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Comparaison des méthodes de fractionnement par chromatographie de perméation et par gradient d'elution pour la détermination des répartitions moléculaires des polypropylénes
Author(s) -
Crouzet P.,
Fine F.,
Mangin P.
Publication year - 1969
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1969.070130119
Subject(s) - fractionation , polypropylene , chemistry , chromatography , molar mass distribution , gel permeation chromatography , materials science , analytical chemistry (journal) , polymer , organic chemistry
Molecular weight distributions for polypropylene samples have been determined by a permeation fractionation method (GPC). Porous silica beads were used as a packing material for the columns. The set of columns allows a good separation of the polypropylene macromolecular chains in a range of molecular weights from 5000 to 1.5 × 10 6 , and the thermal and mechanical stabilities of these beads are very good. The calibration has been carried out with fractions of polypropylene of narrow molecular weight distribution prepared by a large‐scale column fractionation. The molecular weights M̄ w and M̄ n and the ratios M̄ w / M̄ n calculated from the GPC curves show, in general, good agreement with the ones calculated from the column fractionation curves. However, the M̄ w / M̄ n ratios are always highter in the case of GPC fractionation. This could be due to diffusion phenomena.