SPECTROSCOPIC ANALYSIS AND IN-SITU MONITORING OF IMPREGNATION AND EXTRACTION OF POLYMER-FILMS AND POWDERS USING SUPERCRITICAL FLUIDS

A range of vibrational spectroscopic techniques are used to monitor supercritical fluid extraction and impregnation of polymers. Impregnation processes of this type show potential as alternative approaches to the synthesis of polymer based catalysts and new materials. Methods have been devised using conventional Fourier transform infrared spectroscopy for real time monitoring of the extraction and impregnation of polyethylene films using an organometallic complex, CpMn(CO)3 (Cp = eta5 - C5H5) as a spectroscopic probe. Both low and high density powdered polyethylene may be impregnated using supercritical carbon dioxide. The resulting materials are analysed using FTIR photoacoustic spectroscopy, diffuse reflectance infrared spectroscopy and FT Raman spectroscopy to probe both the impregnated bulk of the polymer and surface-coated material. (C) 1994 John Wiley & Sons, Inc.