Effect of the branching morphology of a cationic polymer flocculant synthesized by controlled reversible‐deactivation radical polymerization on the flocculation and dewatering of dilute mature fine tailings

One of the methods used to treat oil sands tailings is to add water‐soluble polymer flocculants to create large flocs that settle to the bottom of the ponds, allowing the supernatant water to be recovered and reused in the oil extraction process. However, a systematic study of how polymer branching affects flocculation has not yet been done to date. Poly((vinylbenzyl)trimethylammonium chloride) (PVB), a cationic and partially hydrophobic polymer, is the focus of this paper. Its positive charges make it adsorb strongly on the negatively charged clay particles, and its partial hydrophobicity produces flocs that retain less water. We synthesized PVB in linear, 3‐arm star, and 4‐arm star configurations using activators regenerated by electron transfer atom transfer radical polymerization. The 3‐arm star polymer outperformed its linear counterpart at every dosage in the initial settling rate tests, while the 4‐arm star polymer performed well only at high dosages. All polymers had similar dewatering performances.