Ammonium persulfate-initiated polymerization of cationic starch-grafted-cationic polyacrylamide flocculant for the enhanced flocculation of oil sludge suspension

In this study, a novel, highly efficient and environmentally friendly flocculant, namely, cationic starch-grafted-cationic polyacrylamide (CS-g-CPAM), was synthesized by initiation polymerization of ammonium persulfate. First, CS-g-CPAM was polymerized with cationic starch(CS), acrylamide(AM) and diallyl dimethyl ammonium chloride (DMDAAC), and then the influence factors of graft polymerization were investigated, including total monomer concentration, initiator dosage, the monomer mass ratio of mAM: mCS: mDMDAAC, post-polymerization temperature and post-polymerization time. And the intrinsic viscosity of the CS-g-CPAM was measured by the one point method accurately. The chemical structures and morphology of the samples were characterized by Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric and differential scanning calorimetry (TG-DSC), and scanning electron microscope (SEM). The CS-g-CPAM was utilized to flocculate the oil sludge suspension, the effects of CS-g-CPAM dosage, temperature and pH value on the flocculation performance were investigated. The results show that CS-g-CPAM has outstanding flocculation effect.