POLYOXYALKYLENATED AMINES FOR BREAKING WATER-IN-OIL EMULSIONS - EFFECT OF STRUCTURAL VARIATIONS ON THE DEMULSIFICATION EFFICIENCY

In the present work, different aliphatic and aromatic amines were etho xylated after a previous propoxylation (PPPEA) with different degrees of propoxylation and ethoxylation in order to obtain polymeric surfact ants having different hydrophilic-lipophilic balance (HLB) values. The influence of the structural variations in the prepared PPPEA on their efficiency as demulsifiers for water-in-oil emulsions was investigate d. Synthetic water-in-benzene emulsions stabilized by petroleum asphal tenes was utilized for the completion of this study. The actual propyl ene oxide (PO)-ethylene oxide (EO) ratios of the PPPEA under investiga tion was elucidated via H-1 NMR spectroscopy. It was found that each d emulsifier practices a maximum demulsification efficiency at an optimu m concentration. At this concentration, the demulsifiers' molecules we re believed to form a monolayer by adsorbance at the benzene-water int erface. The influences of the number of aromatic rings in the molecule , the degree of substitution in the aromatic rings, the number of amin e groups, the number of PO-EO chains and HLB on the demulsification ef ficiency were accomplished. (C) 1998 John Wiley & Sons, Ltd.