POLYMER PROCESSING WITH SUPERCRITICAL FLUIDS: PARTITIONING OF SOLUTES AND COSOLVENTS BETWEEN SUPERCRITICAL FLUIDS AND POLYMER

摘要

Many polymeric matrices can uptake significant amounts of supercritical solvents, which can lead to beneficial changes in the polymer. For example, glassy polymers can be plasticized at relatively low temperatures, and free volume in rubbery polymers increases considerably. Both thermodynamic properties and mass transport processes can be "tuned" for selectivity by changing the processing pressure or temperature. We present partitioning and diffusion results for PMMA and crosslinked PDMS taken by a novel in situ spectroscopic method. The applications of this research range from low temperature dyeing of glassy polymers to tuning of chromatographic stationary phases with cosolvents for specific separations.