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 ethoxylated after a previous propoxylation (PPPEA) with different degrees of propoxylation and ethoxylation in order to obtain polymeric surfactants 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 investigated. Synthetic water-in-benzene emulsions stabilized by petroleum asphaltenes was utilized for the completion of this study. The actual propylene oxide (PO)-ethylene oxide (EO) ratios of the PPPEA under investigation was elucidated via H-1 NMR spectroscopy. It was found that each demulsifier practices a maximum demulsification efficiency at an optimum concentration. At this concentration, the demulsifiers' molecules were believed to form a monolayer by adsorbance at the benzene-water interface. The influences of the number of aromatic rings in the molecule, the degree of substitution in the aromatic rings, the number of amine groups, the number of PO-EO chains and HLB on the demulsification efficiency were accomplished. (C) 1998 John Wiley & Sons, Ltd.