Synthesis and characterization of branched polystyrene. Part II. Fractionation

Fractionations have been carried out by a column‐elution method on mixtures of linear and branched polystyrene. These had been prepared by anionic polymerization followed by a coupling reaction to form star‐shaped branched polymers. Therefore, the components of the mixture were each of narrow distribution, and their molecular weights differed from each other as multiples of the original single chain length. For single chains in the 25,000–30,000 molecular weight range, separations were accomplished in which the multiples (number of branches) were 1, 2, 4, and 6. By this means, virtually monodisperse samples of the branched polymers could be isolated.