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High molecular weight tail and long-chain branching in SRM 1476 polyethylene

โœ Scribed by F. Beer; G. Capaccio; L. J. Rose

Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
133 KB
Volume
73
Category
Article
ISSN
0021-8995

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โœฆ Synopsis

The composition of the high molecular weight tail in the branched polyethylene standard reference material SRM 1476 was studied in detail using size exclusion chromatography coupled with a refractive index, a viscosity, and a light scattering on-line detector. The light scattering determinations of both molecular weight and radius of gyration point at a difference in kind between the molecular species below and above 10 6 Da. In particular, above 10 6 Da, increases in molecular weight resulted in a marked "densification" process. This is consistent with a greater concentration of long-chain branching and/or with a change in molecular architecture. Previous literature results for this polymer and a critical comparison of the performance of the different detectors are also discussed.

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