Synthesis of a novel flocculant with dimethylamino propylmethacrylamide and polyether and its flocculation performance

The widespread use of polymer flooding has resulted in a large number of produced liquids consisting of crude oil emulsions and oily wastewater. Efficient flocculants are required to treat these produced liquids till the oily wastewater satisfies the requirements for reinjection formation in order to maintain the regular manufacturing process. In this work, an unsaturated polyether macromonomer (PEP-30) was prepared by ring-opening polymerization using isobutenol as a starting material. Subsequently, a novel flocculant (PMAP) was obtained by copolymerization of dimethylamino propylmethacrylamide (DMAPMA) and PEP-30. For the produced liquids with different crude oil emulsion content, the oil removal rate of PMAP at a dosage of 150 mg/L was more than 75%, and the oil removal rate and versatility were better than those of conventional cationic flocculants. Furthermore, the findings of the flocculation mechanism investigation demonstrated that PMAP had a low interfacial elastic modulus and a large interfacial adsorption mass. Specifically, the optical tweezers were used to detect the interaction force between oil droplets. PMAP effectively strengthened the attraction between oil droplets, extending their duration in contact during flocculation and promoting their coalescence.