Ja. Incavo et al., DETERMINATION OF PARTITION-COEFFICIENTS AND RESIDUAL SOLVENT FOR POLYMER DRYING APPLICATIONS, Chromatographia, 43(1-2), 1996, pp. 31-38
Citations number
20
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
Gas-solid partition coefficients (K) for n-hexane in high density poly
ethylene (HDPE) have been measured at conditions applicable to large-s
cale drying utilizing a novel headspace method. The method features co
nsiderable versatility and simplicity due to the control of experiment
al conditions designed to favor full extraction of the analyte into th
e headspace. By combining this full extraction technique with a tradit
ional static headspace experimental scheme, a method which measures K
and residual concentration is achieved. The results show that partitio
n coefficients differ significantly between HDPE in its virgin powder
and pellet forms, as well as among various HDPE grades. The difference
s are shown to be attributable to differences in % crystallinity of th
e specific polymer. Data collected over a wide range of hexane concent
rations reveals saturation levels (solubilities) which correspond to c
rossover from evaporative to diffusion-controlled drying.