Etude par diffusion de la lumière de la polydispersité résiduelle des polymères fractionnés

Abstract

The general trend of the theoretical results obtained by Tung on simulated fractionations is verified experimentally, showing that the sharpness of the fractions and the variation of the sharpness in the different fractions of a given fractionation are very much dependent on the fractionation conditions and especially on the polymer starting concentration. For very low starting concentration, the middle fractions can be considered as being monodisperse as far as polydispersity detection by light scattering is concerned. The ratio [Formula: see text] for these fractions can be used as a reference for polydispersity characterization of other samples of the same polymer. The comparison of this ratio to the same ratio obtained on a polydisperse sample yields [Formula: see text]. Results obtained in this way for a moderately sharp fractionation are in good accord with the theoretical predictions of Tung.