13C-NMR spectroscopy and size exclusion chromatography have been used to determine the mean length of long branches in a number of high pressure process low density polyethylenes (LDPEs). 13C-NMR analyses count all branches longer than C5 as "long." The polyethylenes studied all had 2-3 long branche
Detection of low levels of long-chain branching in polydisperse polyethylene materials
โ Scribed by Teresa P. Karjala; Robert L. Sammler; Marc A. Mangnus; Lonnie G. Hazlitt; Mark S. Johnson; Jian Wang; Charles M. Hagen Jr.; Joseph W. L. Huang; Kenneth N. Reichek
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 259 KB
- Volume
- 119
- Category
- Article
- ISSN
- 0021-8995
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## SYNOPSIS The mean length and the indices of long-chain branches (LCBs) of a high-pressure lowdensity polyethylene (HPLDPE) as a function of molecular weight have been determined for its molecular-weight-fractionated parts by the I3C-NMR analysis and the viscosity measurements. The mean LCB leng