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High molecular weight tail and long‐chain branching in low‐density polyethylenes
Author(s) -
Beer F.,
Capaccio G.,
Rose L. J.
Publication year - 2001
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.1398
Subject(s) - branching (polymer chemistry) , radius of gyration , molar mass distribution , molar mass , gel permeation chromatography , intrinsic viscosity , size exclusion chromatography , chemistry , analytical chemistry (journal) , refractometry , molecular mass , polymer chemistry , viscosity , chromatography , multiangle light scattering , light scattering , refractive index , materials science , scattering , polymer , organic chemistry , optics , composite material , physics , optoelectronics , enzyme
The composition of the high molecular weight tail in branched low‐density polyethylenes made by both tubular and autoclave reactors was studied in detail using size‐exclusion chromatography (SEC) coupled with a viscosity detector (VD) and a two‐angle light‐scattering detector (LSD). The detection of a second peak at very small elution volumes in the light‐scattering chromatogram but not in the refractive index chromatogram and viscosity chromatogram is due to high molecular weight species. It is also indicative of a change in the long‐chain branching distribution. It was found that the intrinsic viscosity contraction factor g ′ scales with the radius of the gyration contraction factor, g , with the exponent, ε, having a value in the range 0.4–1.4. Furthermore, ε shows significant molar mass dependence. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2815–2822, 2001