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Estimation of molecular weight distribution of poly(vinylpyrrolidone) from diaphragm‐cell diffusion measurements
Author(s) -
Comelli Fabio,
Francesconi Romolo,
Lanzi Eugenio
Publication year - 1980
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760200509
Subject(s) - viscometer , diffusion , molar mass distribution , macromolecule , materials science , gel permeation chromatography , diaphragm (acoustics) , polymer , permeation , analytical chemistry (journal) , chromatography , polymer chemistry , chemistry , viscosity , thermodynamics , membrane , composite material , physics , acoustics , loudspeaker , biochemistry
Abstract Viscometry, gel permeation chromatography (GPC) and diffusion measurements on three samples of poly(vinylpyrrolidone) (PVP) were made. The diffusion measurements were carried out by means of a Stokes cell. An equation with five parameters was derived, linking the difference in PVP amount between the two compartments of the cell to the time of the experiment: three parameters are related to the diffusional behavior of the macromolecules and the other two define the molecular weight distribution (the Tung expression has been chosen). A least‐squares procedure allowed us to obtain the five parameters and the calculated weight average molecular weights agree with the ones evaluated by viscometry and GPC. The ratio M w / M n (heterogeneity of the polymer) calculated from the parameter z of the Tung expression is very different from the one obtained from GPC.