Star-shaped quaternary ammonium compounds with terminal amino groups for rapidly breaking oil-in-water emulsions

Abstract

Two star-shaped quaternary ammonium compounds, named as T-P-EDA and T-P-DETA, were synthesized with the melamine as the hydrophobic core and the quaternary ammonium moieties as the hydrophilic sub-core. Moreover, they were fully characterized by the FT-IR, 1H NMR, TGA and their demulsification properties were systemically investigated. It was found that both of the compounds showed higher demulsification efficiency than traditional linear cationic demulsifier (CW-01) in breaking the polymer flooding oil-in-water (O/W) emulsions. Notably, for a 1500 mg/L oil containing emulsion, it achieved ~99.5% oil removal ratio in 10 min at 30℃ by adding 80 mg/L T-P-EDA or T-P-DETA, while the oil removal rate of CW-01 was 93.5% at the same conditions. Furthermore, the interfacial tension, turbidity, and zeta potential measurements were performed, which indicated that the electrostatic interaction and hydrogen bonding between the demulsifiers and the surfactants were the driving forces for the enhancement of demulsification efficiency. T-P-EDA and T-P-DETA may potentially serve as the faster, more efficient and inexpensive demulsifiers.