Synthesis and Flotation‐Flocculation Properties of Polyether Monoamine‐Grafted Poly[N‐(3‐Dimethylaminopropyl) Methacrylamide]

ABSTRACT The highly efficient air flotation hydrocyclone separation technology has been gradually promoted and applied. However, the performance of flocculant reported in the literature needs improvement. In this study, a novel flocculant was synthesized using poly[N‐(3‐dimethylaminopropyl)methacry] (PDPM) and polyether monoamine (PMA) as the main raw materials. The synthesis conditions of the flocculant were optimized based on the oil removal rate. It was found that when PMA M‐2095 was used, the resulting product, Cl‐0.4‐P‐0.2‐2095, exhibited the best flotation‐flocculation oil removal performance. At a dosage of 20 mg/L and a treatment time of 7 min, the oil removal rate of Cl‐0.4‐P‐0.2‐2095 reached 90.63%, which was 31.7% higher than that of the reported flocculant. Mechanistic investigations, including measurements of surface tension, interfacial tension, zeta potential, and interfacial elastic modulus, as well as oil‐coated bubble experiments, revealed that Cl‐0.4‐P‐0.2‐2095 adsorbs onto the surfaces of bubbles and oil droplets. This adsorption enhances the collision and adhesion efficiency between bubbles and oil droplets, thereby improving the flotation‐flocculation oil removal performance. This study provides a novel treatment agent for the efficient treatment of produced water from offshore oilfields.