Synthesis and Characterization of Polyelectrolytes for Waste Water Treatment

IGNACIO RINTOUL

Instituto Sabato CNEA-UNSAM

Año: 2001 p. 60

The free radical copolymerization of acrylamide with different monomers has been investigated in inverse emulsion/suspension polymerizations. Different formulations and process parameters were performed to evaluate its influence on the obtained polymer properties and polymerization process control. The emulsion/suspension formulation parameters studied were the type and the percentage of the charge, the percentage of the actives, the dispersant system and the addition of a crosslinker agent. In reference to the polymerization process, the initiator type and its concentration as well as the pre-emulsification and the emulsification time and the temperature conditions during the polymerization were the varied process parameters. The residual monomer concentration and the conversion degree were determined by High Pressure Liquid Chromatography measurements, the rehological behavior of the emulsions during the polymerization were estimated by shear viscosity measurements, the molecular weight characteristics were estimated by intrinsic viscosity measurements. The particle size and the solution properties of the emulsions were estimated by Dynamic Light Scattering  and Inverse Viscosity test respectively.               It was found that the quality of the primary emulsion, that means the appropriate values for the Hydrophilic-Lipophilic Balance and the particle size, is the main factor to make better the heat removal allowing developing the polymerization reaction under isothermal conditions. The polyelectrolytes obtained were tested in practical application as flocculants for municipal waste-water treatment. In most of the cases the obtained polymers reach better performance than the commercial flocculants currently used.