Morphological changes and dye uptake of poly(ethylene terephthalate) and 2,5-cellulose diacetate immersed in supercritical carbon dioxide

Abstract

The dyeing process of poly(ethylene terephthalate) (PET) and 2,5-cellulose diacetate (CA) fibers at 40-100°C using supercritical carbon dioxide (CO2SCF) as solvent system has been kinetically investigated in relation to the morphological modifications induced by the CO2SCF treatment in these fibers, determined through DSC, X-ray diffraction, SEM analysis and shrinkage measurements. A comparison between the effects of annealing both polymer fibers in CO2SCF and in hot air evidenced that CO2SCF has a plastifying action towards PET by lowering its Tg value to 0-5°C and thus favoring the dyeing process at low temperature. Such effect was not observed with CA. © 1998 Elsevier Science Ltd. All rights reserved.