An empirical relationship between distribution coefficients of phenols by polyurethane foams and their octanol-water distribution constants and pK(a) values

Sorption of phenol, 3-cresol, 2-, 3-, 4-nitrophenols, 2,4-, 2,6-dinitrophenol, 2,4,6-trinitrophenol, and 1-naphthol by polyether- and polyester-type polyurethane foams (PUF) was investigated. The effects of sorption time, pH, phenol concentration and the structure of tested phenols and PUF were studied. The mechanism of sorption of tested compounds on foams is discussed. It is shown that the hydrophobicity (logP, octanol-water distribution constant) and pK(a) values of the compounds play an important role in the sorption process. A regression equation connecting distribution coefficient of phenols by PUF with their hydrophobicity parameter and pK(a) values were derived. Good correlation between logD and values logP and pK(a) was observed.