Foam Decomposition Research Articles

Decomposition of polyurethane foams by alkanolamines

AbstractMethylene diphenyl isocyanate (MDI)‐based polyurethane flexible foams were decomposed by alkanolamines without a catalyst at 150°C. The decomposition products were completely separated into two layers. The upper liquid layer was a polyether polyol, and the lower liquid layer was methylene diphenyl amine (MDA) and alkanolamine derivatives. These layers were analyzed using gel permeation chromatography (GPC) and 13C‐NMR. The upper layer was obtained as a relatively pure polyether. The lower layer was observed to be MDA and 2‐hydroxyethyl carbamic acid ester prepared from alcoholysis products during the decomposition reaction. It was thought that the decomposition process of polyurethane foam by alkanolamines was not aminolysis but alcoholysis. © 1994 John Wiley & Sons, Inc.

Stable abnormal foam in activated sludge process produced byrhodococcussp. with strong hydrophobic property

Abstract The foam produced by Rhodococcus sp. in the aeration tanks of the activated sludge treatment plants was more stable than that formed by N. amarae. The stability was determined from the half time of foam decomposition. The stability depended upon the hydrophobicity characterized by the carbon numbers of mycolic acids. The Hydrophobic strengh of Rhodococcus sp. was higher than that of N. amarae. This was determined by using an index of log p = Po/ Pw, P and P are the partition coefficient of mycolic acid in solvent and water, respectively.