H_2O_2/UV-lnitiated Copolymerization of Acrylamide and Dimethyl Diallyl Ammonium Chloride: Characterization and Flocculation Performance

摘要

The cationic polyacrylamide flocculant P(AM-DMDAAC) is prepared by copolymerizing acrylamide (AM) and dimethyl diallyl ammonium chloride (DMDAAC) initiated by H2O2 under UV irradiation conditions. The structural features and thermal stability of P(AM-DMDAAC) are characterized via infrared spectroscopy, thermogravimetry/differential scanning calorimetry, and proton nuclear magnetic resonance spectroscopy. The effects of multiple factors, including monomer concentration, mass monomer ratio, illumination time, initiator H2O2 concentration, solution pH, illumination intensity, and urea concentration, on the intrinsic viscosity of P(AM-DMDAAC) are studied. The optimum preparation conditions are found to be 30% monomer concentration, 1:4 mass monomer ratio, 0.5 parts per thousand initiator concentration, 5.5 pH, 30 min illumination time, 1800 uW/cm(2) illumination intensity, and 0.5% urea concentration. Under optimal conditions, the intrinsic viscosity of P(AM-DMDAAC) reaches 18.31 dL/g, which corresponds to a molecular weight of 9.6 x 10(6). Sludge dewatering experiments show that P(AM-DMDAAC) exhibits superior flocculating performance compared with other flocculants.