Abstract
The goal of the paper was to prepare a class of flocculants by free-radical copolymerization of acrylamide with acrylic acid in aqueous solutions in the presence/absence of potassium persulphate as initiator. Reaction medium was submitted to electron beam treatment of 0.6 to 1.5 kGy in atmospheric conditions and at room temperature. Because of the complexity of reaction mechanisms involved in radio-induced polymerization, was necessary to establish the connection between absorbed dose and initiator concentration, both of them very important in free radical production. Unlike the conversion coefficient and residual monomer concentration, intrinsic viscosity and Huggin’s constant are sensitive to the initiator concentration variation for all used irradiation doses. The copolymerization was confirmed by FTIR measurements. The flocculation characteristics were evaluated in 0.2 wt % kaolin suspension at room temperature using different polymer dosages between 0 to 10 ppm. High flocculation efficiency was obtained using the polymer having high values of intrinsic viscosity, molecular weight and radius of gyration.
Keywords:
poly(acrylamide-co-acrylic acid); synthesis; absorbed dose; flocculation; FTIR