Premium
On the accuracy of SEC analyses of molecular weight distributions of polyethylenes
Author(s) -
Grinshpun V.,
O'Driscoll K. F.,
Rudin A.
Publication year - 1984
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.1984.070290405
Subject(s) - polyethylene , molar mass distribution , molecular mass , polymer , polymer chemistry , materials science , chemistry , analytical chemistry (journal) , thermodynamics , chromatography , organic chemistry , composite material , physics , enzyme
Molecular weights of National Bureau of Standards SRM 1476 polyethylene have been reported by six laboratories. The measured values are in remarkably good agreements and all show that M w from SEC/LALLS analyses is significantly lower than the same average determined by LALLS on the whole polymer itself. This is shown to be due to the presence of high molecular weight species which become too diluted on passage through the SEC columns to be observed in the LALLS detector. The resulting error in M w and higher averages may vary from slight to very serioius, depending on the molecular weight distribution of the particular polyethylene. A procedure is described to detect the presence of such high molecular weight species.