Title page for ETD etd-111897-152623

Type of Document

Master's Thesis

Author

Porter, Shelley Risch Jr.

Author's Email Address

srisch@vt.edu

URN

etd-111897-152623

Title

Supercritical Fluid Extraction of Nylon 6,6 Fiber Finish and Oligomers

Degree

Master of Science

Department

Chemistry

Advisory Committee

Advisor Name	Title
Taylor, Larry T.	Committee Chair
Dillard, John G.	Committee Member
Dorn, Harry C.	Committee Member

Keywords

Supercritical Fluid Extraction
SFE
Fiber Finishes
Oligomers
HPLC
Mass Spectrometry

Date of Defense

1997-12-04

Availability

unrestricted

Abstract

Quantitation of the amount of finish applied during fiber
manufacturing is an important industrial quality control
process. Finish levels that are too low result in excessive
fiber and mechanical wear. On the other hand, overly high
finish levels may cause residue buildup on the processing
equipment. Removal of the finish has traditionally been
done with solvents such as chloroform or Freon followed by
gravimetric or spectroscopic analysis of the removed
material.
Quantitation of low molecular weight oligomeric
material is another important quality control practice for
the fiber industry in that the presence of these species and
their concentration affect the physical properties of the
polymer. Also, excessively high concentrations of oligomers
may result in residue deposits on processing equipment.
Typical conventional methods for determining the
concentration of oligomers present in fibers involve large
quantities of organic solvent for removal of the oligomers
followed by chromatographic analysis
Increased government regulation of chlorinated and
other solvents has led to investigations of alternate
methods of extraction. Several studies have shown that
supercritical fluid extraction (SFE) using carbon dioxide as
the extraction fluid is an important alternative to
conventional organic solvent extraction for the removal of
both textile finishes and oligomeric material. This
research seeks to extend the previous studies regarding the
application of SFE for the quantitation of finish and
oligomers from nylon 6,6 fibers. The effects of pressure,
extraction temperature, modifier percentage, static
extraction time, and dynamic extraction time on the
supercritical fluid extraction efficiency of nylon 6,6
oligomers were examined. Results from the SFE methods for
both finish and oligomer extractions were compared to
results from conventional solvent extraction. The extracted
oligomers were identified by HPLC with coupled on-line
atmospheric pressure chemical ionization mass spectrometry
(APCI-MS) and HPLC fractionation coupled with off-line
Liquid Secondary Ion Mass Spectrometry (LSIMS).

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