The sedimentation parameter of linear polymer molecules in absence of excluded volume effects

Abstract

Abstract A non‐dimensional sedimentation parameter β s = N A [ S ] K M −2/3 is introduced. [ S ] is the intrinsic sedimentation constant, K s is the concentration dependence coefficient. The experimental data for S o and K s are compared with independent data for molecular weights measured by usual absolute methods. It is shown that for unimodal fractions (samples) of flexible chain polymers in Θ‐solvents and rigid chain polymers, β s practically does not depend on molecular weight and structure of the repeating unit. The average experimental value of β s is 1.0 × 10 7 mol −1/3 . With the use of β s one can rewrite the general Wales‐Van Holde expression for the molecular weight of uncharged linear macromolecules as M KS = ( N A /β s ) 3/2 [ S ] 3/2 K .