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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