The molecular weight distributions of two high molecular weight (M[subscript w]>>1
million) polyethylene polymers, WSR-308 and WSR-301, were characterized with gel
permeation chromatography (GPC) coupled with a multi-angle laser light scattering
detector (MALLS). The M[subscript w] of the WSR-308 was found to be 5.10x10⁶ g/mol with a
molecular weight range from about 1 million g/mol to as high as 10 million g/mol.
The M[subscript w] of the WSR-301 was found to be 3.16x10⁶ g/mol with the lowest molecular
weight about 400,000 g/mol while the highest molecular weight component may have
been as high as 8 million g/mol. Attempts to measure the M[subscript w] of the two polymers
using static light scattering (SLS) techniques proved to be difficult.
In conjunction with these studies, drag reduction and shear degradation studies
of the two polymers in water were also conducted. Solutions of the two polymers,
ranging from 1 to 10 ppm including mixtures of the two, were tested in a pipe-flow
apparatus to obtain friction factor and %DR data. In every case, the greater the
concentration and/or the molecular weight of the polymer, the greater the drag
reduction effects. Additionally, the higher molecular weight polymer and mixtures
with a greater weight percentage of the higher molecular weight polymer were found
to shear degrade less quickly than otherwise.
A unique point along the maximum drag reduction asymptote (MDA) termed
the "divergence point" was a focus of this study and an energy model based on
frictional losses correlates well to the data. The correlation developed here relates the
difference in frictional losses between the solvent by itself and the polymer solution
directly to the mass concentration and molecular weight of the polymer. This
frictional difference was proportional to the product of the mass concentration and
molecular weight where both quantities were to approximately the first power. / Graduation date: 2002
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/29401 |
| Date | 13 December 2001 |
| Creators | Jones, Brian Dion |
| Contributors | Rochefort, Willie E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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