| Abstract: | For calculating the ratio of the intrinsic viscosities of branched and linear polymers of the same molecular weight, η]B/η]L, a new theory taking into account the excluded volume effect is presented. By using the modified Flory equation, the excluded volume effect of branched polymers is predicted with the aid of the first-order perturbation theory. The linear expansion factor αs is converted to the hydrodynamic expansion factor αη by using the Kurata-Yamakawa theory. Our calculated results, i.e., η]B/η]L and 〈s2〉B/〈s2〉L, agree well with experiment for various type branched polymers, i.e., randomly branched and comb-shaped polymers of poly(vinyl acetate). |
