Analysis of fiber finishes using SFE coupled to a simple, universal IR flow cell

This paper presents a method for analyzing polyurethane fiber finishes based on supercritical fluid extraction (SFE) coupled directly to an infrared (IR) spectrometer by means of a simple, universal IR now cell. In this method, supercritical CO2 is used to replace environmentally hazardous perchlorinated solvents. An automated sample-loading SFE extractor reduces analysis labor. Extract effluent from the extractor flows through a heated capillary transfer line and a high-pressure, standard-geometry IR now cell. The now cell can be used to couple the SFE extractor with almost any IR spectrometer. The system is tested with a fiber finish analysis method using polyurethane fiber samples, and the data and other fundamental information are presented.