical theory of Douglas and Hubbard aptly described the concentration exponents observed in this work for the zero shear viscosity and the whole chain relaxation data.